Infection and disease among household contacts of patients with multidrug-resistant tuberculosis.
METHODS
Urban public teaching and referral hospital in Espirito Santo, Brazil.


OBJECTIVE
To assess whether rates of infection and progression to active tuberculosis (TB) differed between household contacts of patients with multidrug-resistant (MDR) and drug susceptible (DS) pulmonary tuberculosis.


METHODS
Household contacts were assessed for evidence of TB infection and disease by purified protein derivative (PPD) skin testing, physical examination, chest X-ray, and sputum smear and culture.


RESULTS
Among 133 close contacts of patients with MDR-TB, 44% were PPD-positive (> or =10 mm) compared to 37% of 231 contacts of the DS-TB cases (P = 0.18, chi2 test, OR 1.2, 95%CI 0.8-2). In a multivariate logistic regression analysis, after allowance for between-household variation in PPD responses, PPD positivity among household contacts of patients with MDR-TB remained comparable to PPD positivity in contacts of patients with DS-TB (OR 2.1, 95%CI 0.7-6.5). Respectively six (4%) and 11 (4%) contacts of the MDR- and DS-TB cases were found to have active TB at the time of initial evaluation or during follow-up (P = 0.78, chi2 test). Five of six contacts of MDR-TB cases and nine of nine contacts of DS-TB cases who developed TB, and for whom drug susceptibility test results were available, had the same bacterial susceptibility profiles as their index cases. DNA fingerprinting analysis of Mycobacterium tuberculosis isolates was identical between household contacts with active TB and the index MDR or DS-TB case for all 14 pairs compared.


CONCLUSIONS
Our data suggest that the prevalence of tuberculous infection and progression to active TB among household contacts exposed to DS and MDR-TB cases is comparable, despite a longer duration of exposure of contacts to the index case in patients with MDR-TB.
Teixeira
L
L
Nucleo de Doenças Infecciosas, Universidade Federal do Espirito Santo, Vitória, Brazil. ltj2@po.cwru.edu
Perkins
M D
MD
Johnson
J L
JL
Keller
R
R
Palaci
M
M
do Valle Dettoni
V
V
Canedo Rocha
L M
LM
Debanne
S
S
Talbot
E
E
Dietze
R
R
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D001938:Brazil / Q000453:epidemiology; D015331:Cohort Studies; D016001:Confidence Intervals; D018450:Disease Progression; D018562:Disease Transmission, Infectious / Q000706:statistics & numerical data*; D005191:Family Characteristics; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D017053:Infection Control; D008297:Male; D008400:Mass Chest X-Ray; D008875:Middle Aged; D016017:Odds Ratio; D010808:Physical Examination; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution; D013183:Sputum / Q000382:microbiology; D014374:Tuberculin Test; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis* / Q000453:epidemiology / Q000635:transmission*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000453:epidemiology / Q000635:transmission; D014505:Urban Population