Epidemiological indicators of Chagas disease in the metropolitan region of Salvador, Bahia, Brazil.

BACKGROUND: Chagas disease (CD) is caused by Trypanosoma cruzi and transmitted by triatomines. Historical information from the 20th century demonstrates T. cruzi records in the metropolitan region of Salvador (MRS), the third largest urban agglomeration in the Brazilian Northeast and the eighth largest in Brazil, an area with intense migratory activity from CD-endemic regions. Therefore, this study aimed to evaluate CD indicators (prevalence and mortality) in the MRS. METHODS: A mixed ecological and descriptive study was conducted using secondary data. We analyzed data from 2008 to 2015: deaths due to CD, self-reported cases of CD, and blood donors that were non-negative for T. cruzi infection. RESULTS: São Francisco do Conde was one of the municipalities with the highest mortality rates due to CD. The seroprevalence rates varied by year and municipality; those with the highest values were 2008: Vera Cruz, 2009: Mata de São João, 2010: Dias D'Ávila, 2011 and 2015: São Francisco do Conde, 2012: São Sebastião do Passé, and 2013 and 2014: Pojuca. Spatial correlations between the municipalities were not detected. CONCLUSIONS: We conclude that CD is present in the MRS. The indicators analyzed in the MRS are below-state-level data. Given the importance of indicator analysis for the surveillance and control of CD at the state and national levels, it is important to strengthen the surveillance program at the municipal level, including the regions classified as low risk for T. cruzi vector transmission.

Epidemiological indicators of Chagas disease in the metropolitan region of Salvador, Bahia, Brazil

ABSTRACT Background: Chagas disease (CD) is caused by Trypanosoma cruzi and transmitted by triatomines. Historical information from the 20th century demonstrates T. cruzi records in the metropolitan region of Salvador (MRS), the third largest urban agglomeration in the Brazilian Northeast and the eighth largest in Brazil, an area with intense migratory activity from CD-endemic regions. Therefore, this study aimed to evaluate CD indicators (prevalence and mortality) in the MRS. Methods: A mixed ecological and descriptive study was conducted using secondary data. We analyzed data from 2008 to 2015: deaths due to CD, self-reported cases of CD, and blood donors that were non-negative for T. cruzi infection. Results: São Francisco do Conde was one of the municipalities with the highest mortality rates due to CD. The seroprevalence rates varied by year and municipality; those with the highest values were 2008: Vera Cruz, 2009: Mata de São João, 2010: Dias D'Ávila, 2011 and 2015: São Francisco do Conde, 2012: São Sebastião do Passé, and 2013 and 2014: Pojuca. Spatial correlations between the municipalities were not detected. Conclusions: We conclude that CD is present in the MRS. The indicators analyzed in the MRS are below-state-level data. Given the importance of indicator analysis for the surveillance and control of CD at the state and national levels, it is important to strengthen the surveillance program at the municipal level, including the regions classified as low risk for T. cruzi vector transmission.

COVID-19 outbreaks among crew members in non-cruise vessels anchoring in Salvador, Brazil, 2021.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has affected the maritime sector due to virus transmission onboard and traffic restrictions. However, reports of SARS-CoV-2 transmission on board have been mostly restricted to those occurring on cruise ships. OBJECTIVES: To report COVID-19 outbreaks in eight non-cruise vessels and discuss measures to prevent and control the onboard transmission of SARS-CoV-2. METHODS: We investigated outbreaks of COVID-19 on vessels anchoring in Baía de Todos-os-Santos, Salvador, Brazil, between February and November 2021. FINDINGS: Most vessels were cargo ships that had docked several times before anchoring in Salvador (five had docked in ≥ 9 ports). The crew ranged from 22 to 63 members. The infection attack rate on each vessel ranged from 9.7 to 88.9%. The risk of symptomatic infection largely varied among the crew of each vessel (0 to 91.6%). Overall, the risk of developing COVID-19 signs and symptoms was lower among crew members vaccinated (age-adjusted risk ratio: 0.19; 95% confidence interval 0.06-0.65). SARS-CoV-2 variants not previously identified in Salvador were detected (C.14, B.1.617.2 and B.1.351). MAIN CONCLUSIONS: Despite maritime guidelines to avert COVID-19 on board, outbreaks have happened. The multiple stopovers of non-cruise vessels during their routes may contribute to the spread of SARS-CoV-2 variants worldwide. Reducing the onboard transmission of SARS-CoV-2 depends on joint efforts by the crew and local health authorities and, equally important, achieving high vaccination coverage to prevent infections and illness.

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.

