Hindawi Publishing Corporation
Journal of Tropical Medicine
Volume 2010, Article ID 750978, 12 pages
RapidIncreaseinOwnershipand Useof Long-Lasting
InsecticidalNets andDecreaseinPrevalenceof Malaria in
ThreeRegionalStates of Ethiopia(2006-2007)
EstifanosBiru Shargie,1,2JeremiahNgondi,3,4PatriciaM. Graves,3Asefaw Getachew,5
Jimee Hwang,6,7Teshome Gebre,1Aryc W. Mosher,3Pietro Ceccato,8Tekola Endeshaw,1
Frank O.Richards Jr.,3andTedros AdhanomGhebreyesus9
1The Carter Center, P. O. Box 13373, Woreda 17, Kebele 19, Addis Ababa, Ethiopia
2Strategic Information Team, The Global Fund to Fight AIDS, Tuberculosis and Malaria, Chemin de Blandonnet 8,
Geneva 1214 Vernier, Switzerland
3The Carter Center, 1 Copenhill, Atlanta, GA 30307, USA
4Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge, Robinson Way,
Cambridge CB20SR, UK
5Malaria Control and Evaluation Partnership in Africa (MACEPA), a Programme at PATH, Bole Road, Addis Ababa, Ethiopia
6Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
7Global Health Group, UCSF Global Health Sciences, San Francisco, CA 94143-0443, USA
8International Research Institute for Climate and Society, Columbia University, New York, NY 10016-4309, USA
9Ministry of Health, P. O. Box 1234, Addis Ababa, Ethiopia
10Central Statistical Agency, P. O. Box 1143, Addis Ababa, Ethiopia
11U.S. Agency for International Development, Riverside Building P. O. Box 1014, Addis Ababa, Ethiopia
Correspondence should be addressed to Estifanos Biru Shargie, estifanos email@example.com
Received 21 March 2010; Accepted 19 July 2010
Academic Editor: Hans-Peter Beck
Copyright © 2010 Estifanos Biru Shargie et al. This is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly
Following recent large scale-up of malaria control interventions in Ethiopia, this study aimed to compare ownership and use
of long-lasting insecticidal nets (LLIN), and the change in malaria prevalence using two population-based household surveys in
three regions of the country. Each survey used multistage cluster random sampling with 25 households per cluster. Household
net ownership tripled from 19.6% in 2006 to 68.4% in 2007, with mean LLIN per household increasing from 0.3 to 1.2. Net use
overall more than doubled from 15.3% to 34.5%, but in households owning LLIN, use declined from 71.7% to 48.3%. Parasitemia
declined from 4.1% to 0.4%. Large scale-up of net ownership over a short period of time was possible. However, a large increase
in net ownership was not necessarily mirrored directly by increased net use. Better targeting of nets to malaria-risk areas and
sustained behavioural change communication are needed to increase and maintain net use.
Selective vector control with insecticide treated mosquito
nets (ITNs) and indoor residual household spraying (IRS)
continues to play a key role in malaria control. As a
way to achieving the United Nations Millennium Devel-
opment Goals (MDGs), the World Health Organization
(WHO) recommends rapid scale up of three primary
interventions: ITNs, more specifically long-lasting insecti-
cidal nets (LLINs), IRS and early detection and effective
treatment of malaria cases [1, 2]. In addition, intermit-
tent preventive treatment for pregnant women (IPTp) is
recommended in areas with moderate to high transmis-
2 Journal of Tropical Medicine
The three primary interventions (LLIN, IRS and early
diagnosis and treatment) form the core approach to malaria
control in Ethiopia, where malaria transmission is unstable
and seasonal, characterized by frequent and widespread
focal epidemics. Malaria transmission mainly occurs in areas
below 2,000 meters above sea level, which account for 75%
of the country’s total landmass and in which approximately
two-thirds of the population reside. Recognizing the low
coverage and use of ITNs in the country, the Government
of Ethiopia developed the National ITN Strategy in 2004
. One year later, the Ethiopian Federal Ministry of Health
(FMOH) set an ambitious national goal of full population
coverage in malarious areas with a mean of two LLINs per
household through distribution of about 20 million LLINs
also to be scaled-up, particularly in epidemic-prone districts
throughout the country. This effort also included the rapid
scale-up of provision of rapid diagnostic tests (RDTs) and
antimalarial drugs (artemisinin-based combination therapy
[ACT]) to newly established community health posts. These
health posts are staffed by community-based health exten-
sion workers (HEWs), a cadre of salaried civil service staff
recruited from the posts’ respective communities and given
an intensive one-year long post secondary school training
in the provision of health promotion and prevention-
oriented interventions, including malaria control [4, 5]. The
major partners in the ITN scale-up since 2005 in Ethiopia
included the Global Fund to Fight AIDS, Tuberculosis and
Malaria, UNICEF, World Bank, The Carter Center, and other
To contribute to the rapid scale-up of malaria con-
trol interventions in Ethiopia, The Carter Center assisted
in procurement and distribution of 3 million LLINs in
selected areas of three regions of Ethiopia: Amhara, Oromia
and Southern Nations, Nationalities and Peoples (SNNP)
Regional States where there are also ongoing Carter Center-
supported onchocerciasis and trachoma control programs.
