Table 1 describes the characteristics of the study population. Median age was 47·0 months at the mid-point of longitudinal follow-up (range; 4·9 to 97·1 months) and 54·6% were male. The overall geometric mean plasma hepcidin concentration was 2·45 ng/ml (95% CI; 2·08, 2·90; range; 0·04 to 176·56 ng/ml). ID and inflammation were common at 46% (262/572) and 18% (102/572) respectively. Asymptomatic malaria parasitaemia was also common: 12% (70/582) of routine blood smears were positive for P. falciparum with a mean parasite density of 909 parasites/μl (range; 40 to 380,000 parasites/μl). The gene discussed is HAMP; the disease is malaria.