title: Persisting high prevalence of pneumococcal carriage among HIV-infected adults receiving antiretroviral therapy in Malawi: a cohort study.
abstract: OBJECTIVE
  HIV-infected adults have high rates of pneumococcal carriage and invasive disease. We investigated the effect of antiretroviral therapy (ART) on pneumococcal carriage in HIV-infected adults prior to infant pneumococcal conjugate vaccine (PCV) rollout.
  
  
  METHODS
  Observational cohort study.
  
  
  METHODS
  We recruited HIV-infected adults newly attending a rural HIV clinic in northern Malawi between 2008 and 2010. Nasopharyngeal samples were taken at baseline and after 6, 12, 18 and 24 months. We compared pneumococcal carriage by ART status using generalized estimated equation models adjusted for CD4 cell count, sex, seasonality, and other potential confounders.
  
  
  RESULTS
  In total, 336 individuals were included, of which 223 individuals started ART during follow-up. Individuals receiving ART had higher pneumococcal carriage than individuals not receiving ART (25.9 vs. 19.8%, P = 0.03) particularly for serotypes not included in PCV13 (16.1 vs. 9.6% P = 0.003). Following adjustment, increased carriage of non-PCV13 serotypes was still observed for individuals on ART, but results for all serotypes were nonsignificant [all serotypes: adjusted risk ratio (aRR) 1.22 (0.95-1.56); non-PCV13 serotypes: aRR 1.72, 95% CI 1.13-2.62].
  
  
  CONCLUSIONS
  Pneumococcal carriage in HIV-infected adults in Malawi remained high despite use of ART, consistent with failure of mucosal immune reconstitution in the upper respiratory tract. There was evidence of increased carriage of non-PCV13 serotypes. HIV-infected adults on ART could remain an important reservoir for pneumococcal diversity post infant pneumococcal vaccine introduction. Control of pneumococcal disease in African HIV remains a priority.
authors.affiliation: aDepartment of Clinical Infection, Microbiology, Institute of Infection and Global Health, University of Liverpool, UK bKaronga Prevention Study, Chilumba cThe Polytechnic, University of Malawi, Blantyre, Malawi dDepartment of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London eDepartment of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, UK.
authors.forename: Ellen
authors.initials: E
authors.lastname: Heinsbroek
authors.forename: Terence
authors.initials: T
authors.lastname: Tafatatha
authors.forename: Amos
authors.initials: A
authors.lastname: Phiri
authors.forename: Bagrey
authors.initials: B
authors.lastname: Ngwira
authors.forename: Amelia C
authors.initials: AC
authors.lastname: Crampin
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Read
authors.forename: Neil
authors.initials: N
authors.lastname: French
mesh_terms: D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D002353:Carrier State / Q000453:epidemiology*; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy*; D006801:Humans; D008295:Malawi / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx / Q000382:microbiology; D011008:Pneumococcal Infections / Q000453:epidemiology*; D015995:Prevalence; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000145:classification / Q000302:isolation & purification
chemical_list: D044966:Anti-Retroviral Agents