The distribution of these nets was carried out by FMOH
and local administrative staff, with the assistance of local
trachoma and onchocerciasis workers. In general, net dis-
tribution activities were carried out in the months pre-
ceding major transmission seasons, with earlier waves of
distribution targeting the most at risk areas and the later
waves targeting less at risk areas. Baseline and followup
surveys were conducted in the malarious areas of the three
regional states, so changes in coverage of key malaria control
interventions could be measured, particularly with regards
to household net ownership and use, coverage with IRS and
the national Malaria Indicator Survey in 2007 (“MIS 2007”).
We also sought to compare the results on net ownership
and use in these two surveys with those of the Ethiopia
Demographic and Health Survey (DHS) 2005 .
in the Amhara, Oromia and SNNP Regional States of
Ethiopia (Figure 1, Map).
The baseline survey was conducted between 12 Decem-
ber 2006 and 2 February 2007 (“baseline 2006”). Amhara
was done first between 12Dec 2006 and 13Jan 2007, while
Oromia and SNNPR were done simultaneously between
10Jan and 2Feb 2007. The sample size estimation and
sample selection process for the baseline survey have been
described in detail previously [7, 8]. Clusters were defined
as kebeles (the country’s smallest administrative unit with an
average population of 5,000). The sampling frame was a list
of clusters (kebeles) that were defined by the Regional Health
Bureaus as malarious. This definition of “malarious” is an
expert knowledge classification based on history of malaria,
rainfall, altitude, proximity to water and other factors. It
represented at that time the malaria program target areas
for net distribution and other control activities. Briefly, a
multistage cluster random sampling design was used to
select 224 clusters, and 25 households in each cluster were
2006. All consenting residents (all age groups and gen-
der) of even-numbered households were tested for malaria
The MIS 2007 follow-up survey was conducted from 16
October 2007 to 3 January 2008 and has been described
elsewhere [9, 10]. MIS 2007 was conducted according to Roll
Back Malaria (RBM) Monitoring and Evaluation Reference
Group (MERG) guidelines. Clusters were defined as census
enumeration areas (EA) with each cluster comprising an
estimated population of 200 households. The MIS 2007
sampling frame was a complete list of national population
census 2007 EAs. In brief, a two stage cluster random
areas between 1500m and 2500m, and urban areas between
1500m and 2500m. In Amhara and Oromia, clusters were
oversampled to generate samples for estimating malaria
indicators at regional state level thus allowing for detection
of changes in malaria indicators between the baseline 2006
were listed and mapped using personal digital assistants
(PDAs) with global positioning system (GPS) capability, and
a simple random sample of 25 households were randomly
selected by the PDA for inclusion in MIS 2007. Malaria
parasite testing wasconductedin allchildren underfive years
of age in every household and persons of all ages in eight
randomly selected households per cluster.
We selectedpartof thetotalMIS2007 sample forcompa-
rability between surveys. In the baseline survey, the sampling
frame was only clusters in areas defined as malarious by
the Regional Health Bureaus, whereas in sampling for the
MIS 2007, no attention was paid to whether clusters were
in such areas. Therefore, for appropriate comparison of
baseline 2006 and MIS 2007 surveys, only MIS 2007 clusters
in Amhara, Oromia and SNNP that were comparable to
the baseline survey (i.e., were located in kebeles listed by
the Regional Health Bureaus as being in malarious areas by
the expert knowledge classification) were included in the
For comparison with the two surveys described here, we
also examined previous net ownership and use indicators
Journal of Tropical Medicine3
Dec 06-Jan 07
August 10, 2009/awm
Ethiopia zone outlines
Malaria indicator survey
Oct 07-Dec 08
August 10, 2009/awm
Ethiopia zone outlines
Figure 1: Map of Amhara, Oromia, and SNNP Regional States showing the baseline-2006 and MIS-2007 (subsample) survey clusters.
from DHS 2005 . The DHS sampled both malarious and
2.2. Household Questionnaire. The baseline 2006 and MIS
2007 survey questionnaires were both based on the RBM-
MERG MIS Household Questionnaire, modified for the
local conditions and to include relevant socioeconomic risk
factors . The questionnaires were translated into the
Amharic language and field-tested in a nonsurvey cluster to
determine the validity of the precoded answers. At baseline
2006, a paper-based questionnaire was used while for the
MIS 2007, the survey was conducted using PDAs. Interviews
if the head of household was absent or unable to respond
for any reason. English versions of the two questionnaires are
attached as additional files.
In the household questionnaire, respondents were asked
about: ownership of durable assets; room construction
observation); demographic information on residents; their
net use of the previous night.
testing had a rapid diagnostic test taken, which gave an
on-the-spot diagnosis, and provided thick and thin blood
films for microscopy. The RDT used was ParaScreen (Zephyr
Biomedical Systems, www.tulipgroup.com), which is able
to detect both P. falciparum and other plasmodia species
(in Ethiopia most likely P. vivax). Participants with pos-
itive rapid test results were offered treatment according
to national guidelines, that is, artemether lumefantrine
for other Plasmodium infection, and referral for clinic-based
quinine therapy for self-reported pregnant women .
Two blood slides, each composed of thick and thin films,
were taken for each participant by a clinical technician
according to standard WHO-approved protocol . Slides
were labeled and air dried horizontally in a carrying case
in the field, and stained with Giemsa at the nearest health
facility when the team returned from the field, usually the
same or the next day. Blood slides were read at a reference
laboratory in Addis Ababa and classified qualitatively as
either negative, P. falciparum positive, P.vivax positive, or
4 Journal of Tropical Medicine
mixed infection. One hundred high power fields of the thick
film were examined before calling a slide negative. If positive,
the thin film was read to determine the species; parasite
density was not quantified. To ensure accuracy, all positive
slides and a random sample of 5% of the negative slides were
reexamined by a second microscopist, who was blinded to
the diagnosis of the first slide-reader and the RDT results.
The second slide from each participant was used if the first
was broken or unreadable.
2.4. Climate Data. In order to investigate whether observed
differences in the two surveys were related to climate
variation over time, we obtained data of three types from
sources at the International Research Institute for Climate
(1) Annual summary rainfall, summarized by calendar
year and averaged over Ethiopia from the Climate
Prediction Center Merged Analysis of Precipitation
(CMAP) version 2, 12-Month Weighted Anomaly
Standardized Precipitation (WASP) index .
(2) Rainfall estimates derived from TRMM sensor (orig-
inal spatial resolution of 0.25 degrees, resampled to
0.1 degrees and 8 days temporal resolution) from
Jan 2004 to present, average over Regional State
(3) Land surface temperature acquired during the night
from AQUA-MODIS sensor at 1km spatial resolu-
tion and 8-day temporal resolution since Jan 2004
to present. Comparison of air temperature over
Ethiopia, Eritrea, Botswana and Madagascar 
has shown that land surface temperature is well
correlated with air temperature. These data were
averaged over the Regional State boundaries; when
altitudes rendering the average result invalid (such as
in July 2007 in west Amhara) the result was coded to
Results for (2) and (3) were averaged over the time
periods of the baseline 2006 and MIS 2007 surveys in each
Regional State, respectively.
2.5. Data Analysis. Statistical analysis was conducted using
Stata 9.2 (Stata Corporation, College Station, Texas, USA).
Descriptive statistics were used to explore the characteristics
of the sample. Sampling probabilities were calculated based
on the sampling designs for each survey and sampling
weights derived as the inverse of the product of sampling
probabilities. Point estimates and confidence intervals were
derived using the SURVEY (SVY) routine in Stata which
controls for clustering and allowed for adjustments for
the sampling design as well as weighting for sampling
probability. A household wealth index was derived from
relevant household characteristics using principal compo-
nents analysis as previously described . Although the
household assets documented were more extensive in the
MIS 2007 than in baseline 2006, the SES index reported
here for MIS 2007 used only the same set of asset indicators
as were in the baseline 2006 survey. Malaria prevalence
estimates were adjusted for age to account for the differences
in sampling participants for malaria testing between the
baseline 2006 and MIS 2007 surveys.
2.6. Ethical Considerations. The protocols received ethical
clearance from the Emory University Institutional Review
Board (IRB no. 1816 and 6389), the Centers for Disease
Control and Prevention ethical review committee (IRB no.
990132) and the Ethiopian Science and Technology Agency.
Verbal informed consent to participate in interviews was
sought from the heads of the household, each individual
and the parents of children aged 10 years and younger in
accordance with the tenets of the declaration of Helsinki.
Signed (baseline 2006) or verbal (MIS 2007) informed
consent was sought from each eligible individual and parents
of children aged 6 years and younger for blood films.
Additional verbal informed assent was sought from children
aged 6−18 years.
3.1. Characteristics of Study Households and Participants.
Figures 2(a) and 2(b) show the details of sample populations
included in the two surveys. A total of 5,708 households were
included in the baseline 2006 survey and 2,550 households
in the follow-up MIS 2007 subsample (malarious areas of
Amhara, Oromia, and SNNPR). As shown in Table 1, the
overall mean household size in the baseline survey was 4.9
(95% CI 4.8−5.0) whereas that in the follow-up survey was
4.4 (95% CI 4.2−5.0). The mean number of sleeping rooms
was 1.2 in the baseline survey and 1.0 in the MIS survey. The
number of sleeping spaces was not assessed in the baseline
survey; there were an average of 1.8 sleeping spaces per
household in the MIS 2007.
A total of 27,884 and 10,883 people were included in the
baseline and MIS surveys, respectively, of which 15.7% and
16.9% werechildren under fiveyearsof age.Peripheralblood
testing for malaria was done for a total of 11,601 (46.1%
males and 16.9% under-five children) and 3,249 (51.2%
males and 46.3% under-five children) individuals during
baseline and MIS surveys, respectively.
3.2. Indoor Residual Spraying. Overall, 15.5% (95% CI
11.2%−20.9%) and 16.9% (95% CI 10.3%−26.5%) of the
households were sprayed within the 12 months prior to
baseline 2006 and MIS 2007, respectively. There was no
statistically significant difference in the coverage of IRS in
the last 12 months between the three regional states as well
as between the two surveys.
3.3. Household Net Ownership. As shown in Figure 3(a), the
proportion of households in the malarious areas of the three
regional states owning at least one mosquito net (any type)
significantly increased from 4.5% (95% CI 4.1%−4.9%) in
2005 to 37.0% (95% CI 31.1%−43.3%) at the end of 2006
and to 72.5% (95% CI 64.0%−79.7%) at the end of 2007.
Figure 3(b) shows the proportion of households with at least
Journal of Tropical Medicine5
Households = 5730
Participants = 28074
Excluded due to missing data
Households = 22
Participants = 190
eligible for malaria
testing = 16283
Household net ownership
Households = 5708
Net usage last night
Participants = 27884
Malaria parasite prevalence
Participants = 11601
(a) Baseline survey 2006
Households = 5910
Participants = 25081
Non-malarious clusters excluded
Households = 3360
Participants = 14248
eligible for malaria
testing = 7584
Household net ownership
Households = 2550
Net usage last night
Participants = 10833
Malaria parasite prevalence
Participants = 3249
(b) MIS 2007 subsample in Amhara, Oromia and SNNP Regional States
Figure 2: The sample population by survey.
one insecticidal net (i.e., ITN or LLIN), which significantly
increased from 2.9% (95% CI 2.6%−3.2%) in 2005 to 19.6%
(95% CI 15.5%−24.5%) in 2006 and to 68.4% (95% CI
58.7%−76.6%) in 2007. The mean number of insecticidal
nets per household increased from nearly zero in 2005 to 0.3
in 2007 (Figure 4). These increases over time in net coverage,
that is, from DHS to baseline 2006 and from baseline 2006
to MIS 2007, were all statistically significant. Of the three
regional states, Amhara exhibited the highest household
ownership of LLIN at the end of 2007, followed by SNNPR
3.4. Net Use by Participants. Table 2 shows that the propor-
tion of persons who reported sleeping under a mosquito
net (any type) the previous night significantly increased
from 1.5% (95% CI 1.4%−1.6%) in 2005 to 27.8% (95% CI
23.5%−32.7%) in 2006 and 36.7% (95% CI 30.2%−43.7%)
in 2007. In the respective years, net use went up from 2.0%
(95% CI 1.7%−2.3%) to 31.8% (95% CI 26.8%−37.4%) and
to 42.5% (95% CI 34.0%−51.6%) among children under five
years, and from 1.3% (95% CI 0.7%−2.2%) to 35.9% (95%
CI 28.8%−43.7%) and then to 41.0% (95% CI 30.5%−52.4%)
among pregnant women.
The proportion of individuals sleeping under an insecti-
cidal net (considering all households) increased significantly
from 1.0% (95% CI 0.9%−1.1%) in 2005 to 15.3% (95% CI
12.0%−19.2%) in 2006 and 34.5% (95% CI 27.7%−41.9%)
in 2007. Similarly, insecticidal net use in the respective
years went up significantly from 1.3% (95% CI 1.1%−1.5%)
6 Journal of Tropical Medicine
HH with >= 1 any net (%)
Amhara OromiaSNNP Total
(a) Proportion of households owning one or more nets (any type).
Note: “Total” refers to the weighted average percentage for the three
HH with >= 1 LLIN (%)
AmharaOromia SNNP Total
(b) Proportion of households owning one or more long lasting
insecticidal nets. Note: in DHS 2005 the proportions are for ITN,
not LLIN, as it did not make this distinction “Total” refers to the
weighted average percentage for the three regional states
Figure 3: Proportion of households owning one or more nets.
Table 1: Characteristics of study households and participants in malarious areas of three regional states.
MIS 2007 subsample
105 Number of clusters sampled
Number of households
Proportion sprayed with insecticide in the last year (%)
Mean household size (people)
Household wealth index (quintiles)
All survey participants characteristics
Number of all participants
Proportion of males (%)
Participants tested for malaria
Number blood slides done
Proportion of males (%)
SNNP, Southern Nations, Nationalities and Peoples.
Journal of Tropical Medicine7
Table 2: Proportion of people who reported sleeping under a net last night in all sampled households in malarious areas of three regional
Slept under any net last night (%)
Slept under LLIN last night (%)
Baseline 2006 MIS 2007 MIS 2007
Children under five years of age
∗In DHS 2005 the proportions refer to persons under ITN not LLIN.
Mean number of LLIN per HH
Figure 4: Mean number of long lasting insecticidal nets per
household by survey and regional state.
to 17.4% (95% CI 13.6%−22.0%) and to 38.9% (95% CI
30.2%−48.3%) among children under five years, and from
0.8 (95% CI 0.3%−1.6%) to 18.9% (95% CI 14.0%−25.0%)
and then to 37.4% (95% CI 26.2%−50.1%) among pregnant
However, when net use only in households possessing
at least one net was assessed, net use among residents who
had access to a net exhibited a significant decline between
the baseline 2006 and MIS 2007 surveys. Use of a net the
previous night by persons of all ages declined significantly
from 70.8% (95% CI 66.6%−74.7%) in 2006 to 48.0%
(95% CI 42.2%−54.0%) in 2007 in households owning at
least one net, and from 71.7% (95% CI 66.1%−76.7%) to
48.3% (95% CI 42.3%−54.3%) among those owning at least
one LLIN (Table 3). The decline in net use was observed
in all three regional states and among pregnant women
as well as children under five years of age. Use of LLIN
in households with at least one net declined from 72%
(95% CI 63.9%−78.9%) to 51.3% (95% CI 43.7%−58.9%)
in Amhara, from 72.9% (95% CI 62.8%−81.2%) to 51.5%
(95% CI 41.1%−61.8%) in Oromia and from 68.6% (95%
CI 61.7%−74.7%) to 38.2% (95% CI 26.0%−52.1%) in SNNP
Overall in households that owned an LLIN, 79.5% (95%
CI 72.7%−84.9%) of children under five years of age slept
underanLLINthepreviousnight in baseline 2006 compared
with 58.2% (95% CI 52.9%−63.4%) in MIS 2007. Likewise,
LLIN use among pregnant women declined significantly
from 82.7% (95% CI 70.4%−90.6%) to 58.3% (95% CI
43.0%−72.2%). Due to this lack of use by households that
owned nets, the proportion of nets that were actually being
used decreased significantly from 84.8% of 3,860 nets in the
sample in baseline 2006 to 54.4% of 3,193 nets in the sample
in MIS 2007. There was no statistically significant difference
in the proportion of LLINs that were unused and encased
within their original packages between baseline 2006 and
MIS 2007 (6.0% versus 6.3%).
