ArticlePDF AvailableLiterature Review

Laundry Hygiene and Odor Control – State of the Science

  • RB, Montvale, NJ

Abstract and Figures

Laundering of textiles – clothing, linens, cleaning cloths - functionally removes dirt and bodily fluids which, prevent the transmission and re-exposure to pathogens as well as odor control. Thus, proper laundering is key to controlling microbes that cause illness and produce odors. The practice of laundering varies from region to region and is influenced by culture and resources. This review aims to define laundering as a series of steps that influence the exposure of the person processing the laundry to pathogens – with respect to the removal and control of pathogens and odor causing bacteria, while taking into consideration the types of textiles. Defining laundering in this manner will help better educate the consumer, highlight areas where more research is needed, and how to maximize products and resources. Control of microorganisms during laundering involves mechanical (agitation, soaking), chemical (detergent, bleach), and physical processes (detergent, temperature). Temperature plays the most important role in terms of pathogen control, requiring temperatures exceeding 40°C to 60°C for proper inactivation. While detergents play a role in reducing the microbial load of laundering through release of microbes attached to fabrics and inactivation of microbes sensitive to detergents (e.g. enveloped viruses). The use of additives (enzymes) and bleach (chlorine, activated oxygen) become essential in washes with temperatures below 20°C, especially for certain enteric viruses and bacteria. A structured approach is needed which identifies all the steps in the laundering process and attempts to identify each step relative to its importance to infection risk and odor production.
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Laundry Hygiene and Odor Control: State of the Science
Sarah E. Abney,
M. Khalid Ijaz,
Julie McKinney,
Charles P. Gerba
Department of Environmental Science, University of Arizona, Tucson, Arizona, USA
Global Research & Development for Lysol and Dettol, Reckitt Benckiser LLC, Montvale, New Jersey, USA
Department of Biology, Medgar Evers College of the City University of New York (CUNY), Brooklyn, New York, USA
ABSTRACT Laundering of textilesclothing, linens, and cleaning clothsfunctionally
removes dirt and bodily uids, which prevents the transmission of and reexposure to
pathogens as well as providing odor control. Thus, proper laundering is key to controlling
microbes that cause illness and produce odors. The practice of laundering varies from
region to region and is inuenced by culture and resources. This review aims to dene
laundering as a series of steps that inuence the exposure of the person processing the
laundry to pathogens, with respect to the removal and control of pathogens and odor-
causing bacteria, while taking into consideration the types of textiles. Dening laundering
in this manner will help better educate the consumer and highlight areas where more
research is needed and how to maximize products and resources. The control of microor-
ganisms during laundering involves mechanical (agitation and soaking), chemical (deter-
gent and bleach), and physical (detergent and temperature) processes. Temperature plays
the most important role in terms of pathogen control, requiring temperatures exceeding
40°C to 60°C for proper inactivation, while detergents play a role in reducing the microbial
load of laundering through the release of microbes attached to fabrics and the inactiva-
tion of microbes sensitive to detergents (e.g., enveloped viruses). The use of additives
(enzymes) and bleach (chlorine and activated oxygen) becomes essential in washes with
temperatures below 20°C, especially for certain enteric viruses and bacteria. A structured
approach is needed that identies all the steps in the laundering process and attempts to
identify each step relative to its importance to infection risk and odor production.
KEYWORDS laundry, hygiene, odor, pathogens, laundering
As highlighted in recent reviews, laundering plays an important role in the control
of both pathogenic and odor-causing microorganisms (1, 2). Microora will vary
from one household, community, and region to another. Traditional laundering
practices, socioeconomic factors, the availability of washing facilities, and the selection
of products will inuence many of these factors. Today, most laundry washing is
conducted with machines (;80%) (3), even in less-developed countries. However,
handwashing is still practiced in developed countries, especially with delicate or non-
machine-washable fabrics.
Most studies on laundering have focused their evaluation on practices within high-
income countries, mostly involving machine washing. However, handwashing occurs in
both high- and low-income countries to various degrees (3). Laundering procedures vary
from region to region and are inuenced by cultural practices and resources. Laundering
involves a series of steps, independent of income status or machine access, each of which
can affect the removal and diversity of dermally shed transient microora within the textiles
being processed. The goal of this review is to dene laundering as a series of steps that inu-
ence the exposure of the person processing the laundry to pathogens and the removal and
control of pathogens and odor-causing bacteria while taking into consideration the types of
textiles. Dening laundering in this manner will help better educate the consumer and high-
light areas where more research is needed and how to maximize products and resources.
Citation Abney SE, Ijaz MK, McKinney J, Gerba CP.
2021. Laundry hygiene and odor control: state of
the science. Appl Environ Microbiol 87:e03002-20.
Editor Christopher A. Elkins, Centers for
Disease Control and Prevention
Copyright © 2021 Abney et al. This is an open-
access article distributed under the terms of
the Creative Commons Attribution 4.0
International license.
Address correspondence to Sarah E. Abney,
Accepted manuscript posted online
7 May 2021
Published 25 June 2021
July 2021 Volume 87 Issue 14 e03002-20 Applied and Environmental Microbiology 1
Downloaded from on 25 June 2021 by
The microora of laundry is important from the aspects of both preventing the transmis-
sion of diseases and odor control. The microora of household laundry can be inuenced
by many factors, including textile attributions, handling, and usage (Table 1).
The source of most microbes in clothing is the human skin and bodily excretions and
secretions. Activities such as cooking and eating, outdoor activities, and occupation can
inuence the distribution of the microbial ora present on the skin and within bodily
excretions. Linens (bedsheets), cleaning tools (sponges, kitchen towels, and dishcloths),
TABLE 1 Factors inuencing the occurrence of bacteria/viruses/molds in laundry
Factor(s) Description Reference(s)
Fabric composition Thickness, material, coloring agents; the thicker
the fabric, the greater the survival of bacteria
during laundering; greater survival of coliforms in
hand/face towels after laundering and drying
S. K. Tamimi, S. L. Maxwell, L. Sifuentes, and C. P.
Gerba, unpublished data; Gerba, unpublished
Storage conditions Bacterial no. increases in hampers and if stored
under high humidity (molds and total bacterial
no.); we have found that clothing stored in
hampers between laundering can result in the
growth of bacteria in clothing
Kennedy and Gerba, unpublished
Usage Location on body where worn (higher no. on
undergarments and in pockets than on shirts; face
and kitchen towels have higher no.); length of
time worn; highest no. of enteric bacteria found
in face towels and underwear
(e.g., coliforms)
10; Gerba et al., unpublished
Season Higher no. of bacteria during summer (mold);
warmer weather and perspiration encourage
growth of bacteria
K. A. Reynolds and C. P. Gerba, unpublished data
Age of clothing Possibility of biolm buildup; microorganisms
adapt to repeated washing conditions and are
not always removed
Reynolds Gerba, unpublished
Type of detergent Additives to enhance detergent performance, i.e.,
enzymes and multiple surfactants
Reynolds and Gerba, unpublished
Dirt load Type and quantity affect the performance of
detergent and bleach
Kennedy and Gerba, unpublished
Wash temp and time Greater survival of microbes at lower temp 45, 62; Kennedy and Gerba, unpublished
Drying temp and time Greater survival at lower temp and shorter length
of drying time
45; Kennedy and Gerba, unpublished
Air drying Bacterial no. may increase in the clothing under
humid outdoor conditions; prolonged exposure
to sunlight may decrease no. of fungi
Type of microorganism Resistance of microorganisms to washing varies
with species and strain of microorganism;
Mycobacterium,Enterobacter, and enteric viruses
are more resistant to release from textiles and
13, 45; Kennedy and Gerba, unpublished
Concn of microorganisms in bodily
excretions or secretions
Enteric viruses and bacteria can be excreted in
high concn in feces; Salmonella occurrence at
concn as high as 10
bacteria/g and norovirus
occurrence at concn as high as 10
particles/g of
Concn of bodily excretions or
secretions in clothing
The avg pair of adult underwear contains an avg
of 0.1 g of feces
Method of washing Machine washing versus handwashing; no data
found on handwashing but expected to be less
Quality of wash water In developing countries, fecally contaminated
water may be used, such as in streams
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and bath towels can have their unique microora. Each group of textiles has unique fea-
tures such as types of fabric, usage, and dirt load. This also inuences the occurrence of
pathogens and odor-producing bacteria within laundry.
