Risk of tuberculosis among contacts of isoniazid-resistant and isoniazid-susceptible cases

Tuberculosis Research Centre, Chennai (2011) Risk of tuberculosis among contacts of isoniazid-resistant and isoniazid-susceptible cases. International Journal of Tuberculosis and Lung Disease, 15 (6). pp. 782-788. ISSN Print: 1027-3719 | Electronic: 1815-7920

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Abstract

OBJECTIVE: To compare the risk to household contacts of isoniazid (INH) susceptible and INH-resistant cases of tuberculosis (TB) in a rural community in South India. METHODS: In all, 5562 contacts of INH-susceptible and 779 contacts of INH-resistant patients and 246 845 persons with no TB case in the home were followed for 15 years, with surveys every 2.5 years comprising radiographic and sputum examination, selective follow-up of high-risk individuals and passive surveillance. If a new case developed, the household members were assigned to the ‘INH-susceptible’ (n = 7088) or ‘INH-resistant’ series (n = 526), whichever appropriate. Logistic regression and Cox's proportional hazards model were employed. RESULTS: The baseline prevalence of tuberculous infection was respectively 70% and 56% in contacts of INH-resistant and INH-susceptible patients (P < 0.001), compared to 46% in non-contacts. The incidence of culture-positive TB was respectively 295 and 311 per 100 000, compared to 162/100 000 in non-contacts. The adjusted hazard ratios were 2.4 and 2.0 for contacts of INH-resistant and INH-susceptible patients. CONCLUSION: The baseline prevalence of tuberculous infection was substantially higher in contacts of INH-resistant than INH-susceptible patients, but the incidence of tuberculous disease over a 15-year follow-up was similar in the two series, and twice as high as in non-contacts.

Affiliation:	ICMR-National Institute for Research in Tuberculosis
Item Type:	Article
Uncontrolled Keywords:	INH-resistant TB; contacts; hazard ratios; infectivity; risk, Tuberculosis
Subjects:	Tuberculosis > Clinical Research
Divisions:	Clinical Research
Depositing User:	Dr. Rathinasabapati R
Date Deposited:	17 Jun 2022 09:38
Last Modified:	17 Jun 2022 09:39
URI:	http://eprints.nirt.res.in/id/eprint/1095

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