The cases of active tuberculosis among persons with latent tuberculosis infection residing in the disease hot spots

Abstract

Within the last 10 years some growth of active tuberculosis(TB) cases have been observed among contacts with latent TB infection (LTBI) in Armenia

Aims and objectives: to reveal cases of active TB disease among contacts with LTBI.

Methods: 115 families (main group) with active TB cases(sputum smear positive)from 4 socially disadvantaged areas of Armenia have been observed.95% of members of contact families had positive tuberculin skin test results.Among them 125(24%) adults and children got the disease within the last few years(about 2-3 members in each of 31 families - 71 persons in total).51 families (control group) with active TB cases(sputum smear positive) have been observed for comparison.

Results: it was established that in the main group the families with epidemiologically disadvantaged factors were prevailing(73,1%),such as patients with massive bacterial excretion and drug resistance (39,3%), social and medico-biological aggravating factors,comorbidity.It shows that the development of TB disease among people with LTBI is determined by not only massive bacterial excretion but also by social and medico-biological risk factors.Among persons with TB disease the cases under 35 year turned out to be dominating for both sexes.The morbidity of TB disease among persons with LTBI have exceeded during different years(30-40 times).

Conclusions: The risk of getting the disease for LTBI persons who are in a long and close contact with persons who have active TB (sputum smear positive)increases in the case of existence of drug resistance, medico-biological and social aggravating factors, comorbidity and appears in 6 months after the first contact.