Background Kenya introduced 10-valent pneumococcal conjugate vaccine (PCV10) among children <1 year in 2011 with catch-up vaccination among children 1–4 years in some areas. We assessed changes in pneumococcal carriage and antibiotic susceptibility patterns in children <5 years and adults. Methods During 2009–2013, we performed annual cross-sectional pneumococcal carriage surveys in 2 sites: Kibera (children <5 years) and Lwak (children <5 years, adults). Only Lwak had catch-up vaccination. Nasopharyngeal and oropharyngeal (adults only) swabs underwent culture for pneumococci; isolates were serotyped. Antibiotic susceptibility testing was performed on isolates from 2009 and 2013; penicillin nonsusceptible pneumococci (PNSP) was defined as penicillin-intermediate or -resistant. Changes in pneumococcal carriage by age (<1 year, 1–4 years, adults), site, and human immunodeficiency virus (HIV) status (adults only) were calculated using modified Poisson regression, with 2009–2010 as baseline. Results We enrolled 2962 children (2073 in Kibera, 889 in Lwak) and 2590 adults (2028 HIV+, 562 HIV−). In 2013, PCV10-type carriage was 10.3% (Lwak) to 14.6% (Kibera) in children <1 year and 13.8% (Lwak) to 18.7% (Kibera) in children 1–4 years. This represents reductions of 60% and 63% among children <1 year and 52% and 60% among children 1–4 years in Kibera and Lwak, respectively. In adults, PCV10-type carriage decreased from 12.9% to 2.8% (HIV+) and from 11.8% to 0.7% (HIV−). Approximately 80% of isolates were PNSP, both in 2009 and 2013. Conclusions PCV10-type carriage declined in children <5 years and adults post–PCV10 introduction. However, PCV10-type and PNSP carriage persisted in children regardless of catch-up vaccination.

Background: Data on pneumococcal conjugate vaccine (PCV) indirect effects in low-income countries with high HIV burden are limited. We examined adult pneumococcal pneumonia incidence before and after 10-valent PCV introduction in Kenya in 2011. Methods: From 1/1/2008 to 12/31/2016, we conducted surveillance for acute respiratory infection (ARI) among ~12,000 adults (≥18 years) in western Kenya, where HIV prevalence ~17%. ARI cases (cough or difficulty breathing or chest pain, plus temperature ≥38.0◦C or oxygen saturation <90%) presenting to a clinic underwent blood culture and pneumococcal urine antigen testing (UAT). We calculated ARI incidence and adjusted for healthcare seeking using data from household visits. The proportion of ARI cases with pneumococcus detected among those with complete testing (blood culture and UAT) was multiplied by adjusted ARI incidence to estimate pneumococcal pneumonia incidence. Results: Pre-PCV (2008–2010), crude and adjusted ARI incidence were 3.14 and 5.30/100 person-years-observation (pyo), respectively. Among ARI cases, 39.0% (340/872) had both blood culture and UAT; 21.2% (72/340) had pneumococcus detected, yielding baseline pneumococcal pneumonia incidence of 1.12/100 pyo (95% confidence interval [CI] 1.0–1.3). In each post-PCV year (2012–2016), pneumococcal pneumonia incidence was significantly lower than baseline; with incidence rate ratios (IRR) of 0.53 (95%CI 0.31–0.61) in 2012 and 0.13 (95%CI 0.09–0.17) in 2016. Similar declines were observed in HIV-infected (IRR 0.13, 95%CI 0.08–0.22), and HIV-uninfected (IRR 0.10, 95%CI 0.05–0.20). Conclusions: Adult pneumococcal pneumonia declined in western Kenya following 10-valent PCV introduction, likely reflecting vaccine indirect effects. Evidence of herd protection is critical for guiding PCV policy decisions in resource-constrained areas.

We compared pneumococcal isolation rates and evaluated the benefit of using oropharyngeal (OP) specimens in addition to nasopharyngeal (NP) specimens collected from adults in rural Kenya. Of 846 adults, 52.1% were colonized; pneumococci were detected from both NP and OP specimens in 23.5%, NP only in 22.9%, and OP only in 5.7%. PCV10-type strains were detected from both NP and OP in 3.4%, NP only in 4.1%, and OP only in 0.7%. Inclusion of OP swabs increased carriage detection by 5.7%, however, the added cost of collecting and processing OP specimens may justify exclusion from future carriage studies among adults.

BackgroundKenya introduced 10-valent pneumococcal conjugate vaccine (PCV10) in 2011 (three doses at ages 6, 10, and 14 weeks). Impact of PCV10 on pneumococcal carriage was unknown in this setting. We assessed changes in pneumococcal carriage and antibiotic susceptibility in children aged <5 years (U5) and HIV-infected adults (HIV+ adults) post-PCV10 introduction.MethodsDuring 2009–2013, we performed annual cross-sectional pneumococcal carriage surveys in two sites with ongoing population-based surveillance: Kibera (U5 only) and Lwak (U5 and HIV+ adults, catch-up vaccination for children 1–4 years offered in 2011). Nasopharyngeal swabs (and oropharyngeal swabs in adults) were obtained for culture. Pneumococcal isolates were serotyped by multiplex PCR and Quellung. Antibiotic susceptibility was determined (2009 and 2013). We calculated changes in penicillin nonsusceptible (intermediate or resistant) pneumococci (PNSP) carriage by chi-squared test. Changes in PCV10-type (VT) pneumococcal carriage in 2013 compared with baseline (U5: 2009–10, adults: 2009 only) were calculated by modified Poisson regression by age and site.ResultsOverall, 2,962 U5 (2,073 in Kibera, 889 in Lwak) and 2,028 HIV+ adults were enrolled. VT carriage declined by 52–60% in children 1–4 years, by 60% in children <1 year in Kibera, and by 76% in HIV+ adults (table). PNSP carriage declined from 32.8% to 22.3% (P < 0.01) in HIV+ adults but did not change in U5 (Kibera: 77.0% vs. 75.5%, P =0.10; Lwak: 74.3% vs. 74.6%, P = 0.94).ConclusionThe infant PCV10 program was associated with declines in VT carriage among U5 and HIV+ adults, and declines in PNSP carriage among HIV+ adults; however, VT carriage remained >10% among U5 2 years post-PCV10 introduction.Table. PCV10-Type Carriage by Site and Age GroupsSiteKiberaLwakAge GroupYearCarriage (%)aPR (95% CI)*Carriage (%)aPR (95% CI)*<1 year2009–201038.2Ref.30.0Ref.201314.60.40 (0.26, 0.62)10.30.37 (0.11, 1.24)1–4 years2009–201038.6Ref.34.3Ref.201318.70.48 (0.37, 0.62)13.80.40 (0.27, 0.60)HIV+ adults2009——12.9Ref2013——2.80.24 (0.14, 0.41)aPR, adjusted prevalence ratio; CI, confidence interval.*Adjusted for respiratory illness ≤30 days, antibiotic use ≤7 days, and area used for cooking.Disclosures All authors: No reported disclosures.