Pathogens. Epidemiological studies have suggested the role of fabrics in transmit-
ting infectious agents in facilities (4). Since most pathogens associated with textiles
have multiple transmission routes, tracing epidemiological associations with launder-
ing and transmission is difcult. One study suggested the spread of respiratory illness
associated with public laundromat usage and not using bleach during laundering (5).
Numerous pathogens have been detected in textiles before laundering (Table 2).
Any pathogen associated with human illness is likely to be found in clothing and most
other textiles. Outbreaks of illness have been associated with textiles contaminated
with pathogens (viruses, bacteria, and fungi, where most cases are associated with
health care workers and facilities [1, 6, 7]).
Bacteria. Pathogenic bacteria causing enteric disease (Salmonella) and skin infec-
tions (MRSA [methicillin resistant Staphylococcus aureus]) have been associated with
textiles. In one study, Salmonella was detected in 15% of household sponges in the
United States and 3% of hand/face towels (8). Escherichia coli and other enteric bacteria
were also common. E. coli has also been detected in reusable grocery bags (9). Fecal
bacteria are common in undergarments of both children and adults (10). Under condi-
tions of storage (hamper or closet) before or after laundering, bacterial numbers can
increase (11).
Fungi. It has been suggested that fungi present in clothing may also play a role in
the transmission of dermatitis and onychomycosis (infection of the nails) (12). Fungal
pathogens have been isolated from patients suffering from tinea pedis (13). Clothing
has been linked to the transmission of Microsporum canis (1). M. canis belongs to the
TABLE 2 Some pathogens detected in textiles before washing
Salmonella enterica serovar Typhimurium 1
S. enterica serovar Hadar 1
Acinetobacter baumannii 1
Bacillus cereus 64
Clostridium difcile 33,42
Neisseria gonorrhoeae 1
Vancomycin-resistant enterococci 42
Microsporum canis 1
Sarcoptes scabiei 64
Alternaria alternata 65
Trichophyton mentagrophytes 13
Hepatitis B virus 1
Hepatitis A virus 66
Papillomavirus 67
Rhinovirus 68
Adenovirus 69
Inuenza virus 68
SARS-CoV-2 58
Parainuenza virus 68
RSV 68
Rotavirus 70
Helminths and protozoa
Pinworms 18
RSV, respiratory syncytial virus.
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group of dermatophyte fungi, which are closely related microorganisms that can
invade the stratum corneum of the epidermis and keratinized tissues derived from it,
such as the skin, nails, and hair of humans and animals. These fungi produce an infec-
tion called dermatophytosis, commonly referred to as ringworm or tinea. Of 70 house-
hold washing machines sampled in one study, 79% were positive for fungi (14).
Among the species detected, the opportunistic fungi Candida and Fusarium were
detected. Fungi can also cause life-threatening infections among the immunocompro-
mised. Mucormycosis, an infection of the order Mucorales, can cause mortality rates
that can exceed 50% (15). Outbreaks have been associated with linens in health care
(16). It was found that 33% to 73% of recently laundered linens were contaminated
with Aspergillus (16).
Protozoa. While no studies on the occurrence of protozoa in fabrics could be
found, they can be expected to be present in fecally soiled clothing from infected indi-
viduals as well as individuals who work with animals, such as farmers, cattle operators,
and veterinarians. In an outbreak of cryptosporidiosis, a wife was infected through
washing her husbands soiled veterinary clothing (17).
Viruses. A wide range of enteric and respiratory viruses have been detected in tex-
tiles, including rotavirus, hepatitis A and B viruses, herpes simplex virus, severe acute
respiratory syndrome coronavirus 2 (SARS-CoV-2), inuenza virus, HIV, and papillomavi-
rus (Table 2). A blood-borne pathogen, hepatitis B virus has been transmitted by shar-
ing bathroom towels. Hepatitis A virus and vaccinia virus (smallpox virus) have also
been shown to be transmitted by textiles (1).
Helminths. Fecally contaminated clothing and fabrics can also be expected to contain
helminths (worms) and their eggs. These include tapeworms, Ascaris,andpinworms,etc.
Good hygiene and water and food supplies have resulted in a low incidence of most intesti-
nal worm infestations in the developed world. Pinworms are the most common helminth in
the United States and Western Europe, with prevalence rates in some communities being as
high as 30% to 50% (18). It has been suggested that pinworm (Enterobius vermicularis)con-
tamination of bed linen and clothing could be involved in their transmission (18). Pinworm
and Ascaris eggs can survive for 2 to 3 weeks on clothing and bed linens (19, 20). No data
on the occurrence of helminths in clothing and fabrics could be located.
The survival of microorganisms in stored-before-laundering fabrics depends on sev-
eral factors, including relative humidity (RH), temperature, and material. Proceeded by
a lower rate of inactivation, most microbial inactivation takes place during drying of
the original suspension that contains the microorganism (e.g., saliva or mucus). Drying
of respiratory viruses results in a usual 10- to 100-fold reduction in titers (21). Some
microorganisms survive better at certain relative humidities than others. For example,
rotavirus survives well at high (85% 65%) and low (25% 65%) relative humidities on
cotton-polyester (22). The type of material and the presence of dyes or coloring agents
may also affect the persistence of microorganisms on/in textiles (23, 24; C. P. Gerba,
unpublished data). Water loss was observed to be greater in more hydrophobic fabrics.
Certain fabrics such as cotton towels hold moisture to a higher degree, reducing drying
and allowing the potential growth of bacteria and mold (C. P. Gerba and L. Sifuentes,
unpublished data). Kampf (21) found that bacteria at room temperature survived the
longest on polyester (up to 206 days), compared to 90 days in cotton and mixed bers.
Most bacteria were found to survive better at higher relative humidities. Enveloped
viruses survived for less than 1 day on cotton fabrics, while they survived for 7 to
12 days on polyester. The thickness of the clothing/fabric may also affect drying and
cause the regrowth of bacteria, such as coliforms in face towels (Gerba, unpublished).
Dyes used in the manufacturing of fabrics may also have antibacterial activity (23).
Most respiratory viruses, including SARS-CoV-2, do not survive more than a day or
two in clothing (25, 26). The survival of inuenza virus in clothing was found to be
related to the rate of water loss during drying (24). The thickness of the cloth and its
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color were related to survival, with faster inactivation in black cloth. However, some en-
teric viruses, such as rotavirus and hepatitis A virus, may survive for weeks (25, 27).
Pathogenic bacteria and molds, such as Salmonella and MRSA, may survive for
weeks in clothing (1). Naturally occurring Pseudomonas aeruginosa and Acinetobacter
spp. can grow in clothing even after laundering the clothing of wastewater treatment
workers (28). Apparently, naturally occurring bacteria have adapted to laundering con-
ditions, and enough organic matter remains for their regrowth during storage after
At a temperature of 25°C and an RH of 50%, 21 days were required for a 90% reduction
in Giardia cysts in soiled 100% cotton (29). Under the same conditions, Cryptosporidium
oocysts required ;60 days. Furthermore, Entamoeba histolytica cysts, pinworm (Enterobius
vermicularis), and Ascaris suum ova at temperatures of ,25°C and 50% RH required 21, 26,
and 188 days for 3-log
reductions in soiled 100% cotton (30).
