Carriage prevalence of Neisseria meningitidis in the Americas in the 21st century: a systematic review

Abstract Neisseria meningitidis is a bacterium that colonizes the human nasopharynx and is transmitted by respiratory droplets from asymptomatic or symptomatic carriers. Occasionally, the pathogen invades the mucosa and enters the bloodstream, causing invasive meningococcal disease, a life-threatening infection. While meningococcal colonization is the first step in the development of invasive disease, the risk factors that predict progression from asymptomatic to symptomatic status are not well-known. The present report aimed to describe the prevalence of N. meningitidis carriers throughout the Americas, emphasizing the risk factors associated with carrier status, as well as the most prevalent serogroups in each studied population. We conducted a systematic review by searching for original studies in the MEDLINE/PubMed, Embase, LILACS and SciELO databases, published between 2001 and 2018. Exclusion criteria were articles published in a review format, case studies, case control studies, investigations involving animal models, and techniques or publications that did not address the prevalence of asymptomatic carriers in an American country. A total of 784 articles were identified, of which 23 were selected. The results indicate that the highest prevalence rates are concentrated in Cuba (31.9%), the United States (24%), and Brazil (21.5%), with increased prevalence found among adolescents and young adults, specifically university students and males. The present systematic review was designed to support epidemiological surveillance and prevention measures to aid in the formulation of strategies designed to control the transmission of meningococci in a variety of populations and countries throughout the Americas.

Community violence and childhood asthma prevalence in peripheral neighborhoods in Salvador, Bahia State, Brazil / Violência comunitária e prevalência de asma em crianças na periferia de Salvador, Bahia, Brasil

This study aimed to identify degrees of exposure to community violence reported by parents and guardians of children from four to 12 years of age and the association with childhood asthma symptoms. A cross-sectional study was conducted with 1,232 parents/guardians in 24 peripheral neighborhoods in Salvador, the capital of Bahia State, Brazil. The authors investigated asthma symptoms in children and acts of violence in the community. More than 75 percent of parents/guardians had been exposed to community violence in the previous year, with 20 percent reporting high levels of exposure. Children that were more exposed to violence showed higher asthma prevalence (28.4 percent) as compared to non-exposed children (16.4 percent). Children exposed to maximum levels of violence were nearly twice as likely to present asthma symptoms (adjusted OR = 1.94; 95 percentCI: 1.12-3.36). The study highlighted the relevance of community violence as a risk factor for asthma and the need for further research to elucidate methodological issues.

O objetivo deste artigo foi identificar o grau de violência comunitária relatado por cuidadores de crianças entre quatro e 12 anos, além da influência dessa exposição na ocorrência de sintomas de asma nas crianças. Realizou-se um estudo transversal com 1.232 cuidadores residentes na cidade de Salvador, Bahia, Brasil. Investigaram-se sintomas de asma nas crianças e atos violentos na comunidade. Aproximadamente 75 por cento dos cuidadores foram vítimas de violência comunitária no último ano, com 20 por cento convivendo com graus elevados deste fenômeno. Encontrou-se prevalência de 28,4 por cento de sintomas asmáticos entre crianças expostas ao grau máximo de violência, e 16,4 por cento entre as não expostas. Encontrou-se associação estatisticamente significante entre exposição ao nível máximo de violência e ocorrência de sintomas asmáticos (OR ajustada = 1,94; IC95 por cento: 1,12-3,36). Nossos achados sugerem a importância da violência comunitária como um dos fatores de risco associados com asma, sendo fundamental o desenvolvimento de novas pesquisas para esclarecer as limitações do presente estudo.