- Ghebreyesus TA, Alemayehu T, Bosman A, Witten KH, Teklehaimanot A / Acta Trop. 1996 Apr;61(2):145-56
- Epidemiology and Diagnostics Division, National Malaria Control Organization, Addis Ababa, Ethiopia.
During the Ethiopian civil war from 1974 to 1991, the Tigrean People's Liberation Front established
a primary health care system in Tigray in which community residents helped to plan and implement health
services through health committees and community health workers (CHWs). To strengthen and update this system,
a Community-Based Malaria Control Programme was initiated in 1992. The primary objectives of
the Programme are to reduce malaria morbidity and mortality and to prevent malaria in pregnant
women through early diagnosis and treatment of cases, chemoprophylaxis during pregnancy, and vector control
by environmental management. A secondary objective is to introduce a cost-sharing scheme for eventual
development of a village revolving fund. A total of 681 volunteers chosen by their communities have
received malaria training and serve a rural population of 1,682319 (CHW/population ratio 1:2,500).
The principal success of the programme at this stage is that a significant proportion of the rural
population at risk for malaria is now being treated at the village level. During the last major transmission
season from September through November 1993, each CHWs treated a mean of 45178 clinical malaria cases per month.
Under-utilization of treatment services by women and children under 5 years and low chemoprophylaxis
coverage of pregnant women have been documented. After focus group discussions with community members
and CHWs to identify the reasons for these problems, changes in programme policies were made to improve
coverage of these groups. Since 1992, considerable progress toward meeting programme objectives has been made,
and continued evaluation will allow for interventions that should further strengthen the malaria control efforts in the region.
-
Ghebreyesus TA, Haile M, Getachew A, Alemayehu T,
Witten KH, Medhin A, Yohannes M, Asgedom Y, Ye-ebiyo
Y, Lindsay SW, Byass P / J Public Health Med. 1998
Jun;20(2):238-40
- Epidemiology and Diagnostics Division, National Malaria Control Organization, Addis Ababa, Ethiopia.
- Alemayehu T, Ye-ebiyo Y, Ghebreyesus TA, Witten KH, Bosman A, Teklehaimanot A / Parassitologia. 1998 Sep;40(3):259-67.
- Department for the Control of Malaria and Other Vector Borne Diseases, Tigray Health Bureau, Ethiopia
A survey was undertaken in Tigray, Northern Ethiopia, to assess the prevalence of malaria, schistosomiasis,
and intestinal helminths in relation to microdams. The survey took place from March to June 1995,
during the dry season, at 41 microdams. At each site the village nearest the dam (within thirty minutes walk)
was selected, ten households were randomly chosen, and all family members were examined for malaria and
intestinal parasites. The overall study sample was 2271 people, of all age groups. Plasmodium falciparum
infection was documented in four villages (at 10% of microdams); prevalence was 1.2%
(range 0-20% by village). Larvae of Anopheles gambiae s.l. were found at one microdam.
Infection with intestinal schistosomiasis was documented in 20 villages (at 49% of microdams),
and one third of those infected had moderate to heavy infections. Biomphalaria species,
the intermediate host snails of Schistosoma mansoni, were found at 16 microdams (39%),
and snails infected by mammalian cercariae were found in one locality. Infections with soil-transmitted
nematodes were prevalent: hookworm was detected in more than two thirds of the villages,
and Ascaris lumbricoides and Trichuris trichiura were present in almost half of the villages.
Out of 2078 stool examinations, the prevalence of S. mansoni infection was 7.2% (range 0-48% by village),
of A. lumbricoides 2.3% (range 0-31%), of T. trichiura 2.4% (range 0-21%), and of hookworm 8.9%
(range 0-78%). The prevalence of malaria, S. mansoni and hookworm was higher at altitudes
below 2000 metres above sea level. S. mansoni was more prevalent in microdams built
more than 5 years before the survey, while T. trichiura was more prevalent at recently constructed
microdams. The widespread distribution of schistosomiasis and intestinal helminths,
and the presence of malaria infection during the dry season confirm that microdams create favourable
conditions for the transmission of these parasitic diseases. Health safeguards must be incorporated
into the planning, construction, and operation of microdams and irrigation systems in order
to prevent or reduce these diseases. In areas with high prevalence, control activities should be intensified.
- Ghebreyesus TA, Haile M, Witten KH, Getachew A, Yohannes AM, Yohannes M, Teklehaimanot HD, Lindsay SW, Byass P / BMJ. 1999 Sep 11;319(7211):663-6.
-
Tigray Health Bureau, Department of Malaria Control,
Mekelle, Ethiopia. witten@telecom.net.et
OBJECTIVE: To assess the impact of construction of microdams on the incidence of malaria in nearby
communities in terms of possibly increasing peak incidence and prolonging transmission.
DESIGN: Four quarterly cycles of malaria incidence surveys, each taking 30 days, undertaken
in eight at risk communities close to dams paired with eight control villages at similar altitudes
but beyond flight range of mosquitoes.
SETTING: Tigray region in northern Ethiopia at altitudes of 1800 to 2225 m.
SUBJECTS: About 7000 children under 10 years living in villages within 3 km of microdams and in control villages 8-10 km distant.
MAIN OUTCOME MEASURES: Incidence of malaria in both communities.
RESULTS: Overall incidence of malaria for the villages close to dams was
14.0 episodes/1000 child months at risk compared with 1.9 in the control villages-a sevenfold ratio.
Incidence was significantly higher in both communities at altitudes below 1900 m.
CONCLUSIONS: There is a need for attention to be given to health issues in the implementation of
ecological and environmental development programmes, specifically for appropriate malaria control
measures to counteract the increased risks near these dams.
PIP: This paper assesses the impact of microdam construction on the incidence of malaria in nearby
communities in Tigray, Ethiopia, in terms of possibly increasing peak incidence and prolonging transmission.
Four quarterly cycles of malaria incidence surveys, each taking 30 days, were undertaken
in eight at-risk communities close to dams paired with eight control villages at similar
altitudes but beyond the flight range of mosquitoes. Samples included about 700 children
under 10 years of age living in villages within 3 km of microdams and in control villages 8-10 km distant.
Results showed that the overall incidence of malaria for the villages close to the dams was
14.0 episodes/1000 child-months at risk compared with 1.9 in the control villages.
Incidence was significantly higher in both communities at altitudes below 1900 m.
This paper suggests the need to address health issues in the implementation of ecological
and environmental development programs, specifically regarding appropriate malaria control
measures to counteract the increased risks near these dams.
- Ghebreyesus TA, Witten KH, Getachew A, O'Neill K, Bosman A, Teklehaimanot A / Parassitologia. 1999 Sep;41(1-3):367-71.
- Department for the Control of Malaria, Tigray Health Bureau, Ethiopia.
Community-based control activities have been a major component of the Tigray regional malaria control
programme since 1992. A team of 735 volunteer community health workers treat on average 60,000 clinical
malaria cases monthly during the high malaria transmission season. Ensuring access for the rural
population to early diagnosis and treatment has contributed to a significant decrease in death
rate in under-five children at the village level from 1994 to 1996. Mapping and geographic
information system (GIS) technologies have been introduced to support planning for control
by assessment of community-based coverage. With further development, GIS will be used
in stratification, and to assess the impact of water resources development on malaria transmission
and intensity.
- Ghebreyesus TA, Haile M, Witten KH, Getachew A, Yohannes M, Lindsay SW, Byass P / Trans R Soc Trop Med Hyg. 2000 Jan-Feb;94(1):17-21.
- Tigray Health Bureau, Mekelle, Ethiopia.
Malaria transmission varies from village to village and even from family to family in the same village.
The current study was conducted in northern Ethiopia to identify risk factors responsible for such
variations in a hypoendemic highland malaria setting: 2114 children aged < 10 years living in 6 villages
situated close to small dams at altitudes from 1775 to 2175 m were monitored. Monthly malaria incidence
was determined 4 times over a 1-year period during 1997. Incidence results were then analysed
by 14 individual and household factors using Poisson multivariate regression.
Among 14 factors analysed, use of irrigated land (rate ratio[RR] = 2.68, 95% CI 1.64-4.38),
earth roof (RR = 2.15, 95% CI 1.31-3.52), animals sleeping in the house (RR = 1.92, 95% CI 1.29-2.85),
windows (RR = 1.84, 95% CI 1.30-2.63), open eaves (RR = 1.85, 95% CI 1.19-2.88),
no separate kitchen (RR = 1.57, 95% CI 1.10-2.23), and 1 sleeping room (RR = 1.52, 95% CI 1.05-2.20),
were significantly associated with malaria. The proportion of infection among children exposed
to one or no risk factor was 2.1%, increasing with the number of risk factors and reaching 29.4%
with 5 or more. Further studies are needed to confirm the importance of particular risk factors,
possibly leading to simple health education and control measures that could become
part of routine control programmes, implemented with inter-sectoral collaboration.
- Ghebreyesus TA, Witten KH, Getachew A, Yohannes AM, Tesfay W, Minass M, Bosman A, Teklehaimanot A / Parassitologia. 2000 Dec;42(3-4):255-90.
-
Tigray Health Bureau, Malaria Control Department,
P.O. Box 89, Mekelle, Ethiopia.
Tigray, the northernmost state of Ethiopia, has a population of 3.5 million, 86% rural, and 56% living in
malarious areas. In 1992 a Community-Based Malaria Control Programme was established to provide region-wide
and sustained access to early diagnosis and treatment of malaria at the village level. 735 volunteer
community health workers (CHWs) serve 2,327 villages with a population of 1.74 million, treating an average
of 489,378 patients yearly from 1994 to 1997. Recognition of clinical malaria is similar for CHWs and health
staff at clinics where there is no access to microscopy. In 1996 a pilot community-financing scheme of
insecticide-treated bednets was well accepted, but re-impregnation rates fell in 1998 because of war-related social
upheaval. Indicators from health institutions show a progressive increase in malaria morbidity from 1994 to 1998.
