Effect of delay in diagnosis on the rate of tuberculosis among close contacts of tuberculosis patients

ABSTRACT

Few studies have explored diagnosis delay by tuberculosis [TB] patients and its effects on the rate of infection among their close contacts. A cross-sectional study of the close contacts of 505 newly diagnosed TB patients was conducted in a TB referral centre in Sana'a, Yemen from 2008 to 2010. Only the close contacts of 89 new TB patients agreed to participate and completed the tuberculin skin test [TST]. Of the 239 close contacts investigated, 133 [55.6%] had a positive TST result. Index patients were classified as long or short diagnosis delay [above or below the median]. There was no significant difference in the number of infected close contacts between long and short delay index patients [Mann-Whitney U-test]. A larger sample size, with more incentives for patients to participate and the use of other investigative tools could provide a better picture of the pattern of TB transmission among all contacts