title: Source case identification in HIV-exposed infants and tuberculosis diagnosis in an isoniazid prevention study.
abstract: Identifying source cases of children exposed to tuberculosis (TB) is challenging. We examined the time-point of obtaining contact information of TB source cases in human immunodeficiency virus (HIV) infected and HIV-exposed uninfected (HEU) children in a randomised, placebo-controlled trial of pre-exposure to isoniazid prophylaxis.
  
  
  
  A total of 543 HIV-infected and 808 HEU infants without TB exposure aged 3-4 months were enrolled between 2004 and 2008. At 3-monthly follow-up, infants were evaluated for TB and care givers were asked about new TB exposure.
  
  
  
  In total, 128 cases of TB disease and 40 deaths were recorded among 19% (105/543) of the HIV-infected and 8% (63/808) of the HEU children; 229 TB contact occasions were reported in 205/1351 (15%) children, of which 83% (189/229) were in the household. Of the 189 household contacts, 108 (53%) underwent microbiological evaluations; 81% (87/108) were positive. HIV-infected and HEU infants had similar frequencies of TB contact: in 48% of infants with definite TB, 58% with probable TB and 43% with possible TB. Of 128 children diagnosed with TB, a TB contact was identified for 59. Of these, 29/59 (49%) were identified at or after the child's TB diagnosis.
  
  
  
  TB source cases are often identified at or after a child's TB diagnosis. More effort is required for earlier detection.
authors.affiliation: Children's Infectious Diseases Clinical Research Unit, Department of Paediatrics & Child Health, Stellenbosch University, Cape Town, South Africa; Swiss Children's Hospital, Liestal, Switzerland.
authors.forename: E R
authors.initials: ER
authors.lastname: Maritz
authors.affiliation: Center for Biostatistics in AIDS Research, Harvard School of Public Health, Boston, Massachusetts, USA.
authors.forename: G
authors.initials: G
authors.lastname: Montepiedra
authors.affiliation: Center for Biostatistics in AIDS Research, Harvard School of Public Health, Boston, Massachusetts, USA.
authors.forename: L
authors.initials: L
authors.lastname: Liu
authors.affiliation: Leonard M Miller School of Medicine, University of Miami, Miami, Florida, USA; Respiratory and Meningeal Pathogens Research Unit, Medical Research Council, and Department of Science & Technology, National Research Foundation, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: C D
authors.initials: CD
authors.lastname: Mitchell
authors.affiliation: Department of Paediatrics, University of KwaZulu-Natal, Durban, South Africa.
authors.forename: S A
authors.initials: SA
authors.lastname: Madhi
authors.affiliation: Perinatal HIV Research Unit, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: R
authors.initials: R
authors.lastname: Bobat
authors.affiliation: Botswana-Harvard School of Public Health AIDS Institute, Gaborone, Botswana.
authors.forename: A
authors.initials: A
authors.lastname: Violari
authors.affiliation: Botswana-Harvard School of Public Health AIDS Institute, Gaborone, Botswana.
authors.forename: A
authors.initials: A
authors.lastname: Ogwu
authors.affiliation: Department of Paediatrics & Child Health, Desmond Tutu TB Centre, Stellenbosch University, Cape Town, South Africa.
authors.forename: A C
authors.initials: AC
authors.lastname: Hesseling
authors.affiliation: Children's Infectious Diseases Clinical Research Unit, Department of Paediatrics & Child Health, Stellenbosch University, Cape Town, South Africa.
authors.forename: M F
authors.initials: MF
authors.lastname: Cotton
mesh_terms: D000367:Age Factors; D000995:Antitubercular Agents / Q000008:administration & dosage* / Q000009:adverse effects; D060085:Coinfection; D042241:Early Diagnosis; D005260:Female; D015658:HIV Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D006801:Humans; D007223:Infant; D007538:Isoniazid / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D015995:Prevalence; D011322:Primary Prevention; D012307:Risk Factors; D013019:South Africa; D013997:Time Factors; D016896:Treatment Outcome; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000401:mortality / Q000517:prevention & control* / Q000635:transmission
chemical_list: D000995:Antitubercular Agents; D007538:Isoniazid