title: Immunodeficiency in children starting antiretroviral therapy in low-, middle-, and high-income countries.
abstract: BACKGROUND
  The CD4 cell count or percent (CD4%) at the start of combination antiretroviral therapy (cART) is an important prognostic factor in children starting therapy and an important indicator of program performance. We describe trends and determinants of CD4 measures at cART initiation in children from low-, middle-, and high-income countries.
  
  
  METHODS
  We included children aged <16 years from clinics participating in a collaborative study spanning sub-Saharan Africa, Asia, Latin America, and the United States. Missing CD4 values at cART start were estimated through multiple imputation. Severe immunodeficiency was defined according to World Health Organization criteria. Analyses used generalized additive mixed models adjusted for age, country, and calendar year.
  
  
  RESULTS
  A total of 34,706 children from 9 low-income, 6 lower middle-income, 4 upper middle-income countries, and 1 high-income country (United States) were included; 20,624 children (59%) had severe immunodeficiency. In low-income countries, the estimated prevalence of children starting cART with severe immunodeficiency declined from 76% in 2004 to 63% in 2010. Corresponding figures for lower middle-income countries were from 77% to 66% and for upper middle-income countries from 75% to 58%. In the United States, the percentage decreased from 42% to 19% during the period 1996 to 2006. In low- and middle-income countries, infants and children aged 12-15 years had the highest prevalence of severe immunodeficiency at cART initiation.
  
  
  CONCLUSIONS
  Despite progress in most low- and middle-income countries, many children continue to start cART with severe immunodeficiency. Early diagnosis and treatment of HIV-infected children to prevent morbidity and mortality associated with immunodeficiency must remain a global public health priority.
authors.affiliation: *Institute of Social & Preventive Medicine (ISPM), University of Bern, Bern, Switzerland; †Department of Epidemiology, Harvard School of Public Health, Boston, MA; ‡Centre for Infectious Disease Research in Zambia, Lusaka, Zambia; §Department of Medicine, Indiana University School of Medicine, Indianapolis, IN; ‖Department of Pediatrics, Gabriel Toure Hospital, Bamako, Mali; ¶Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand; #Newlands Clinic, Harare, Zimbabwe; **Maternal and Pediatric Infectious Disease Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), Bethesda, MD; ††Department of Pediatrics, College of Health Sciences, Moi University, Kenya; ‡‡INSERM, French National Institute for Health and Medical Research, U897, Bordeaux, France; §§Children's Hospital 1, Ho Chi Minh City, Vietnam; and ‖‖School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa.
authors.forename: Manuel
authors.initials: M
authors.lastname: Koller
authors.forename: Kunjal
authors.initials: K
authors.lastname: Patel
authors.forename: Benjamin H
authors.initials: BH
authors.lastname: Chi
authors.forename: Kara
authors.initials: K
authors.lastname: Wools-Kaloustian
authors.forename: Fatoumata
authors.initials: F
authors.lastname: Dicko
authors.forename: Kulkanya
authors.initials: K
authors.lastname: Chokephaibulkit
authors.forename: Cleophas
authors.initials: C
authors.lastname: Chimbetete
authors.forename: Dorita
authors.initials: D
authors.lastname: Avila
authors.forename: Rohan
authors.initials: R
authors.lastname: Hazra
authors.forename: Samual
authors.initials: S
authors.lastname: Ayaya
authors.forename: Valeriane
authors.initials: V
authors.lastname: Leroy
authors.forename: Huu Khanh
authors.initials: HK
authors.lastname: Truong
authors.forename: Matthias
authors.initials: M
authors.lastname: Egger
authors.forename: Mary-Ann
authors.initials: MA
authors.lastname: Davies
mesh_terms: D019380:Anti-HIV Agents / Q000276:immunology / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D002648:Child; D019049:Developed Countries; D003906:Developing Countries; D006801:Humans
chemical_list: D019380:Anti-HIV Agents