COVID-19 outbreaks among crew members in non-cruise vessels anchoring in Salvador, Brazil, 2021

BACKGROUND The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has affected the maritime sector due to virus transmission onboard and traffic restrictions. However, reports of SARS-CoV-2 transmission on board have been mostly restricted to those occurring on cruise ships. OBJECTIVES To report COVID-19 outbreaks in eight non-cruise vessels and discuss measures to prevent and control the onboard transmission of SARS-CoV-2. METHODS We investigated outbreaks of COVID-19 on vessels anchoring in Baía de Todos-os-Santos, Salvador, Brazil, between February and November 2021. FINDINGS Most vessels were cargo ships that had docked several times before anchoring in Salvador (five had docked in ≥ 9 ports). The crew ranged from 22 to 63 members. The infection attack rate on each vessel ranged from 9.7 to 88.9%. The risk of symptomatic infection largely varied among the crew of each vessel (0 to 91.6%). Overall, the risk of developing COVID-19 signs and symptoms was lower among crew members vaccinated (age-adjusted risk ratio: 0.19; 95% confidence interval 0.06-0.65). SARS-CoV-2 variants not previously identified in Salvador were detected (C.14, B.1.617.2 and B.1.351). MAIN CONCLUSIONS Despite maritime guidelines to avert COVID-19 on board, outbreaks have happened. The multiple stopovers of non-cruise vessels during their routes may contribute to the spread of SARS-CoV-2 variants worldwide. Reducing the onboard transmission of SARS-CoV-2 depends on joint efforts by the crew and local health authorities and, equally important, achieving high vaccination coverage to prevent infections and illness.

Clinical and epidemiological features of pertussis in Salvador, Brazil, 2011-2016.

Pertussis, a severe respiratory infection caused by Bordetella pertussis, is distributed globally. Vaccination has been crucial to annual reductions in the number of cases. However, disease reemergence has occurred over the last decade in several countries, including Brazil. Here we describe the clinical and epidemiological aspects of suspected pertussis cases in Salvador, Brazil, and evaluate factors associated with case confirmation. This descriptive and retrospective study was conducted in the five hospitals in Salvador that reported the highest number of pertussis cases between 2011-2016. Demographic and clinical data were recorded for each patient. Bivariate analysis was performed to evaluate differences between groups (confirmed vs. unconfirmed cases) using Pearson's Chi-square test or Fisher's exact test. Results: Of 529 suspected pertussis cases, 29.7% (157/529) were confirmed by clinical, clinical-epidemiological or laboratory criteria, with clinical criteria most frequently applied (63.7%; 100/157). Unvaccinated individuals (43.3%; 68/157) were the most affected, followed by age groups 2-3 months (37.6%; 59/157) and <2 months (31.2%; 49/157). Overall, ≤50% of the confirmed cases presented a complete vaccination schedule. All investigated cases presented cough in association with one or more symptoms, especially paroxysmal cough (66.9%; 105/529) (p = 0.001) or cyanosis (66.2%; 104/529) (p<0.001). Our results indicate that pertussis occurred mainly in infants and unvaccinated individuals in Salvador, Brazil. The predominance of clinical criteria used to confirm suspected cases highlights the need for improvement in the laboratory tools used to perform rapid diagnosis. Fluctuations in infection prevalence demonstrate the importance of vaccination strategies in improving the control and prevention of pertussis.

Brain abnormalities on neuroimaging in Children with Congenital Zika Syndrome in Salvador, Brazil, and its possible implications on neuropsychological development.

OBJECTIVE: To characterize the spectrum of brain damages presented in children affected by Congenital Zika Syndrome (CZS), verify the existence of a co-occurrence pattern of these damages and discuss possible implications for the neuropsychological development. METHODS: Descriptive, quantitative, individualized, and cross-sectional study using secondary sources. We selected 136 children with CZS from the database of the Center of Strategic Information on Health Vigilance of the Municipal Office of Salvador, Brazil. We conducted descriptive and multiple correspondence analyses. RESULTS: Among the set of analyzed variables, microcephaly (51.5%), ventriculomegaly (57.4%), and brain calcifications (77.2%) were identified as the most frequent. The multiple correspondence analysis showed that the combination of these three variables (32.4%) was what better represented the spectrum of brain damages in the Central Nervous System. INTERPRETATION: Damage in the sensory-motor, cognitive and language development, as well as neurodevelopmental disorders, are described in the literature as impairments associated, either isolated or combined, with these damages, and it is worth highlighting that, in combined brain damages, impairments tend to be more severe. The findings of this study may contribute to understanding the repercussions of CZS on the neuropsychological development of children affected by the epidemic.

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.

Dissemination of the ST-103 clonal complex serogroup C meningococci in Salvador, Brazil.

