Meningococcal Carriage among Adolescents after Mass Meningococcal C Conjugate Vaccination Campaigns in Salvador, Brazil

Abstract

Neisseria meningitidis is a commensal bacterium of the human nasopharynx. In rare cases, it penetrates the mucosa, entering the blood stream and causing various forms of disease. Meningococcal conjugate vaccines can prevent invasive disease not only by direct effect in vaccinated individuals but also by herd protection, preventing acquisition of carriage, which interrupts transmission and leads to protection of unvaccinated persons. In 2010 in Salvador, Brazil, an outbreak of group C meningococcal disease led to a mass meningococcal serogroup C conjugate vaccination drive, targeting those <5 and 10–24 years of age. The present study aimed to estimate the prevalence of and identify factors associated with N. meningitidis carriage among adolescents from Salvador, Brazil, in the post-vaccination period. In spring 2014, we performed a cross-sectional study involving 1,200 public school students aged 11–19 years old. Oropharyngeal swabs were collected to identify N. meningitidis. Of the 59 colonized participants, 36 (61.0%) carried non-groupable N. meningitidis, while genogroup B (11.9%), Y (8.5%), E (6.8%), Z (5.1%), C (3.4%), and W (3.4%) were also detected. The overall prevalence of N. meningitidis carriage was 4.9% (95% confidence interval [CI], 3.6–6.1%); the prevalence of N. meningitidis genogroup C was 0.17% (95% CI, 0.0–0.40%). There was no difference by age. Factors associated with carriage were having only one, shared, bedroom in the household (PR, 2.02; 95% CI, 0.99–4.12, p = 0.05); the mother being the only smoker in the home (PR, 2.48; 95% CI, 1.16–5.29; p = 0.01); and going to pubs/parties more than 5 times/month (PR, 2.61; 95% CI, 1.38–4.92; p = 0.02). Our findings show that the N. meningitidis carriage rate in adolescents from Salvador, Bahia, is low and is potentially influenced by the low prevalence of N. meningitidis genogroup C. However, continued surveillance is important to identify changes in the dynamics of N. meningitidis, including the emergence of diseases due to a non-C serogroup.

Carriage of Neisseria Meningitidis in Low and Middle Income Countries of the Americas and Asia: A Review of the Literature

“…North American and European studies have found an association between smoking and carriage [14,15], and a study from sub-Saharan Africa found an association between both passive and active smoking and carriage, the latter of which was statistically significant [12]. In comparison, our review found a significant association of carriage with passive smoking in only three studies from the Americas [33,35,42] and no significant association with active smoking.…”

“…1). Of these, 14 met the inclusion criteria and were included in the review, including seven studies from Brazil [33][34][35][36][37][38][39], three from Chile [40][41][42], and one each from Colombia [43], Cuba [32], Mexico [44], and Paraguay [45] (Fig. 2; Table 2).…”

“…The most recent data were from two separate publications of the same sample. From September to December 2014, Nunes and colleagues assessed the meningococcal carriage of 1200 students aged 11-19 years enrolled in 134 municipal or state public schools in Salvador [33]. Participants were selected by a two-stage probabilistic method in which 155 schools were initially randomly selected and weighted according to the probability of school selection by the proportion of students in each of the schools in Salvador.…”

A critical analysis of serogroup B meningococcal disease burden in Brazil (2001–2015): implications for public health decisions

“…30 Carriage studies performed in Brazil after the implementation of the MCC vaccination programme consistently found genogroup B strains as the most frequent groupable isolate emphasizing the need for continuous MD surveillance to detect changes in the incidence of MenB disease in the future. 31,32 Despite the declining incidence rates of Men B disease, currently at historical low levels, our epidemiological data showed that the highest burden of MenB disease is consistently observed in children younger than 5 years, particularly young infants. Incorporation of MenB recombinant protein vaccines into the national immunization programmes targeting infants, the age group with the highest incidence rates of IMD, in the region will depend on continuous surveillance to provide quality information to guide future vaccination strategies.…”

Neisseria meningitidis carriage and risk factors among teenagers in Suizhou city in China

“…Up to now, many studies all over the world have investigated the asymptomatic carriage of N. meningitidis. Currently, the carriage rate in healthy populations is highly variable, and ranges from 0% to 30% worldwide [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. With regard to carriage according to age, teenagers have been found to have the highest carriage rate [5,7,10].…”