Global, regional and national estimates of Toxoplasma gondii seroprevalence in pregnant women: a protocol for a systematic review and modelling analysis

IntroductionTo set priorities for public health policy, funding for public health interventions, and healthcare planning which will ultimately contribute in bending the burden of toxoplasmosis towards maternal and neonatal health, it is necessary to have accurate data on the prevalence of toxoplasmosis in pregnancy. Therefore, we aimed to estimate the seroprevalence of Toxoplasma gondii infection in pregnant women by countries, WHO regions and globally.Methods and analysisWe will search multiple databases to identify studies that reported the prevalence (or enough data to compute this estimate) of Toxoplasma gondii in the global population of pregnant women up till December 31, 2018 without any language restrictions. Study selection, data extraction and risk of bias assessment will be conducted independently by three pairs of investigators. For each country, we will estimate the prevalence based on empirical studies if there is either one nationally representative study, or two or more not nationally representative studies. Then, we will perform a country-specific random-effects meta-analyses. The heterogeneity will be evaluated using the χ² test on Cochrane’s Q statistic and quantified with H and I² statistics. For countries with one or no empirical studies or where the meta-analysis will result in a wide CI of 0%–100%, we will predict the country’s prevalence by using a Bayesian generalised non-linear multilevel model. The model will have a hierarchical structure in which estimates for each country will be informed by its own data, if available, or by data from other countries in the same WHO region.Ethics and disseminationSince this study will be based on published data, it does not require any ethical approval. Its findings will be published in a scientific peer-reviewed journal. They will also be presented at scientific conferences and to relevant public health sectors.PROSPERO registration numberCRD42019125572.