Date of this Version
Epidemiol. Infect. (2003), 131, 791–797.
Migrants from Java arrive in hyperendemic Papua, Indonesia lacking exposure to endemic malaria. We evaluated records of evacuation to hospital with a diagnosis of severe malaria from a transmigration village in northeastern Papua. During the first 30 months, 198 residents with severe disease were evacuated (7.5 evacuations/100 person-years). During this period the risk of evacuation for adults (>15 years of age) was 2.8. (95% CI=2.1–3.8; P<0.0001) relative to children, despite apparently equal exposure to risk of infection. Relative risk (RR) for adults was greatest during the first 6 months (RR>16; 95% CI>2.0–129; P=0.0009), and diminished during the second 6 months (RR=9.4; 95% CI=2.7–32.8; P<0.0001) and the third 6 months (RR=3.7; 95% CI=1.7–7.9; P=0.0004). During the next two 6-month intervals, the RR for adults was 1.6 and 1.5 (95% CI range 0.8–2.6; P<0.18). Adults lacking chronic exposure were far more likely to progress to severe disease compared to children during initial exposure, but not after chronic exposure to infection.