Status of smear-positive TB patients at 2-3 years after initiation of treatment under a DOTS programme

Objective: To describe the status of cases 2-3 years after the initiation of treatment under DOTS. Setting: After DOTS implementation in Tiruvallur district, south India, we followed up a cohort of smear-positive TB patients registered during 2002-03 after initiation of treatment. Results: The overall mortality rate was 15.0% and among the remaining 18.6% had active disease. In multivariate analysis, a higher mortality rate was independently associated with age, sex, occupation, treatment outcome and initial body weight of patients. Conclusion: The mortality and morbidity rates are still high during follow-up and needs to be curtailed by addressing these issues effectively in TB control programm

Active community surveillance of the impact of different tuberculosis control measures, Tiruvallur, South India, 1968-2001

Background: Tuberculosis is curable, but community surveys documenting epidemiological impact of the WHO-recommended DOTS strategy on tuberculosis prevalence have not been published. We used active community surveillance to compare the impact of DOTS with earlier programmes. Methods: We conducted tuberculosis disease surveys using random cluster sampling of a rural population in South India approximately every 2.5 years from 1968 to 1986, using radiography as a screening tool for sputum examination. In 1999, DOTS was implemented in the area. Prevalence surveys using radiography and symptom screening were conducted at the start of DOTS implementation and after 2.5 years. Results: From 1968 to 1999, culture-positive and smear-positive tuberculosis declined by 2.3 and 2.5% per annum compared with 11.9 and 5.6% after DOTS implementation. The 2.5 year period of DOTS implementation accounted for one-fourth of the decline in prevalence of culture-positive tuberculosis over 33 years. Multivariate analysis showed that prevalence of culture-positive tuberculosis decreased substantially (10.0% per annum, 95% CI: 2.8–16.6%) owing to DOTS after only slight declines related to temporal trends (2.1% annual decline, 95% CI: 1.1–3.2%) and short-course chemotherapy (1.5% annual decline, 95% CI: �9.7% to 11.5%). Under DOTS, the proportion of total cases identified through clinical care increased from 81 to 92%. Conclusions: Following DOTS implementation, prevalence of culture-positive tuberculosis decreased rapidly following a gradual decline for the previous 30 years. In the absence of a large HIV epidemic and with relatively low levels of rifampicin resistance, DOTS was associated with rapid reduction of tuberculosis prevalenc

Cost-Effectiveness of HIV Testing Referral Strategies among Tuberculosis Patients in India

Background: Indian guidelines recommend routine referral for HIV testing of all tuberculosis (TB) patients in the nine states with the highest HIV prevalence, and selective referral for testing elsewhere. We assessed the clinical impact and cost-effectiveness of alternative HIV testing referral strategies among TB patients in India. Methods and Findings: We utilized a computer model of HIV and TB disease to project outcomes for patients with active TB in India. We compared life expectancy, cost, and cost-effectiveness for three HIV testing referral strategies: 1) selective referral for HIV testing of those with increased HIV risk, 2) routine referral of patients in the nine highest HIV prevalence states with selective referral elsewhere (current standard), and 3) routine referral of all patients for HIV testing. TB-related data were from the World Health Organization. HIV prevalence among TB patients was 9.0% in the highest prevalence states, 2.9% in the other states, and 4.9% overall. The selective referral strategy, beginning from age 33.50 years, had a projected discounted life expectancy of 16.88 years and a mean lifetime HIV/TB treatment cost of US$100. The current standard increased mean life expectancy to 16.90 years with additional per-person cost of US$10; the incremental cost-effectiveness ratio was US$650/year of life saved (YLS) compared to selective referral. Routine referral of all patients for HIV testing increased life expectancy to 16.91 years, with an incremental cost-effectiveness ratio of US$730/YLS compared to the current standard. For HIV-infected patients cured of TB, receiving antiretroviral therapy increased survival from 4.71 to 13.87 years. Results were most sensitive to the HIV prevalence and the cost of second-line antiretroviral therapy. Conclusions: Referral of all patients with active TB in India for HIV testing will be both effective and cost-effective. While effective implementation of this strategy would require investment, routine, voluntary HIV testing of TB patients in India should be recommended