Invasive meningococcal disease (IMD) is a major public health problem worldwide. An epidemic of serogroup C (NmC) IMD occurred in 2010 in the city of Salvador. In this study, we describe the antigenic and genetic characterization of meningococcal isolates collected from meningitis cases in Salvador from 2001 to 2012. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were performed for the analysis of IMD isolates. A total of 733 cases were identified, and the serogroup was determined for 391 (53.0%) of these. Most cases were caused by NmC (53%) or B (47%). The most prevalent strains were B:4,7:P1.19,15 (32.9%; 129/391) and C:23:P1.14-6 (28.6%; 112/391). Based on PFGE/MLST analysis, 71.3% (77/108 PFGE-tested isolates) clustered as two clones of sequence type ST-3779 and ST-3780, both belonging to the ST-103 clonal complex. ST-3779 has been detected in Salvador since 1996 and together with ST-3780 became predominant after 2005. There was a predominance of C:23:P1.14-6, ST-3779/3780 in Salvador during the period of 2007-2012, establishing a major clonal lineage, which remained in the community for a long time; this has serious implications for public health, particularly in terms of prevention and control strategies of IMD.

Effectiveness of meningococcal C conjugate vaccine in Salvador, Brazil: a case-control study.

BACKGROUND: During a citywide epidemic of serogroup C meningococcal disease in Salvador in 2010, Brazil, the state government initiated mass vaccination targeting two age groups with high attack rates: individuals aged <5 years and 10-24 years. More than 600,000 doses of meningococcal serogroup C conjugate vaccines were administered. We performed a case-control study to evaluate vaccine uptake, document vaccine effectiveness and identify reasons for non-vaccination. METHODS AND FINDINGS: Population-based surveillance identified patients with laboratory-confirmed invasive meningococcal C (MenC) disease during 2010. Information on MenC vaccination was obtained from case patients and age-matched individuals from the same neighborhoods. MenC vaccine effectiveness was estimated based on the exact odds ratios obtained by conditional logistic regression analysis. Of 51 laboratory-confirmed cases of serogroup C meningococcal disease among patients <5 and 10-24 years of age 50 were included in the study and matched with 240 controls. Overall case-fatality was 25%. MenC vaccine coverage among controls increased from 7.1% to 70.2% after initiation of the vaccination campaign. None of the 50 case patients but 70 (29.2%) of the 240 control individuals, including 59 (70.2%) of 84 matched with cases from the period after MenC vaccination, had received at least one MenC vaccine dose. Overall effectiveness of MenC was 98% with a lower 95% exact confidence limit of 89%. CONCLUSIONS: MenC vaccines administered during the meningococcal epidemic were highly effective, suggesting that rapid vaccine uptake through campaigns contributed to control of meningococcal disease.

Efetividade da vacina meningocócica C conjugada e caracterização da neisseria miningitidis em Salvador Bahia / Effectiveness of meningococcal C conjugate vaccine and characterization of Neisseria meningitidis in Salvador, Bahia

Introdução: A doença meningocócica (DM) é causada pela bactéria Neisseria meningitidis, sendo um importante problema de saúde pública no mundo. Atualmente, a Neisseria meningitidis sorogrupo C (NmC) tem sido o principal agente da DM na Bahia. Em 2010 ocorreu uma epidemia de DM pela NmC em Salvador, e a fim de contê-la, a Secretaria Estadual de Saúde introduziu em fevereiro de 2010, a vacina meningocócica C conjugada (MenC) para crianças menores de cinco anos, incluindo campanhas de vacinação para indivíduos de 10 a 24 anos. Objetivos: Descrever a incidência da DM, avaliar a efetividade da vacina MenC e caracterizar os fenótipos e genótipos das cepas circulantes da N. meningitidis nos períodos pré e pós-introdução da vacina MenC. Metodologia: Realizamos um estudo descritivo-analítico, comparando incidências nas coortes de vacinados e não vacinados nos períodos pré e pós-introdução da vacina MenC. Analisamos a efetividade da vacina MenC utilizando o método “screening” e um estudo tipo caso-controle. A efetividade da vacina MenC foi baseada no odds-ratio (IC 95%; pvalor <0,05). Para caracterização molecular da NmC, utilizamos a técnica de Eletroforese em Campo Pulsátil (PFGE) e da Tipagem de Sequências Multilocus (MLST)...

Introduction: Meningococcal disease (MD) is caused by bacterium Neisseria meningitidis and is a major public health problem worldwide. Currently the Neisseria meningitidis serogroup C (NmC) has been the main cause of MD in Bahia, Brazil. In order to contain the 2010 epidemic of MD caused by NmC that occurred in the city of Salvador, the State Department of Health introduced in February 2010 the meningococcal C conjugate vaccine (MenC) to <5 year-old children, including vaccination campaigns for individuals from 10-24 years. Objectives: Describe trends in incidence of MD, estimate the effectiveness of MenC vaccine, and characterize the phenotypes and genotypes of the circulating strains of N. meningitidis in the pre and post-introduction of the MenC vaccine. Methods: A descriptive analytical study was realized comparing incidences in cohorts vaccinated and unvaccinated pre and post introduction of the MenC vaccine. We analyze the effectiveness of MenC vaccine using the screening method and a case-control study. The effectiveness of MenC vaccine was based on the odds-ratio (CI 95%). We performed molecular analyses by pulsed field gel electrophoresis (PFGE) and by multi-locus sequencing typing (MLST)...