Chikungunya seroprevalence in population-based studies: a systematic review and meta-analysis.

BACKGROUND: Seroprevalence studies about chikungunya infection are usually conducted after epidemics to estimate the magnitude of the attack. This study aimed to estimate the seroprevalence of CHIKV by WHO region, considering the periods of introduction of the virus in these regions and its potential to lead to epidemics. METHODS: We systematically reviewed Medline/Pubmed, Embase, Lilacs, Scopus and Web of Science for original articles published up to 2020. Cohort, case-control and cross-sectional studies were eligible for inclusion, based on the results of laboratory diagnosis of previous or previous and recent infection. Those conducted with symptomatic individuals were excluded. RESULTS: 596 articles were identified, 197 full-text were reviewed and 64 were included, resulting in 71 seroprevalences. Most were cross-sectional studies (92%), between 2001 and 2020 (92%), with population of all ages (55%), conducted in Kenya (10.9%), Brazil (9.4%) and French Polynesia (7.8%). The pooled estimates were 24% (95%CI 19-29; I2 = 99.7%; p < 0.00), being 21% (95%CI 13-30; I2 = 99.5%; p < 0.00) for adults, 7% (95%CI 0-23; I2 = 99.7%; p < 0.00) for children and 30% (95%CI 23-38; I2 = 99.7%; p < 0.00) for all ages. The higher seroprevalences were found in African, the Americas and South-East Asian Regions. CONCLUSIONS: The great heterogeneity of seroprevalences points to the persistence of viral circulation. Even where the seroprevalence is high, the population replacement and the absence of vaccines mean that the risk of virus spread and epidemics remains. REGISTRATION: PROSPERO CRD42020166227.

Seroprevalence of Chikungunya virus and living conditions in Feira de Santana, Bahia-Brazil.

BACKGROUND: Chikungunya is an arbovirus, transmitted by Aedes mosquitoes, which emerged in the Americas in 2013 and spread rapidly to almost every country on this continent. In Brazil, where the first cases were detected in 2014, it currently has reached all regions of this country and more than 900,000 cases were reported. The clinical spectrum of chikungunya ranges from an acute self-limiting form to disabling chronic forms. The purpose of this study was to estimate the seroprevalence of chikungunya infection in a large Brazilian city and investigate the association between viral circulation and living condition. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a population-based ecological study in selected Sentinel Areas (SA) through household interviews and a serologic survey in 2016/2017. The sample was of 1,981 individuals randomly selected. The CHIKV seroprevalence was 22.1% (17.1 IgG, 2.3 IgM, and 1.4 IgG and IgM) and varied between SA from 2.0% to 70.5%. The seroprevalence was significantly lower in SA with high living conditions compared to SA with low living condition. There was a positive association between CHIKV seroprevalence and population density (r = 0.2389; p = 0.02033). CONCLUSIONS/SIGNIFICANCE: The seroprevalence in this city was 2.6 times lower than the 57% observed in a study conducted in the epicentre of the CHIKV epidemic of this same urban centre. So, the herd immunity in this general population, after four years of circulation of this agent is relatively low. It indicates that CHIKV transmission may persist in that city, either in endemic form or in the form of a new epidemic, because the vector infestation is persistent. Besides, the significantly lower seroprevalences in SA of higher Living Condition suggest that beyond the surveillance of the disease, vector control and specific actions of basic sanitation, the reduction of the incidence of this infection also depends on the improvement of the general living conditions of the population.

Chikungunya chronic disease: a systematic review and meta-analysis.

Background: Chikungunya is a mosquito-borne disease caused by an arthritogenic alphavirus, with four genotypes: East Central South African (ECSA), West African, ECSA-diverged or Indian Ocean Lineage (IOL) and Asian lineage. Overall, the disease is self-limited; however, in some patients, joint pain and other non-specific symptoms can last for months or years. This systematic review and meta-analysis aims to estimate the proportion of people that self-report chikungunya-related chronic non-specific symptoms. Methods: Medline, EMBASE, Global Health Library and Scopus were searched for articles published before March 2017. Case-control, cohort, cross-sectional, clinical trials studies and outcome-independent case series were eligible. It was estimated that the proportion of patients who did not recover, by virus genotype, and by the time between disease onset and assessment of chronic symptoms. Results: A total of 38 studies were included in the review and 34 in the meta-analysis. Of 6532 chikungunya patients, 3157 did not recover fully after 3 months. The overall no recovery rate associated with chikungunya was 43% (95% CI, 35-52%); Inter-genotype group heterogeneity was observed, the highest prevalence in the ECSA-diverged genotype: 50% (95% CI; 40-60%), followed by the Asian lineage genotype: 36% (95% CI; 20-52%). After 12 months follow-up, the overall no-recovery rate was 21% (95% CI; 19-22%). Conclusion: The evidence suggests that the prevalence of chronic discomfort associated with chikungunya illness varies by virus lineage. The proportion of people that do not fully recovered after chikungunya was high and, therefore, health authorities must prepare to treat patients with symptoms of long-lasting chikungunya adequately addressing the physical, psychological and social needs.

Seroprevalence of Chikungunya Virus after Its Emergence in Brazil.

Chikungunya has had a substantial impact on public health because of the magnitude of its epidemics and its highly debilitating symptoms. We estimated the seroprevalence, proportion of symptomatic cases, and proportion of chronic form of disease after introduction of chikungunya virus (CHIKV) in 2 cities in Brazil. We conducted the population-based study through household interviews and serologic surveys during October-December 2015. In Feira de Santana, we conducted a serologic survey of 385 persons; 57.1% were CHIKV-positive. Among them, 32.7% reported symptoms, and 68.1% contracted chronic chikungunya disease. A similar survey in Riachão do Jacuípe included 446 persons; 45.7% were CHIKV-positive, 41.2% reported symptoms, and 75.0% contracted the chronic form. Our data confirm intense CHIKV transmission during the continuing epidemic. Chronic pain developed in a high proportion of patients. We recommend training health professionals in management of chronic pain, which will improve the quality of life of chikungunya-affected persons.

Social contextual factors contributing to child and adolescent labor: an ecological analysis / Fatores sociocontextuais para o trabalho da criança e do adolescente: uma análise ecológica / Factores sociocontextuales para el trabajo del niño y del adolescente: un análisis ecológico

OBJECTIVE: To examine the relationship between social contextual factors and child and adolescent labor. METHODS: Population-based cohort study carried out with 2,512 families living in 23 subareas of a large urban city in Brazil from 2000 to 2002. A random one-stage cluster sampling was used to select families. Data were obtained through individual household interviews using questionnaires. The annual cumulative incidence of child and adolescent labor was estimated for each district. New child and adolescent labor cases were those who had their first job over the two-year follow-up. The annual cumulative incidence of child and adolescent labor was the response variable and predictors were contextual factors such as lack of social support, social deprivation, unstructured family, perceived violence, poor school quality, poor environment conditions, and poor public services. Pearson's correlation and multiple linear regression were used to assess the associations. RESULTS: There were selected 943 families corresponding to 1,326 non-working children and adolescents aged 8 to 17 years. Lack of social support, social deprivation, perceived violence were all positively and individually associated with the annual cumulative incidence of child and adolescent labor. In the multiple linear regression model, however, only lack of social support and perceived violence in the neighborhood were positively associated to child and adolescent labor. No effect was found for poor school quality, poor environment conditions, poor public services or unstructured family. CONCLUSIONS: Poverty reduction programs can reduce the contextual factors associated with child and adolescent labor. Violence reduction programs and strengthening social support at the community level may contribute to reduce CAL.

OBJETIVO: Analisar a relação entre as variáveis sociocontextuais e o trabalho de crianças e adolescentes. MÉTODOS: Estudo de coorte com 2.512 famílias residentes em 23 áreas urbanas de Salvador, BA, entre 2000 e 2002. A seleção das áreas e a identificação das famílias foram realizadas por amostragem por conglomerados. Entrevistas domiciliares foram realizadas com questionários individuais. A incidência cumulativa anual do trabalho de crianças e adolescentes foi estimada para cada área. Crianças e adolescentes que se tornaram trabalhadores ao longo dos dois anos de seguimento do estudo foram considerados casos novos. A incidência cumulativa anual do trabalho de crianças e adolescentes foi analisada como variável resposta e fatores contextuais foram as preditoras (ausência de apoio social, deprivação social e famílias não-estruturadas, percepção de violência, má qualidade das escolas e dos serviços públicos, e existência de problemas ambientais na vizinhança). Regressão linear múltipla foi utilizada para análise. RESULTADOS: Foram encontradas 943 famílias com 1.326 crianças e adolescentes não trabalhadores de 8 a 17 anos. Ausência de apoio social, deprivação social e percepção de violência na vizinhança associaram-se positivamente ao trabalho de crianças e adolescentes quando analisadas separadamente. Ausência de apoio social e percepção de violência foram positivamente associadas com o desfecho na regressão linear múltipla. Má qualidade da escola e dos serviços públicos urbanos e a existência de problemas ambientais e familiares não apresentaram associação. CONCLUSÕES: Programas que visem à redução da pobreza podem atuar positivamente nos fatores contextuais considerados. Programas de pacificação em áreas violentas, assim como o fortalecimento das redes sociais nas comunidades, podem contribuir para a diminuição do trabalho de crianças e adolescentes.

OBJETIVO: Analizar la relación entre las variables sociocontextuales y el trabajo de niños y adolescentes. MÉTODOS: Estudio de cohorte con 2.512 familias residentes en 23 áreas urbanas de Salvador, Noreste de Brasil, entre 2000 y 2002. La selección de las áreas y la identificación de las familias fueron realizadas por muestreo por conglomerados. Entrevistas domiciliares fueron realizadas con cuestionarios individuales. La incidencia acumulada anual del trabajo de niños y adolescentes fue estimada para cada área. Niños y adolescentes que se tornaron trabajadores a lo largo de dos años de seguimiento del estudio fueron considerados casos nuevos. La incidencia acumulada anual del trabajo de niños y adolescentes fue analizada como variable respuesta y factores contextuales fueron los predictivos (ausencia de apoyo social; privación social y familias no estructuradas, percepción de violencia, mala calidad de las escuelas, de los servicios públicos, y existencia de problemas ambientales en la vecindad). Regresión linear múltiple fue utilizada para análisis. RESULTADOS: Se encontraron 943 familias con 1.326 niños y adolescentes no trabajadores de 8 a 17 años. Ausencia de apoyo social, privación social y percepción de violencia en la vecindad se asociaron positivamente al trabajo de niños y adolescentes al analizarlos separadamente. Ausencia de apoyo social y percepción de violencia fueron positivamente asociados con el resultado en la regresión linear múltiple. Mala calidad de la escuela y de los servicios públicos urbanos y la existencia de problemas ambientales y familiares no presentaron asociación. CONCLUSIONES: Programas que busquen reducir la pobreza pueden actuar positivamente en los factores contextuales considerados. Programas de pacificación en áreas violentas, así como el fortalecimiento de las redes sociales en las comunidades, pueden contribuir para la disminución del trabajo de niños y adolescentes.

Social contextual factors contributing to child and adolescent labor: an ecological analysis.

OBJECTIVE: To examine the relationship between social contextual factors and child and adolescent labor. METHODS: Population-based cohort study carried out with 2,512 families living in 23 subareas of a large urban city in Brazil from 2000 to 2002. A random one-stage cluster sampling was used to select families. Data were obtained through individual household interviews using questionnaires. The annual cumulative incidence of child and adolescent labor was estimated for each district. New child and adolescent labor cases were those who had their first job over the two-year follow-up. The annual cumulative incidence of child and adolescent labor was the response variable and predictors were contextual factors such as lack of social support, social deprivation, unstructured family, perceived violence, poor school quality, poor environment conditions, and poor public services. Pearson's correlation and multiple linear regression were used to assess the associations. RESULTS: There were selected 943 families corresponding to 1,326 non-working children and adolescents aged 8 to 17 years. Lack of social support, social deprivation, perceived violence were all positively and individually associated with the annual cumulative incidence of child and adolescent labor. In the multiple linear regression model, however, only lack of social support and perceived violence in the neighborhood were positively associated to child and adolescent labor. No effect was found for poor school quality, poor environment conditions, poor public services or unstructured family. CONCLUSIONS: Poverty reduction programs can reduce the contextual factors associated with child and adolescent labor. Violence reduction programs and strengthening social support at the community level may contribute to reduce CAL.

[Non-fatal work-related accidents in adolescents]. / Acidentes de trabalho não fatais em adolescentes.

This community-based survey estimates the annual incidence of non-fatal work-related injuries in adolescents and describes their characteristics. Using a random area sampling design, 2,513 households were selected from the city of Salvador, capital of Bahia State, Northeast Brazil. The study population included 361 young people 10 to 20 years of age who answered individual questionnaires on socio-demographic, occupational, and health data. Annual incidence of non-fatal work-related injuries was 6.4%. Among females, most injuries were mild and were related to household chores; some 38.5% required medical care, and 36.4% caused permanent non-disabling lesions. Among males, work-related injuries took place mainly in public byways, and the majority (60.0%) were treated in emergency-care facilities. These results show that work-related injuries need to be considered in adolescent protection policies.

Acidentes de trabalho näo fatais em adolescentes / Non-fatal work-related injuries in adolescents

Neste estudo estima-se a incidência anual e descrevem-se as características dos acidentes de trabalho näo fatais em adolescentes com dados de um inquérito conduzido na cidade de Salvador, Bahia, Brasil. Utilizou-se amostra aleatória de superfície para selecionar 2.513 famílias, cujos membros foram entrevistados individualmente. A populaçäo do estudo compunha-se de 361 jovens entre 10 e 20 anos. A incidência anual de acidentes de trabalho näo fatais foi 6,4 por cento. Entre as mulheres, a maioria dos acidentes ocorreu no ambiente de trabalho doméstico e tinha pequena gravidade, mas 38,5 por cento dos casos necessitaram de assistência médica, e 36,4 por cento deixaram seqüelas permanentes näo incapacitantes. Entre os rapazes, os acidentes típicos na via pública predominaram, e a maioria (60,0 por cento) foi atendida em serviço de emergência. Esses resultados evidenciam que acidentes de trabalho entre jovens estäo a merecer atençäo nas políticas sociais no país