Assessing Tuberculosis Case Fatality Ratio: A Meta-Analysis

Background: Recently, the tuberculosis (TB) Task Force Impact Measurement acknowledged the need to review the assumptions underlying the TB mortality estimates published annually by the World Health Organization (WHO). TB mortality is indirectly measured by multiplying estimated TB incidence with estimated case fatality ratio (CFR). We conducted a meta-analysis to estimate the TB case fatality ratio in TB patients having initiated TB treatment. Methods: We searched for eligible studies in the PubMed and Embase databases through March 4(th) 2011 and by reference listing of relevant review articles. Main analyses included the estimation of the pooled percentages of: a) TB patients dying due to TB after having initiated TB treatment and b) TB patients dying during TB treatment. Pooled percentages were estimated using random effects regression models on the combined patient population from all studies. Main Results: We identified 69 relevant studies of which 22 provided data on mortality due to TB and 59 provided data on mortality during TB treatment. Among HIV infected persons the pooled percentage of TB patients dying due to TB was 9.2% (95% Confidence Interval (CI): 3.7%-14.7%) and among HIV uninfected persons 3.0% (95% CI: 21.2%-7.4%) based on the results of eight and three studies respectively providing data for this analyses. The pooled percentage of TB patients dying during TB treatment was 18.8% (95% CI: 14.8%-22.8%) among HIV infected patients and 3.5% (95% CI: 2.0%-4.92%) among HIV uninfected patients based on the results of 27 and 19 studies respectively. Conclusion: The results of the literature review are useful in generating prior distributions of CFR in countries with vital registration systems and have contributed towards revised estimates of TB mortality This literature review did not provide us with all data needed for a valid estimation of TB CFR in TB patients initiating TB treatmen

Yield of pulmonary tuberculosis cases by employing two screening methods in a community survey

OBJECTIVE: To compare the yield of tuberculosis (TB) cases by two screening methods. SETTING: Two disease surveys conducted in Tiruvallur, south India. RESULTS: Of bacteriologically confirmed cases, 60% were identified by symptom inquiry alone whereas 82% were identified using chest radiography (CXR). CONCLUSION: The prevalence of TB was underestimated by both methods. The total cases in this community can be estimated by multiplying the number of identified cases by a correction factor (CF) of 1.7 when symptom inquiry alone is used or 1.2 when CXR is used. The CF may be different in other settings

Predictors of relapse among pulmonary tuberculosis patients treated in a DOTS programme in South India

OBJECTIVE: To identify risk factors associated with relapse among cured tuberculosis (TB) patients in a DOTS programme in South India. DESIGN: Sputum samples collected from a cohort of TB patients registered between April 2000 and December 2001 were examined by fluorescence microscopy for acidfast bacilli and by culture for Mycobacterium tuberculosis at 6, 12 and 18 months after treatment completion. RESULTS: Of the 534 cured patients, 503 (94%) were followed up for 18 months after treatment completion. Of these, 62 (12%) relapsed during the 18-month period; 48 (77%) of the 62 relapses occurred during the first 6 months of follow-up. Patients who took treatment irregularly were twice more likely to have a relapse than adherent patients (20% vs. 9%; adjusted odds ratio [aOR] 2.5; 95%CI 1.4–4.6). Other independent predictors of relapse were initial drug resistance to isoniazid and/or rifampicin (aOR 4.8; 95%CI 2.0–11.6) and smoking (aOR 3.1; 95%CI 1.6–6.0). The relapse rate among nonsmoking, treatment adherent patients with drug-sensitive organisms was 4.8%. CONCLUSIONS: The relapse rate under the DOTS programme may be reduced by ensuring that patients take their treatment regularly and are counselled effectively about quitting smoking

A baseline survey of the prevalence of tuberculosis in a community in south India at the commencement of a DOTS programme