3.5. Malaria Prevalence. Table 4 presents malaria parasite
prevalence by blood slide microscopy by age group. The
overall prevalence of malaria decreased significantly from
4.1% (95% CI 3.4%−4.9%) in 2006 to 0.4% (95% CI
in all age groups and in all three regional states. No case of
malaria was detected during MIS 2007 in the age group older
than 14 years. Age-adjusted prevalence figures by regional
state are presented in Figure 5. SNNPR and Amhara had
significantly higher prevalence during baseline 2006 while
8 Journal of Tropical Medicine
Table 3: Proportion of people who reported sleeping under a net in households that owned at least one net in malarious areas of three
Slept under any net last night (%)∗
Slept under LLIN last night (%)∗∗
Baseline 2006 MIS 2007MIS 2007
Children under five years of age
LLIN, long lasting insecticidal nets; MIS, malaria indicator survey; SNNP, Southern Nations, Nationalities and Peoples.
∗In a household that owns at least one net (any type).
∗∗In a household that owns at least one LLIN.
Table 4: Prevalence of malaria by blood slide microscopy by age group in malarious areas of three regional states.
∗One-sided exact binomial 97.5% confidence interval.
Prevalence of malaria (%)
Figure 5: Age adjusted prevalence of malaria by blood slide
microscopy, by survey and regional state.
there was no statistically significant difference between the
three regional states during MIS 2007.
There was no significant difference in malaria parasite
prevalence between individuals who did or did not report
using a net the previous night. For individuals in baseline
2006, the prevalence was 3.7% (95% CI 2.9%−4.6) in
net users and 4.2% (95% CI 3.4%−5.3%) in non users.
The equivalent figures for MIS 2007 were 0.7% (95% CI
0.3%−1.8%) in users and 0.2% (95% CI 0.04%−1.1%) in non
users. Similarly there was no significant difference in parasite
all, some or no nets were used. At baseline 2006 these
percentages were 3.8% (95% CI 2.9%−4.9%), 3.3% (95% CI
2.0%−5.6%) and 4.3% (95% CI 3.3%−5.4%), respectively. By
MIS 2007, prevalence was 0.9% (95% CI 0.3%−2.2%), 0.0%
and 0.3% (95% CI 0.05%−1.3%) in households using all,
some or no nets.
Plasmodium falciparum remained the dominant parasite
species in both surveys and in all three regional states, but
P. vivax represented a significant proportion of cases. During
baseline 2006, P. falciparum prevalence was 2.5% compared
with P. vivax prevalence of 1.6%, and the corresponding pro-
portions during MIS 2007 were 0.3% and 0.2%, respectively.
Journal of Tropical Medicine9
Average night temp per 8day period (deg C)
Precipitation per 8day period (mm)
Figure 6: Average nighttime temperature and rainfall over 8 day periods, by survey and regional state. AM: Amhara; OR: Oromia; SN:
The overall ratio of P. falciparum to P. vivax was similar at
baseline 2006 (1.6) compared to MIS 2007 (1.5).
3.6. Climate. The country-averaged annual CMAP rainfall
estimates for 2006 and 2007 were 859mm and 773mm,
respectively. These are both above the annual average for
the 29-year period (1979−2007). Figure 6 shows rainfall
and temperature data over the respective survey periods
represented by the boxes at top of the figure. In Amhara,
average nighttime temperature was 12.9◦C in baseline 2006
and 13.0◦C in MIS 2007; Oromia average temperature went
down from 14.8◦C in baseline 2006 to 13.5◦C in MIS 2007;
and SNNPR average temperature decreased from 16.0◦C in
baseline 2006 to 15.3◦C in MIS 2007.
The household ownership of long-lasting insecticidal nets in
these three regional states of Ethiopia exhibited an enormous
increase over less than a year’s time compared to the
baseline estimates. The proportion of households owning at
least one net nearly doubled and the proportion of those
owning at least one LLIN more than tripled. The increase
in coverage was significant in all three regional states but
more pronounced in Amhara, which saw a five-fold increase
in the proportion of households owning at least one LLIN.
From the results of our survey, it is clear that large scale-
up of net ownership is possible over short periods of time
in countries given the availability of adequate resources and
strong commitment to increasing coverage . Ethiopia is
one of a few countries in the African region with high ITN
coverage, and the only highly populous one .
Overall, net use and LLIN use by persons of all ages in all
households went up between baseline 2006 and MIS 2007:
from 27.7% to 36.7% for any type of net and from 15.3%
to 34.5% for LLIN, with slightly higher rates for children
under five years of age and pregnant women. However, when
restricted to households owning at least one net, use in
all three regional states was higher during baseline 2006
compared to MIS 2007 among persons of all ages, as well
as children under five years of age and pregnant women.
