Bacterial shedding and serologic responses following an outbreak of Salmonella Typhi in an endemic cohort

Typhoid Fever and Non-typhoidal Salmonella Outbreaks: A Portrait of Regional Socioeconomic Inequalities in Brazil

Typhoid fever occurs in an endemic form in Brazil and is a serious public health problem in some regions. In this scenario, further research is urgently needed to identify the associations between socioeconomic factors and typhoid fever, contributing to guiding policy decisions in the country. We aimed to investigate the influence of socioeconomic disparities on the prevalence of typhoid fever and non-typhoidal Salmonella (NTS) in Brazil. A search for data from 2010 to 2019 was carried out with the national health and human development agencies. As milk and derivatives are the fourth food incriminated in food outbreaks in Brazil, analyses for detecting Salmonella spp. in commercial dairy products allowed us to assess whether the outbreaks associated with these foods are due to inadequacies in sanitary control in dairy establishments or whether they are mainly home-based outbreaks. Predictive models validated by the bootstrapping method demonstrate an association of NTS prevalence reduction with improvements in the Sanitation Service Index (Rv ≥  -8 0.686; p ≤ 0.01) and Municipal Human Development Index - MHDI - (Rv =  -0.789; p ≤ 0.02). In the North, typhoid fever prevalence had seasonal variability with the rainfall, while sanitation services (Rv ≥-0.684; p ≤ 0.04) and MHDI (Rv ≥-0.949; p ≤ 0.003) directly influenced Northeast and South Brazil. Thus, the unequal distribution of investments in the sanitation sector contributed to disparities in typhoid fever prevalence among Brazilian regions. The absence of Salmonella spp. in commercial samples ratified the collected data that the outbreaks of Salmonella spp. in the Brazilian population occur mainly at residences. These findings show that implementing public health education and increasing investments in sanitation in regions with poor service can control outbreaks of Salmonella spp. in Brazilian endemic areas.