OBJECTIVE: To determine the baseline prevalence of culture-positive and smear-positive tuberculosis and the annual risk of tuberculous infection (ARTI) in a community in south India where DOTS is being implemented. METHODS: Using cluster sampling, 50 rural panchayats (villages) and three urban units in Tiruvallur district were selected randomly. All adults aged �15 years underwent symptom and radiographic examination, and those with abnormal shadows and/or chest symptoms had sputum smear and culture examination. In another cluster sample of 73 villages and three urban units, all children aged �10 years were tuberculin tested. RESULTS: The prevalence of culture-positive and smearpositive tuberculosis was respectively 605 and 323/ 100 000. Both increased appreciably with age, and were substantially higher in males than in females at all ages; the overall male:female ratio was 5.5 for culture-positive and 6.5 for smear-positive tuberculosis. The ARTI in children aged under 10 years was 1.6%, and was unaffected by sex. Over three decades there was an overall decline of 1.8% per annum in the prevalence of culture-positive and 2.1% for smear-positive tuberculosis. CONCLUSION: Tuberculosis is a major problem in this rural community in south India, with a prevalence of 605/100 000 for culture-positive tuberculosis and 323/ 100 000 for smear-positive tuberculosis

The prevalence of tuberculosis in different economic strata: a community survey from South India

A cross-sectional socio-economic survey to assess the standard of living index (SLI) of a rural population in South India was undertaken along with a tuberculosis (TB) prevalence survey during 2004–2006. Of 32 780 households, the SLI was low, medium and high in 22%, 36% and 42%, and TB prevalence was 343, 169 and 92 per 100 000 population, respectively, a significant decrease in trend (P � 0.001); 57% of the TB patients had a low SLI and the prevalence of TB was higher amongst the landless (P � 0.001), those living below the poverty line (P � 0.01) and in katcha houses (P � 0.001), suggesting that TB disproportionately affects those with a low SLI

Tuberculous infection in Saharia, a primitive tribal community of Central India

A cross-sectional tuberculin survey was carried out to estimate the prevalence of tuberculous infection and the annual risk of tuberculosis infection (ARTI) among children of Saharia, a primitive ethnic group in Madhya Pradesh, Central India. A total of 1341 children aged 1—9 years were subjected to tuberculin testing with 1 TU of PPD RT 23 and the reaction sizes were read after 72 h. The proportion of BCG scar-positive children was 34.6%. The frequency distribution of children by reaction sizes indicated a clear-cut anti-mode at 11mm and a mode at 18mm at the right-hand side of the distribution. The prevalence of infection among children irrespective of BCG scar was estimated as 20.4% (95% CI 18.2—22.5%) and the ARTI was 3.9% (95% CI 3.5—4.3%). The corresponding figures were 21.1% (95% CI 18.3—23.8%) and 3.9% (95% CI 3.4—4.5%) among BCG scar-negative children and 19.0% (95% CI 15.4—22.5%) and 4.0% (95% CI 3.2—4.8%) among BCG scar-positive children. The findings of the present study show a high prevalence of tuberculous infection and high ARTI in this primitive ethnic group. There is an urgent need to further intensify tuberculosis control measures on a sustained and long-term basis in this area

Annual risk of tuberculosis infection among tribal population of central India

objective To estimate the annual risk of tuberculosis infection (ARTI) among tribal children of Madhya Pradesh, central India. methods Community-based, cross-sectional tuberculin survey among children aged 1–9 years in the tribal population of Madhya Pradesh. Multistage stratified cluster sampling was used to select a representative random sample of villages predominated by tribal population from selected districts. A total of 4802 children were tuberculin-tested with 1TU of PPD RT 23 and the reaction sizes read after 72 h. results A total of 3062 (64%) children had no BCG scar. The frequency distribution of children by reaction sizes indicated a fair mode at 18 mm in the right hand side of the distribution. By mirror-image technique, the prevalence of infection among children with no recognizable BCG scar was estimated as 6.8% (95% CI: 4.8–8.9%). The ARTI was computed as 1.3% (0.9–1.7%). The corresponding figures for children irrespective of scar status were 7.1% (95% CI: 5.5–8.8%) and 1.3% (1.0–1.7%) respectively. conclusions The risk of tuberculosis infection in tribal population of Madhya Pradesh, central India is not different from other areas of the country. There is, however, a need to further intensify tuberculosis control measures on a sustained and long-term basis