Purpose: Toxoplasmosis is widely distributed worldwide infecting almost a third of the world's population. To date, no research has explored the overall Toxoplasma gondii infection seroprevalence among women in Angola, nor have the risk factors associated with the infection been examined in region context. Therefore we aim to study the seroprevalence of toxoplasmosis in pregnant women in Luanda and to establish the potentially risk factors.
Methods: A prospective cross-sectional study was conducted in 2016 and 2017 to study the prevalence of toxoplasmosis in pregnant women attending on prenatal consultation at Lucrécia Paim Maternity (LPM) of Luanda, Angola. Blood samples were collected and specific anti-T.gondii (IgG and IgM) antibodies were quantified being the IgG avidity test used for exclude the primary infection. DNA detection was performed by PCR assays targeting T. gondii (B1) regions. Demographic and clinical data were collected by questionnaire after written consent. The statistical and descriptive analysis of the data was developed using SPSS software version 20.0. Statistical significance was considered when P < 0.05.
Results: Anti-T. gondii antibodies were quantified in 878 pregnant women and 346 (39.4%) samples were IgG positive, 2 (0.2%) positive for IgM and IgG and 530 (60.4 %) are negative for both immunoglobulins. The results showed that the seroprevalence by prior exposure with T. gondii was 39.6%. In this study, we also evaluated the possible risk factors associated with this infection where we find that most pregnant women (637, 72.6%) washed the fruits and vegetables before consuming them. The majority (812, 92.5%) revealed a lack of knowledge of the toxoplasmosis disease. The univariate and binary analysis showed that there was statistical association between the age groups, gestational age, HIV status, hepatitis status, history of abortion, pet at home and the positivity for IgG anti-Toxoplasma gondii. The IgG anti-T. gondii positive samples presented also high IgG avidity. The nested-PCR using B1 gene locus was negative in DNA samples extracted from placental fragment from two participants which were positive for IgM and IgG antibodies.
Conclusion: The study showed that there are a high number of women attending the LPM in Luanda that are not immunized for toxoplasmosis and are at risk of acquiring the primary infection. The consequence of primary infection in pregnant women is the potential vertical transmission to the fetus, resulting in congenital toxoplasmosis. Therefore, it is crucial establishing the diagnosis of maternal primary infection as well the appropriate diagnosis of congenital toxoplasmosis. Prenatal counseling should include education on toxoplasmosis prevention.