Repeated mortality surveys show a 40% reduction in death rates in under-5 children from 1994 to 1996 and a 10%
increase from 1996 to 1998. These trends may be related to increased malaria transmission with water resources development,
increased seasonal labour migration to malarious lowlands, prolongation of the transmission season with climate changes,
and increasing chloroquine resistance throughout Ethiopia. Progressive extension of CHW services to ensure better coverage
of women, children, migrant workers and communities near water development projects, change to first-line
treatment with sulfadoxine-pyrimethamine, extension of the impregnated bednet initiative, and development of a regional
warning system for epidemics should result in a greater impact on morbidity and mortality.
- Ghebreyesus TA, Witten KH, Getachew A, Haile M, Yohannes M, Lindsay SW, Byass P / Ann Trop Med Parasitol. 2002 Jul;96(5):489-95.
-
Tigray Health Bureau, Malaria Control Department,
Mekelle, Ethiopia.
Schistosomiasis continues to be a major public-health problem, not least in association with water-resource
developments. The impact of microdam construction in the northern Ethiopian highlands,
in relation to possible increased risks of Schistosoma mansoni infection, has now been assessed.
The results of incidence studies, carried out on 473 individuals sampled across eight microdam
sites at altitudes of 1800-2225 m above sea level, indicated an overall annual incidence
of 0.20 infections/person at risk. A multivariate Poisson regression model showed altitude
and sex to be significant risk factors for infection, whereas proximity to a microdam was
not significant, except possibly at very high altitudes. It was concluded that altitude
was the major factor in this environment and that therefore, at least in terms of public-health planning,
microdams should be sited as high as local geography permits.
- Ghebreyesus TA, Byass P, Witten KH, Getachew A, Haile M, Yohannes M, Lindsay SW / Appropriate tools and methods for tropical microepidemiology: a case-study of malaria clustering in Ethiopia. Ethiop J Health Dev. 2003; 17(1):1-8.
-
Tigray Health Bureau, Malaria Control Department,
Mekelle, Ethiopia.
Background: The importance of local variations in patterns of health and disease are increasingly recognised,
but, particularly in the case of tropical infections, available methods and resources for characterising
disease clusters in time and space are limited. Whilst the Global Positioning System (GPS) allows accurate and easy determination of latitude and longitude,
sophisticated Geographical Information Systems (GIS) that can process the data may not be available
and accessible where they are most needed.
Objective: To describe an appropriate procedure for interpreting
GPS information.
Methods: An example of space-time clustering of malaria cases around a dam in Ethiopia
(106 cases in 129.7 child-years-at-risk) is used to demonstrate that GPS data can be interpreted simply
and cheaply in under-resourced health service settings to provide timely and appropriate epidemiological
assessments.
Results: Malaria cases were clustered in time and space in the area surrounding a micro-dam.
Conclusion: Quickly identifying disease foci in this manner could lead to better informed control
and treatment activities which would represent a better use of resources as well as improved health for the community.
- Yohannes M, Haile M, Ghebreyesus TA, Witten KH, Getachew A, Byass P, Lindsay SW / Can source reduction of mosquito larval habitat reduce malaria transmission in Tigray, Ethiopia? Trop Med Int Health 2005; 10: 1274-85.
-
Tigray Health Bureau, Malaria Control Department,
Mekelle, Ethiopia.
The development of irrigation schemes by dam construction has led to an increased risk of malaria in Tigray, Ethiopia.
We carried out a pilot study near a microdam to assess whether environmental management could reduce malaria transmission
by Anopheles arabiensis, the main vector in Ethiopia. The study took place in Deba village, close to a dam; Maisheru village,
situated 3-4 km away from the dam, acted as a control. Baseline entomological and clinical data were collected
in both villages during the first 12 months. Source reduction, involving filling, draining and shading of potential
mosquito-breeding habitats was carried out by the community of Deba in the second year and routine surveillance continued
in both villages during the second year. Anopheles arabiensis was highly anthropophilic (Human Blood Index=0.73),
biting early in the night before people went to bed. The major breeding habitats associated with the dam were areas
of seepage at the dam base (28%), leaking irrigation canals (16%), pools that formed along the bed of streams
from the dam (13%), and man-made pools (12%). In the pre-intervention year, 5.9-7.2 times more adult vectors
were found in the dam village compared with the control village. There was a 3.1% higher prevalence of an enlarged
spleen in children under 10 years in the dam village than in the control village during the pre-intervention period,
but no statistically significant difference was found in the incidence of falciparum malaria between the two villages
during the same period. Source reduction was associated with a 49% (95% CI=46.6-50.0) relative reduction in An.
arabiensis adults in the dam village compared with the pre-intervention period. There were very few cases of malaria
during the intervention period in both villages making it impossible to judge whether malaria incidence had been reduced.
These preliminary findings suggest that in areas of low intensity transmission community-led larval control may be
a cheap and effective method of controlling malaria. Further, large-scale studies are needed to confirm these findings.
Tigray Health Bureau, Health Information Unit, P.O.BOX 7, Mekelle, Tigray, Ethiopia
TEL (+251) 034-440-02-22 / (+251) 034-440-93-66
Fax (+251) 034-440-88-30
E-MAIL tigrayhealth@ethionet.et
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