Diagnostic accuracy and case management of clinical malaria in the primary health services of a rural area in south-eastern Tanzania

Malaria control continues to rely on the diagnosis and prompt treatment of both suspected and confirmed cases through the health care structures. In south-eastern Tanzania malaria is one of the leading causes of morbidity and mortality. The absence of microscopic examination in most of the health facilities implies that health workers must rely on clinical suspicion to identify the need of treatment for malaria. Of 1558 randomly selected paediatric consultations at peripheral health facilities throughout Kilombero District, 41.1% were diagnosed by the attending health worker as clinical malaria cases and 42.5% prescribed an antimalarial. According to our malaria case definition of fever or history of fever with asexual falciparum parasitaemia of any density, 25.5% of all children attending the health services had malaria. This yielded a sensitivity of 70.4% (IC95% = 65.9-74.8%) and a specificity of 68.9% (IC95% = 66.2-71.5%). Accordingly, 30.4% of confirmed cases left with no antimalarial treatment. Among malaria-diagnosed patients, 10% were underdosed and 10.5% were overdosed. In this area, as in many African rural areas, the low diagnostic accuracy may imply that the burden of malaria cases may be overestimated. Greater emphasis on the functioning and quality of basic health services in rural endemic areas is required if improved case management of malaria is to help roll back this scourge.