Community Dental Health (2009) 26, 99–103
Received 19 April 2006; Accepted 10 March 2007
© BASCD 2009
Seroepidemiology of hepatitis C antibodies among dentists and
their self-reported use of infection control measures
M. Ashkenazi1, N. Fisher2, L. Levin3 and M. M. Littner4
1Departments of Pediatric Dentistry, 3Oral Rehabilitation, and 4Oral Pathology and Oral Medicine, The Maurice and Gabriela Goldschleger
School of Dental Medicine, Tel-Aviv University, Tel-Aviv, Israel, 2Private practice, Tel Aviv, Israel
Objectives. To determine the prevalence of hepatitis C virus (HCV) antibodies among dentists graduated from various countries and assess
the use of infection control measures in their dental practice. Research design. The study included 301 Israeli dentists who attended an
annual dental conference. Participants filled out a structured questionnaire regarding demographic (age, gender, number of siblings, number
of children) and occupational characteristics. Venous blood was examined for presence of HCV antibodies by enzyme immunoassay and
confirmed by a third generation line immunoassay, which assesses antibodies to HCV-core antigens (INN-LIATM HCV Ab III update,
100% sensitivity, 100% specificity). Results. The prevalence of HCV antibodies among Israeli dentists was 1/301 (0.33%), similar to
the prevalence range (0.1-0.5%) among the general Israeli population. The studied population included dentists (30.6%) who immigrated
from Asia, Eastern Europe and the former USSR, where HCV prevalence ranges from 3.1% to 26.5%. Dentists routinely used gloves
(99.6%), gown (93.3%), autoclaves (90.3%), dry heat (29.1%) and mask (81%). Dentists who graduated after 1985 used a mask or gown
significantly more often than dentists who graduated before 1985 (p<0.001 and p=0.004, respectively). Conclusion. It seems that dentists
who usually adhere to basic infection control measures are not at an increased risk for HCV.
Key words: Dentist, hepatitis C virus, infection control
The Centers for Disease Control and Prevention (Was-
ley 2007) estimate that approximately 20,000 people
are infected with hepatitis C virus (HCV) each year in
the US and about 170 million people around the world
(World Health Organization, 2000). HCV is a major cause
of acute hepatitis and chronic liver disease, including
cirrhosis and liver cancer (World Health Organization,
2000). Therefore, infection by HCV has an important
impact worldwide. This RNA virus proliferates in the liver
and circulates in the blood. Hepatitis C is a particularly
insidious disease. The acute infection is often asympto-
matic with fever, malaise, and jaundice, which occurs in
only 25% of the patients (Mondelli and Colombo, 1991).
Furthermore, the chronicity rate after HCV infection is
up to 80%, which is higher relative to other forms of
viral hepatitis (Mondelli and Colombo, 1991). Chronic
hepatitis C can progress to liver failure, cirrhosis, and
hepatocellular carcinoma and is also associated with a
carrier state. Asymptomatic chronic hepatitis C patients
serve as an increasing reservoir of individuals who in-
fect others. Spontaneous healing is rare and treatment is
targeted toward antiviral (INFα) and immune-modulation
(Ribavirin) medications. However, treatment is very
expensive and its effectiveness with only interferon is
approximately 10% to 20%. Interferon combined with
Ribavirin is effective in about 30% to 50% of patients.
Ribavirin used alone appears to be ineffective (World
Health Organization, 2000).
Correspondence to: Dr. Malka Ashkenazi, Department of Pediatric Dentistry, School of Dental Medicine, Tel-Aviv University, Tel-Aviv,
Israel. E-mail: firstname.lastname@example.org
Today, prevention is the key to eliminate HCV infec-
tion, usually transmitted through contaminated blood,
e.g., transfusion, hemodialysis, infected solid organ
transplantation, a sharp infected instrument, drug abuse
by injection, multiple sex partners, application of tattoo,
or acupuncture, or through a wound of the skin or mucosa
during medical treatment (World Health Organization,
2000). Since the etiology is unknown in 40% of the
infected patients, there may be an additional infection
route, e.g., saliva, although still controversial. HCV RNA
has been detected in the saliva of 0-100% of the infected
individuals (Pastore et al. 2006). In primates, HCV can
be transmitted by saliva and in humans by human bite
(Abe and Inchauspe, 1991).
Health care workers are frequently exposed to blood
and saliva and are prone to needle pricks. Since HCV is
primarily spread through occupational needle sticks and
sharp instruments, they are at a higher risk for HCV
infection and transmission than the general population
(Centers for Disease Control and Prevention, 2000) .
