Malaria prevalence and mosquito net coverage in Oromia and SNNPR regions of Ethiopia.

BACKGROUND: Malaria transmission in Ethiopia is unstable and seasonal, with the majority of the country's population living in malaria-prone areas. Results from DHS 2005 indicate that the coverage of key malaria interventions was low. The government of Ethiopia has set the national goal of full population coverage with a mean of 2 long-lasting insecticidal nets (LLINs) per household through distribution of about 20 million LLIN by the end of 2007. The aim of this study was to generate baseline information on malaria parasite prevalence and coverage of key malaria control interventions in Oromia and SNNPR and to relate the prevalence survey findings to routine surveillance data just before further mass distribution of LLINs. METHODS: A 64 cluster malaria survey was conducted in January 2007 using a multi-stage cluster random sampling design. Using Malaria Indicator Survey Household Questionnaire modified for the local conditions as well as peripheral blood microscopy and rapid diagnostic tests, the survey assessed net ownership and use and malaria parasite prevalence in Oromia and SNNPR regions of Ethiopia. Routine surveillance data on malaria for the survey time period was obtained for comparison with prevalence survey results. RESULTS: Overall, 47.5% (95% confidence interval (CI) 33.5-61.9%) of households had at least one net, and 35.1% (95% CI 23.1-49.4%) had at least one LLIN. There was no difference in net ownership or net utilization between the regions. Malaria parasite prevalence was 2.4% (95% CI 1.6-3.5%) overall, but differed markedly between the two regions: Oromia, 0.9% (95% CI 0.5-1.6); SNNPR, 5.4% (95% CI 3.4-8.5), p < 0.001. This difference between the two regions was also reflected in the routine surveillance data. CONCLUSION: Household net ownership exhibited nearly ten-fold increase compared to the results of Demographic and Health Survey 2005 when fewer than 5% of households in these two regions owned any nets. The results of the survey as well as the routine surveillance data demonstrated that malaria continues to be a significant public health challenge in these regions-and more prevalent in SNNPR than in Oromia.

Magnitude of malaria admissions and deaths at hospitals and health centers in Oromia, Ethiopia.

Health facility records are important sources of malaria data, not only to describe the disease patterns and trends, but also useful for planning malaria control and evaluating the impact of health interventions. The aim of this study was to assess the burden of malaria admissions and deaths on the services of hospitals and health centers in Oromia, over a period of five years, 1995-2000. A retrospective record review of data routinely collected on malaria admissions and deaths was conducted at all hospitals and health centers located in Oromia during March-May 2001. The total number of admissions and deaths from all causes registered at hospitals and health centers for the overall 1995-2000 period were 302,035 and 16,061. respectively. Malaria accounted for 11.20% of all admissions and 14.26% of all deaths. From 33,808 malaria inpatients, 2,291 (6.78%) died during the period Two thousand and one hundred thirty (92.97%) deaths occurred in hospitals and 161 (7.03%) deaths in health centers. A total of 78,062 (25.85%) admissions among children < 15 years occurred, of whom 12,273 (15.72%) had malaria. The overall percentage of malaria specific admissions during the period was higher for children in the age group of 1-4 (16.59%) and 5-14 years old (20.40%), compared to 7.93% for infants < 1 year and 9:62% for adults greater than 15 years old. Malaria specific admission ratios ranged from 2.95% in Jimma hospital to 47.12% at Merti hospital. Similarly, the proportionate malaria mortality ranged from 7.60% in Jimma hospital to 44.20% in Merti hospital. The majority of malaria admissions and deaths were due to Plasmodium falciparum. This retrospective analysis of records of hospitals and health centers reveals the heavy burden of malaria. Although cost-effective interventions for malaria are available, the burden of the disease is still unacceptably high. In this context, improving the quality of services at health care facilities for accurate diagnosis and effective antimalarial treatment, and increasing the accessibility of health services are crucial steps to reduce the burden of the disease. In addition, improving the quality of surveillance systems to pick up malaria cases and deaths at health care facilities enables decision makers to evaluate the impact of current interventions against the disease.

Effect of a large dam on malaria risk: the Koka reservoir in Ethiopia.

OBJECTIVE: To determine whether the Koka water reservoir in the Rift Valley of Ethiopia contributes to the malaria burden in its vicinity. METHODS: Frequency of malaria diagnosis in fever clinics was correlated with distance of residence from the margin of the Koka reservoir. Annual as well as seasonal malaria case rates were determined in cohorts residing < 3, 3-6 and 6-9 km from the reservoir. Plasmodium falciparum risk was compared with that of Plasmodium vivax. A multiple variable regression model was used to explore associations between malaria case rates and proximity to the reservoir, controlling for other suspected influences on malaria transmission. RESULTS: Malaria case rates among people living within 3 km of the reservoir are about 1.5 times as great as for those living between 3 and 6 km from the reservoir and 2.3 times as great for those living 6-9 km from the reservoir. Proximity to the reservoir is associated with greater malaria case rates in periods of more intense transmission. Plasmodium falciparum is most prevalent in communities located close to the reservoir and P. vivax in more distant villages. The presence of the reservoir, coupled with inter-annual climatic variations, explains more than half of the region's variability in malaria case rates. CONCLUSION: Large water impoundments are likely to exacerbate malaria transmission in malaria-endemic parts of sub-Saharan Africa.

Forecasting malaria incidence from historical morbidity patterns in epidemic-prone areas of Ethiopia: a simple seasonal adjustment method performs best.

The aim of this study was to assess the accuracy of different methods of forecasting malaria incidence from historical morbidity patterns in areas with unstable transmission. We tested five methods using incidence data reported from health facilities in 20 areas in central and north-western Ethiopia. The accuracy of each method was determined by calculating errors resulting from the difference between observed incidence and corresponding forecasts obtained for prediction intervals of up to 12 months. Simple seasonal adjustment methods outperformed a statistically more advanced autoregressive integrated moving average method. In particular, a seasonal adjustment method that uses mean deviation of the last three observations from expected seasonal values consistently produced the best forecasts. Using 3 years' observation to generate forecasts with this method gave lower errors than shorter or longer periods. Incidence during the rainy months of June-August was the most predictable with this method. Forecasts for the normally dry months, particularly December-February, were less accurate. The study shows the limitations of forecasting incidence from historical morbidity patterns alone, and indicates the need for improved epidemic early warning by incorporating external predictors such as meteorological factors.