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The effectiveness of a nationwide universal coverage campaign of insecticide-treated bed nets on childhood malaria in Malawi


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Abstract Background Although the universal coverage campaign of insecticide-treated mosquito bed nets (ITNs) has been associated with improved malaria outcomes, recent reports indicate that the campaign is losing its sparkle in some countries. In Malawi, the universal coverage campaign was implemented in 2012, but its impacts are yet to be ascertained. Thus, this study examined the effects of the campaign on malaria morbidity among children in Malawi. Methods This is a repeated cross-sectional study. The study used nationally-representative malaria indicator survey (MIS) data collected in 2012 and 2014. In total, the analysis included 4193 children between the ages of 6 and 59 months (2171 from 2012 MIS and 2022 from 2014 MIS). ITNs coverage and malaria morbidity before (2012 = pre-test/control) and after (2014 = post-test/treated) the universal coverage campaign of ITNs were compared. The treated and control samples were matched on measured relevant covariates using propensity scores. Results The mean number of ITNs per household improved significantly from 1.1 (SD 1.0) in 2012 to 1.4 (SD 1.1) in 2014 (p
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Zamawe et al. Malar J (2016) 15:505
DOI 10.1186/s12936-016-1550-9
The eectiveness ofa nationwide
universal coverage campaign
ofinsecticide-treated bed nets onchildhood
malaria inMalawi
Collins O. F. Zamawe, Kanan Nakamura, Akira Shibanuma* and Masamine Jimba
Background: Although the universal coverage campaign of insecticide-treated mosquito bed nets (ITNs) has been
associated with improved malaria outcomes, recent reports indicate that the campaign is losing its sparkle in some
countries. In Malawi, the universal coverage campaign was implemented in 2012, but its impacts are yet to be ascer-
tained. Thus, this study examined the effects of the campaign on malaria morbidity among children in Malawi.
Methods: This is a repeated cross-sectional study. The study used nationally-representative malaria indicator sur-
vey (MIS) data collected in 2012 and 2014. In total, the analysis included 4193 children between the ages of 6 and
59 months (2171 from 2012 MIS and 2022 from 2014 MIS). ITNs coverage and malaria morbidity before (2012 = pre-
test/control) and after (2014 = post-test/treated) the universal coverage campaign of ITNs were compared. The
treated and control samples were matched on measured relevant covariates using propensity scores.
Results: The mean number of ITNs per household improved significantly from 1.1 (SD 1.0) in 2012 to 1.4 (SD 1.1) in
2014 (p < 0.001). Nonetheless, the prevalence of malaria among children increased considerably from 27.7 % (2012) to
32.0 % (2014) (p = 0.002). The risk of malaria was also significantly higher in 2014 compared to 2012 (RR = 1.14; 95 %
CI 1.01–1.29). Besides, the use of bed nets was not significantly associated with malaria morbidity in 2014 (RR = 0.92;
95 % CI 0.76–1.12), but it was in 2012 (RR = 0.83; 95 % CI 0.70–1.00).
Conclusions: The universal coverage campaign of ITNs was not associated with a reduced burden of malaria among
children in Malawi. This was likely due to increased insecticide resistance, inconsistent use of bed nets and under-uti-
lization of other methods of malaria control. This calls for a multifaceted approach in the fight against malaria instead
of simple dependence on ITNs. In particular, local or community level malaria interventions should go hand in hand
with the universal coverage campaign.
Keywords: Malaria, Insecticide-treated bed nets, Children, Plasmodium falciparum
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publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
e global incidence and mortality rate of malaria have
fallen by 37 and 58%, respectively in the last decade [1].
Nevertheless, malaria is still a major life-threatening dis-
ease in the world. For instance, almost half of the world’s
population (3.3 billion) remains at risk of being infected
with malaria and over 200 million cases of malaria and
438,000 malaria attributable deaths were reported in
2015 [2]. Globally, children aged under-five years are
the most susceptible group to malaria [1, 2]. Malaria
kills a child every minute and accounts for one-sixth of
all childhood deaths in high malaria transmission areas
[3]. In 2013, around 80% of the malaria deaths occurred
among under-five children [4].
Open Access
Malaria Journal
Department of Community and Global Health, Graduate School
of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku,
Tokyo 113-0033, Japan
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Page 2 of 8
Zamawe et al. Malar J (2016) 15:505
e World Health Organization (WHO) recog-
nizes five key interventions for preventing and treating
malaria. ese are prompt diagnosis and effective treat-
ment of malaria, the use of insecticide-treated mosquito
nets (ITNs) or long-lasting insecticidal nets (LLINs),
indoor residual spraying, chemo-prevention and inter-
mittent preventive therapy for pregnancy/infancy [5].
Since malaria is largely transmitted through mosquito
bites, the use of ITNs is the most popular, practical and
cost-effective intervention [6, 7]. Evidence is available
to show that ITNs can save about six lives each year for
every 1000 children [8].
e burden of malaria is heaviest in low income coun-
tries [2]. e recent world malaria report indicates that
about 80% of the global malaria cases and deaths in 2013
occurred in Africa, particularly in the sub-Saharan region
[2]. Additionally, malaria is also one of the top ten causes
of mortality in low income countries [2, 9]. erefore,
to ensure that all those at risk of malaria are protected
(especially in malaria endemic countries), WHO recom-
mended universal access to ITNs [10, 11].
Malawi is one of the malaria endemic countries. It is
among the 18 high-risk countries accounting for 90% of
the estimated number of Plasmodium falciparum infec-
tions in sub-Saharan Africa [2]. Almost everyone in
Malawi is at risk of malaria (>1 case/1000 population)
[2]. In particular, about six million suspected malaria
cases are treated each year and malaria is the number
one cause of morbidity and mortality in the country [12].
Of the suspected malaria cases, about 50% occur among
under-five children [12]. Malaria is also responsible for
about 40 % of the under-five children hospitalization
annually [12, 13].
An ITN policy has been at the centre of malaria con-
trol in Malawi since 2006 [13]. In the first few years, the
focus was on free distribution of ITNs to all under-five
children and pregnant women during their first visit to
a health facility/antenatal care [13, 14]. is approach
proved insufficient to achieve the universal coverage of
ITNs [14]. For that reason, a nationwide mass distribu-
tion of ITNs (hereinafter universal coverage campaign)
was implemented in 2012 [12]. e goal was to have 90%
of all households owning at least one ITN and achieve a
net utilization rate of 80% [12]. About 5.6 million ITNs
were distributed across the country [12, 13]. e cam-
paign reached 87 % of the people who were registered
and the number of persons per net ranged from 1.6 to
2.4. Specific details of the campaign, including logistics in
the field are described elsewhere [12].
Even though the universal coverage campaign is evi-
dence driven and has been shown to reduce malaria-
associated morbidity and mortality [8, 15, 16], recent
reports suggest that the campaign is losing its sparkle in
some countries. In Burkina Faso, for instance, childhood
malaria increased after the campaign [17]. Similarly,
the scale-up of ITN coverage was not associated with
decreased incidence of malaria in Zambia and Mali [18,
19]. Considering that huge amount of resources are being
channelled towards the universal coverage campaign [2,
13], it is critical to understand how increased access to
ITNs relates to the population health. is would ensure
efficient use of the limited resources in the fight against
malaria. So far, the effect of the universal coverage cam-
paign in Malawi has not been ascertained. erefore, this
study examined the effectiveness of the universal cover-
age campaign on malaria morbidity among under-five
children in Malawi.
Study design anddata
is is a repeated cross-sectional study. Nationally rep-
resentative data collected in 2012 and 2014 through the
malaria indicator survey (MIS) were used. In 2012, the
MIS was conducted from April to May [20]. is was just
before the universal coverage campaign—though about
500,000 of the 5.6 million ITNs had already been distrib-
uted. e 2014 MIS was undertaken from May to June
[21]. us, the 2012 and 2014 surveys were carried out
around the same time of the year. In this study, bed net
coverage and malaria morbidity among under five chil-
dren before and after the universal coverage campaign
were compared.
