BACKGROUND: Data on pneumococcal conjugate vaccine (PCV) indirect effects in low-income countries with high human immunodeficiency virus (HIV) burden are limited. We examined adult pneumococcal pneumonia incidence before and after PCV introduction in Kenya in 2011. METHODS: From 1 January 2008 to 31 December 2016, we conducted surveillance for acute respiratory infection (ARI) among ~12 000 adults (≥18 years) in western Kenya, where HIV prevalence is ~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. 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 incidences 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 a baseline pneumococcal pneumonia incidence of 1.12/100 pyo (95% confidence interval [CI]: 1.0-1.3). In each post-PCV year (2012-2016), the incidence was significantly lower than baseline; with incidence rate ratios (IRRs) 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) adults. CONCLUSIONS: Adult pneumococcal pneumonia declined in western Kenya following PCV introduction, likely reflecting vaccine indirect effects. Evidence of herd protection is critical for guiding PCV policy decisions in resource-constrained areas.
BACKGROUND: Data on pneumococcal conjugate vaccine (PCV) indirect effects in low-income countries with high human immunodeficiency virus (HIV) burden are limited. We examined adult pneumococcal pneumonia incidence before and after PCV introduction in Kenya in 2011. METHODS: From 1 January 2008 to 31 December 2016, we conducted surveillance for acute respiratory infection (ARI) among ~12 000 adults (≥18 years) in western Kenya, where HIV prevalence is ~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. 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 incidences 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 a baseline pneumococcal pneumonia incidence of 1.12/100 pyo (95% confidence interval [CI]: 1.0-1.3). In each post-PCV year (2012-2016), the incidence was significantly lower than baseline; with incidence rate ratios (IRRs) 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) adults. CONCLUSIONS: Adult pneumococcal pneumonia declined in western Kenya following PCV introduction, likely reflecting vaccine indirect effects. Evidence of herd protection is critical for guiding PCV policy decisions in resource-constrained areas.
Authors: Maria da Gloria Carvalho; Fabiana C Pimenta; Delois Jackson; Alexis Roundtree; Yusra Ahmad; Eugene V Millar; Katherine L O'Brien; Cynthia G Whitney; Adam L Cohen; Bernard W Beall Journal: J Clin Microbiol Date: 2010-03-10 Impact factor: 5.948
Authors: Marta C Nunes; Anne von Gottberg; Linda de Gouveia; Cheryl Cohen; David P Moore; Keith P Klugman; Shabir A Madhi Journal: AIDS Date: 2011-02-20 Impact factor: 4.177
Authors: Daniel J Isaacman; David R Strutton; Edward A Kalpas; Nathalie Horowicz-Mehler; Lee S Stern; Roman Casciano; Vincent Ciuryla Journal: Clin Ther Date: 2008-02 Impact factor: 3.393
Authors: Warren Dalal; Daniel R Feikin; Manase Amolloh; Ray Ransom; Heather Burke; Fillet Lugalia; Alice Ouma; Kayla F Laserson; Jonathan Mermin; Robert F Breiman; Rebecca Bunnell Journal: J Acquir Immune Defic Syndr Date: 2013-02-01 Impact factor: 3.731
Authors: Daniel R Feikin; Geoffrey Jagero; Barrack Aura; Godfrey M Bigogo; Joseph Oundo; Bernard W Beall; Angela Karani; Susan Morpeth; M Kariuki Njenga; Robert F Breiman Journal: BMC Infect Dis Date: 2010-06-23 Impact factor: 3.090
Authors: S M Thumbi; M Kariuki Njenga; Thomas L Marsh; Susan Noh; Elkanah Otiang; Peninah Munyua; Linus Ochieng; Eric Ogola; Jonathan Yoder; Allan Audi; Joel M Montgomery; Godfrey Bigogo; Robert F Breiman; Guy H Palmer; Terry F McElwain Journal: PLoS One Date: 2015-03-23 Impact factor: 3.240
Authors: Jennifer D Loo; Laura Conklin; Katherine E Fleming-Dutra; Maria Deloria Knoll; Daniel E Park; Jennifer Kirk; David Goldblatt; Katherine L O'Brien; Cynthia G Whitney Journal: Pediatr Infect Dis J Date: 2014-01 Impact factor: 2.129
Authors: Laura Conklin; Jennifer D Loo; Jennifer Kirk; Katherine E Fleming-Dutra; Maria Deloria Knoll; Daniel E Park; David Goldblatt; Katherine L O'Brien; Cynthia G Whitney Journal: Pediatr Infect Dis J Date: 2014-01 Impact factor: 2.129
Authors: Claire von Mollendorf; Mukhchuluun Ulziibayar; Bradford D Gessner; Lien Anh Ha Do; Cattram D Nguyen; Rohini Beavon; Bujinlkham Suuri; Dashtseren Luvsantseren; Dorj Narangerel; Adam Jenney; Eileen M Dunne; Catherine Satzke; Badarchiin Darmaa; Tuya Mungun; E Kim Mulholland Journal: BMC Public Health Date: 2021-09-23 Impact factor: 3.295