Determination of the residual efficacy of carbamate and organophosphate insecticides used for indoor residual spraying for malaria control in Ethiopia.

Background: Indoor residual spraying is one of the key vector control interventions for malaria control in Ethiopia. As malaria transmission is seasonal in most parts of Ethiopia, a single round of spraying can usually provide effective protection against malaria, provided the insecticide remains effective over the entire malaria transmission season. This experiment was designed to evaluate the residual efficacy of bendiocarb, pirimiphos-methyl, and two doses of propoxur on four different wall surfaces (rough mud, smooth mud, dung, and paint).

Insecticide resistance in Anopheles arabiensis from Ethiopia (2012-2016): a nationwide study for insecticide resistance monitoring.

Background: Indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) remain the cornerstones of malaria vector control. However, the development of insecticide resistance and its implications for operational failure of preventative strategies are of concern. The aim of this study was to characterize insecticide resistance among Anopheles arabiensis populations in Ethiopia and describe temporal and spatial patterns of resistance between 2012 and 2016.

Comparison of the Kato-Katz and FLOTAC techniques for the diagnosis of soil-transmitted helminth infections.

Decisions on individual or community treatment and evaluation of chemotherapy based control programs depend on parasitological diagnostic techniques. The aim of this study was to compare the accuracy of a single Kato-Katz thick smear and a single FLOTAC for the determination of the prevalence and intensity of soil-transmitted helminth infections. A total of 271 faecal specimens were collected from schoolchildren in Ethiopia, and microscopically examined using the Kato-Katz method (41.

New evidence of the effects of agro-ecologic change on malaria transmission.

Although maize pollen is known to provide nutrition for larval anopheline mosquitoes, the epidemiologic relationship between maize agriculture and malaria transmission has never been defined. To determine whether recent changes in malaria transmission in Ethiopia might be linked to the spread of maize as a commercial crop, we compared malaria transmission and maize cultivation intensity in 21 villages in the Bure District of northwestern Ethiopia where maize cultivation has recently expanded. The cumulative incidence in high maize cultivation areas was 9.

A component of maize pollen that stimulates larval mosquitoes (Diptera: Culicidae) to feed and increases toxicity of microbial larvicides.

To explain how larval Anopheles arabiensis Patton feed effectively in the turbid water in which they frequently develop, we determined whether an extractable component of maize, Zea mays L., pollen enhances feeding by these mosquitoes. Maturing maize produces a copious amount of wind-borne pollen that is nutritious enough and produced over a sufficient period to support the development of at least one generation of anopheline mosquitoes.

Enhancement of development of larval Anopheles arabiensis by proximity to flowering maize (Zea mays) in turbid water and when crowded.

To determine whether proximity to flowering maize enhances the development of larval anopheline mosquitoes breeding in turbid water and when crowded, we evaluated the development of larval Anopheles arabiensis under various conditions of turbidity, larval density, and proximity to pollen-shedding maize in simulated breeding puddles in a malaria-endemic site. In naturally formed puddles, water turbidity, as well as larval density, increased as the rainy season progressed. In sites remote from flowering maize, more pupae developed and the resulting adults were larger in relatively clear water than in turbid water, and larval crowding inhibited development.