Overview ofthe MIS: objectives, population andsampling
e MIS is a nationally representative cross-sectional
study that is periodically conducted as part of the
national malaria surveillance program in malaria bur-
dened countries [20, 21]. In Malawi, the key objectives of
MIS are to (a) monitor and evaluate the coverage and use
of malaria control interventions, (b) assess knowledge,
attitudes, and practices of malaria and (c) measure the
prevalence of fever, malaria and anaemia among children
[20, 21]. e survey is implemented by the Ministry of
Health through the National Malaria Control Programme
[20, 21].
In 2012 and 2014, MIS collected data from 3404 to
3405 households, respectively. ese households were
identified through a two-stage cluster sampling method.
e first stage involved selecting 140 clusters (or enumer-
ation areas) out of about 12,474 by means of probability
proportional to size. In the second stage, 25 households
were selected from each chosen cluster using a system-
atic random sampling approach. All women of repro-
ductive age (15–49 years) and children aged between
6 and 59 months (hereinafter children) in the selected
households were eligible to participate. For the children,
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Zamawe et al. Malar J (2016) 15:505
malaria and haemoglobin tests were conducted in the
field and a thick blood smear was taken for a confirma-
tory malaria parasite laboratory test.
Data analysis andstatistical procedures
MIS 2012 and 2014 children’s datasets were pooled.
ese datasets also contained information about the chil-
dren’s mothers. In total, 4193 children were included in
the analysis (2171 from 2012 MIS and 2022 from 2014
MIS). Variables wereincluded in the analysis based on
their relevance to the study objectives.e outcome vari-
able was malaria status (positive or negative) based on
confirmed laboratory results. Key covariates included
‘child slept under a bed net’ (‘yes’ if the child slept under
bed net the night before the survey, otherwise ‘no’), num-
ber of bed nets per household and social-demographic
characteristics of the child and his/her mother.
e analysis proceeded in three stages. First, descrip-
tive statistics were computed and the predictors of
malaria in 2012 and 2014 were separately examined. In
particular, Chi-squared tests for independence were per-
formed and multivariable logistic regression modelswere
fitted. e level of significance was 5% and we used 95%
confidence interval (CI). In each year (2014/2012), the
urban–rural ratio of the selected clusters was not propor-
tional to the population distribution in Malawi. For that
reason, sample weights were used to make the data rep-
resentative of the entire population [20, 21].
e second stage involved examining the impact of
ITN scale-up on childhood malaria. e universal cov-
erage campaign was the treatment variable or interven-
tion. is study compared malaria morbidity before
(2012= control/pre-test) and after (2014= treatment/
post-test) the intervention. e 2012 and 2014 samples
were matched using propensity scores to correct for
selection bias [22]. e treated (2014) were matched with
the control (2012) on the following covariates using a cal-
iper of 0.001 [23]: age of the child, sex of the child, area
of residence, cluster attitude, wealth index score, sex of
the household head, years of education (mother), num-
ber of under five children (household), number of house-
hold members, literacy (mother) and mother’ access to
malaria messages. Standardized differences (0.10 cut-off
point) were used to evaluate how well the treated and
control groups were balanced in the matched samples
[23, 24]. Propensity score matching (PSM) minimized
systematic differences between samples to acceptable
levels (see Additional file1). In addition to estimating the
overall treatment effect, the samples were also stratified
into rural and urban (area of residence).
Lastly, this study assessed the effect of ITNs on malaria
morbidity. e use of bed net was the treatment vari-
able or intervention. Malaria morbidity was compared
between children who slept under a bed net (treated) and
those who did not (control) after correcting for selection
bias through PSM [22]. In 2014, data concerning the use
of bed nets were available for 1934 out of 2022 partici-
pants. Of these, 1411 (73.0%) used bed nets (treated) and
523 (27.0%) did not (control). In 2012, the sample con-
sisted of 2171 participants. However, data regarding the
use of bed nets were available for 2011 participants, of
whom 1238 (61.6%) slept under a bed net (treated) and
773 (38.4%) did not (control). e participants for each
year were matched separately (see Additional file2) using
the same specifications as in stage two above. All analyses
were performed using Stata 13.1 (StataCorp LP, Texas,
Ethics statement
e MIS data and permission to use it were obtained
from the demographic health survey (DHS) program.
Besides, the study protocol was reviewed and approved
by the Research Ethics Committee of the University of
Tokyo. e original study obtained ethical clearance from
the Malawi’s National Health Sciences Research Com-
mittee (NHSRC). Mothers provided verbal informed
consents for their children’s haemoglobin and malaria
tests [20, 21].
e coverage and use of ITNs increased between 2012
and 2014 in Malawi. More precisely, the mean num-
ber of ITNs per household improved significantly from
1.1 (SD 1.0) in 2012 to 1.4 (SD 1.1) in 2014 (p<0.001).
e proportion of children who had at least one mos-
quito net also increased from 70.8 to 78.4% during the
same period (p<0.001). Similarly, the proportion of chil-
dren who slept under a bed net increased from 62.1%
(2012) to 69.4 % (2014) (p < 0.001). Notwithstanding,
the national prevalence of malaria parasite among chil-
dren increased considerably from 27.7% (2012) to 32.0%
(2014) (p= 0.002). Figure1 depicts ITN coverage, bed
net use and malaria morbidity in 2012 and 2014. Social
and demographic particulars of the participants in 2012
and 2014 with respect to malaria outcomes are described
in Table1.
Besides, the determinants of malaria morbidity among
children were examined. In 2012, the odds of being
infected with malaria were significantly lower among
children who slept under a bed net than those who did
not (AOR=0. 65; 95% CI 0.47–0.89). In contrast, sleep-
ing under bed net was not a significant predictor of
malaria in 2014 (AOR=0.77; 95% CI 0.57–1.06). In both
years, the number of bed nets per household was not
significantly associated with malaria morbidity among
children. Table 2 presents the predictors of childhood
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Zamawe et al. Malar J (2016) 15:505
malaria in 2012 and 2014, including all the variables that
were included (adjusted for) in the models.
Furthermore, the effect of ITN scale-up on childhood
malaria in Malawi was examined using the matched data.
Particularly, this study compared malaria morbidity in
2014 (treatment) and 2012 (control). Overall, the risk of
malaria was 14% higher in 2014 than 2012 (RR=1.14;
95% CI 1.01–1.29). Said differently, Malawian children
were at a significantly greater risk of malaria after the
universal coverage campaign than before (Table3).
In addition, this study also investigated the impact of
using bed nets on malaria outcomes among children in
2012 and 2014. In 2014, the overall risk of malaria was
lower among children who used bed nets compared to
those who did not (RR=0.92; 95% CI 0.76–1.12). How-
ever, the result was not statistically significant, even
after stratification by areas of residence (rural/urban).
In contrast, the use of bed nets in 2012 was significantly
associated with decreased risk of childhood malaria
(RR=0.83; 95% CI 0.70–1.00). Detailed results are pro-
vided in Table3.
ere are three key findings from this study. First, the
2012 universal coverage campaign improved both bed
net coverage and use among children in Malawi. Sec-
ondly, the use of bed nets was significantly associated
with reduced risk of childhood malaria in 2012, but not
in 2014. is simply suggests that ITNs were relatively
ineffective after the 2012 universal coverage campaign in
Malawi. Lastly, the prevalence of malaria among children
in Malawi was higher in 2014 than 2012. In other words,
the universal coverage campaign was not associated with
improved malaria outcomes.
Improved access to ITNs between 2012 and 2014 was
not associated with reduced malaria morbidity among
children in Malawi. is finding challenges the current
public health understanding that the universal cover-
age campaign reduces the burden of malaria [8, 2527].
Until now, the effects of ITN scale-up have been uneven.
For example, malaria morbidity/mortality declined in
south-west Cameroon, rural Tanzania and Rwanda after
the coverage of ITNs was enhanced [2830]. In con-
trast, higher/unchanged malaria prevalence/mortality
were reported in Zambia, Burkina Faso, Mali and west-
ern Myanmar following the ITN scale-up [17, 19, 31]. In
some cases, better access to ITNs was accompanied by
reduced incidence of malaria at the outset, but the gains
could not be sustained [32, 33]. ese variations could
be because most of the studies were confined to a par-
ticular population or setting in their respective countries
[31, 34]. is study analysed nationally representative
data with a special focus on children. As such, the results
provide a richer or wider perspective of the impact of the
universal coverage campaign.
Besides, ITN usage had an inconsequential impact on
malaria morbidity in Malawi, especially after the univer-
sal coverage campaign. As noted, the use of ITNs pro-
vided substantial protection against childhood malaria in
2012, but the effects attenuated and became insignificant
in 2014. e rise of insecticide resistance among Anoph-
eles mosquitoes is one of the plausible reasons for this
phenomenon [35, 36]. is hypothesis concurs with the
findings of a study in Malawi, which has recently reported
that there is reduced efficacy of bed nets in the country as
a consequence of increased intensity of insecticide resist-
ance [37]. Related outcomes have also been reported by
another study in Mozambique, which has clearly shown
that resistance to pyrethroids is extremely high in the
country [36]. erefore, amid serious concerns of insec-
ticide resistance, the universal coverage campaign may
not effectively reduce the burden of malaria in affected
Comparable studies have attributed the reduced effi-
cacy of ITNs to the community-wide effects of ITNs [17,
28, 38]. e reasoning is that ITNs do not only protect
individuals from direct mosquito bites, they also kill
the mosquitoes and thereby protecting from malaria
even those who do not sleep under bed nets [38]. us,
increased ITN coverage reduces to a greater extent the
swarm of mosquitoes in an area and in so doing protect-
ing from malaria more and more people with no access
to ITNs. is notion provides an alternative explanation
about why malaria morbidity was not significantly differ-
ent between users and non-users of bed nets after ITN
scale-up in Malawi. Nonetheless, the community-wide
effects of ITNs fall short of elucidating the impact of
the universal coverage campaign in Malawi. In general,
the campaign increased ITN coverage and this suggests
ITN ownership Slept under bed netMalaria morbidity
MIS2012 MIS2014
Fig. 1 2012 and 2014 trends in ITN coverage and childhood malaria
in Malawi (n = 4495—weighted). MIS malaria indicator survey, ITN
insecticide treated bed net
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Zamawe et al. Malar J (2016) 15:505
relatively far-reaching community-wide effects. As a
result, malaria prevalence was not supposed to increase
in 2014.
Knowledge about the causes of malaria (i.e. mosquito
bites can cause malaria) and malaria prevention/control
strategies (i.e. sleeping under ITNs prevents malaria)
decreased among the children’s mothers between 2012
and 2014 in Malawi. Existing literature point out that
knowledge of malaria transmission and prevention is
associated with regular use of ITNs [3941]. Accordingly,
inconsistent use of ITNs was bound to be greater in 2014.
Since the success of the universal coverage campaign
Table 1 Under ve children malaria morbidity in 2012 and 2014 by socio demographic characteristics (weighted,
SD standard deviation, KM kilometres, ITN insecticide-treated bed net
* Signicant (p0.05); ** non signicant (p>0.05)
Variable name Category Year=2012 (n=2312) Year=2014 (n=2183)
Malaria test outcome Malaria test outcome
Total Negative Positive p value Total Negative Positive p value
Age of the child (months) Mean (SD) 31.4 (15.3) 30.5 (15.2) 34.5 (15.1) <0.001* 30.9 (15.3) 30.0 (15.5) 35.1 (14.9) <0.001*
Sex of the child Female 1001 (52.9 %) 769 (53.0 %) 300 (54.0 %) 0.955** 1111 (50.9 %) 665 (51.5 %) 289 (47.4 %) 0.149**
Male 892 (47.1 %) 681 (47.0 %) 255 (46.0 %) 1072 (49.1 %) 626 (48.5 %) 319 (52.6 %)
Area of residence Rural 2009 (86.9 %) 1211 (83.5 %) 527 (95.0 %) <0.001* 1862 (85.3 %) 1052 (81.5 %) 582 (95.8 %) <0.001*
Urban 303 (13.1 %) 239 (16.5 %) 28 (5.0 %) 321 (14.7 %) 239 (18.5 %) 25 (4.2 %)
Cluster attitude (KM) Mean (SD) 0.9 (0.3) 0.9 (0.3) 0.9 (0.3) 0.169** 0.9 (0.3) 1.0 (0.0) 0.9 (0.0) 0.001*
Child slept under bed net No 810 (37.9 %) 492 (36.6 %) 228 (44.2 %) <0.001* 637 (30.6 %) 353 (28.3 %) 224 (39.2 %) 0.016*
Yes 1327 (62.1 %) 852 (63.4 %) 288 (55.8 %) 1444 (69.4 %) 891 (71.7 %) 347 (60.8 %)
Sex of household head Female 497 (21.5 %) 319 (22.0 %) 115 (20.7 %) 0.632** 320 (14.7 %) 194 (15.0 %) 93 (15.4 %) 0.398**
Male 1815 (78.5 %) 1130 (78.0 %) 440 (79.3 %) 1863 (85.3 %) 1098 (85.0 %) 513 (84.6 %)
Age of the mother (years) Mean (SD) 28.4 (6.7) 28.2 (6.5) 28.3 (6.9) 0.863** 28.0 (6.5) 28.1 (6.4) 28.4 (6.7) 0.411**
Wealth index score Mean (SD) 2.8 (1.4) 3.3 (1.5) 2.5 (1.3) <0.001* 2.8 (1.4) 3.3 (1.4) 2.5 (1.3) <0.001*
Mother’s total years of
education Mean (SD) 4.8 (3.6) 5.8 (3.8) 3.9 (3.1) <0.001* 5.4 (3.7) 6.3 (3.6) 4.7 (3.2) <0.001*
Number of under five
children (mother) Mean (SD) 1.7 (0.7) 1.7 (0.7) 1.8 (0.7) 0.004* 1.7 (0.7) 1.6 (0.6) 1.7 (0.7) 0.002*
Number of bed nets
(household) Mean (SD) 1.1 (1.0) 1.2 (1.1) 0.9 (0.9) <0.001* 1.4 (1.1) 1.6 (1.1) 1.4 (1.1) 0.001*
Child’s mother can read No 846 (36.6 %) 474 (32.7 %) 262 (47.1 %) <0.001* 682 (31.2 %) 354 (27.4 %) 253 (41.6 %) <0.001*
Yes 1466 (63.4 %) 976 (67.3 %) 293 (52.9 %) 1501 (68.8 %) 938 (72.6 %) 354 (58.4 %)
Mother heard messages
about malaria (<6 weeks
No 1586 (73.4 %) 973 (70.6 %) 407 (81.9 %) <0.001* 1593 (78.9 %) 938 (76.4 %) 455 (84.5 %) 0.203**
Yes 574 (26.6 %) 405 (29.4 %) 90 (18.1 %) 427 (21.1 %) 290 (23.6 %) 83 (15.5 %)
Mother knowns mosquito
bites cause malaria No 149 (6.9 %) 70 (5.1 %) 54 (10.8 %) <0.001* 286 (14.2 %) 153 (12.5 %) 94 (17.5 %) 0.084**
yes 2011 (93.1 %) 1307 (94.9 %) 443 (89.2 %) 1734 (85.8 %) 1074 (87.5 %) 444 (82.5 %)
Mother knows fever is the
main sign of malaria No 190 (8.8 %) 127 (9.2 %) 32 (6.5 %) 0.082** 266 (13.2 %) 167 (13.6 %) 44 (8.1 %) 0.020*
Yes 1970 (91.2 %) 1250 (90.8 %) 464 (93.5 %) 1754 (86.8 %) 1060 (86.4 %) 495 (91.9 %)
Mother knowns sleep-
ing under ITN prevents
No 1187 (54.9 %) 755 (54.8 %) 283 (57.0 %) 0.245** 1514 (74.9 %) 890 (72.5 %) 422 (78.5 %) 0.023*
Yes 973 (45.1 %) 623 (45.2 %) 214 (43.0 %) 506 (25.0 %) 337 (27.5 %) 116 (21.5 %)
Mother knows mosquito
repellant prevents malaria No 2099 (97.2 %) 1333 (96.8 %) 490 (98.6 %) 0.064** 1991 (98.5 %) 1202 (97.9 %) 537 (99.8 %) 0.017*
Yes 61 (2.8 %) 11 (3.2 %) 7 (1.4 %) 29 (1.5 %) 26 (2.1 %) 1 (0.3 %)
Mother knowns mosquito
coil prevents malaria No 2114 (97.9 %) 1343 (97.5 %) 489 (98.5 %) 0.112** 2003 (99.2 %) 1214 (98.9 %) 535 (99.4 %) 0.800**
Yes 46 (2.1 %) 35 (2.5 %) 7 (1.5 %) 17 (0.8 %) 13 (1.1 %) 3 (0.6 %)
Mother knowns cutting
grass around house
prevents malaria
No 1950 (90.3 %) 1238 (89.8 %) 455 (91.6 %) 0.046* 1905 (94.3 %) 1145 (93.3 %) 519 (96.4 %) 0.059**
Yes 210 (9.7 %) 140 (10.2 %) 42 (8.4 %) 115 (5.7 %) 82 (6.7 %) 19 (3.6 %)
Mother knowns children are
vulnerable to Malaria No 275 (12.7 %) 159 (11.6 %) 85 (17.1 %) 0.002* 388 (19.2 %) 232 (18.9 %) 102 (19.0 %) 0.864**
Yes 1885 (87.3 %) 1218 (88.4 %) 411 (82.9 %) 1632 (80.8 %) 995 (88.1 %) 436 (81.0 %)
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Zamawe et al. Malar J (2016) 15:505
partly depends on stable use of ITNs by those at risk of
malaria, noncompliance might have contributed to the
increase in malaria morbidity among Malawian children
in 2014.
