title: Household contact investigation of multidrug-resistant and extensively drug-resistant tuberculosis in a high HIV prevalence setting.
abstract: METHODS
  Multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) are now a nationwide epidemic in South Africa. Epidemiological data suggest nosocomial transmission as the primary route of spread; however, transmission among household contacts has not yet been  investigated.
  
  
  OBJECTIVE
  To determine the incidence rates of MDR- and XDR-TB among household contacts of MDR- and XDR-TB index cases diagnosed between January 2005 and September 2008 in a high human immunodeficiency virus prevalence setting.
  
  
  METHODS
  Prospective, observational study evaluating  adult household contacts for active TB by culture and drug susceptibility testing at index case diagnosis and again 1 year later. Outcomes were incidence and time to diagnosis of MDR- and XDR-TB.
  
  
  RESULTS
  A total of 1766 contacts of 221 MDR-TB and 287 XDR-TB index cases were screened. Of  793 contacts of MDR-TB index cases, 14 (1.8%) were diagnosed with MDR-TB (incidence 1765/100 000); 19 (2.0%) of 973 XDR-TB contacts had XDR-TB (incidence 1952/100 000). Median time to diagnosis of household cases was 70 days (interquartile range 57-89).
  
  
  CONCLUSIONS
  Incidence  rates of MDR- and XDR-TB among household contacts were extremely high, with most secondary cases occurring shortly after the diagnosis of the index case. Active case finding of drug-resistant TB is a high-yield public health activity and must be a priority, as early diagnosis may stem further  disease spread and improve survival.
authors.affiliation: Italian Cooperation, Pietermaritzburg, KwaZulu-Natal, South Africa. Thevellas@yahoo.it
authors.forename: V
authors.initials: V
authors.lastname: Vella
authors.forename: V
authors.initials: V
authors.lastname: Racalbuto
authors.forename: R
authors.initials: R
authors.lastname: Guerra
authors.forename: C
authors.initials: C
authors.lastname: Marra
authors.forename: A
authors.initials: A
authors.lastname: Moll
authors.forename: Z
authors.initials: Z
authors.lastname: Mhlanga
authors.forename: M
authors.initials: M
authors.lastname: Maluleke
authors.forename: H
authors.initials: H
authors.lastname: Mhlope
authors.forename: B
authors.initials: B
authors.lastname: Margot
authors.forename: G
authors.initials: G
authors.lastname: Friedland
authors.forename: N S
authors.initials: NS
authors.lastname: Shah
authors.forename: N R
authors.initials: NR
authors.lastname: Gandhi
mesh_terms: D000293:Adolescent; D000328:Adult; D000995:Antitubercular Agents / Q000494:pharmacology*; D054908:Extensively Drug-Resistant Tuberculosis / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D005191:Family Characteristics; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D013019:South Africa / Q000453:epidemiology; D013997:Time Factors; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents