For this Consortial Project 2 study the Malaria Research and Training Centre, University of Bamako contributed samples from individuals in rural villages in Manteourou county in the Dogon region of Mali (circled on map). Malaria transmission is seasonal here, with most malaria occurring in the rainy season (June to October, EIR around 200 ib/p/year), and very little during the dry season (October to May).

The 976 samples contributed to CP2 come from three consecutive cross-sectional studies - two at the end of the transmission seasons of 2006 and 2007 respectively and one during the dry season of 2007.

 Description of Study Population

Dogon and Fulani live in sympatry in the study area and this is reflected in the sample composition (50% from each group). Of special interest for CP2 is that a distinct difference in malaria susceptibility between these two groups had been found in earlier studies.

About half of the sample population are adults (> 15 years), and about a fifth of the children (≤ 15 years) are under the age of 5.

 Morbidity and Infection Density

Infection with malaria parasites (Plasmodium falciparum and malariae) was determined by inspection of blood smears on slides. Asexual (blood stage) and sexual (gametocyte) forms of the parasites were counted and parasite density calculated per microlitre of blood.

 Clinical Information

Clinical information, namely temperature and splenomegaly were recorded for all individuals in this survey. For patients with malaria an assessment was also made as to whether the disease episode was symptomatic or asymptomatic. Of the 179 infected individuals, 86 (48%) were found to be symptomatic.