The purpose of the present study was to evaluate
the seroepidemiology of HCV antibodies among dentists
who have graduated from various countries vs the pos-
sible effect of the self-reported use of infection control
measures in their daily dental practice.
The study population consisted of 301 dentists who at-
tended an annual dental conference in Israel. Participation
2231-Ashkenazi.indd 9905/06/2009 15:58:50
was on a first come basis. Participants were asked to sign
an informed consent, fill out a structured questionnaire
(described below), and provide 8 ml of venous blood.
The Ethics Committee of Tel Aviv University approved
The structured questionnaire was designed to assess
variables associated with exposure to HCV. a) Demo-
graphic characteristics and risk factors: age, gender,
ethnicity, marital status, place of birth, date of immigra-
tion, years of education, history of jaundice, history of
jaundice in the family, history of operations, unprotected
sexual relations, and intravenous drug use. b)Occupational
characteristics: dental subspecialty, duration (years) of
work in dentistry, duration (years) of work in hospital (if
any), average hours of work during each week, typical
patient population, exposure to blood and past treatment
of HCV-infected patients. c) Use of infection control
measures in dental office: gloves (changed between pa-
tients), protective glasses, gown, autoclave and dry heat
sterilization as recommended by the Centers for Disease
Control and Prevention (William et al. 2003)
Venous blood, 8 ml, was collected in dry tubes.
After clotting and centrifugation, sera were separated
and stored in -20ºC until tested. HCV antibodies were
detected by enzyme immunoassay (Abbott AxSYM sys-
tem, HCV version 3.0 ref: 3B44-20, specificity 99.84%
and sensitivity 100%, Abbott Laboratories, Germany).
Positive sera were confirmed by a third generation line
immunoassay that assesses antibodies to HCV-core anti-
gens (INNO-LIA HCV-antibody test III, 100% sensitivity,
100% specificity, Innogenetics N.V., Haven, Belgium).
Only positive confirmation tests were defined as HCV-
Univariate analysis: χ2 test was used to determine the
significance of differences among proportions (rate of
seropositivity for HCV) and Student-t test for continuous
variables (e.g., years of work). SPSS software Number
9.0 for Windows (SPSS Inc. Chicago, IL, USA) was
used for statistical analyses.
More than half (67.4%) of the 301 participating dentists
were male. The group consisted of 233 general dentists
and 68 (23%) specialists in various fields of dentistry.
Table 1 shows the distribution of the studied population
according to place of birth.
Participants were mostly Jewish (92.7%). Of the
participants, 113 immigrated to Israel before 1985 and
133 graduated in dentistry before 1985.
Table 2 shows the potential risk factors associated with
HCV infection among the studied population. Accord-
ingly, 59.1% of the participants had surgery in the past,
83.1% performed surgery in their daily dental practice,
and 52.6% treated HCV infected patients.
Serum could be analyzed in 299 samples; two were
excluded due to technical failure. Only one blood sam-
ple was positive for HCV antibodies. The profile of the
seropositive dentist was a drug- abuser, treated mostly
(70%) immigrants, among them HCV positive patients
and had several per-cutaneous injuries. The subject was
not aware of their own seropositive status.
Table 3 describes the self-reported use of infection
control measures according to the country of graduation.
Accordingly, dentists who graduated in Asia and Eastern
Europe used masks more frequently than dentists who
graduated in Israel or in Western Europe and USA (90%
vs 75.7% and 75.7%, p=0.012). However, no statistical
differences were found between country of graduation
and the use of protective glasses, gloves, autoclave, or
dry heat sterilization.
Among the studied population work, duration ranged
from 1 to 52 years (mean 17.5 + 10.8 y). A significant
negative correlation was found between years of occupa-
tion in dentistry and use of a mask or gown during work
(p<0.001 and p=0.047, respectively), but no correlation
between years of occupation and use of gloves and
glasses. Similarly, dentists who graduated before 1985
reported significantly less usage of a mask and gown than
dentists who graduated after 1985 (p<0.001 and p=0.004,
respectively). In contrast, no statistically significant cor-
relations were found between years of work in dentistry
or graduation after 1985 and use of protective glasses,
gloves, autoclave, or dry heat sterilization though the
same tendency was observed (Figure 1). Infection control
guidelines were first published by Centers for Disease
Control in 1986 .
No correlations were found between performance of
dental surgery and use of a mask, protective glasses,
gloves, gown, autoclave and dry heat sterilization. No
correlation was found between work with children and
use of a mask, protective glasses, gloves or dry heat steri-
lization. In contrast, dentists who worked with children
used a gown (73.9% vs. 90.7%, respectively, p=0.085) or
autoclave (78.3% vs. 97.7%, respectively, p= 0.017) less
frequently than dentists who did not work with children.
