Determinants of drug-resistant tuberculosis: analysis of 11 countries.
METHODS
Eleven countries/territories.


OBJECTIVE
Global information on the determinants of drug-resistant tuberculosis (TB) based on representative data is not available. We therefore studied the relationship between demographic characteristics, prior TB treatment, and human immunodeficiency virus (HIV) infection with anti-tuberculosis drug resistance.


METHODS
Population-based representative data on new and previously treated patients with TB collected within an international drug resistance surveillance network.


RESULTS
Of 9,615 patients, 8,222 (85.5%) were new cases of TB and 1,393 (14.5%) were previously treated cases. Compared with new cases, previously treated cases were significantly more likely to have resistance to one (OR = 2.5,95% CI 2.1-3.0; P < 0.001), two (OR = 4.6, 95%CI 3.7-5.6; P < 0.001), three (OR = 11.5, 95%CI 8.6-15.3; P < 0.001), and four (OR = 18.5, 95% CI 12.0-28.5; P < 0.001) drugs. An approximately linear increase in the likelihood of having multidrug-resistant tuberculosis (MDR-TB) was observed as the total time (measured in months) of prior anti-tuberculosis treatment increased (P < 0.001, chi2 for trend). In multivariate analysis, prior TB treatment for 6-11 months (OR = 7.6, 95% CI 2.6, 22.4; P < 0.001) and > or = 12 months (OR 13.7, 95% CI 4.5-41.6; P < 0.001), but not HIV positivity, was associated with MDR-TB.


CONCLUSIONS
This study shows that prior but ineffective treatment is a strong predictor of drug resistance, and that HIV is not an independent risk factor for MDR-TB. The association between length of treatment and drug resistance may reflect longer treatment as a result of treatment failure in patients with drug resistance; it may also reflect irregular prior treatment for TB, leading to drug resistance.
Espinal
M A
MA
World Health Organization, Communicable Diseases, Geneva, Switzerland. espinalm@who.ch
Laserson
K
K
Camacho
M
M
Fusheng
Z
Z
Kim
S J
SJ
Tlali
R E
RE
Smith
I
I
Suarez
P
P
Antunes
M L
ML
George
A G
AG
Martin-Casabona
N
N
Simelane
P
P
Weyer
K
K
Binkin
N
N
Raviglione
M C
MC
D000293:Adolescent; D000328:Adult; D000349:Africa / Q000453:epidemiology; D000367:Age Factors; D000569:Americas / Q000453:epidemiology; D000904:Antibiotics, Antitubercular / Q000627:therapeutic use; D001208:Asia / Q000453:epidemiology; D002648:Child; D002669:Child Welfare; D002675:Child, Preschool; D018432:Drug Resistance, Multiple; D004977:Ethambutol / Q000627:therapeutic use; D005060:Europe / Q000453:epidemiology; D005260:Female; D006678:HIV / Q000187:drug effects; D015658:HIV Infections / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007229:Infant Welfare; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011159:Population Surveillance; D015995:Prevalence; D012293:Rifampin / Q000627:therapeutic use; D018088:Tuberculosis, Multidrug-Resistant / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology*
D000904:Antibiotics, Antitubercular; D004977:Ethambutol; D012293:Rifampin