Haff Disease in Salvador, Brazil, 2016-2021: Attack rate and detection of toxin in fish samples collected during outbreaks and disease surveillance.

Background: From late 2016 to early 2021, cases of Haff disease, a rare cause of rhabdomyolysis, possibly due to poisoning by palytoxin-like compounds in seafood, were detected in Salvador, Brazil. Surveillance was established to detect additional cases aiming at describing the clinical characteristics of the cases, identifying associated factors, estimating disease attack rate, and investigating the presence of biotoxins and trace metals in selected fish specimens obtained from cases. Method: Between December/2016-January/2021, surveillance investigated Haff disease suspected cases, and obtained clinical and fish samples to test. Findings: Of 65 cases investigated during the 2016-2017 outbreak, 43 (66%) had high creatine phosphokinase (CPK) levels. Among those with laboratory-confirmed rhabdomyolysis, 38 (88%) were hospitalized, 11 (26%) required intensive care, and three (7%) dialysis. Ingestion of marine fish 24h before disease onset was reported by 74% of the cases with elevated CPK and by 41% of those without CPK measurement (P=0·02). Attack rate for individuals who ate fish related to the outbreak was 55%. Following this outbreak, surveillance identified 12 suspected cases between 2017-2019, and a second outbreak in 2020-2021, with 16 laboratory-confirmed rhabdomyolysis patients (five required intensive care; one died). No traces of ciguatoxins and metals were detected in fish specimens obtained in 2016, found to be Seriola rivoliana. Some fish samples from 2020 were screened for palytoxin (PlTX)-like compounds and contained detectable levels of molecule fragments characteristics of isobaric PlTX, ovatoxin-a (OVTX-a), OVTX-b and OVTX-d. Interpretation: These findings support the hypothesis that compounds related to PlTX accumulated in marine fish may be the toxic agent causing the disease. Haff disease is a life-threatening condition, requiring clinical suspicion for patients with sudden-onset myalgia following fish ingestion. Suspected cases should be reported to health authorities for investigation.

The changing profile of schistosomiasis in a changing urban landscape.

Since 2007, most of humanity resides in urban areas, a trend which continues worldwide. Diseases usually associated with rural contexts are now emerging or newly recognised in cities. In the neighbourhood of São Bartolomeu in Salvador, Brazil, the prevalence of Schistosoma mansoni infection in 2011 was >20%. Following enrollment and treatment of a portion of the community, ~25% of the area underwent urban renewal. In 2015, we returned to enrol individuals who had previously participated and a cohort that had not taken part in 2011. Thus, infected individuals in one group experienced specific drug treatment plus improved living conditions and the second group only improved living conditions. Between 2011 and 2015 there were no organised treatment programs, but adequate sanitation increased from 69% to 92% coverage, household flooding decreased, and the presence of indoor toilets increased to 99% of households. Ownership of household appliances also increased significantly. The overall prevalence of schistosome infections was 6.2%. In 2015, the cohort first seen in 2011 had a higher prevalence (8.7%) than those first seen in 2015 (4.8%) and showed a few demographic differences. The 2011 cohort was older, more likely born in Salvador, less likely to have lived outside of Salvador, spent a greater percentage of their lifetime in Salvador, but more likely to have travelled. The population structure of the parasites from both cohorts underwent a marked change with similar increased component and infrapopulation differentiation and >10 fold decrease in effective population size. There was a 4-5 year shift in age-specific prevalence in 2015 for all compared with 2011. While praziquantel may have helped reduce prevalence, our evidence suggests that the structural changes and improvements in living conditions had the biggest impact on schistosomiasis in this community.

Spatial distribution of triatomines (Reduviidae: Triatominae) in urban areas of the city of Salvador, Bahia, Brazil.

Environmental changes have a strong influence on the emergence and/or reemergence of infectious diseases. The city of Salvador, Brazil--currently the focus of a housing boom linked to massive deforestation--is an example in point as the destruction of the remaining areas of the Atlantic Forest around the city has led to an increased risk for Chagas disease. Human domiciles have been invaded by the triatomine vectors of Trypansoma cruzi, the flagellate protozoan causing Chagas disease, a problem of particular concern in urban/suburban areas of the city such as the Patamares sector in the north-east, where numbers of both the vector and human cases of the disease have increased lately. To control and prevent further deterioration of the situation, the control programme for Chagas disease, developed by the Bahia Center for Zoonosis Control, has divided the area into a grid of designated surveillance units (ZIs) that are subjected to vector examination. In six out of 98 of these ZIs, 988 triatomes were collected and georeferenced during the 3-year period between 2006 and 2009. The hottest months, that are also generally the driest, showed the highest numbers of triatomines with Triatoma tibiamaculata being the predominant species (98.3%) with Panstrongylus geniculatus present only occasionally (0.6%). Fifty-four percent of all triatomines captured were found inside the homes, and 48.6% out of 479 individuals in the affected ZIs selected for analysis tested positive for T. cruzi infection. The study presented here is a pioneering initiative to map the spatial distribution of triatomines based on geographical information systems with the additional aim of contributing to an expanded knowledge-base about T. cruzi and its vectors in urban areas and raise public health awareness of the risks involved.

Fatores associados à mortalidade neonatal precoce: análise de situação no nível local / Factors Associated with Neonatal Mortality: Situation Analysis at the Local Level

Este estudo analisou os fatores que têm exercido maior influência na manutenção da Mortalidade Infantil Neonatal Precoce, entre os anos de 2000 e 2005, no Distrito Sanitário Liberdade, Salvador, Bahia. Os dados foram coletados das declarações de nascimento e de óbito e validados através de linkage; para a identificação dos fatores associados à mortalidade, foram realizadas análises univariada e bivariada. A taxa de mortalidade neonatal precoce foi de 24,22 óbitos por mil nascidos vivos. A análise bivariada mostrou que características maternas como baixa escolaridade, idade gestacional até 36 semanas, relato de realização de menos de seis consultas de pré-natal, gestação múltipla, parto vaginal, além do baixo peso ao nascer dorecém-nascido estiveram associadas com a mortalidade neonatal precoce, em níveis de significância estatística. A assistência pré-natal e pós-natal deve se organizar no Distrito para prevenir alguns desses fatores e reduzir as iniquidades originadasnas diferenças sociais.

This study examined the factors that have exerted greater influence in the maintenance of Early Neonatal Infant Mortality, between the years of 2000 and 2005, in the Liberdade Health District. Data were collected from birth and death records and validated through linkage; for the identification of factors associated with mortality, univariate and bivariate analysis were taken. The early neonatal mortality rate was 24.22 deaths/1,000 live births. Bivariate analysis showed that the effects of variables – low education of the mother; gestational age up to 36 weeks; less than six prenatal visits; low birth weight; multiple pregnancy and vaginal delivery – were significant to mortality. Prenatal and post-natal care must be organized in order to prevent some of these factors and to reduce inequities due to social differences.