The removal of microbes by the laundering process depends upon several factors,
as illustrated in Fig. 1. As can be seen, many factors may inuence the removal (detach-
ment and/or inactivation) of microorganisms but also the potential for contamination
(e.g., occupation, such as a wastewater worker versus a schoolteacher). It is likely that
these factors also result in the establishment of a resident microora adapted to com-
binations of these factors. This is important to note as processes intended to detach
and inactivate microorganisms may introduce additional microbial communities (e.g.,
resident microora from washers and dryers) and may inuence malodors.
The removal of pathogens from the laundry is largely dependent on washing and dry-
ing practices. The reduction-release and/or inactivation of pathogens is inuenced by de-
tergent selection, other additives (bleach), water temperature, and drying. In North
America, cold-water washes, using water from a cold-water tap, are commonly practiced.
Enveloped viruses such as SARS-CoV-2 and inuenza virus are very sensitive to the re-
moval/inactivation capability of some detergents, which can result in the elimination of
these viruses even in cold-water washes (31, 32). The median cold-water wash tempera-
ture is 14.4°C (57.9°F) in the United States. It has been recommended that temperatures of
40°C to 60°C (104°F to 140°F) and/or the use of bleach is needed for more resistant enteric
and dermal pathogens (1, 33). Drying also provides an additional barrier to transmission/
survival, with both the temperature and duration playing a role in disinfection (C. P. Gerba
and D. Kennedy, unpublished data). Higher-temperature settings and longer drying can
signicantly reduce microbial numbers. Acinetobacter baumannii and Staphylococcus
FIG 1 Factors inuencing the removal of microorganisms by laundering.
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aureus are among the non-spore-forming bacteria that are the most resistant to drying
and heat found in the laundry. Washing at temperatures above 60°C is necessary to
achieve a 99.9% reduction (35). Mycobacterium, fungi, and enteric viruses (hepatitis A virus,
adenovirus, and rotavirus) also require higher washing and drying temperatures for signi-
cant reductions (1, 36; Gerba and Kennedy, unpublished). The use of activated-oxygen
bleach (AOB) in cold-water washes (,40°C) will signicantly reduce the levels of bacteria
and viruses but may not eliminate them (2, 35). Gerba and Kennedy (unpublished data)
found that AOB was more effective in reducing Mycobacterium and enteric viruses than
chlorine bleach in the presence of detergent, probably because both the high pH of deter-
gent and the presence of dirt loads adversely impacted chlorine bleach activity.
Machine laundering is a series of steps involving sorting of cloths, loading of the
washer, removal from the washer, drying, and storage. Handwashing of textiles may
involve washing in a basin, public facility, or surface water source (river or reservoir).
Each step in the process results in the exposure of the individual handling the clothing to
pathogens in the clothing and potentially to any present in the water. Exposure may occur
by both contamination of the hands and microbial aerosols (37). Today, machine laundering
is the most common method of practice, but hand laundering is practiced in all regions of
the world (3). In high-income countries, this is usually limited to ne fabrics or other items
for which machine washing is not recommended (e.g., reusable grocery bags made of plastic
bers). In North America, 82% of the laundry is machine washed, while in Africa and the
Middle East, only 45% is machined washed (3). From 6% to 14% of household laundry is still
handwashed depending upon the region of the world.
Delicate fabrics, such as lingerie and reusable grocery bags, can be signicantly con-
taminated with bacterial and viral pathogens (9, 38; Gerba, unpublished). The use of
sinks or plastic basins, often used for handwashing of fabrics, can result in contamina-
tion of the hands and cross-contamination if multiple items are washed. In addition,
such items are not washed at temperatures as high as those in washing machines and
are hang dried, not reaching temperatures reached in machine dryers.
In low-income countries, laundry bar soap is often used for washing instead of
detergents, which may reduce the efcacy of the processes in terms of dirt removal
and microbes (Fig. 2). In addition, water with fecal contamination may be used. A study
in India suggested that handwashing of laundry in fecally contaminated rivers was a
potential risk factor for the transmission of hepatitis E virus (39).
Laundry processing involves several steps, as shown in Fig. 3. Each step not only
involves potential exposure to pathogens but also can affect the overall microbial load,
including odor-producing bacteria.
Storage of the laundry in a hamper or humid environment can result in the growth
of odor-producing bacteria, molds, and, potentially, pathogenic bacteria (11, 40). The
FIG 2 Steps in handwashing as practiced in some regions of the developing world.
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soil load may also enhance the potential for the growth of these microorganisms.
Bacteria and fungi may survive for weeks to months in textiles (11). Enteric bacteria
and viruses are also capable of prolonged survival (weeks), with some respiratory
viruses surviving for at least several days (1, 25).
Sorting of the textiles could result in both cross-contamination of the textiles, the
surfaces where it is conducted, as well as the hands of the person doing the sorting
and aerosolization of pathogen-associated particulates. The same is true for loading of
the washing machine, removal of the laundry from the washing machine, and place-
ment in the dryer or hanging of the clothes to air dry (Gerba, unpublished). The dry
heat from the dryer can result in a signicant reduction of microbes. Drying in the out-
door environment may result in a reduction of microorganisms from the UV rays in
sunlight. Still, the presence of humid air conditions could result in the regrowth of
some microorganisms, including recontamination events from bird droppings. Sorting
prior to hanging of the clothes can result in additional exposure. Sorting of the clean
clothes in the same area as the one used for sorting of the unwashed clothes can result
in additional cross-contamination. Also, handling dirty clothes and then sorting
washed clothes can result in cross-contamination. This cross-contamination web has
been reported in commercial laundries (41, 42). Furthermore, storage of the clothing
can result in the growth of bacteria and molds under humid conditions (28).
Pathogens. The removal of pathogens from the laundry is largely dependent on
washing (release and/or inactivation) and drying (inactivation) practices. The reduction
of pathogens is inuenced by detergent selection, other additives (bleach), water tem-
perature, and drying (43). In North America, cold-water washes are the common practice,
while in Europe, hot-water washes are much more common; hot-water taps in the
United States alone are recommended to be set at a maximum of 49°C (120°F) to 52°C
(125°F) to avoid scalding (44). In Europe, the temperature on the washing machine is
selected by the user, and hot-water washes of .40°C are the usual practice (1). It has
been recommended that a minimum wash temperature of .40°C is necessary to impact
the detachment and sterilization of pathogens from laundry where AOB detergents are
not used (1). Wash temperatures of 60°C are recommended for fungi (13). Microorganisms
with greater resistance to removal by washing and drying include spore-forming bacteria
(Clostridium difcile), Mycobacterium spp., Bacillus cereus,Acinetobacter spp., Aspergillus and
other fungi, hepatitis A virus, adenovirus, rotavirus, and enteroviruses (45; C. P. Gerba,
S. Maxwell, L. Y. Sifuentes, and A. H. Tamimi, submitted for publication). Table 3 illustrates
the removal of different types of microorganisms by machine washing.
Enveloped viruses such as SARS-CoV-2 and inuenza virus are very sensitive to the inac-
tivation action of detergents, which can result in the elimination of these viruses even in
FIG 3 Steps involved in home laundering using a washing machine.
