Seroprevalence of infection among pregnant women in Windhoek, Namibia, in 2016.

Background: When a pregnant woman contracts () infection during pregnancy, it may be vertically transmitted to the foetus. Information on the incidence of congenital toxoplasmosis (CT) in developing countries is scarce. Most studies focus on the seroprevalence of infection among pregnant women. This study aimed to determine the seroprevalence of infection among pregnant women attending public antenatal care in Windhoek, Namibia, in 2016.

Methods: In this descriptive study, 344 urban pregnant women attending public antenatal care were voluntarily enrolled in the study. Seroprevalence of anti- Immunoglobulin G (IgG) was determined by automated immunoassay. Samples with a positive IgG result were tested for Immunoglobulin M (IgM) and specific IgG avidity by using an enzyme-linked immunosorbent assay (ELISA) test. A questionnaire captured demographic data and exposure to risk factors. Data were analysed using Statistical Package for the Social Sciences (SPSS) and R.

Results: Anti- IgG was found in nine (2.61%) pregnant women. There was no association of anti- IgG with demographic characteristics or exposure to risk factors.Anti- IgM was positive in one (0.3%) woman, while three (0.9%) women had borderline anti- IgM results. Specific IgG avidity was low, equivocal and high in 0%, 33% and 67% of seropositive pregnant women, respectively.

Conclusion: Seroprevalence of anti- IgG is much lower in Namibia than is reported in other developing countries. Investigation into specific IgM seropositivity and IgG avidity showed that pregnant women in the central region of Namibia are at low risk of vertical transmission and development of CT.