Abstract:
Background: Both lymphatic filariasis (LF) and human immunodeficiency virus (HIV) are major public health problems in endemic areas worldwide. There is geographical overlap in their distribution in sub-Saharan Africa. Individuals may be co-infected, raising the possibility of important interactions between these two pathogens and their control.
Methodology and Principal Findings: We analysed circulating filarial antigenaemia (CFA) and night blood microfilaraemia among HIV-infected and HIV-uninfected adults in Karonga district in rural northern Malawi, a region endemic for both LF and HIV. Stored blood samples and data from two studies were used: one was a clinical trial of anti-filarial agent dosing regimens in the north of the district, and the other was a whole population annual HIV sero-survey of the Karonga Health and Demographic Surveillance System in the south of the district. In study one, 1851 consecutive adult volunteers were screened for HIV and LF infection. CFA prevalence was 25.4% (43/169) in HIV-infected and 23.6% (351/1487) in HIV–uninfected (p=0.57) while geometric mean CFA concentrations were 859 and 1553 respectively (p=0.38). Microfilariae were detected in 12 (41.4%) and 123 (49.6%) of HIV-infected and HIV-uninfected respectively (p=0.40). The geometric mean microfilarial counts were 29.4 and 85.6 for HIV-infected and HIV-uninfected respectively (p=0.14). In study two, 7863 adults were assessed. CFA prevalence was 20.9% (86/411) in HIV-infected and 24.0% (1789/7452) in HIV–uninfected (p=0.28). Geometric mean CFA concentration was 630 in HIV-infected and 841 in HIV-uninfected respectively (p=0.02). There was no meaningful change in results after adjusting for age and sex in both studies.
Conclusions/Significance: In this cross-sectional study of two separate LF exposed groups, HIV co-infection did not significantly affect markers of LF infection. This study does not support any meaningful public health impact of HIV on LF epidemiology.
