Spatiotemporal dynamics of syphilis in pregnant women and congenital syphilis in the state of São Paulo, Brazil

Spatiotemporal Bayesian modeling of the risk of congenital syphilis in São Paulo, SP, Brazil

The aim of this study is to analyze the spatiotemporal risk of congenital syphilis (CS) in high-prevalence areas in the city of São Paulo, SP, Brazil, and to evaluate its relationship with socioeconomic, demographic, and environmental variables. An ecological study was conducted based on secondary CS data with spatiotemporal components collected from 310 areas between 2010 and 2016. The data were modeled in a Bayesian context using the integrated nested Laplace approximation (INLA) method. Risk maps showed an increasing CS trend over time and highlighted the areas that presented the highest and lowest risk in each year. The model showed that the factors positively associated with a higher risk of CS were the Gini index and the proportion of women aged 18-24 years without education or with incomplete primary education, while the factors negatively associated were the proportion of women of childbearing age and the mean per capita income.

The prevalence of gestational syphilis in Malawi between 2014 and 2022: spatiotemporal modeling of population-level factors

Background

Mother-to-child transmission of syphilis remains high especially in the WHO AFRO region with a prevalence of 1.62%, resulting in a congenital syphilis rate of 1,119 per 100,000 live births. Elimination efforts can be supported by an understanding of the spatial and temporal changes in disease over time, which can identify priority areas for targeted interventions aimed at reducing transmission.

Methods

We collated routine surveillance data from health facilities and covariate data from demographic and health surveys conducted in Malawi between 2014 and 2022. We fitted a Bayesian hierarchical mixed model with spatial and temporally structured random effects to model the district-level monthly counts of maternal syphilis notifications as a function of individual- and district-level predictors. We then generated district-level spatiotemporally explicit risk profiles to estimate the effect of individual- and district-level covariates on maternal syphilis notifications and to identify hotspot areas.

Results

Overall, the national prevalence of maternal syphilis increased from 0.28% (95% CI: 0.27-0.29%) in 2014 to peaking in 2021 at 1.92% (95% CI: 1.89-1.96%). Between 2020 and 2022, there was a decline in prevalence, with the most significant decline seen in Zomba District (1.40, 95% CI: 1.12-1.66%). In regression models, a one percentage point increase in district-level antenatal HIV prevalence was associated with increased maternal syphilis (prevalence ratio [PR]: 1.15, 95% credible interval [CrI]: 1.10-1.21). There was also an increased prevalence of maternal syphilis associated with an increased district-level mean number of sex partners (PR: 1.05, 95% CrI: 0.80-1.37). The number of districts with a high prevalence of maternal syphilis also increased between 2014 and 2022, especially in the southern region, where most had a high probability (approaching 100%) of having high maternal syphilis (defined as relative risk >1 compared to the standard population of women aged 15-49 years) in 2022.

Conclusion

Maternal syphilis prevalence in Malawi shows an increasing upward trend, with an estimated six times relative increase between 2014 and 2022 (0.28% to 1.73%) and strong associations with higher district-level HIV prevalence. Controlling syphilis depends on reaching vulnerable populations at the sub-national level, which may be disproportionately affected. Our findings support the move to integrate the elimination of mother-to-child transmission (EMTCT) of syphilis programs with existing prevention of mother-to-child transmission (PMTCT) of HIV programs.

Gestational and congenital syphilis across the international border in Brazil

BACKGROUND

Brazil lacks data from syphilis in its border areas. We aimed to describe the spatial and temporal distribution of acquired syphilis (AS), in pregnancy (SP) and congenital syphilis (CS) in Brazilian municipalities in the arches border contexts.

METHODS

An ecological, cross-sectional study was conducted from 2010 to 2020. The study was based on the cases of syphilis available in the Notifiable Diseases Information System (SINAN), and on the Primary Health Care Information System. The detection rates of AS and SP, and the incidence of CS were estimated, and the time series was analyzed. Data between the border arches were compared.

