Lessons about the reliability of congenital syphilis and vertical HIV transmission data learned from case reviews in Uruguay: a cross-sectional study

BACKGROUND: In Uruguay it is mandatory to review all cases of positive HIV or reactive syphilis tests in pregnancy and peripartum. We compared the rates of mother-to-child transmission of syphilis and HIV detected by case reviews to those obtained from the usual surveillance system and described the characteristic of vertical transmission cases. METHODS: This is a cross-sectional study performed with secondary data obtained from official government sources, for all the country cases of maternal to child transmission of HIV and syphilis from 2012 to 2017, with descriptive analyses. For congenital syphilis analyses, the following pregnancy characteristics were investigated: number of antenatal checks, gestational age at pregnancy diagnosis, gestational age at syphilis test and diagnosis, adequate treatment, and treatment of partners. Sociodemographic characteristics included type of health care (public/private), maternal age, distribution of ethnic minorities, maximum educational attainment, presence of partner, planned pregnancy, drug and alcohol use, domestic violence, previous maternal diagnosis of syphilis, and previous children with congenital syphilis. RESULTS: Coverage of syphilis case reviews increased from 82% in 2014 to 97.4% in 2017. For HIV, this coverage reached 100% in 2017 and elimination of mother to child transmission was achieved. A marked decline in congenital syphilis was noted in the public health care sector, especially in the capital Montevideo, whereas the private sector has remained below the elimination target. Variables related with congenital syphilis in exposed children were late pregnancy diagnosis, < 5 antenatal checks, delayed diagnosis of gestational syphilis, lower rate of correct treatment for gestational syphilis, untreated partner, low maternal schooling, unplanned pregnancy, history of syphilis, and having other children with syphilis. CONCLUSION: The use of case reviews provided knowledge regarding the accurate number of mother-to-child transmission cases and the evolution of elimination of mother to child transmission in the country. The results suggest that rates must be adjusted, providing an opportunity to improve the reliability of surveillance data, and point the need to address specific gaps in order to improve the quality of care during pregnancy, delivery, and the neonatal period.