Furthermore, awareness of interventions that may
limit malaria transmission before sleep time (i.e. cutting
grass around the house, mosquito repellent and mos-
quito coil) was lower among the children’s mothers in
Table 2 Predictors ofmalaria morbidity inunder ve children (unmatched data)
CI condence interval, KM kilometres, ITN insecticide-treated bed net
* Signicant (p0.05); ** non signicant (p>0.05)
Variable Year 2012 Year 2014
AOR 95% CI p value AOR 95% CI p value
Child slept under bed net 0.65 0.47–0.89 0.007* 0.77 0.57–1.06 0.109**
Child is male 0.92 0.73–1.15 0.463** 1.15 0.92–1.44 0.215**
Age of the child 1.02 1.01–1.03 <0.001* 1.02 1.02–1.03 <0.001*
Residential area is urban 0.42 0.26–0.67 <0.001* 0.35 0.21–0.59 <0.001*
Cluster altitude (KM) 1.17 0.83–1.66 0.380** 0.54 0.37–0.77 0.001*
Wealth index score 0.87 0.79–0.96 0.004* 0.80 0.73–0.88 <0.001*
Age of the mother 0.98 0.96–1.00 0.017* 0.99 0.97–1.01 0.342**
Mother’s years of education 0.93 0.88–0.99 0.023* 0.97 0.92–1.00 0.240**
Mother can read 1.22 0.83–1.79 0.325** 0.88 0.61–1.28 0.501**
Number of under five children 1.21 1.04–1.42 0.015* 1.25 1.05–1.48 0.011*
Number of bed nets (household) 1.14 0.98–1.33 0.102** 0.93 0.81–1.08 0.367**
Male household head 1.11 0.84–1.46 0.464** 0.96 0.71–1.29 0.768**
Heard malaria messages (<6 months ago) 0.66 0.49–0.87 0.004* 0.79 0.58–1.07 0.126**
Mother knowns mosquito bites cause malaria 0.49 0.32–0.74 0.001* 0.90 0.64–1.25 0.521**
Mother knows fever is the main sign of malaria 1.70 1.08–2.69 0.023* 1.85 1.26–2.71 0.002*
Mother knowns ITN prevents malaria 1.17 0.92–1.48 0.205** 1.00 0.76–1.32 0.999**
Mother knows mosquito repellant prevents malaria 0.58 0.24–1.40 0.227** 0.22 0.04–1.29 0.094**
Mother knowns mosquito coil prevents malaria 1.33 0.56–3.20 0.517** 0.60 0.16–2.20 0.437**
Mother knowns cutting grass around house prevents malaria 0.86 0.58–1.27 0.451** 0.89 0.51–1.56 0.693**
Mothers knowns children are vulnerable to malaria 0.71 0.51–0.99 0.043* 1.32 0.98–1.78 0.071**
Table 3 The eects of the universal coverage campaign (UCC) ofITNs and the use ofbed nets on childhood malaria
RR risk ratio, ITNs insecticide-treated bed nets, CI condence interval
* Signicant (p0.05); ** non signicant (p>0.05)
Year/period Intervention Level ofanalysis Malaria outcomes RR (95% CI) p value
Control (n) Treatment (n)
negative Positive Negative Positive
2012 vs 2014 UCC of ITNs Overall 1359 381 1205 401 1.14 (1.00–1.29) 0.036*
2012 vs 2014 UCC of ITNs Rural 898 373 779 358 1.07 (0.95–1.21) 0.254**
2012 vs 2014 UCC of ITNs Urban 454 59 373 37 0.78 (0.53–1.16) 0.223**
2014 Bed net use Overall 313 115 682 224 0.92 (0.76–1.12) 0.399**
2014 Bed net use Rural 227 100 448 197 1.00 (0.82–1.22) 0.990**
2014 Bed net use Urban 96 5 110 7 1.21 (0.40–3.69) 0.740**
2012 Bed net use Overall 465 164 719 200 0.83 (0.70–1.00) 0.049*
2012 Bed net use Rural 304 140 451 168 0.86 (0.71–1.04) 0.119**
2012 Bed net use Urban 156 29 121 11 0.53 (0.28–1.03) 0.060*
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Page 7 of 8
Zamawe et al. Malar J (2016) 15:505
2014 compared to 2012. Because of the limited protec-
tion provided by ITNs (usually during bed time only)
[42], supplementary interventions play a crucial role
in malaria control. In Kenya and Myanmar, for exam-
ple, ITNs offered incomplete protection against malaria
due to early biting habits of the vectors [31, 42]. Due to
low awareness, it is likely that additional malaria control
methods were relatively under-utilized in 2014 [43, 44].
is resonate calls for broader vector control strategies to
limit malaria transmission before bedtime [42].
Taken together, insecticide resistance and inadequate
knowledge of malaria transmission and prevention pose
a serious threat to the efficacy of ITNs and the future
of the universal coverage campaign. is highlights
the need to constantly monitor the level of insecticide
resistance and the effects of ITNs to ensure that all peo-
ple at risk of malaria are protected. Moreover, there is
an urgent need to intensify and regularly update resist-
ance management strategies. In the long run, alternative
insecticides should be identified or developed. An inte-
grated approach is called for to malaria control in lieu of
simple dependence on ITNs. In particular, effective local
malaria control strategies (i.e. fill in puddles and clear-
ing bushes around residential areas) should be preserved
and promoted in malaria endemic areas. Accordingly,
the universal coverage campaign should go hand in hand
with intensive community based malaria awareness
is study had limitations and strengths. First, both
2012 and 2014 MIS relied on reported data except for
malaria status. So, recall and social desirability biases
cannot be ruled out. e strengths of this study include
the use of nationally representative data with relatively
large sample sizes. Although each survey was cross-sec-
tional in nature, the pooling of the two datasets permitted
comparison of the study outcomes over time. Moreover,
PSM allowed to balance measured covariates across 2012
and 2014 samples [24]. us, the study design mimicked
some of the characteristics of a randomized controlled
trial [23].
e universal coverage campaign improved both the
access and use of bed nets among children between 2012
and 2014 in Malawi. Nonetheless, the campaign was not
associated with a reduced burden of malaria. is is likely
due to increased insecticide resistance, inconsistent use
of bed nets and under-utilization of other malaria con-
trol methods. ese observations accentuate the need for
a composite intervention in malaria control. us, while
applauding the massive contribution of ITNs in the fight
against malaria, it is important to recognize that a mul-
tifaceted approach is required to effectively reduce the
burden of malaria. To this end, the utility of local solu-
tions and community level approaches in malaria control
should be stressed.
ITNs: insecticide-treated mosquito bed nets; LLINs: lost lasting insecticidal
treated mosquito bed nets; SD: standard deviation; CI: confidence interval;
PSM: propensity score matching; WHO: World Health Organization; MIS:
malaria indicator survey; DHS: demographic health survey; AOR: adjusted
odds ratio; RR: risk ratio.
Authors’ contributions
CZ and MJ conceived and designed the study. CZ, KN and MJ developed the
study protocol. CZ requested data from the DHS programme. CZ, AS and MJ
performed data analysis or provided guidance. CZ wrote the manuscript. All
authors read and approved the final manuscript.
Many thanks to the DHS programme team for allowing us to use the dataset
and the support they rendered during data cleaning and merging process. We
are also grateful to Chrispin Mandiwa for his contribution during the protocol
development and study design.
Competing interests
The authors declare that they have no competing interests.
Availability of data and materials
The datasets supporting the conclusions of this article are available upon
request from the Demographic Health Survey Programme Team http://www.
Ethics approval and consent to participate
Permission to use malaria indicator survey was obtained from the DHS
program. In addition, the study protocol was reviewed and approved by the
Research Ethics Committee of the University of Tokyo. All participants of the
primary studies provided informed consent.
Collins O.F Zamawe is a Monbukagakusho Scholar supported by the Japanese
Received: 4 May 2016 Accepted: 5 October 2016
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... It is generally accepted that ITN coverage has helped decrease malaria prevalence in Malawi [6][7][8][9]. However, retrospective studies have also found that a 13% increase in bed net access from 2012 to 2014 was not associated with a reduction in malaria burden in children [10]. This was corroborated by a similar study investigating overall trends within the 2012 and 2014 malaria indicator survey (MIS) data [11]. ...
... These MIS, together, capture the malaria situation and dynamics throughout the country and represent an essential source of information for policy development [1]. For example, MIS studies helped recognize the possible ineffectiveness of ITNs [10,11], which led to the recent addition of pyrethroid-Piperonyl butoxide (PBO) nets to the vector control programme. The latest MIS survey was conducted in Malawi in April 2021. ...
... This study revealed spatial heterogeneity in the relationship between malaria prevalence and the ITN indicators, with child malaria prevalence higher in rural than urban areas. It is widely accepted that malaria dynamics differ between rural and urban areas due to differences in demographics, socioeconomics, housing, drainage and access to health care [22,[56][57][58][59]. Generally, in Malawi malaria is more prevalent in rural areas, although high case numbers have also been reported in urban areas [10,11,22,56,58,60]. Malaria control likely has a different impact in the urban and rural habitats, due to environmental differences and population movements. ...
Full-text available
Background To achieve malaria elimination it is essential to understand the impact of insecticide-treated net (ITNs) programmes. Here, the impact of ITN access and use on malaria prevalence in children in Malawi was investigated using Malaria Indicator Survey (MIS) data. Methods MIS data from 2012, 2014 and 2017 were used to investigate the relationship between malaria prevalence in children (6–59 months) and ITN use. Generalized linear modelling (GLM), geostatistical mixed regression modelling and non-stationary GLM were undertaken to evaluate trends, spatial patterns and local dynamics, respectively. Results Malaria prevalence in Malawi was 27.1% (95% CI 23.1–31.2%) in 2012 and similar in both 2014 (32.1%, 95% CI 25.5–38.7) and 2017 (23.9%, 95% CI 20.3–27.4%). ITN coverage and use increased during the same time period, with household ITN access growing from 19.0% (95% CI 15.6–22.3%) of households with at least 1 ITN for every 2 people sleeping in the house the night before to 41.7% (95% CI 39.1–44.4%) and ITN use from 41.1% (95% CI 37.3–44.9%) of the population sleeping under an ITN the previous night to 57.4% (95% CI 55.0–59.9%). Both the geostatistical and non-stationary GLM regression models showed child malaria prevalence had a negative association with ITN population access and a positive association with ITN use although affected by large uncertainties. The non-stationary GLM highlighted the spatital heterogeneity in the relationship between childhood malaria and ITN dynamics across the country. Conclusion Malaria prevalence in children under five had a negative association with ITN population access and a positive association with ITN use, with spatial heterogeneity in these relationships across Malawi. This study presents an important modelling approach that allows malaria control programmes to spatially disentangle the impact of interventions on malaria cases.
... [12][13][14][15] Malawi also recently implemented annual indoor residual spraying (IRS) in one district in 2018, expanding to additional districts each year. 9 Prior research on mass distribution campaign effectiveness in Malawi has been limited by the use of cross-sectional survey data 16 and narrow geographic range, 17 and there has never been a national longitudinal assessment or comparison between various LLIN types and application of IRS. ...
... Prior research in Malawi has depicted increased malaria prevalence among children 2 years after mass distribution of 5.6 million nets. 16 Individual ITN use was associated with a lower individual risk of malaria at baseline, but this association disappeared within 2 years. Similarly, research among adolescents and adults has shown that sleeping under an LLIN was not associated with reduced risk of malaria prevalence 3-4 years after a mass distribution campaign, even after stratifying by bed net insecticide type, 25 perhaps due to LLIN damage and repurposing. ...
Full-text available
Introduction Malawi’s malaria burden is primarily assessed via cross-sectional national household surveys. However, malaria is spatially and temporally heterogenous and no analyses have been performed at a subdistrict level throughout the course of a year. The WHO recommends mass distribution of long-lasting insecticide-treated bed nets (LLINs) every 3 years, but a national longitudinal evaluation has never been conducted in Malawi to determine LLIN effectiveness lifespans. Methods Using District Health Information Software 2 (DHIS2) health facility data, available from January 2018 to June 2020, we assessed malaria risk before and after a mass distribution campaign, stratifying by age group and comparing risk differences (RDs) by LLIN type or annual application of indoor residual spraying (IRS). Results 711 health facilities contributed 20 962 facility reports over 30 months. After national distribution of 10.7 million LLINs and IRS in limited settings, malaria risk decreased from 25.6 to 16.7 cases per 100 people from 2018 to 2019 high transmission seasons, and rebounded to 23.2 in 2020, resulting in significant RDs of −8.9 in 2019 and −2.4 in 2020 as compared with 2018. Piperonyl butoxide (PBO)-treated LLINs were more effective than pyrethroid-treated LLINs, with adjusted RDs of −2.3 (95% CI −2.7 to −1.9) and −1.5 (95% CI −2.0 to −1.0) comparing 2019 and 2020 high transmission seasons to 2018. Use of IRS sustained protection with adjusted RDs of −1.4 (95% CI −2.0 to −0.9) and −2.8% (95% CI −3.5 to −2.2) relative to pyrethroid-treated LLINs. Overall, 12 of 28 districts (42.9%) experienced increases in malaria risk in from 2018 to 2020. Conclusion LLINs in Malawi have a limited effectiveness lifespan and IRS and PBO-treated LLINs perform better than pyrethroid-treated LLINs, perhaps due to net repurposing and insecticide-resistance. DHIS2 provides a compelling framework in which to examine localised malaria trends and evaluate ongoing interventions.
... Universal malaria interventions, such as bed nets (i.e. insecticide-treated nets and long-lasting insecticidal nets) access and usage, and access to prompt diagnosis and treatment (use of artemisinin-based combination therapy), have targeted these two groups at the highest risk for malaria disease [35,36]. However, previous researchers have demonstrated that school-aged children (SAC) bear an under-appreciated burden of malaria, yet this age group is often not prioritized [37,38]. ...
