Nasopharyngeal Pneumococcal Carriage in Nigeria: a two-site, population-based survey

Abstract

Changes in nasopharyngeal (NP) carriage of vaccine-type (VT) Streptococcus pneumoniae can be used to assess the effectiveness of a pneumococcal conjugate vaccine (PCV10). We conducted a baseline carriage survey in rural (Kumbotso, Kano) and urban (Pakoto, Ogun) Nigeria. In this cross-sectional study, we obtained data on demography, clinical history, risk factors, and took NP swabs for pneumococcal culture. We calculated crude and age-standardised carriage prevalence and used log-binomial regression to assess risk factors for carriage. Among children aged <5 years, 92% (95% CI: 88–95%) and 78% (73–82%), respectively, carried any pneumococcus and 48% and 50%, respectively, carried PCV10 serotypes. In Kumbotso, carriage prevalence was >40% across all ages. The age-standardized prevalence of pneumococcal carriage was 66% in Kumbotso and 40% in Pakoto. The most commonly identified serotypes were 19 F, 6 A and 23 F. Risk factors for carriage were young age, recent rhinorrhoea, cohabitation with ≥2 children aged <5 years, and sharing a bed with ≥2 persons. Pneumococcal carriage prevalence is high in this Nigerian population. Persisting prevalence of VT-carriage in older children and adults suggests that PCV10 introduction in children will not eliminate transmission of vaccine serotypes rapidly. High vaccine coverage will therefore be required to ensure full protection of children.

Pneumococcal Carriage in Burkina Faso After 13-Valent Pneumococcal Conjugate Vaccine Introduction: Results From 2 Cross-sectional Population-Based Surveys

“…Consistent with previous pneumococcal colonization studies [ 9 , 41 ], carriage of serotype 1 in our study was very rare, contrasting with its frequent implication in pneumococcal meningitis. Consequently, it may be that unique schedules or approaches to immunization, such as a booster during later childhood or direct vaccination of a large segment of the population as was done for persons aged 1–29 years with serogroup A meningococcal conjugate vaccine [ 42 , 43 ], are required to address serotype 1 in the meningitis belt.…”

“…A second limitation was that all 3 studies were limited to sampling conducted in the urban setting of Bobo-Dioulasso, the second-largest city of Burkina Faso; thus, findings are not necessarily generalizable to the entire country, given that carriage often differs by setting, especially between urban and rural areas [ 41 ]. Third, the cross-sectional design added to the limited number of time points studied cannot fully account for temporal trends.…”

Pneumococcal carriage among children under five in Accra, Ghana, five years after the introduction of pneumococcal conjugate vaccine

“…Of the four non-PCV serotypes, only 11A is included in the PPV-23, while the three other serotypes are not part of PPV-23 [13]. Although carriage studies cannot provide information on which new replacement serotypes might be the future dominant cause of pneumococcal disease, it can indicate whether the vaccine coverage might continue to be low with regard to detected serotypes [28], and a new PCV vaccine may have limited impact on the pneumococcal epidemiology in Ghana.…”

Direct and indirect effect of 10 valent pneumococcal vaccine on nasopharyngeal carriage in children under 2 years of age in Matiari, Pakistan

“…Loughlin et al reported having respiratory symptoms at time of enrollment, especially having a runny nose or earache as strong predictors of colonization [20] . Mackenzie et al showed over 3-fold higher rates of VT carriage in children with runny nose in the previous week [36] and Adetifa et al showed nearly 50% increased rates of VT carriage in children with recent runny nose [37] . Finn et al reported associations between both rhinitis symptoms and respiratory viral infections and pneumococcal carriage in the nasopharynx.…”