Adjusting for age and gender, prior or current malaria infection (prior: Hb β = −0.99, 95% CI: −1.49 to −0.49, P = 0.01), or having any current infection with hookworm, Trichuris, Strongyloides, Ascaris, and/or malaria (β = −0.84, 95% CI: −1.36 to −0.33, P = 0.01) was associated with decreased current Hb. The gene discussed is GSTM1; the disease is malaria.