Full-text available
Background Iron status is considered as a continuum from an iron deficiency with anaemia, without anaemia, varying amounts of stored iron to iron overload. The burden of Plasmodium falciparum infections is typically high among school-aged children (SAC). Nonetheless, SAC are often less likely to be covered by malaria interventions, making them a group with an untreated reservoir of parasite transmission. This study aimed to assess the effects of asymptomatic and clinical malaria infections on biochemical markers of iron status among SAC in Malawi. Methods Data from the 2015–2016 Malawi Micronutrient Survey (MNS) was used and multivariable logistic regression models using a generalized estimating equation to account for the complex cluster survey design were constructed. Blood samples of 684 children aged 5 to 14 years old were evaluated for clinical and asymptomatic malaria infections. Furthermore, blood samples were used to estimate haemoglobin (Hb), serum ferritin (SF) and, soluble transferrin receptors (sTfR) concentrations. Results Of the 684 SAC analysed, approximately 42% had asymptomatic malaria, while 41.0% had clinical malaria. Anaemia (low Hb levels), iron deficiency (low SF concentration), and functional iron deficiency (high sTfR levels) were found in 20%, 5%, and 30% of the children, respectively. School-aged children with asymptomatic malaria had increased odds of being anaemic (adjusted odds ratio [aOR]: 3.71, 95% confidence interval [CI]: 2.29–5.99) and increased levels of sTfR (aOR: 3.00, 95% CI 2.01–4.47). Similarly, SAC with clinical malaria had increased odds of being anaemic (aOR: 3.54, 95% CI 2.19–5.72) and increased levels of sTfR (aOR: 3.02, 95% CI 2.02–4.52). Conclusions Both asymptomatic and clinical malaria were independent risk factors for anaemia and functional iron deficiency (FID). The notion that asymptomatic and clinical malaria were associated with both anaemia and FID underscores the need for public health programmers to consider adding mass screening and treatment for malaria to existing school-based health programmes.
... 19 Highly mosquitocidal synthetic pyrethroids were formulated for use as indoor residual sprays and in impregnated bednets. [20][21][22][23] Subsequent chemical manipulation and altered impregnation processes produced long-lasting insecticidetreated nets with more sustained protective effectiveness and greater practicability. ...
... While the general population receives bed nets every three years as part of regular mass distribution campaigns, Malawi's National Malaria Control Programme has given out free LLINs to pregnant women through antenatal care clinics since 2006 11 with 79-87% of pregnant women who attended antenatal clinics receiving LLINs in 2015-16 11 . Although WHO recommendations allow for up to three years between mass distribution campaigns 34 , field research in Benin, Malawi, Rwanda, Senegal, and Tanzania suggests that ITNs have a limited lifespan of two years before protection is compromised by holes, insecticide-resistance, and reduced concentrations of insecticide [35][36][37][38][39] . In Burkina Faso, a third of people had stopped using LLINs within a year of distribution 40 . ...
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Malaria remains a significant cause of morbidity and mortality in Malawi, with an estimated 18–19% prevalence of Plasmodium falciparum in children 2–10 years in 2015–2016. While children report the highest rates of clinical disease, adults are thought to be an important reservoir to sustained transmission due to persistent asymptomatic infection. The 2015–2016 Malawi Demographic and Health Survey was a nationally representative household survey which collected dried blood spots from 15,125 asymptomatic individuals ages 15–54 between October 2015 and February 2016. We performed quantitative polymerase chain reaction on 7,393 samples, detecting an overall P. falciparum prevalence of 31.1% (SE = 1.1). Most infections (55.6%) had parasitemias ≤ 10 parasites/µL. While 66.2% of individuals lived in a household that owned a bed net, only 36.6% reported sleeping under a long-lasting insecticide-treated net (LLIN) the previous night. Protective factors included urbanicity, greater wealth, higher education, and lower environmental temperatures. Living in a household with a bed net (prevalence difference 0.02, 95% CI − 0.02 to 0.05) and sleeping under an LLIN (0.01; − 0.02 to 0.04) were not protective against infection. Our findings demonstrate a higher parasite prevalence in adults than published estimates among children. Understanding the prevalence and distribution of asymptomatic infection is essential for targeted interventions.
... This distribution provided more national coverage than had previously been achieved. Despite the distribution campaign improving access to and use of ITNs, the burden of P. falciparum infections did not lead to any further recent decreases in malaria in Malawi [15]. The Malaria Indicator Survey from 2012 reported a nationwide malaria prevalence of 28%, but by the 2014 report the prevalence had increased to 33% [12,16]. ...
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Background: Distribution campaigns for insecticide-treated nets (ITN) have increased the use of ITNs in Malawi, but malaria prevalence remains high even among those using the nets. Previous studies have addressed ITN ownership, insecticide resistance, and frequency of ITN use as possible contributing factors to the high prevalence of malaria infection despite high ITN coverage, but have rarely considered whether the condition of the ITN, or how many people use it, impacts efficacy. This study assessed how ITN integrity, ITN age, and the number of persons sharing a net might mitigate or reduce protective efficacy among self-identified ITN users in Malawi. Methods: From 2012 to 2014, six cross-sectional surveys were conducted in both the rainy and dry seasons in southern Malawi. Data were collected on ITN use, integrity (number and size of holes), and age. Blood samples for detecting Plasmodium falciparum infection were obtained from reported ITN users over 6 months of age. Generalized linear mixed models were used to account for clustering at the household and community level. The final model controlled for gender, household eaves, and community-level infection prevalence during the rainy season. Results: There were 9646 ITN users with blood samples across six surveys, 15% of whom tested positive for P. falciparum infection. Among children under 5 years old, there was a 50% increased odds of P. falciparum infection among those sleeping under an ITN older than two years, compared to those using an ITN less than 2 years old (OR = 1.50; 95% CI 1.07-2.08). ITN integrity and number of individuals sharing an ITN were not associated with P. falciparum infection. Conclusions: Older ITNs were associated with higher rates of P. falciparum in young children, which may indicate that insecticide concentrations play a larger role in infection prevention than the physical barrier of an ITN. ITN use was self-reported and the integrity measures lacked the precision of newer methods, suggesting a need for objective measures of ITN use and more precise assessment of ITN integrity.
... In Malawi, malaria continues to be a major public health burden, with over 6 million presumed and confirmed cases reported in 2015 in a population of 17 million [15], although the malaria mortality rate has shown a steady decline over the past 15 years [16]. Insecticidetreated nets are the primary intervention for malaria prevention, but problems have been reported with net use and the development of insecticide resistance [17][18][19][20][21]. ...
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Background: Increased engagement of communities has been emphasized in global plans for malaria control and elimination. Three interventions to reinforce and complement national malaria control recommendations were developed and applied within the context of a broad-based development initiative, targeting a rural population surrounding a wildlife reserve. The interventions, which were part of a 2-year research trial, and assigned to the village level, were implemented through trained local volunteers, or 'health animators', who educated the community and facilitated collective action. Results: Community workshops on malaria were designed to increase uptake of national recommendations; a manual was developed, and training of health animators conducted, with educational content and analytical tools for a series of fortnightly community workshops in annual cycles at village level. The roll-back malaria principle of diagnosis, treatment and use of long-lasting insecticidal nets was a central component of the workshops. Structural house improvement to reduce entry of malaria vectors consisted of targeted activities in selected villages to mobilize the community into voluntarily closing the eaves and screening the windows of their houses; the project provided wire mesh for screening. Corrective measures were introduced to respond to field challenges. Committees were established at village level to coordinate the house improvement activities. Larval source management (LSM) in selected villages consisted of two parts: one on removal of standing water bodies by the community at large; and one on larviciding with bacterial insecticide Bacillus thuringiensis israelensis by trained village committees. Community workshops on malaria were implemented as 'core intervention' in all villages. House improvement and LSM were implemented in addition to community workshops on malaria in selected villages. Conclusions: Three novel interventions for community mobilization on malaria prevention and control were described. The interventions comprised local organizational structure, education and collective action, and incorporated elements of problem identification, planning and evaluation. These methods could be applicable to other countries and settings.
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Background: To achieve malaria elimination it is essential to understand the impact of insecticide-treated net (ITNs) programmes. Here, the impact of ITN access and use on malaria prevalence in children in Malawi was investigated using Malaria Indicator Survey (MIS) data. Methods: MIS data from 2012, 2014 and 2017 were used to investigate the relationship between malaria prevalence in children (6 to 59 months) and ITN use. Generalised linear modelling (GLM), geostatistical mixed regression modelling and non-stationary GLM were undertaken to evaluate trends, spatial patterns and local dynamics, respectively. Results: Malaria prevalence in Malawi was 27.1 % (95% CI 23.1 -31.2 ) in 2012 and similar in both 2014 (32.1 %, 95%CI 25.5-38.7) and 2017 (23.9 %, 95%CI 20.3-27.4). ITN coverage and use increased during the same time period, with population access growing from 33.1 % (95%CI 29.8-36.4) of the population potentially sleeping under an ITN the previous night to 58.4 % (95%CI 56.2-60.6) and ITN use from 41.1 % (95% CI 37.3-44.9) of the population sleeping under an ITN the previous night to 57.4 % (95% CI 55.0-59.9). The behavioural gap disappeared while the ownership gap persisted. Both the geostatistical and non-stationary GLM regression models showed child malaria prevalence had a negative association with ITN population access and a positive association with ITN use. The non-stationary GLM highlighted the large variation in the relationship between childhood malaria and ITN use across the country. Conclusion: ITNs are effective in controlling childhood malaria in Malawi, although the impact was heterogeneous across the country. This study presents an important modelling approach that allows malaria control programs to spatially disentangle the impact of interventions on malaria cases.