RESULTS

In 2020, data showed 7,603 cases of AS (detection rate 64.8/100,000 inhabitants), 3,960 cases of SP (detection rate of 21.6/1,000 live births) and 836 cases of CS (incidence of 4.6/1,000 live births) in the border region. Between 2010 and 2020, the mean annual increase of detection rate of SP was 53.4% in Brazil, 48.0% in the border region, 59.6% in the North Arch, 28.8% in the Central and 67.2% in the South. Annual variation on the incidence of CS for the same period was 31.0% in Brazil 38.4% at the border, in the North and South Arcs 18.3% and 65.7% respectively. The Central Arch showed an increase only between 2010 and 2018 (62.7%). A total of 427 (72.6%) municipalities has primary health care coverage ≥ 95% of the population. In 2019, 538 (91.8%) municipalities reported using rapid tests for syphilis, which decreased to 492 (84%) in 2020. In 2019, 441 (75.3%) municipalities reported administering penicillin, and 422 (72%) in 2020.

CONCLUSION

Our data show syphilis reman problem at the Brazilian border, rates in pregnant are high. It was observed a reduction in the detection rates, SP and the incidence of CS between 2018 and 2020. Syphilis should be included on the agenda of all management levels, aiming at expanding access and quality care.

Spatiotemporal distribution analysis of syphilis in Brazil: Cases of congenital and syphilis in pregnant women from 2001-2017

In Brazil, the notification of congenital (CS) and syphilis in pregnant women (SiP) is compulsory. Notification data provided by the Ministry of Health in combination with the mapping of vulnerable geographic areas is essential to forecasting possible outbreaks and more effectively combating infection through monitoring. We aim to evaluate the spatiotemporal distribution and epidemiological aspects of reported cases of CS and SiP in Brazil. A retrospective ecological study was carried out using secondary surveillance data obtained from the Brazilian National Notifiable Diseases Information System (SINAN) database, considering all reported cases of CS and SiP between 2001 to 2017. Epidemiological characteristics and time trends were analyzed using joinpoint regression models and spatial distribution, considering microregions or states/macroregions as units of analysis. A total of 188,630 (359/100,000 birth lives) CS and 235,895 of SiP (6.3/100,000 inhabitants) were reported during the period studied. In general, the epidemiologic profile of Brazil indicates most reported CS cases occurred in "mixed-race" newborns who were diagnosed within seven days of birth and whose mothers had received prenatal care, but the epidemiologic profile varies by Brazilian macroregion. Regarding SiP, most cases were among women who self-reported 'mixed-race', were aged 20-39 years, had up to eight years of formal education and were diagnosed with primary or latent syphilis. Approximately 549 (98.4%) and 558 (100%) microregions reported at least one case of CS and SiP, respectively. From 2012 to 2016, CS cases increased significantly in almost all Brazilian states, most notably in the South, Southeast, and Central-West macroregions, from 2001-2017 and the relative risk (RR) of SiP increased around 400% (RR: 1,00 to 445,50). Considering the epidemiological scenario of the infection in Brazil, it is necessary to enhance preventive, control and eradication measures.

New trends in congenital syphilis: epidemiology, testing in pregnancy, and management

PURPOSE OF REVIEW

In light of alarming increases in the incidence of congenital syphilis in many middle and higher income countries across the globe, this review summarizes recent changes in the epidemiology of syphilis, highlights recommended changes to testing in pregnancy and provides an update for the management of syphilis infection in pregnancy (SIP) and of the infant born to a mother with SIP.

RECENT FINDINGS

The re-emergence of congenital syphilis is a result of increasing infectious syphilis in women of childbearing age, which is in turn a result of increasing syphilis in the general population particularly in Indigenous and marginalized populations. Potential reasons for the increase include changing sexual practices and increased travel and migration, as well as factors that limit healthcare access, particularly access to antenatal care and limited awareness and education amongst mothers and maternity services. A single antenatal test for syphilis is insufficient; more frequent testing in pregnancy is necessary even for women deemed to be low risk. The management of SIP and of the newborn is complex and guidelines should be readily available with clear recommendations.

SUMMARY

Congenital syphilis is preventable. The current crisis calls for a global and national multipronged, co-ordinated approach involving public health and hospital systems which includes education of individuals and healthcare workers, availability of updated guidelines for prevention and treatment, prioritization of antenatal testing, assurance of accessible and prompt treatment and appropriate assessment and follow-up of infants.