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cold-water washes. However, viruses and some bacteria and fungi may require hot-water
washes, bleach, and high settings on dryers (31, 45). Heinzel et al. (31) found that while
enveloped viruses were inactivated by .99.99% as a result of washing textiles at 20°C,
temperatures of 30°C to 40°C in addition to a sanitizing detergent (AOB) were necessary
for the inactivation of nonenveloped viruses. Both chlorine bleaches and activated-oxygen
sanitizers result in increased reductions of pathogens in textiles (1, 35). Activated-oxygen
bleaches are common in detergents used in Europe but not the United States (1). While
bleach effectively reduces the number of bacteria and viruses, AOB was found to be more
by the laundry detergent resulting in a lower efcacy of the bleach.
Recently, Zinn and Bockmuhl (47) found that the addition of acetic acid (nal concentra-
tion, 0.75%) to a wash load of soiled fabrics and detergent reduced Pseudomonas aeruginosa,
E. coli,andStaphylococcus hominis by more than 7 log
units, while S. aureus was reduced
by 5.8 log
units. Such approaches may be useful in reducing pathogens in resource-limited
Odor-producing microorganisms. Bacteria and fungi are the major causes of mal-
odors in clothing. Odor-producing bacteria and fungi may originate not only from use but
also during storage or from cross-contamination between articles, the washing machine,
and even machine or hang drying (40, 48, 49). During slow air drying, these microorgan-
isms may increase in numbers (48). Greater malodors are more often associated with poly-
esters because the odor-producing hydrophobic compounds attach more strongly to
these fabrics than to cotton and are more difcult to remove by detergents alone (48).
Washing machines develop a unique biolm inuenced by detergents and high
temperatures. Thermophilic bacteria are more common in washing machines and
clothing as a result (50, 51). Proteobacteria are the predominant phylum of bacteria in
washing machines (51). Pseudomonas putida was found to be the most resilient biolm
former in washing machines (52). Washing machines are believed to be a signicant
source of bacteria and fungi that cause malodors in laundry (49). Kubota et al. (40)
reported that the species Mycobacterium osloensis was primarily responsible for mal-
odor in laundry. They found that it had the potential to generate the odor compound
4M3H (4-methyl-3-hexenoic acid) as well as a high tolerance to desiccation and UV
Overall, it appears that the major causes of malodors are bacteria and fungi that
can survive laundering. Upon wetting, these bacteria can grow both in the washing
machine itself and within textiles.
Type of textiles. The ability to release microbes from textiles by washing is inu-
enced by their structure, fabric type, and thickness. For example, bath and face towels
reductions by machine drying temperature and duration
Organism(s) Log
reduction Method, drying temp, and time Reference
Rotavirus 0.32 Permanent cycle, 55°C, 28 min, cotton sheets 45
Hepatitis A virus 0.29
Adenovirus 1.36
S. aureus 2.892.50 Huebsch gas dryer, medium temp, 16 min,
cotton-polyester sheets
S. aureus 3.23 Cotton-polyester, 10 min, 46°C, 20 min 72
Serratia marcescens .3.84
Bacillus stearothermophilus 0.73
S. aureus 1.82 Permanent press cycle, 55°C, 28 min, cotton Gerba and Kennedy, unpublished
E. coli .4.16
S. Typhimurium 4.83
Mycobacterium fortuitum 0.14
Naturally occurring bacteria 0.51.0 175.6°C177.8°C, 2 min 73
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make it more difcult to remove bacteria because of their thickness. Coliform bacteria
within bath towels have been found to survive washing in hot water and extended
drying (Gerba, unpublished). This suggests that the occurrence of odor-causing bacte-
ria may be greater in some types of materials than others (i.e., sponges and bath and
kitchen cleaning towels) (53).
Type of washing machine. Front-loader machines have become more common
since they reduce water usage and are more efcient. However, residual water that
remains in the machine may affect odors and result in cross-contamination of laundry.
In a survey of washing machines in homes, ;20% were found to harbor E. coli in the
drum (Gerba, unpublished). Fungal pathogens such as Candida and Fusarium species
have been detected in residential washing machines (14).
Exposure. The greatest exposure to pathogens occurs from handling the soiled
laundry before it is placed in the washing machine and handling the washed laundry
when either putting it in the dryer or hanging it to dry. The contamination of the
hands during these events can lead to infection of the individual handling the laundry.
This is especially true for enteric pathogens since movement of the hands to the
mouth (lips) results in direct access to the intestinal tract. Contact with contaminated
skin can result in the transmission of skin infections, and respiratory infections can be
transmitted from contact to the nose, eyes, and mouth.
The next greatest exposure results from removing the laundry from a dryer or dur-
ing collection after it has been hung to dry. Finally, the reuse of the fabric results in a
potential additional exposure. Exposure events from handling laundry are shown in
Fig. 4. The microorganisms may be transferred from the hand to the face, other
fomites, and food. We consider that the greatest risk is likely from hand-to-mouth con-
tact from directly handling the laundry.
Only a certain percentage of the microorganisms on the fabric is transferred to the
hand from contact with each other (54). The number transferred to the hands may depend
the individual. Exposure will also depend upon how many contaminated fabrics are
handled and how many times the face or mouth is touched (55). Generally, less transfer of
virus occurs from fabrics than from hard nonporous surfaces. Lopez et al. (56) found that
0.03% of MS2 virus was transferred to the hands from dry cotton fabric at low relative hu-
midity (15 to 32%) and that 0.3% was transferred at high relative humidity (40 to 65%).
Indoor humidity in the United States ranges typically from 40% to 60%. In contrast, the
rate of transfer of MS2 from hard surfaces (stainless steel) to the nger was 21% to 79%
depending upon the relative humidity (56). Rusin et al. (54) found that only 0.005% of the
bacterial virus PRD1 was transferred from dry cotton cloth to the hands. Alternatively, the
rate of transfer was 0.0005% from a cotton-polyester fabric. From a moist wet cotton dish-
The rate of transfer of human rotavirus from a stainless steel surface to the nger was
found to be 16.6% (57). Rusin et al. (54) found that 33.9% of the coliphage PRD1 virus was
FIG 4 Exposure events for handing and washing laundry.
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transferred from the hand to the mouth. No data could be found on the transfer of envel-
oped viruses from fabrics to hands or from hands to face. Such information would help
better dene risks from handling laundry from persons with respiratory infections, includ-
ing SARS-CoV-2-associated coronavirus disease 2019 (COVID-19). Recently, SARS-CoV-2
RNA was detected from a sheet, a duvet cover, and a pillow cover, further highlighting the
paramount importance of proper handling procedures during the replacement and/or
laundering of used clothing of SARS-CoV-2 patients (58).
The goal of laundering is to control both the exposure to pathogenic microorganisms
and odor. Both are interrelated, and the control of one implies the control of the other.
One of the biggest problems in assessing the efcacy of these goals for domestic laun-
dering processes is the lack of a consistent, structured approach to all the factors
involved. A structured approach is needed that identies all the steps in the process and
attempts to quantify both risks of infection and mitigation of odor. One factor that needs
to be assessed is the strategies in the home that can be used to minimize environmental
impacts (energy usage) while still minimize odor and exposure to illness-causing
microbes. The use of low temperatures during laundering may require additional strat-
egies such as the use of a sanitizer and/or extended machine drying, especially when
certain enteric viruses and bacteria may be present. There is also a need to consider the
laundering of work and professional clothing, demographics of the household, regional
differences in laundering practices, and types of textiles. All of these are needed to pro-
vide guidance to households to maximize the benets of laundering.
Research should be focused on providing information that can be used to identify
risks and how they can be reduced in a more quantitative fashion. Using event trees to
dene the impacts of each process in laundering and quantitative microbial risk assess-
ment (10, 59) can quantify the impact of each process in terms of odor reduction and
risk of infection. These can then be used to develop guidance for domestic laundering,
which is not yet available and would have the greatest benet. In fact, there are no
understandings of a denition for what it means to achieve a safelevel of risk reduc-
tion in laundering practices. Research on the efcacy of machine washing alone has
only recently been detailed (60, 61). Figure 5 illustrates these needs. More information
on the types and concentrations of odor-causing and pathogenic bacteria in the laun-
dry can be used to better dene strategies for processing while also taking into consid-
eration the demographics of the household with respect to the types and coarseness
of textiles (professional clothing, thickness, and use). In this regard, the best combina-
tion of products can be selected. Better information on the impact of storage before
and after laundering of textiles is also needed. We are now in an age of increasing con-
cern about the spread of emerging pathogens and means of prevention and control,
FIG 5 Research studies to better dene and communicate risks associated with laundering.
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particularly with the ongoing SARS-CoV-2-associated COVID-19 pandemic. With addi-
tional information through future research endeavors, we can provide the best laun-
dering options to ensure a healthy household.
M.K.I. and J.M. are employed through Global Research & Development for Lysol and
Dettol, Reckitt Benckiser LLC, Montvale, NJ, which is the funding source for this research.
Sarah E. Abney is funded by the National Science Foundation NRT Indigenous Food,
Energy, and Water Sovereignty research training grant #DGE1735173.
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... Some of these secretions carry microorganisms while others promote growth of microorganisms which may persist within the fabric for a long period of time (Agbbulu et al., 2016). According to Abney et al. (2021), there is a likelihood that any pathogen associated with human illness may be found in clothing and most other textiles. Several studies indicate that microorganisms may survive on textiles for extended periods of time and infectious diseases can be transmitted directly by contact with contaminated textiles (Owen and Laird, 2020) In an assessment conducted by Briones et al. (2016) to determine the prevalence of bacterial and fungal pathogens on different types of second-hand clothing, Staphylococcus epidermidis was the only bacterium isolated. ...
... Also, gram negative bacterial isolates such as Pseudomonas sp. and Escherichia coli have been previously reported as inherent in second hand female undergarments (Awe and Abuh, 2016;Olajubu et al., 2017). Abney et al. (2021) Trichophyton is known to be a dermatophyte capable of infecting the skin, hair and nails. Also, Fusarium sp. is capable of inducing fusarial infections on skin and wound sites even with immunocompetent individuals. ...
Full-text available
Secondhand female undergarments sold in Abraka, Nigeria, were analyzed for bacteria and fungi using standard methods. Bacteria isolated were subjected to antibiotic susceptibility tests and analyzed for Multi-Antibiotic Resistance (MAR) using the Kirby-Bauer disc diffusion method. Microbial load of samples revealed lower counts in control (new undergarments (Pants and bras))-2 x 10 2 , 5.5 x 10 3 and 0.5 x 10 2 cfu//ml; counts for fairly used pants were 4.6 x 10 4 , 3.7 x 10 4 and 3.2 x 10 2 cfu/ml while fairly used bras were 2.7 x 10 3 , 4.8 x 10 4 and 1.5 x 10 2 cfu/ml for total aerobic counts(TAC), coliform counts (CC) and fungal counts (FC) respectively. Among the bacteria isolated were Staphylococcus spp, Bacillus spp, Escherichia spp, Klebsiella spp and Pseudomonas spp. Fungi isolated were Trichoderma spp, Geotrichum spp, Rhizopus spp, Trichophyton spp, Fusarium spp, Penicillium spp and Aspergillus spp. The highest frequencies of occurrence were recorded for Klebsiella spp and Pseudomonas spp with each accounting for 20.7% of the bacteria isolated. Rhizopus spp, on the other hand, had the highest prevalence (30.8%) among isolated fungi. In respect to sample types, second hand pants were found to be most colonized by microorganisms as they accounted for 43% and 53% of the isolated bacteria and fungi respectively. Bacillus spp isolated from fairly used bras generally presented resistance to antibiotics with MAR index values of 0.4-0.7. All gram positive bacteria isolated were resistant to amoxicillin. Escherichia spp isolates from second pants were resistant to septrin, chloramphenicol, gentamycin, streptomycin, cotrimoxazole and sparfloxacin. However, fluoroquinolone antibiotics (ciprofloxacin and ofloxacin) were most effective against isolated bacteria with 100% susceptibility recorded. The isolation of fungi and MAR bacteria are of public health concern and suggest the need for proper laundry of second hand clothes prior to use.
... While these modern clothes washing technologies may be efficient at removing stains, they may be less effective at sanitizing the washed clothes. In addition, the modern cycle parameters may permit the build-up of odor-causing microbes or pathogens in the machine itself, as well as on laundered articles [22]. ...
... Unfortunately, certain human pathogens, such as P. aeruginosa, form biofilms efficiently, and the present results suggest that washing machine biofilms might represent a source of infection via pathogen shedding and transfer to washed garments. Opportunistic pathogens, such as P. aeruginosa, A. baumanii, and S. aureus, are able to colonize skin and wounds [20][21][22][23][24][25], and are members of the so-called ESKAPE pathogens, which have been singled out as threats to global health due to their high virulence and potential for acquiring multi-drug resistance [13]. Transfer of such pathogens from laundered clothes to open wounds may represent an especial concern for highly susceptible populations (e.g., immunosuppressed individuals [8] or those who suffer from conditions that pre-dispose to skin wounds, such as diabetes or psoriasis). ...
Full-text available
Although clothes washing machines remove dirt, microorganisms are not reliably removed by modern cold-water machine-washing practices. Microbial bioburden on clothing originates from the wearer’s skin, the environment (indoor and outdoor), and the washing machine itself. While most clothing microbes are commensals, microbes causing odors and opportunistic pathogens may also be present. Understanding the extent of microbial transfer from washing machines to clothes may inform strategies for odor control and for mitigating the transmission of microbes through the laundering process. This study was designed to quantify and identify bacteria/fungi transferred from laundromat machines to sentinel cotton washcloths under standard cold-water conditions. Bacterial 16S rRNA and fungal ITS sequencing enabled identification of microorganisms in the washcloths following laundering. Total plate-based enumeration of viable microorganisms also was performed, using growth media appropriate for bacteria and fungi. Opportunistic human bacterial pathogens, including Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp., were recovered. The fungal bioburden was ~two-fold lower than the bacterial bioburden. Most sequences recovered were assigned to non-pathogenic fungi, such as those from genera Malassezia and Ascomycota. These results suggest that public washing machines represent a source of non-pathogenic and pathogenic microbial contamination of laundered garments.
... Storage cabinets are common in households and are used to store household items. To maintain the tidiness of a kitchen, many people store dishes, chopsticks, knives, and cutting boards in storage cabinets, which poses a risk of bacterial infection because of the high humidity inside such cabinets [4][5][6]. Storage cabinets are typically enclosed, with little ventilative air exchange, very low interior air movement, and often high levels of humidity. Bacteria in cabinets are important sources of infection and pollution and have adverse effects on air quality and human health, sometimes leading to infections of the respiratory ...
Full-text available
Background: Bacteria are readily nourished in airtight environments with high humidity, such as storage cabinets, clothing closets, and corners, where ventilation is normally low and humidity is high. Objectives: We characterized the role of humidity and ventilation in bacterial growth and genus distribution at different temperatures (26 °C and 34 °C). Methods: Fresh pork, which was used as the substrate for bacterial culture, was placed in storage cabinets. Bacterial growth and genera distribution on the surface of pork placed in a storage cabinet under different temperatures (26 °C and 34 °C); relative humidity levels (RH: 50%, 70%, 90%); and ventilation conditions (no ventilation and low, medium, and high levels of ventilation) were assessed by rDNA sequencing. Results: Increased ventilation and reduced humidity significantly decreased bacterial growth at 26 °C and 34 °C. The contribution of increased ventilation to the reduction in bacterial growth exceeded that of decreased humidity. Ventilation had the greatest effect on reducing bacterial growth compared to the unventilated conditions at 70% RH. At 34 °C, medium and high levels of ventilation were required to reduce bacterial growth. High temperatures greatly increased bacterial growth, but ventilation could reduce the degree of this increase.
... Contaminated clothing, coveralls, and reusable fabric materials should be collected and washed at 60°C cycles preferably with bleach. 72 If the coveralls are flame, thermal, and/or arc resistant and laundering at high temperatures interferes with those properties, use of disposable PPE is recommended. If disposable cleaning equipment is not available, the cleaning material (cloth, sponge, etc.) should be placed in a disinfectant solution effective against viruses or 0.1% sodium hypochlorite. ...
Full-text available
Recent water sector safety concerns during the COVID-19 pandemic highlight the need for industry-focused reviews of emerging pathogens to support evidence-based utility decision-making. Between May 7 and August 20, 2022, more than 41 358 cases of human monkeypox were reported globally from over 87 countries in which the disease is not endemic. Given that the presence and persistence of monkeypox virus (MPXV) in feces, water, and wastewater has not been investigated, we summarize the available evidence on MPXV and related orthopoxviruses to provide sector-wide recommendations and identify knowledge gaps. On the basis of the information available to date, this outbreak is unlikely to pose an exposure and transmission risk from wastewater, biosolids, or water due to the absence of any evidence to date that suggests that infectious MPXV is present in wastewater or biosolids or has caused human cases, clusters, or outbreaks from exposure to these sources. In addition, remaining smallpox vaccine immunity in the population, availability of vaccines and treatments, susceptibility of poxviruses to disinfection (e.g., UV and chlorine), and evidence from health care confirming the efficacy of infection control measures all suggest that current treatment and recommended wastewater worker protection practices are sufficient to protect public and occupational health.
... Further, the bactericidal activity was found to be intact even after 20 industrial washing cycles. The presence Page 18 of 33 AUTHOR SUBMITTED MANUSCRIPT -ERX-101746.R1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 A c c e p t e d M a n u s c r i p t 19 of TiO2 NPs after 20 washing cycles were validated through SEM images [ Fig. 7]. Also, many other fabrics and their activity against bacterial strain are mentioned in Table 7. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 A c c e p t e d M a n u s c r i p t Likewise, there are several other nanoparticles that are used to modify fabric which are listed in Table 8. ...
The spread of infectious diseases by the bacterial cells through hospital-acquired infections (HAIs) has become a major threat throughout the world. Fabrics used in the healthcare sector such as bedsheets, healthcare uniforms, and patient gowns can act as growing substrates for infectious bacterial cells and have become one of the causes of the spread of HAIs. The development of MDR by the bacterial cells further makes the situation worse. However, the metal ion toxicity and generation of reactive oxygen species by the metal/metal oxide-based nanoparticles (NPs) have the ability to counteract the proliferation of MDR bacterial strains. In this context, several NPs have been synthesized and functionalized over fabric to impart antibacterial activity. This process could hinder bacterial growth and biofilm formation over fabrics and thus, can prevent the spread of HAIs through contaminated fabrics. Therefore, the present review focuses on the types of NPs that are utilized to develop antibacterial fabrics.
... According to several studies, these odours seem to at least partly be caused by microbial colonizers of the washing machine and might be related to low-temperature laundry [18,23,24]. Although the formation of malodour must be considered a multi-factorial problem, the washing machine as a source of malodorous water-borne and ubiquitous bacteria might play a pivotal role in malodour development [1,25]. ...
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Microorganisms are an important factor in the wash-and-use cycle of textiles since they can cause unwanted aesthetic effects, such as malodour formation, and even pose health risks. In this regard, a comprehensive view of the microbial communities in washing machines and consideration of the microbial contamination of used textiles is needed to understand the formation of malodour and evaluate the infection risk related to laundering. So far, neither the compositions of washing machine biofilms leading to the formation of or protection against malodour have been investigated intensively, nor have microbial communities on used towels been analysed after normal use. Our results link the qualitative and quantitative analysis of microbial communities in washing machines and on used towels with the occurrence of malodour and thus not only allow for a better risk evaluation but also suggest bacterial colonizers of washing machines that might prevent malodour formation. It was shown that soil bacteria such as Rhizobium, Agrobacterium, Bosea, and Microbacterium in particular are found in non-odourous machines, and that Rhizobium species are able to prevent malodour formation in an in vitro model.
... Although they were the subject of some in vitro investigations, the examined conditions did not fully reflect natural conditions [10][11][12]. Furthermore, physical factors such as freezing or heating were shown to possess antimicrobial activity, which could influence the survival of dermatophytes [13]. The main goal of this study was to evaluate the lethal temperatures and times required for the chemical-free eradication of dermatophytes on linens by laundering, heat drying, or freezing in various situations, simulating a domestic setting. ...
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Dermatomycoses are one of the most common dermatological infectious diseases. Dermatophytoses, such as tinea pedis (athlete’s foot) in adults and tinea capitis in children, are the most prevalent fungal diseases caused by dermatophytes. The transmission of anthropophilic dermatophytoses occurs almost exclusively through indirect contact with patient-contaminated belongings or environments and, subsequently, facilitates the spread of the infection to others. Hygienic measures were demonstrated to have an important role in removing or reducing the fungal burden. Herein, we evaluated the effectiveness of physical-based methods of laundering, heat drying, and freezing in the elimination of Trichophyton tonsurans, T. rubrum, and T. interdigitale conidia in diverse temperatures and time spectra. Based on our findings, laundering at 60 °C was effective for removing the dermatophyte conidia from contaminated linens. On the contrary, heat drying using domestic or laundromat machines; freezing at −20 °C for 24 h, 48 h, or one week; and direct heat exposure at 60 °C for 10, 30, or 90 min were unable to kill the dermatophytes. These results can be helpful for clinicians, staff of children’s communities, and hygiene practitioners for implementing control management strategies against dermatophytoses caused by mentioned dermatophyte species.
... Depending on the duration of time between contamination of a clothing article and laundering of the contaminated article, further contamination of the laundry appliance and the wash solutions with infectious virus is therefore possible. Manual (as opposed to machine) clothes washing, which still occurs to some extent even in developed countries, presents additional opportunities for contamination of secondary surfaces with infectious virus 34 . Infectious SARS-CoV-2 dried upon a hard surface (such as steel laundry tumbler) may remain infectious for days, based on a review of the survival data from the literature 26 . ...
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The clothes laundering process affords numerous opportunities for dissemination of infectious virus from contaminated clothing to appliance surfaces and other household surfaces and eventually to launderer’s hands. We have explored the efficacy of laundry sanitizers for inactivating coronaviruses and influenza viruses. Virucidal efficacy was tested using standardized suspension inactivation methods (EN 14476) or hard-surface inactivation methods (ASTM E1053-20) against SARS-CoV-2, human coronavirus 229E (HCoV 229E), influenza A virus (2009-H1N1 A/Mexico), or influenza B virus (B/Hong Kong). Efficacy was measured in terms of log10 reduction in infectious virus titer, after 15 min contact time (suspension studies) or 5 min contact time (hard surface studies) at 20 ± 1 °C. In liquid suspension studies, laundry sanitizers containing p-chloro-m-xylenol (PCMX) or quaternary ammonium compounds (QAC) caused complete inactivation (≥ 4 log10) of HCoV 229E and SARS-CoV-2 within 15 min contact time at 20 ± 1 °C. In hard surface studies, complete inactivation (≥ 4 log10) of each coronavirus or influenza virus, including SARS-CoV-2, was observed following a 5-min contact time at 20 ± 1 °C. Respiratory viruses may remain infectious on clothing/fabrics and environmental surfaces for hours to days. The use of a laundry sanitizer containing microbicidal actives may afford mitigation of the risk of contamination of surfaces during handling of the laundry and washing appliances (i.e., washer/dryer or basin), adjacent surfaces, the waste water stream, and the hands of individuals handling clothes contaminated with SARS-CoV-2, influenza viruses, or other emerging enveloped viruses.
... However, these washing methods cannot guarantee the sufficient cleanliness of the laundry and especially the sufficient disinfection of the laundry [9]. It is worth noting that any pathogen associated with human disease is likely to be found on textile clothing [10]. Since these are environmental pathogens, contamination of textile surfaces could have occurred after or during the laundering process. ...
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In the Water, Energy and Waste Directive, the European Commission provides for the use of household washing programmes with lower temperatures (30–40 °C) and lower water consumption. However, low washing temperatures and the absence of oxidising agents in the liquid detergents, and their reduced content in powder detergents, allow biofilm formation in washing machines and the development of an unpleasant odour, while the washed laundry can become a carrier of pathogenic bacteria, posing a risk to human health. The aim of the study was to determine whether the addition of hydrogen peroxide (HP) to liquid detergents in low-temperature household washing allows disinfection of the laundry without affecting the properties of the washed textiles even after several consecutive washes. Fabrics of different colours and of different raw material compositions were repeatedly washed in a household washing machine using a liquid detergent with the addition of 3% stabilised HP solution in the main wash, prewash or rinse. The results of the antimicrobial activity, soil removal activity, colour change and tensile strength confirmed the excellent disinfection activity of the 3% HP, but only if added in the main wash. Its presence did not discolour nor affect the tensile strength of the laundry, thus maintaining its overall appearance.
Background Hyperkeratotic flexural erythema (HKFE), also known as granular parakeratosis, is a scaly, erythematous or brown eruption, which usually occurs in the intertriginous and flexural areas. It has been linked to the use of benzalkonium chloride (BAK). Aim To review the clinical presentation of patients diagnosed with HKFE who had been exposed to laundry sanitizer containing BAK, and the therapies trialled to treat these patients. Methods This was a retrospective cases series of 45 patients seen by dermatologists in Victoria, Australia. Information was collected on clinical presentation, investigation and management. Results The patients varied in age from 18 months to 89 years. The rash typically presented as a symmetrical erythema with characteristic multilayered brownish epidermal scaling. The most common location of the rash was the inguinal/anogenital area (32 of 45 patients; 71.1%) and there was a female predominance. Regarding treatment, topical corticosteroids were frequently prescribed and antibiotics were trialled in 11 patients; however, the condition resolved spontaneously over time in all patients with use of emollients, along with cleaning of the washing machine by running an empty wash, and repeated washing or sometimes disposal of BAK-contaminated clothing. Conclusion This large case series highlighted the characteristic clinical presentation of HKFE in the setting of BAK used in laundry sanitizer, demonstrating a potential causal link. Further studies are required to evaluate the role of the skin microbiome.
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A new coronavirus (SARS-CoV-2) emerged in the winter of 2019 in Wuhan, China, and rapidly spread around the world. The extent and efficiency of SARS-CoV-2 pandemic is far greater than previous coronaviruses that emerged in the 21st Century. Here, we modeled stability of SARS-CoV-2 on skin, paper currency, and clothing to determine if these surfaces may factor in the fomite transmission dynamics of SARS-CoV-2. Skin, currency, and clothing samples were exposed to SARS-CoV-2 under laboratory conditions and incubated at three different temperatures (4°C± 2°C, 22°C± 2°C, and 37°C ± 2°C). We evaluated stability at 0 hours (h), 4 h, 8 h, 24 h, 72 h, 96 h, 7 days, and 14 days post-exposure. SARS-CoV-2 was stable on skin through the duration of the experiment at 4°C (14 days). Virus remained stable on skin for at least 96 h at 22°C and for at least 8h at 37°C. There were minimal differences between the tested currency samples. The virus remained stable on the $1 U.S.A. Bank Note for at least 96 h at 4°C while we did not detect viable virus on the $20 U.S.A. Bank Note samples beyond 72 h. The virus remained stable on both Bank Notes for at least 8 h at 22°C and 4 h at 37°C. Clothing samples were similar in stability to the currency. Viable virus remained for at least 96 h at 4°C and at least 4 h at 22°C. We did not detect viable virus on clothing samples at 37°C after initial exposure. This study confirms the inverse relationship between virus stability and temperature. Furthermore, virus stability on skin demonstrates the need for continued hand hygiene practices to minimize fomite transmission both in the general population as well as in workplaces where close contact is common.
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Background: Acetic acid has been used to clean and disinfect surfaces in the household for many decades. The antimicrobial efficacy of cleaning procedures can be considered particularly important for young, old, pregnant, immunocompromised people, but may also concern other groups, particularly with regards to the COVID-19 pandemics. This study aimed to show that acetic acid exhibit an antibacterial and antifungal activity when used for cleaning purposes and is able to destroy certain viruses. Furthermore, a disinfecting effect of laundry in a simulated washing cycle has been investigated. Results: At a concentration of 10% and in presence of 1.5% citric acid, acetic acid showed a reduction of > 5-log steps according to the specifications of DIN EN 1040 and DIN EN 1275 for the following microorganisms: P. aeruginosa, E. coli, S. aureus, L. monocytogenes, K. pneumoniae, E. hirae and A. brasiliensis. For MRSA a logarithmic reduction of 3.19 was obtained. Tests on surfaces according to DIN EN 13697 showed a complete reduction (> 5-log steps) for P. aeruginosa, E. coli, S. aureus, E. hirae, A. brasiliensis and C. albicans at an acetic acid concentration of already 5%. Virucidal efficacy tests according to DIN EN 14476 and DIN EN 16777 showed a reduction of ≥4-log-steps against the Modified Vaccinia virus Ankara (MVA) for acetic acid concentrations of 5% or higher. The results suggest that acetic acid does not have a disinfecting effect on microorganisms in a dosage that is commonly used for cleaning. However, this can be achieved by increasing the concentration of acetic acid used, especially when combined with citric acid. Conclusions: Our results show a disinfecting effect of acetic acid in a concentration of 10% and in presence of 1.5% citric acid against a variety of microorganisms. A virucidal effect against enveloped viruses could also be proven. Furthermore, the results showed a considerable antimicrobial effect of acetic acid when used in domestic laundry procedures.
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Background Infectious diseases are a significant threat in both healthcare and community settings. Healthcare associated infections (HCAIs) in particular are a leading cause of complications during hospitalisation. Contamination of the healthcare environment is recognised as a source of infectious disease yet the significance of porous surfaces including healthcare textiles as fomites is not well understood. It is currently assumed there is little infection risk from textiles due to a lack of direct epidemiological evidence. Decontamination of healthcare textiles is achieved with heat and/or detergents by commercial or in-house laundering with the exception of healthcare worker uniforms which are laundered domestically in some countries. The emergence of the COVID-19 pandemic has increased the need for rigorous infection control including effective decontamination of potential fomites in the healthcare environment. This article aims to review the evidence for the role of textiles in the transmission of infection, outline current procedures for laundering healthcare textiles and review studies evaluating the decontamination efficacy of domestic and industrial laundering. Methodology Pubmed, Google Scholar and Web of Science were searched for publications pertaining to the survival and transmission of microorganisms on textiles with a particular focus on the healthcare environment. Results A number of studies indicate that microorganisms survive on textiles for extended periods of time and can transfer on to skin and other surfaces suggesting it is biologically plausible that HCAIs and other infectious diseases can be transmitted directly through contact with contaminated textiles. Accordingly, there are a number of case studies that link small outbreaks with inadequate laundering or infection control processes surrounding healthcare laundry. Studies have also demonstrated the survival of potential pathogens during laundering of healthcare textiles, which may increase the risk of infection supporting the data published on specific outbreak case studies. Conclusions There are no large-scale epidemiological studies demonstrating a direct link between HCAIs and contaminated textiles yet evidence of outbreaks from published case studies should not be disregarded. Adequate microbial decontamination of linen and infection control procedures during laundering are required to minimise the risk of infection from healthcare textiles. Domestic laundering of healthcare worker uniforms is a particular concern due to the lack of control and monitoring of decontamination, offering a route for potential pathogens to enter the clinical environment. Industrial laundering of healthcare worker uniforms provides greater assurances of adequate decontamination compared to domestic laundering, due to the ability to monitor laundering parameters; this is of particular importance during the COVID-19 pandemic to minimise any risk of SARS-CoV-2 transmission.
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Hand-to-face contacts are important for estimating chemical and microbial exposures. Few studies describe children’s hand-to-eye or -nose contacts or adults’ hand-to-face contacts. The study objective was to characterize hand-to-head (mouth, eyes, nose, and other) contacts for children in a daycare and adults in multiple locations. Macro-activities and sequences of hand-to-face contacts were recorded for 263 people observed for 30 min each. Statistically significant differences between locations, males and females, adults and children, and during eating and non-eating macro-activities were evaluated. Discrete Markov chains were fit to observed contact sequences and compared among adults and children during eating and non-eating macro-activities. No significant differences in contact frequency were observed between males and females with the exception of hand-to-nose contacts. Children tended to touch the mouth, eyes, and nose more frequently than adults during non-eating macro-activities. Significant differences in contact frequency were observed between locations. Transitional probabilities indicated that children make repetitive mouth, eye, and nose contacts while adults frequently transition to contacts of the head other than the mouth, eyes, or nose. More data are needed to evaluate the effect of age on adults’ contact frequencies and to confirm lack of statistically significant differences between adults and children during eating macro-activities.
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Aims: Healthcare-associated infections linked to contaminated textiles are rare but underline their potential role as a source for transmission. The aim of the review was to summarize the experimental evidence on the survival and persistence of the different types of nosocomial pathogens on textiles. Methods: A literature search was performed on MedLine. Original data on the survival of bacteria, mycobacteria, and fungi and persistence of viruses on textiles were evaluated. Results: The survival of bacteria at room temperature was the longest on polyester (up to 206 days), whereas it was up to 90 days for some species on cotton and mixed fibers. Only low inocula of 100 CFU were found on all types of textiles with a short survival time of ≤3 days. Most bacterial species survived better at elevated air humidity. The infectivity of viruses on textiles is lost much faster at room temperature, typically within 2-4 weeks. Conclusions: Contaminated textiles or fabrics may be a source of transmission for weeks. The presence of pathogens on the coats of healthcare workers is associated with the presence of pathogens on their hands, demonstrating the relevance of textile contamination in patient care.
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We investigated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) environmental contamination in 2 rooms of a quarantine hotel after 2 presymptomatic persons who stayed there were laboratory-confirmed as having coronavirus disease. We detected SARS-CoV-2 RNA on 8 (36%) of 22 surfaces, as well as on the pillow cover, sheet, and duvet cover.
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During the last decades, the strive for energy efficiency lead to lower washing temperatures in laundering processes. In this regard, there is a rising need to measure the antimicrobial action of laundry detergents and additives, since chemistry must be considered an important means to compensate for the loss of temperature. Although there is an existing standard method (EN 16616) to evaluate the antimicrobial efficacy of detergents for the medical area, this method does not reflect the domestic situation and neglects important steps, such as the rinse cycles. Hence, we developed an experimental setup, which represents the whole washing process and reflects the domestic situation by using a household‐related setting. The suggested method uses a lab‐scale washing machine, which does not only allow to test products that can be applied throughout the whole laundering process (including the rinse steps) but also proved to be able to show the impact of different parameters (e.g., detergent ingredient or different types of textiles) in a very systematic manner.
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Modern, mainly sustainability-driven trends, such as low-temperature washing or bleach-free liquid detergents, facilitate microbial survival of the laundry processes. Favourable growth conditions like humidity, warmth and sufficient nutrients also contribute to microbial colonization of washing machines. Such colonization might lead to negatively perceived staining, corrosion of washing machine parts and surfaces, as well as machine and laundry malodour. In this study, we characterized the bacterial community of 13 domestic washing machines at four different sampling sites (detergent drawer, door seal, sump and fibres collected from the washing solution) using 16S rRNA gene pyrosequencing and statistically analysed associations with environmental and user-dependent factors. Across 50 investigated samples, the bacterial community turned out to be significantly site-dependent with the highest alpha diversity found inside the detergent drawer, followed by sump, textile fibres isolated from the washing solution, and door seal. Surprisingly, out of all other investigated factors only the monthly number of wash cycles at temperatures ≥ 60 °C showed a significant influence on the community structure. A higher number of hot wash cycles per month increased microbial diversity, especially inside the detergent drawer. Potential reasons and the hygienic relevance of this finding need to be assessed in future studies.
The effects of wash-water temperature, cold-water or regular detergent, wash-cycle design, drying, and drying temperature on survival of four microorganisms on polyester-cotton sheeting were examined. Escherichia coli T3 bacteriophage survived washing at 24, 35, 46, and 57 C, but not at 68 C. Serratia marcescens survived only the lowest three wash temperatures. Levels of residual Staphylococcus aureus were diminished at the highest two wash temperatures, but survival was substantial even at 68 C. Counts of Bacillus stearothermophilus spores were not altered appreciably by wash temperature. Type of detergent had no practical effect on observed counts. The regular wash cycle was significantly more efficient in removal of microorganisms than the permanent-press cycle. Counts, especially of the bacteriophage and the gramnegative bacterium, were decreased by drying; after drying, the effects of wash-water temperature on S. aureus and B. stearothermophilus were not significantly different. Microorganisms were transferred from inoculated to sterilized sheeting during laundering. The public health significance of these observations is discussed.
Pathogenic bacteria on abiotic surfaces such as fabrics, bedding, patient wears, and surgical tools are known to increase the risk of bacterial diseases in infants and the elderly. The desiccation tolerance of bacteria affects their viability in cotton. Thus, washing and drying machines are required to use conditions that ensure the sterilization of bacteria in cotton. The objective of this study is to determine the effects of various sterilization conditions of washing and drying machines on the survival of three pathogenic bacteria (Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus) commonly presented in contaminated cotton and two non-pathogenic bacteria (Bacillus subtilis and Escherichia coli) in cotton. High survival rates of A. baumannii and S. aureus in desiccated cotton were observed based on scanning electron microscope and replicate organism direct agar contact assay. The survival rates of A. baumannii and S. aureus exposed in desiccated cotton for 8 h were higher (14.4 and 5.0%, respectively) than those of other bacteria (< 0.5%). All tested bacteria were eradicated at low-temperature (< 40°C) washing with activated oxygen bleach (AOB). However, bacterial viability was shown in low temperature washing without AOB. High-temperature (> 60°C) washing was required to achieve 99.9% of the sterilization rate in washing without AOB. The sterilization rate was 93.2% using a drying machine at 60°C for 4 h. This level of sterilization was insufficient in terms of time and energy efficiency. High sterilization efficiency (> 99.9%) at 75°C for 3 h using a drying machine was confirmed. This study suggests standard conditions of drying machines to remove bacterial contamination in cotton by providing practical data.