BMC Infect Dis. 2016 Jan 16;16(1):18. doi: 10.1186/s12879-015-1312-2.

High Streptococcus pneumoniae colonization prevalence among HIV-infected Kenyan parents in the year before pneumococcal conjugate vaccine introduction.

Conklin LM1,2, Bigogo G3,4, Jagero G5, Hampton L6, Junghae M7, da Gloria Carvalho M8, Pimenta F9, Beall B10, Taylor T11, Plikaytis B12, Laserson KF13, Vulule J14, Van Beneden C15, Whitney CG16, Breiman RF17, Feikin DR18.

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Abstract

BACKGROUND:

Streptococcus pneumoniae is a leading cause of pneumonia, meningitis and sepsis in developing countries, particularly among children and HIV-infected persons. Pneumococcal oropharyngeal (OP) or nasopharyngeal (NP) colonization is a precursor to development of invasive disease. New conjugate vaccines hold promise for reducing colonization and disease.

METHODS:

Prior to introduction of 10-valent pneumococcal conjugate vaccine (PCV10), we conducted a cross-sectional survey among HIV-infected parents of children <5 years old in rural Kenya. Other parents living with an HIV-infected adult were also enrolled. After broth enrichment, NP and OP swabs were cultured for pneumococcus. Serotypes were identified by Quellung. Antimicrobial susceptibility was performed using broth microdilution.

RESULTS:

We enrolled 973 parents; 549 (56.4 %) were HIV-infected, 153 (15.7 %) were HIV-uninfected and 271 (27.9 %) had unknown HIV status. Among HIV-infected parents, the median age was 32 years (range 15-74) and 374/549 (68 %) were mothers. Pneumococci were isolated from 237/549 (43.2 %) HIV-infected parents and 41/153 (26.8 %) HIV-non-infected parents (p = 0.0003). Colonization with PCV10 serotypes was not significantly more frequent in HIV-infected (12.9 %) than HIV-uninfected parents (11.8 %; p = 0.70). Among HIV-infected parents, cooking site separate from sleeping area and CD4 count >250 were protective (OR = 0.6; 95 % CI 0.4, 0.9 and OR = 0.5; 95 % CI 0.2, 0.9, respectively); other associations were not identified. Among 309 isolates tested from all parents, 255 (80.4 %) were penicillin non-susceptible (MIC ≥0.12 μg/ml).

CONCLUSIONS:

Prevalence of pneumococcal colonization is high among HIV-infected parents in rural Kenya. If young children are the pneumococcal reservoir for this population, PCV10 introduction may reduce vaccine-type colonization and disease among HIV-infected parents through indirect protection.

PMID: 26774803 [PubMed - in process] PMCID: PMC4715316