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Background: Malaria is still a burden to Ethiopia, especially among the productive ages of the society. Although insecticide-treated mosquito nets (INTs) are widely practiced by the rural community, malaria remains a leading public health issue. This study aimed to evaluate a 5-year trend, current prevalence and community knowledge, attitude and practice (KAP) towards malaria and use of ITNs as a strategy for prevention of malaria among the rural setting of Welkait district, northwest Ethiopia. Methods: A cross-sectional study was carried out on 403 households to identify the prevalence rate of malaria. Besides, a 5-year (2015-2019) retrospective data was analyzed. Random sampling technique was used to select representative households among the community members. Well-structured questionnaires were used to collect KAP data towards the utilization of ITNs against malaria infection. Blood samples were examined for identification of malaria parasites following standard procedure. SPSS version 22 was used for the analysis of quantitative data. Results: Of 36,219 outpatients examined, 7,309 (20.2%) malaria-positive cases were reported during 2015-2019. Overall prevalence of malaria was continually declined from 2015-2019. Male slide-confirmed (61.4%, N = 4,485) were significantly higher than female (38.6%, N = 2,824) (p < 005). Nineteen (4.7%) confirmed malaria cases were screened during parasitological survey (12 cases of P. falciparum and 7 cases of P. vivax). Most 78.4% (316) and 84.1% (339) of the respondents knew malaria is a communicable and curable disease respectively and 75.6% (239) of them associated it with mosquito bit. From 82.4% (332) respondents who believed malaria is preventable, 81.0% (269) of respondents considered ITNs as the main prevention method. About 64% (257) of the respondents possessed ITNs, of these, 66.9% (172) consistently used during peak season. Majority 83.6% (337) of the respondents have a positive attitude toward ITNs. Conclusion: Although the retrospective analysis showed a declining trend of malaria in the district, the current prevalence survey revealed a significant increase of malaria in the locality. This was contributed by unsustainable distribution and inconsistent use of ITNs among the population. We recommend the governments and stockholders to give emphasis on full coverage of ITNs and educate the community about ITNs usage.
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Background Mass media is critical in disseminating public health information, improving health knowledge and changing health behaviours. However, most of the mass media public health interventions do not sufficiently engage the local people; they are externally determined. Due to this, very little is known about the effects of locally instigated mass media promotion. Therefore, the aim of this study was to examine the impact of a community driven mass media campaign called Phukusi la Moyo (tips of life) on the utilisation of maternal health care services. Methods A community-based cross-sectional study involving 3825 women of reproductive age (15–49 years) was conducted in rural Malawi to evaluate the Phukusi la Moyo (PLM) campaign. To do this, we compared the utilisation of maternal health care services between women who were exposed to the PLM campaign and those who were not. Respondents were identified using a multistage cluster sampling method. This involved systematically selecting communities (clusters), households and respondents. Associations were examined using Pearson chi square test and a multivariable logistic regression model. Results The likelihood of using contraceptives (AOR = 1.61; 95 % CI = 1.32–1.96), sleeping under mosquito bed-nets (AOR = 1.65; 95 % CI = 1.39–1.97), utilising antenatal care services (AOR = 2.62; 95 % CI = 1.45–4.73) and utilising postnatal care services (AOR = 1.59; CI = 1.29–1.95) were significantly higher among women who had exposure to the PLM campaign than those who did not. No significant association was found between health facility delivery and exposure to the PLM campaign. Conclusion Women exposed to a community driven mass media campaign in rural Malawi were more likely to utilise maternal health care services than their unexposed counterparts. Since, the use of maternal health care services reduces the risk of maternal morbidity and mortality, community-led mass media could play a significant role towards improving maternal health outcomes in low-and-middle-income countries. Therefore, we recommend the use of locally driven mass media in disseminating public health information in limited resource settings.
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Objective To investigate if the first national insecticide-treated bed-net campaign in Burkina Faso, done in 2010, was followed by a decrease in childhood malaria in a district with high baseline transmission of the disease. Methods We obtained data on the prevalence of Plasmodium falciparum parasitaemia in children aged 2 weeks to 36 months from malaria surveys in 2009 and 2011. We assessed morbidity in children younger than 5 years by comparing data from the Nouna health district’s health management information system before and after the campaign in 2010. We analysed mortality data from 2008 to 2012 from Nouna’s health and demographic surveillance system. Findings The bed-net campaign was associated with an increase in the reported use of insecticide-treated nets. In 2009, 73% (630/869) of children reportedly slept under nets. In 2011, 92% (449/487) did. The campaign had no effect on the proportion of young children with P. falciparum parasitaemia after the rainy season; 52% (442/858) in 2009 and 53% (263/499) in 2011. Cases of malaria increased markedly after the campaign, as did the number of children presenting with other diseases. The campaign was not associated with any changes in child mortality. Conclusion The 2010 insecticide-treated net campaign in Burkina Faso was not associated with a decrease in care-seeking for malaria or all-cause mortality in children younger than 5 years. The most likely explanation is the high coverage of nets in the study area before the campaign which could have had an effect on mosquito vectors, limiting the campaign’s impact.
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Background: Deciphering the dynamics and evolution of insecticide resistance in malaria vectors is crucial for successful vector control. This study reports an increase of resistance intensity and a rise of multiple insecticide resistance in Anopheles funestus in Malawi leading to reduced bed net efficacy. Methods: Anopheles funestus group mosquitoes were collected in southern Malawi and the species composition, Plasmodium infection rate, susceptibility to insecticides and molecular bases of the resistance were analysed. Results: Mosquito collection revealed a predominance of An. funestus group mosquitoes with a high hybrid rate (12.2 %) suggesting extensive species hybridization. An. funestus sensu stricto was the main Plasmodium vector (4.8 % infection). Consistently high levels of resistance to pyrethroid and carbamate insecticides were recorded and had increased between 2009 and 2014. Furthermore, the 2014 collection exhibited multiple insecticide resistance, notably to DDT, contrary to 2009. Increased pyrethroid resistance correlates with reduced efficacy of bed nets (<5 % mortality by Olyset(®) net), which can compromise control efforts. This change in resistance dynamics is mirrored by prevalent resistance mechanisms, firstly with increased over-expression of key pyrethroid resistance genes (CYP6Pa/b and CYP6M7) in 2014 and secondly, detection of the A296S-RDL dieldrin resistance mutation for the first time. However, the L119F-GSTe2 and kdr mutations were absent. Conclusions: Such increased resistance levels and rise of multiple resistance highlight the need to rapidly implement resistance management strategies to preserve the effectiveness of existing insecticide-based control interventions.