No significant correlation was found between working
in public clinics and practicing universal precautions of
The highest known frequencies of HCV seropositivity,
up to 44%, are in developing countries, particularly in
Africa (el-Nanawy et al., 1995). Between 1952 and 1989,
the annual number of immigrants to Israel ranged from
10,000 to 70,000. According to the Israel Central Bureau
of Statistics, there was a dramatic increase (10-fold) in
the 1990s, reaching 100,000 immigrants per year from
the former USSR. In one study of 136,977 blood donors
in Israel during 1992, the prevalence of seropositivity to
HCV was positively correlated with age and country of
birth, with the highest seropositivity noted among people
born in the former USSR (3.1%) and Eastern Europe
(2%), and the lowest among native-born Israelis (0.4%)
(Bar-Shany et al., 1995). Nevertheless, there are specific
Jewish populations in Israel with significantly higher
seropositivity. For example, among the healthy Bukhar-
ian Jewish population, who immigrated from Uzbekistan
and Tajikistan to Israel from 1972 to 1989, 26.5% were
positive to HCV antibodies, with the highest prevalence
rates among the older population (Glikberg et al., 1997).
In another study the prevalence of anti-HCV among
5,444 employees of a large university hospital in Israel
was 0.1% among native-born Israelis and 5.7% among
2231-Ashkenazi.indd 10005/06/2009 15:58:50
Table 1. Distribution of the study population according to the place of birth and
place of graduation from dental school
Country Place of birth (%) Country of graduation from
dental school (%)
Australia and South Africa
Table 2. Potential risk factors for HCV infection among the studied population
*Results expressed as positive answers divided by number of negative answers
Potential risk factors Number (%)*
Used intravenous drugs in the past
Had surgery in the past
Received blood infusion
Perform surgery in daily dental practice
Had HBV infection
Had HAV infection
Immunized against HBV
Immunized against HAV
Had HCV infected person in their family
Treated HCV infected patients in the past
Percutaneous injury during treatment of HCV infected patient
Never treated HCV infected patients
Unprotected sexual relations with 0 to 5 persons
Unprotected sexual relations with 5 to 10 persons
Unprotected sexual relations with 10 to 15 persons
Unprotected sexual relations with more than 15 persons
*South America, South Africa and Australia
Table 3. Distribution of self-reported use of infection control measures according to country of graduation.
Self-reported use of infection control strategists
Israel (%) Asia and Eastern
and USA (%)
those born in Central Asia. Prevalence positively cor-
related with 10 or more years of occupational exposure
to blood (Sermoneta-Gertel et al., 2001).
The present study is the first to evaluate the seroepi-
demiology of HCV antibodies among dentists who were
born in Israel and those who have immigrated to Israel
from various countries. The prevalence of HCV antibodies
among this dentist population was only 0.3%, which is in
agreement with the prevalence found among blood donors
in Israel, although the study group included 30.6% dentists
from Asia, the former USSR, and Eastern Europe, where
the prevalence of HCV is higher (Sermoneta-Gertel et al.,
2001; World Health Organization, 2000). These results
indicate that dentists in Israel are not at an increased
risk for HCV infection and are actually at a lower risk
for HCV infection than other health workers in Israel
(Sermoneta-Gertel et al., 2001). This could be attributed
to a higher awareness of infection control measures, to
the higher socioeconomic level, or to less behavioral risk
factors among the dentists. It is noteworthy that the one
2231-Ashkenazi.indd 10105/06/2009 15:58:50
positive HCV participant was an intravenous drug abuser.
Since HCV infection is much more frequent among IV
drug users, it is more likely that this subject was infected
by drug use than by the subject’s occupation. Therefore,
it is suggested that no occupational transmission was
detected in the study group.
Studies in which the risk of dentists’ infection with
HCV compared to the general population have shown
controversial results. In Switzerland and in the USA
the prevalence of Anti-HCV among general dentists was
lower than in the general population ( 0.095% vs. 0.5-1%
and 0.7% vs. 2%, respectively) (Othman and Monem,
2001; Chou et al., 2004,). It should be emphasized that
a higher prevalence in USA was found in older dental
personnel with more years of practice (Chou et al.,
2004). In Taiwan and Scotland, the prevalence of HCV
antibodies among dentists was similar to the general
population (Kuo et al., 1993, Roy et al., 2003.) In
contrast, studies in the United States (New York) and in
a United Kingdom dental hospital show that dentists are
2 to 15 times at higher risk for HCV infection relative
to the general population, and oral surgeons a 10-fold
higher risk (Lodi et al., 1997).
These different results can be explained by the wide
range of differences in the regular use of universal
precautions required for infection control and year of
graduation from dental school. Since the mid-1980s, with
an increase in awareness of blood-borne infections in
general, and of human immunodeficiency virus (HIV) in
particular, the recommended infection control measures,
such as wearing gloves, masks, and the autoclaving of
hand instruments, have increased. The concept that all
patients must be regarded as potentially infectious and,
as such, require the use of standard precautions, has
become accepted in many countries. However, there are
limited data describing the acceptance of these guide-
lines among dentists and the increasing use of infection
control measures over the years. In the present study,
gloves were the most commonly used among the studied
population (99.3%) with the highest reported rate. There
was no significant increase in glove use between dentists
who graduated before or after 1985 (99.2% vs. 100%,
respectively), which indicates a continuous extensive
use. This confirms other studies (Mitchell and Russell,
1989) that showed a definite increase in glove use be-
tween 1983 and 1988. A high rate of routine glove use
was found in 1995 (97%) (McCarthy et al., 1999), but a
low rate can still be found in some countries (Ammon et
al., 2000). Glove use is correlated with age and gender,
with younger female dentists more likely to wear them
(Hudson-Davies et al., 1995).
Use of wearing protective glasses and a mask ranges
from 29% to 82% (Ammon et al., 2000; McCarthy et
al., 1999) and from 38% to 82% (Ammon et al., 2000;
McCarthy et al., 1999), respectively. In the present
study the prevalence of wearing protective glasses and a
mask was in accordance with the higher reported rates:
60.1% and 81%, respectively. A statistically significant
improvement (p<0.001) was shown in the prevalence of
mask use among dentists who graduated after 1985, while
there were no differences in wearing protective glasses
among these dentists. This indicates that there is a need
to further emphasize to the dentists the importance of
wearing protective glasses.
Wearing of gloves, gowns and facemasks are abso-
lutely basic requirements of dental healthcare providers.
In the present study, the fact that a number of responders
still claimed not to use gloves, gowns and facemasks is
Another important measure to decrease cross in-
fections is sterilization by an autoclave (Bagg et al.,
2001;McCarthy et al, 1999). In the present study, 90.3%
of the studied population reported used autoclaves and
29% used dry heat, which indicate that all the dentists
use autoclave or dry heat, and few dentists use both
sterilization techniques. Moreover, 93% of the dentists
Figure 1. Association between year of graduation from dental school (before and after
1985) and use of different infection control measures.
2231-Ashkenazi.indd 10205/06/2009 15:58:51
103 Download full-text
graduated after 1985 used autoclave, which is the high-
est prevalence reported for this preventive measure.
Dry heat is not considered an appropriate or acceptable
method for sterilizing dental instruments nowadays. The
fact that 29% of the dentists in this study were still us-
ing dry heat (even if combined with autoclave) might
warrant health care intervention. Adherence to infec-
tion control guidelines have improved in the last decade
mainly in some of the developed countries (Bagg et al.,
2001; McCarthy et al, 1999). A Canadian study showed
an increase in compliance from 83% in 1994 to 94% in
1995 in heat sterilization of hand instruments (McCarthy
et al , 1999). Notwithstanding, when the dentists were
asked whether they autoclave their handpieces after each
patient, the compliance was reduced to 77% (McCarthy et
al , 1999). In 2001, only 10 (3%) of the 327 dentists in
private practice in the UK possessed a vacuum autoclave
(Bagg et al., 2001).
In the present study, 86.3% of the dentists reported
to be immunized against HBV and 46.7% against HAV
(Table 2), which are in the higher range of the reports
related to vaccination of dentists against HBV: 68% and
74% (Ammon et al., 2000; Leggat et al., 2001). This is
the first study to report the prevalence of HAV vaccination
among dentists in Israel. To date, there is no vaccination
against HCV, and only infection control measures can
prevent dental professionals from infection.
Although the present study showed a relatively high
compliance with infection control measures among our
dentists, yet, a substantial percent of the dentists did not
follow the recommendation of WHO. Nevertheless, the
infection rate of dentists was comparable to the general
population. These results are in accordance with Roy
et al (2003) who did not find evidence of patient to
patient transmission of HCV among patients attending
the practice of dentists who admitted using periodically
The present study did not reveal that HCV was a
hazard to dental professionals. Although the risk for
HCV infection among dental practitioners was relatively
low, compliance with the guidelines for infection control
should be strictly followed.
The authors thank Ms. Rita Lazar for editorial assistance.
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