Effects of community-wide vaccination with PCV-7 on pneumococcal nasopharyngeal carriage in the Gambia: a cluster-randomized trial.

Background: Introduction of pneumococcal conjugate vaccines (PCVs) of limited valency is justified in Africa by the high burden of pneumococcal disease. Long-term beneficial effects of PCVs may be countered by serotype replacement. We aimed to determine the impact of PCV-7 vaccination on pneumococcal carriage in rural Gambia.

Seasonality and outbreak of a predominant Streptococcus pneumoniae serotype 1 clone from The Gambia: expansion of ST217 hypervirulent clonal complex in West Africa.

Background: Streptococcus pneumoniae serotype 1 causes > 20% of invasive disease, among all age groups combined, in The Gambia. In contrast, it is rarely detected in carriage studies. This study compares the molecular epidemiology of S.

Nasopharyngeal carriage of Streptococcus pneumoniae in Gambian infants: a longitudinal study.

Background: To prepare for national introduction of a pneumococcal conjugate vaccine of restricted valency, we studied nasopharyngeal carriage of Streptococcus pneumoniae in Gambian infants.

Methods: We studied 236 infants in 21 villages. We collected nasopharyngeal swab samples at birth, twice per month for 6 months, and every second month until 1 year of age.

Re-emergence of Haemophilus influenzae type b (Hib) disease in The Gambia following successful elimination with conjugate Hib vaccine.

Invasive Hib disease, which remains a major cause of childhood mortality and morbidity in most of the developing world, was eliminated in The Gambia by 2002 following the introduction of conjugate Hib vaccine in 1997. Formal disease surveillance was stopped in 2002 but five cases (including three of meningitis) were detected non-systematically between July 2005 and April 2006. This equates to an incidence of 3 per 100,000 annually for meningitis, a likely underestimate.

Nasopharyngeal carriage of Streptococcus pneumoniae in Gambian villagers.

Background: To prepare for the introduction of a pneumococcal conjugate vaccine of restricted valency, we studied the nasopharyngeal carriage of Streptococcus pneumoniae in Gambian villagers.

Methods: A cross-sectional survey was conducted in 21 villages after a census. We recorded demographic characteristics, information on medical history, and data on possible risk factors for carriage from subjects.