P02. Hepatitis e virus epidemiology among HIV infected women in an urban area in Tanzania

Ebba Mannheimer1, Lene Holm Harritshøj2, Zahra Persson Theilgaard1, Mercy Chiduo3, Sofie Midgley4, Jan Gerstoft1, Henrik Ullum2, Terese L. Katzenstein1
Affiliates: 1Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, 2Department of Clinical Immunology, Rigshospitalet, 3National Institute of Medical Research (NIMR), Tanga, Tanzania, 4Department of Microbiological Diagnostics and Virology, State Serum Institute, Copenhagen

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Background
Hepatitis E virus (HEV) (genotype 1 and 2) is the single most important agent causing acute viral hepatitis in the world. HEV outbreaks leads to large scale water borne epidemics by fecal-oral transmission in developing countries in Africa, Asia and Central America. HEV mainly attacks young adults causing a self-limiting acute infection, but with a high mortality rate (15-25%) among pregnant women, especially during the third trimester. HEV seroprevalence studies among pregnant women in Africa are scanty, with study results showing seroprevalences among the general female population ranging from 0% and 7% in Tanzania to 84% in rural areas of Egypt.
Although HIV prevalence in pregnant women in Sub-Saharan countries is high, there is limited knowledge of HEV co-infection rates in this group of susceptible patients. In this study the HEV seroprevalence among HIV-1 infected young women in Tanzania was investigated.

Methods
Plasma samples from a cohort of HIV-1 infected pregnant women in Tanga, Tanzania were retrospectively tested. The patients participated in a clinical trial of short course antiretroviral therapy for prevention of mother-to-child transmission among women with CD4 > 200 cells/µL during 2006 to 2011 (the ComTru Study). Blood samples collected at month 9 postpartum (9PP) were analyzed for anti-HEV antibodies (IgG and IgM). From patients testing positive earlier samples (at enrollment in 2nd or 3rd trimester, at delivery and at day; 7, 28 and 42 PP) were tested for antibodies and/or HEV RNA.
If both the enrollment sample and the 9PP sample were anti-HEV IgG positive and IgM negative, the infection was defined as a past HEV infection. HEV incidence was estimated from anti-HEV seroconverting. If any samples were anti-HEV IgM and/or HEV RNA positive, the infection was defined as a recent infection or an active infection.

Results
Two hundred and eight participants (37.8% of the 550 women included in the ComTru study) with samples available from both enrollment and 9PP were included.
Mean age of study participants at study enrollment were 27.6 years (SE 0.2), mean gestational age were 23.4 weeks (SE 0.4) and mean CD4 count were 515 cells/µL (SE 27).
Fourteen patients were anti-HEV IgG positive/IgM negative at time of enrollment yielding a seroprevalence rate of 6.7% (CI 4.1-11.0%) among HIV-1 infected women. Two of 194 participants seroconverted from anti-HEV negative to anti-HEV IgG positive/IgM negative, between time of delivery and 9PP with an incidence of HEV of 1.0% (CI 0.3-3.7%). Both tested negative for HEV RNA.

Conclusion
The seroprevalence among HIV-1 infected pregnant women in an urban area in Tanzania was 7 % and furthermore approximately 1 % (2/194) seroconverted during 12 months of follow-up, indicating ongoing HEV transmission.