Cross-sectional relationship between HIV, lymphatic filariasis and other parasitic infections in adults in coastal northeastern Tanzania.

The relationship between HIV, lymphatic filariasis, malaria (Plasmodium falciparum) and intestinal helminths (Ascaris lumbricoides, Trichuris trichiura and hookworm) was assessed in a cross-sectional study conducted in 2002 among 907 adults in Tanga Region, Tanzania. Overall prevalences were 7.9% for HIV, 43.5% for Wuchereria bancrofti-specific circulating filarial antigen (CFA), 12.3% for P. falciparum, 1.2% for A. lumbricoides, 7.1% for T. trichiura and 75.7% for hookworm. Anaemia was assessed separately for males and females and was found to be more prevalent among females (58.8%) than males (34.8%). When sex and age were controlled for, there was a statistically significant positive association between HIV and W. bancrofti (CFA) infection and between malaria and HIV, but not between malaria and W. bancrofti (CFA) infection. Hookworm infection was positively associated with W. bancrofti (CFA) infection but, surprisingly, negatively associated with HIV. Infection with HIV and hookworms, but not malaria, was associated with a significant reduction in haemoglobin concentration. These associations are likely to reflect underlying mechanisms that need to be clarified to better understand the role of co-infections in HIV pathogenesis, and vice versa.