This is an interesting and important observation since, while
net use generally lags behind ownership, the assumption has
been that if ownership increases sufficiently, then increased
use will follow. A review of net surveys elsewhere in Africa
from 1991 and 2001 showed that while ownership of at
least one net ranged from 0.1% to 29% of households, use
by children under five reached a maximum of 16% of that
10Journal of Tropical Medicine
age group . A more recent comparative analysis of net
use covering 15 countries over the period 2003 to 2006
by Eisele et al. suggested that higher net use by children
under five (in households owning ITN) was associated with
increased availability of nets in the household . Thus, as
the number of nets per household member increased (i.e.,
mean ratio of residents per net decreased from 6.8 to 3.7 by
country), children under 5 were 2.1 to 5.5 times more likely
to have slept under an ITN the previous night. However,
when analyzed by country, Ethiopia was the sole exception
among the fifteen countries surveyed, since there was no
association between increased net availability (as assessed
by decreased number of persons per net) and likelihood of
use by children under five. Although this study used the
Ethiopia DHS 2005 as a prebaseline, and few households
owned nets at that time, this observation is corroborated
with the findings in our study, that is, that ownership alone
(even of multiple nets per household), although necessary,
may not automatically lead to increased net use.
There are many possible explanations for the declining
trend in use among households owning a net. First of all,
more recent distribution of nets may have targeted less
malarious areas. The results reported here are for areas
in each regional state traditionally classified as malarious
based on expert knowledge of malaria history as well as
climate and other factors. However, these program target
areas encompass a range of transmission intensities. Based
on the prioritization approach that the country followed
during the scaled-up LLIN distribution process, most of the
highly malarious areas may have had the nets by 2006 while
the lower incidence areas (where the need to use nets is
less appreciated) may have received them later. Secondly,
the education given about use of LLINs may not have been
sufficient, especially in areas where transmission intensity
is low. Thirdly, fewer malaria cases since 2006 may have
resulted in less perceived risk of getting the disease, which
in turn, may mean that people were again less inclined to use
LLINs. Fourthly, deterioration in nets (e.g., wear and tear,
dirt) could lead to the point where a proportion of people no
longer want to use them. There was no significant difference
in household socioeconomic status between the two surveys.
Recent study report from Madagascar shows that net use was
not associated with socioeconomic status .
in selected urban and rural localities of Oromia and Amhara
have also shown that not all nets owned by the households
were being used properly [23, 24]. However, only 6% of
nets were still encased within their original packages during
protective effect of ITN scale-up has been well documented
in several rural African settings [25–29]. As such, it is likely
that with such high LLIN coverage as was observed in MIS
2007, the hanging but unused nets would still contribute to
reduction of malaria transmission.
Prevalence of malaria decreased significantly between the
two surveys. This sharp decline in both P. falciparum and
P. vivax malaria was seen across the three regional states
and in all age groups. Contrary to earlier findings elsewhere
that documented slower declines in P. vivax compared to P.
falciparum [28, 30], both species saw proportionally sharp
declines in our study areas. Although similar findings have
been documented in other settings [28, 31, 32], attributing
the decrease in prevalence solely to the scale-up of key
malaria interventions (mainly LLIN and ACT), should be
done cautiously. It is to be noted that Ethiopia carried
out a nationwide Millennium Malaria Control Campaign
involving malaria mass treatment with CoArtem starting
in September 2007, just prior to MIS 2007. The campaign
involved treatment of all febrile cases in malarious areas
of the country through health extension workers. Further-
more, there is variation and year-to-year fluctuation in the
incidence of malaria due to the unstable nature of malaria
transmission in Ethiopia [33, 34].
Evidence from climate data sources suggests that neither
rainfall differences between the survey years nor increase in
mean temperature at the time of the surveys are likely to be
responsible for change in net use or decrease in prevalence.
Although nationwide, 2006 entertained more total annual
rainfall (859mm) compared with 2007 (773mm); the MIS
2007 was actually conducted closer to the normal rainy
season (July to September) and peak malaria months of
October-December (see Figure 6), which would tend to bias
the results towards higher prevalence in the second survey.
Analysis of temperature data by 8 day period shows that
over the respective survey time periods, Amhara average
nighttime temperature was essentially the same between
the survey years, while it decreased slightly in Oromia and
SNNPR. If temperature affects net use, this would tend to
bias the results towards higher use in 2007.
