The Karonga Health and Demographic Surveillance System (Karonga HDSS) in northern Malawi currently has a population of more than 35 000 individuals under continuous demographic surveillance since completion of a baseline census (2002–2004). The surveillance system collects data on vital events and migration for individuals and for households. It also provides data on cause-specific mortality obtained by verbal autopsy for all age groups, and estimates rates of disease for specific presentations via linkage to clinical facility data. The Karonga HDSS provides a structure for surveys of socio-economic status, HIV sero-prevalence and incidence, sexual behaviour, fertility intentions and a sampling frame for other studies, as well as evaluating the impact of interventions, such as antiretroviral therapy and vaccination programmes. Uniquely, it relies on a network of village informants to report vital events and household moves, and furthermore is linked to an archive of biological samples and data from population surveys and other studies dating back three decades.

BACKGROUND AND OBJECTIVES: Cerebral malaria (CM) causes significant mortality and morbidity in sub-Saharan African children. Reliable morbidity estimates are scarce because of methodological variability across studies. We describe the incidence, course, and severity of neurodevelopmental impairments in survivors of CM and the associated patient characteristics to inform epidemiologic estimates of malaria morbidity rates and prevention and treatment efforts. METHODS:We conducted an exposure-control study of 85 survivors of CM and 100 age-matched patients in a control group who were enrolled at hospital discharge and assessed after 1, 6, and 12 months using caregiver interviews and standardized developmental, cognitive, and behavioral measures.RESULTS: Developmental or cognitive impairment (,10th percentile of the control distribution) and/or new onset of caregiver-reported behavior problems occurred in 53% of case patients compared with 20% of the patients in the control group (odds ratio 4.5; 95% CI: 2.4 to 8.6; P , .001). In case patients, developmental or cognitive impairment at the 12-month assessment was associated with HIV-positive status and short stature at presentation, more prolonged fever and coma during admission, and severe atrophy or multifocal abnormalities being found on MRI at the 1-month assessment. CONCLUSIONS: One-half of survivors of CM were neurodevelopmentally impaired at the 1-year assessment. With these results, we support prevention trials of acute, neuroprotective interventions and the allocation of resources to evaluation, education, and rehabilitation efforts to reduce the significant long-term burden of CM-associated impairments on families and their communities.WHAT'S KNOWN ON THIS SUBJECT: In some studies, survivors of cerebral malaria have performed poorly on measures of development, cognition, and behavior. It is unclear how many of these children are frankly impaired, who are most likely to be impaired, and whether impairment persists.WHAT THIS STUDY ADDS: One-half of survivors of cerebral malaria have some kind of impairment 1 year after the illness. Developmental or cognitive impairment is associated with having HIV, shorter stature, prolonged fever and coma during the initial illness, and abnormalities found on MRI.