title: Lower incidence of Pneumocystis jirovecii pneumonia among Africans in the Netherlands host or environmental factors?
abstract: OBJECTIVE
  HIV-associated Pneumocystis jirovecii pneumonia (PJP) remains one of the commonest opportunistic infections in Western countries. Although it has been suggested that racial differences in PJP incidence exist, early studies report conflicting results. This study aimed to investigate differences in PJP incidence in a developed country among patients originating from sub-Saharan Africa compared with other regions of origin.
  
  
  METHODS
  A retrospective observational cohort study was performed among 13,844 HIV-infected patients from the Dutch ATHENA cohort. The main outcome measure was occurrence of PJP.
  
  
  RESULTS
  A total number of 1055 PJP infections were diagnosed. Patients originating from sub-Saharan Africa had a significantly lower risk of having PJP at the time of HIV diagnosis after adjustment of confounders compared with patients from Western origin [Western Europe, Australia and New Zealand; adjusted odds ratio (aOR) 0.21 (95% confidence interval (CI) 0.15-0.29)]. Other factors associated with higher PJP risk were increasing age [aOR 1.01 per year (95% CI 1.00-1.02)], a low CD4 count at HIV diagnosis [CD4 <50 versus >350 cells/μl aOR 123.3 (95% CI 77.8-195.5)] and a high plasma HIV-RNA (>100,000 copies/ml) at HIV diagnosis [aOR 1.41 (95% CI 1.19-1.66)]. Moreover, a clearly lower risk for PJP acquisition later during follow-up was observed among sub-Saharan Africans versus Western patients [adjusted hazard ratio 0.60 (95% CI 0.39-0.90)].
  
  
  CONCLUSIONS
  Among HIV-infected patients living in the Netherlands, PJP occurrence is substantially lower in patients originating from sub-Saharan Africa, as compared to Western patients. Differences in genetic susceptibility may partially explain the lower PJP incidence in these patients.
authors.affiliation: Department of Internal Medicine and Infectious Diseases, University Medical Centre Utrecht, Utrecht, the Netherlands. A.F.Schoffelen@umcutrecht.nl
authors.forename: Annelot F
authors.initials: AF
authors.lastname: Schoffelen
authors.forename: Steven F L
authors.initials: SF
authors.lastname: van Lelyveld
authors.forename: Roos E
authors.initials: RE
authors.lastname: Barth
authors.forename: Luuk
authors.initials: L
authors.lastname: Gras
authors.forename: Frank
authors.initials: F
authors.lastname: de Wolf
authors.forename: Mihai G
authors.initials: MG
authors.lastname: Netea
authors.forename: Andy I M
authors.initials: AI
authors.lastname: Hoepelman
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D017954:Africa South of the Sahara / Q000208:ethnology; D017677:Age Distribution; D018791:CD4 Lymphocyte Count; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease; D015658:HIV Infections / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D006801:Humans; D015994:Incidence; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D016017:Odds Ratio; D045363:Pneumocystis carinii / Q000302:isolation & purification; D011020:Pneumonia, Pneumocystis / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D012189:Retrospective Studies; D019562:Viral Load