A few caveats of the surveys and the data presented have
to be outlined. The two surveys were conducted nearly one
year apart, with the MIS 2007 follow-up survey being part
of the nationwide MIS. Results on net use are based on self-
reporting, and such cross-sectional surveys around the peak
transmission season may not represent behavior at other
times of the year. While both surveys employed multistage
cluster sampling, the sampling frames were slightly different.
target areas defined by expert knowledge) in the three
largest regional states were included in the sampling frame;
oversampling (with appropriate weighting) in Amhara zones
and in areas coendemic for onchocerciasis was done. In the
baseline survey, clusters were defined as kebeles (the smallest
administrative unit with an average of 1000 households). In
MIS 2007, the sampling frame was all areas below 2500m,
stratified (with appropriate weighting) to three domains:
areas below 1500m, rural areas between 1500m and 2500m,
and urban areas between 1500m and 2500m; oversampling
in Amhara and Oromia was also done to obtain regional
estimates. In MIS 2007, clusters were defined as census
enumeration areas (with an average of 200 households in
To partially account for the sampling differences in this
comparative analysis between the two surveys, we excluded
MIS 2007 clusters that were outside the three regional
states of interest. We also excluded MIS 2007 clusters that
were not in “malarious” kebeles, using the same sampling
frame as provided for the baseline 2007 survey. We used
Journal of Tropical Medicine11
the multilevel sample weights estimated for each survey.
Sensitivity analysis in which we included all (malarious and
nonmalarious) clusters from MIS 2007 in the three regional
states of interest gave similar results for net ownership
and use (data not shown), but we believe that the current
approach of restriction to “malarious” areas for both surveys
is more conservative and appropriate, despite the resulting
large decrease in sample size for the MIS 2007.
up of malaria interventions. To build further on the encour-
aging increase in net ownership and maintain the low levels
of malaria parasite prevalence, proper and consistent use of
all nets available in the household must be promoted more
widely. Health extension workers and/or onchocerciasis and
trachoma community workers will identify remaining gaps
in net coverage and the factors associated with use or nonuse
of mosquito nets qualitatively. Appropriate educational
to intensify promotion of proper use and care of LLINs.
Our study showed that large scale-up of net ownership over
a short period of time is possible in countries strongly
committed to mobilizing all available resources to expand
access. It also showed that in these three regional states of
Ethiopia, malaria prevalence declined significantly over the
course of less than a year. However, our findings suggest
that a large increase in net ownership is not necessarily
mirrored directly by increased net use. Better targeting
of nets to malaria risk areas and more aggressive and
campaigns are needed to increase and maintain net use.
The EthiopiaMIS WorkingGROUP
Mekonnen Amena, Laurent Bergeron, Hana Bilak, Brian
Chirwa, Firew Demeke, Wubishet Dinkessa, Yeshewamebrat
Ejigsemahu, Paul M Emerson, Tekola Endeshaw, Kebede
Etana, Gashu Fente, Scott Filler, Anatoly Frolov, Khoti Gausi,
Teshome Gebre, Tedros Adhanom Gebreyesus, Alemayehu
Getachew, Asefaw Getachew, Patricia M Graves, Zelalem
HaileGiorgis, Afework Hailemariam, Jimee Hwang, Daddi
Jima, Henok Kebede, Abraham Lilay, Christopher Lungu,
Ambachew Medhin, Addis Mekasha, John Miller, Hussein
Mohamed, Aryc W Mosher, Sirgut Mulatu, Rory Nefdt,
JeremiahNgondi, DerejeOlana,RichardReithinger,Frank O
Richards Jr, Judith Robb-McCord, Amir Seid, Estifanos Biru
Shargie, Richard Steketee, Zerihun Tadesse, Tesfaye Teferri,
Agonafer Tekalegn, Eskindir Tenaw, Abate Tilahun, Adam
Wolkon, Biratu Yigezu, Gedeon Yohannes.
by The Carter Center and carried out in collaboration with
the Amhara, Oromia, and SNNP Regional Health Bureaus.
The follow-up Malaria Indicator Survey 2007 was the result
of joint efforts by multiple partners, including the Federal
Ministry of Health of Ethiopia, The Carter Center, Malaria
Control and Evaluation Partnership for Africa (MACEPA,
a program at PATH), World Health Organization (WHO),
United Nations Children’s Fund (UNICEF), U.S. Agency
for International Development (USAID), U.S. Centers for
Disease Control and Prevention (CDC), the Central Statis-
tical Agency, Center for National Health Development in
Ethiopia, and Malaria Consortium. The opinions expressed
are those of the authors and may not reflect the position
of their employing organization or of their work’s sources
of funding. We are grateful to Michael Bell and Stephen
Connor, International Research Institute for Climate and
Society at Columbia University for assistance with climate
data. The authors owe sincere gratitude to all the survey
participants who gave freely of their time in the surveys.
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