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Chemical insecticides are crucial to malaria control and elimination programmes. The frontline vector control interventions depend mainly on pyrethroids; all long-lasting insecticidal nets (LLINs) and more than 80% of indoor residual spraying (IRS) campaigns use chemicals from this class. This extensive use of pyrethroids imposes a strong selection pressure for resistance in mosquito populations, and so continuous resistance monitoring and evaluation are important. As pyrethroids have also been used for many years in the Manhiça District, an area in southern Mozambique with perennial malaria transmission, an assessment of their efficacy against the local malaria vectors was conducted. Female offspring of wild-caught Anopheles funestus s.s. females were exposed to deltamethrin, lambda-cyhalothrin and permethrin using the World Health Organization (WHO) insecticide-resistance monitoring protocols. The 3-min WHO cone bioassay was used to evaluate the effectiveness of the bed nets distributed or available for purchase in the area (Olyset, permethrin LLIN; PermaNet 2.0, deltamethrin LLIN) against An. funestus. Mosquitoes were also exposed to PermaNet 2.0 for up to 8 h in time-exposure assays. Resistance to pyrethroids in An. funestus s.s. was extremely high, much higher than reported in 2002 and 2009. No exposure killed more than 25.8% of the mosquitoes tested (average mortality, deltamethrin: 6.4%; lambda-cyhalothrin: 5.1%; permethrin: 19.1%). There was no significant difference in the mortality generated by 3-min exposure to any net (Olyset: 9.3% mortality, PermaNet 2.0: 6.0%, untreated: 2.0%; p = 0.2). Six hours of exposure were required to kill 50% of the An. funestus s.s. on PermaNet 2.0. Anopheles funestus s.s. in Manhiça is extremely resistant to pyrethroids, and this area is clearly a pyrethroid-resistance hotspot. This could severely undermine vector control in this district if no appropriate countermeasures are undertaken. The National Malaria Control Programme (NMCP) of Mozambique is currently improving its resistance monitoring programme, to design and scale up new management strategies. These actions are urgently needed, as the goal of the NMCP and its partners is to reach elimination in southern Mozambique by 2020.
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The human population in the highlands of Nyanza Province, western Kenya, is subject to sporadic epidemics of Plasmodium falciparum. Indoor residual spraying (IRS) and long-lasting insecticide treated nets (LLINs) are used widely in this area. These interventions are most effective when Anopheles rest and feed indoors and when biting occurs at times when individuals use LLINs. It is therefore important to test the current assumption of vector feeding preferences, and late night feeding times, in order to estimate the extent to which LLINs protect the inhabitants from vector bites. Mosquito collections were made for six consecutive nights each month between June 2011 and May 2012. CDC light-traps were set next to occupied LLINs inside and outside randomly selected houses and emptied hourly. The net usage of residents, their hours of house entry and exit and times of sleeping were recorded and the individual hourly exposure to vectors indoors and outdoors was calculated. Using these data, the true protective efficacy of nets (P*), for this population was estimated, and compared between genders, age groups and from month to month. Primary vector species (Anopheles funestus s.l. and Anopheles arabiensis) were more likely to feed indoors but the secondary vector Anopheles coustani demonstrated exophagic behaviour (p < 0.05). A rise in vector biting activity was recorded at 19:30 outdoors and 18:30 indoors. Individuals using LLINs experienced a moderate reduction in their overall exposure to malaria vectors from 1.3 to 0.47 bites per night. The P* for the population over the study period was calculated as 51% and varied significantly with age and season (p < 0.01). In the present study, LLINs offered the local population partial protection against malaria vector bites. It is likely that P* would be estimated to be greater if the overall suppression of the local vector population due to widespread community net use could be taken into account. However, the overlap of early biting habit of vectors and human activity in this region indicates that additional methods of vector control are required to limit transmission. Regular surveillance of both vector behaviour and domestic human-behaviour patterns would assist the planning of future control interventions in this region.
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Insecticide Treated Nets (ITNs) have been shown to reduce morbidity and mortality, but coverage and proper utilization continues to be moderate in many parts of sub-Saharan Africa. The gains made through a nationwide free distribution were explored as well as the effect on malaria prevalence in semi-urban and rural communities in south western Cameroon. A cross sectional survey was conducted between August and December 2013. Information on net possession, status and use were collected using a structured questionnaire while malaria parasitaemia was determined on Giemsa-stained blood smears by light microscopy. ITN ownership increased from 41.9% to 68.1% following the free distribution campaign, with 58.3% (466/799) reportedly sleeping under the net. ITN ownership was lower in rural settings (adjusted OR = 1.93, 95%CI = 1.36-2.74, p<0.001) and at lower altitude (adjusted OR = 1.79, 95%CI = 1.22-2.62, p = 0.003) compared to semi-urban settings and intermediate altitude respectively. Conversely, ITN usage was higher in semi-urban settings (p = 0.002) and at intermediate altitude (p = 0.002) compared with rural localities and low altitude. Malaria parasitaemia prevalence was higher in rural (adjusted OR = 1.63, 95%CI = 1.07-2.49) compared to semi-urban settings and in those below 15 years compared to those 15 years and above. Overall, participants who did not sleep under ITN were more susceptible to malaria parasitaemia (adjusted OR = 1.70, 95%CI = 1.14-2.54, p = 0.009). Despite the free distribution campaign, ITN ownership and usage, though improved, is still low. As children who reside in rural settings have greater disease burden (parasitemia) than children in semi-urban settings, the potential gains on both reducing inequities in ITN possession as well as disease burden might be substantial if equitable distribution strategies are adopted.
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Background The recent decline in malaria incidence in many African countries has been attributed to the provision of prompt and effective anti-malarial treatment using artemisinin-based combination therapy (ACT) and to the widespread distribution of long-lasting, insecticide-treated bed nets (LLINs). At a malaria vaccine-testing site in Bandiagara, Mali, ACT was introduced in 2004, and LLINs have been distributed free of charge since 2007 to infants after they complete the Expanded Programme of Immunization (EPI) schedule and to pregnant women receiving antenatal care. These strategies may have an impact on malaria incidence. Methods To document malaria incidence, a cohort of 400 children aged 0 to 14 years was followed for three to four years up to July 2013. Monthly cross-sectional surveys were done to measure the prevalence of malaria infection and anaemia. Clinical disease was measured both actively and passively through continuous availability of primary medical care. Measured outcomes included asymptomatic Plasmodium infection, anaemia and clinical malaria episodes. Results The incidence rate of clinical malaria varied significantly from June 2009 to July 2013 without a clear downward trend. A sharp seasonality in malaria illness incidence was observed with higher clinical malaria incidence rates during the rainy season. Parasite and anaemia point prevalence also showed seasonal variation with much higher prevalence rates during rainy seasons compared to dry seasons. Conclusions Despite the scaling up of malaria prevention and treatment, including the widespread use of bed nets, better diagnosis and wider availability of ACT, malaria incidence did not decrease in Bandiagara during the study period.
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Background Under-five mortality has been declining rapidly in a number of sub-Saharan African settings. Malaria-related mortality is known to be a major component of childhood causes of death and malaria remains a major focus of health interventions. The paper explored the contribution of malaria relative to other specific causes of under-five deaths to these trends. Methods This paper uses longitudinal demographic surveillance data to examine trends and causes of death of under-five mortality in Rufiji, whose population has been followed for over nine years (1999–2007). Causes of death, determined by the verbal autopsy technique, are analysed with Arriaga’s decomposition method to assess the contribution of declining malaria-related mortality relative to other causes of death as explaining a rapid decline in overall childhood mortality. Results Over the 1999–2007 period, under-five mortality rate in Rufiji declined by 54.3%, from 33.3 to 15.2 per 1,000 person-years. If this trend is sustained, Rufiji will be a locality that achieves MDG4 target. Although hypotrophy at birth remained the leading cause of death for neonates, malaria remains as the leading cause of death for post-neonates followed by pneumonia. However, declines in malaria death rates accounted for 49.9% of the observed under-five mortality decline while all perinatal causes accounted for only 19.9%. Conclusion To achieve MDG 4 in malaria endemic settings, health programmes should continue efforts to reduce malaria mortality and more efforts are also needed to improve newborn survival.
Objectives To model the steps involved in preparing for and carrying out propensity score analyses by providing step-by-step guidance and Stata code applied to an empirical dataset.Study DesignGuidance, Stata code, and empirical examples are given to illustrate (1) the process of choosing variables to include in the propensity score; (2) balance of propensity score across treatment and comparison groups; (3) balance of covariates across treatment and comparison groups within blocks of the propensity score; (4) choice of matching and weighting strategies; (5) balance of covariates after matching or weighting the sample; and (6) interpretation of treatment effect estimates.Empirical Application: We use data from the Palliative Care for Cancer Patients (PC4C) study, a multisite observational study of the effect of inpatient palliative care on patient health outcomes and health services use, to illustrate the development and use of a propensity score.Conclusions Propensity scores are one useful tool for accounting for observed differences between treated and comparison groups. Careful testing of propensity scores is required before using them to estimate treatment effects. Full text available at: