Seroprevalence and risk factors associated with anti-Toxoplasma gondii antibodies in pregnant women attending antenatal clinics in Benue state, Nigeria

Abstract

Background: Toxoplasmosis causes serious economic losses in livestock. Congenital transmission can occur in pregnant women, commonly with serious consequences.Methods: A cross-sectional study was designed to screen for the absence or presence of anti-T. gondii IgM or IgG antibodies and explore associated risk factors in pregnant women (n=261) that attended antenatal clinics in selected hospitals in Benue state, Nigeria. Blood samples were subjected to enzyme linked immunosorbent assay (ELISA). Information on sociodemographic data and possible risk factors were obtained using a structured questionnaire.Results: Out of 261 pregnant women, 19 (7.3%) and 108 (41.1%) were seropositive for anti-T. gondii IgM and IgG respectively. Comparison of IgM and IgG results suggested that 4.4% presented evidence of possible primary infection, 38.7% previous exposure, 2.8% possible reactivated or chronic infections and 51.8% were susceptible to T. gondii infection. The nature of women’s housing was significantly associated with anti-T. gondii IgM seropositivity (p <0.05). Pregnant women that lived in mud houses with thatched roofs were three times more likely to be seropositive than those who lived in concrete/brick houses with aluminium/zinc roofs (OR=3.123, 95% CI:1.027, 9.495). The study also showed that 17.7% of apparent infections were attributable to the nature of housing. More than half of the women sampled were at risk of contracting primary toxoplasmosis.Conclusion: Screening for anti- T. gondii antibodies during antenatal care is advocated in order to detect affected women so that appropriate management strategies can be implemented.

Detection and genetic characterisation of Toxoplasma gondii circulating in free-range chickens, pigs and seropositive pregnant women in Benue state, Nigeria

“…We have previously found high seropositivity for T. gondii in the pregnant women tested here, primarily represented by chronic infections (i.e. IgM negative, IgG positive; [27]). Using a sensitive nested PCR targeting the T. gondii 529 bp PLOS NEGLECTED TROPICAL DISEASES multi-copy repeat as an indirect measure of occurrence [37,38,29], recognising that the presence of DNA does not necessarily indicate active infection, we suggest a high occurrence of blood parasitaemia in pregnant women in Benue state, Nigeria.…”

“…gondii in the pregnant women tested here, primarily represented by chronic infections (i.e. IgM negative, IgG positive; [ 27 ]). Using a sensitive nested PCR targeting the T .…”

“…For human subjects, ~3 ml of blood was aseptically collected from each participant via the median cubital vein by a trained medical laboratory scientist. Approximately 2.5 ml whole blood was dispensed into a 5 ml plain vacutainer (for serology; as described previously [ 27 ]), with the remaining 0.5 ml placed in an EDTA sample bottle. Samples were placed in a cool box containing ice and transported to the Ahmadu Ali Center for Public Health and Comparative Medicine laboratory, Makurdi, for processing.…”

“…Samples collected from women found to be seropositive for T . gondii (IgM and/or IgG, or found to be inconclusive [ 27 ]) were prioritised to improve parasite detection. Specifically, 83 samples had previously achieved a definitive result for IgM (14 positive, 69 negative), with 9 found to be inconclusive.…”

“…For human blood, DNA was extracted from samples preserved on Whatman FTA cards using 5% (w/v) Chelex 100 resin (Bio-Rad Laboratories, France) prepared in molecular grade water (Thermo Fisher Scientific, UK) [28]. Samples collected from women found to be seropositive for T. gondii (IgM and/or IgG, or found to be inconclusive [27]) were prioritised to improve parasite detection. Specifically, 83 samples had previously achieved a definitive result for IgM (14 positive, 69 negative), with 9 found to be inconclusive.…”