Trends in the prevalence of Pulmonary Tuberculosis over a period of seven and half years in a rural community in south India with DOTS.

Setting: Tiruvallur district In Tamil Nadu where DOTS was implemented by the State Government as the tuberculosis control measure in 1999, and monitored by the National Institute for Research in Tuberculosis for over five years. Objective: To estimate trends in TB prevalence in a rural community with DOTS. Design: Surveys of pulmonary tuberculosis were undertaken in representative samples of subjects aged >15 years (N = 83,000 – 92,000), initially and after two and half, five and seven and half years of implementation of DOTS. Sputa were collected from those with abnormal radiograph and/or presence of chest symptoms, and examined by direct smear and culture. Results: The prevalence of culture-positive tuberculosis was 607, 454, 309 and 388 per 100,000 in the four surveys, and that of smear-positive tuberculosis was 326, 259, 168 and 180. In the first five years; annual decrease was 12.4% (95% CI 10.4 - 14.4%) for culture-positive tuberculosis, and 12.2% (95% CI 8.0–16.2) for smear-positive tuberculosis. This was, however, followed by a significant increase in the next two and half years. The average new smear-positive case-notification rate was 75 per 100,000 during first four years but declined to 49 in subsequent years. There were no methodological differences during this period and information on changes in socio-economic indicators and nutritional standards was unavailable. Conclusion: Despite the average annual success rate (78%) in this tuberculosis unit being lower than the expected rate of 85%, the implementation of DOTS was followed by a substantial decrease in the prevalence of pulmonary tuberculosis over the seven and half year period. Our findings suggest that sustaining the high effectiveness of DOTS programme needs vigilant supervision.

DOTS Reacdes Socially Marginalized Population in the Community a Study from a Rural Area of South India.

We report here that the Directly Observed Treatment, Short course (DOTS) is reaching all tuberculosis patients in the community irrespective of social classification based on the analysis from the tuberculosis prevalence survey and programme performance during 1999-2003 from a rural area in Tamilnadu, South India. New smear- positive cases treated under a DOTS programme were classified in two groups namely; scheduled caste living in colony and other population. The prevalence of smear- positive cases among the scheduled caste population was 1.9 times higher than the other population and this was reflected in the notification also. The successful treatment outcome was also similar in these two groups (75% and 78% respectively; overall 77%). From these findings it is concluded that people living in colony have equal access to DOTS as those in the village.

Weight gain in patients with tuberculosis treated under directly observed treatment short-course (DOTS).

SET UP: One Tuberculosis Unit (TU) in Tiruvallur district, Tamil Nadu, India where Tuberculosis (TB) patients treated under Directly Observed Treatment Short Course (DOTS) programme. OBJECTIVE: To identify the effects of weight gain among TB patients at the end of treatment on different factors such as socio-economic and demographic characteristics, smoking and drinking habits, treatment under supervision, the type of DOTS centres and problems in taking drugs. METHODS: TB patients registered between May 1999 and December 2004 formed the study population. Multiple regression method was used for the analysis. RESULTS: Among 1557 smear-positive TB patients registered under DOTS programme, the changes in weight ranged from a loss of 4 kgs to a gain of 20 kgs at the end of TB treatment; the average change in weight was 3.22 kgs. The gain in weight at the end of treatment was associated with age (<45 years), DOT at government centres, no problems in taking drugs as reported by patients and cure rate. CONCLUSION: The findings showed that there is an association between gain in weight with DOT at government centres and cure of patients.

DOTS reaches socially marginalized population in the community: a study from a rural area of South India.

We report here that the Directly Observed Treatment, Short course (DOTS) is reaching all tuberculosis patients in the community irrespective of social classification based on the analysis from the tuberculosis prevalence survey and programme performance during 1999-2003 from a rural area in Tamilnadu, South India. New smear- positive cases treated under a DOTS programme were classified in two groups namely; scheduled caste living in colony and other population. The prevalence of smear- positive cases among the scheduled caste population was 1.9 times higher than the other population and this was reflected in the notification also. The successful treatment outcome was also similar in these two groups (75% and 78% respectively; overall 77%). From these findings it is concluded that people living in colony have equal access to DOTS as those in the village.

Annual risk of tuberculosis infection in Chennai city.

AIM: To study the proportion of children infected with Mycobacterium Tuberculosis in Chennai city. METHODOLOGY: A cluster sampling methodology was adopted to select an estimated sample size of 7000 children from five corporation zones selected systematically from ten zones of the city. A total of 7098 children aged 1-9 years were subjected to Mantoux and test read; 1897 (27%) from slum area and 5201 (73%) from non-slum area. RESULTS: The prevalence of infection among children without BCG scar was estimated to be 10.5 % (ARTI of 2.0%) and was similar to that among children irrespective of scar status. The prevalence of infection was higher among children in slum areas (11.1%; ARTI 2.1%) compared to non-slum areas (8.9%; ARTI 1.7%); but the difference was not statistically different. CONCLUSION: The tuberculosis situation in Chennai as measured by risk of infection was higher in urban city area than rural areas and comparable to that found in other cities as reported from earlier studies. This information can be used as baseline information for monitoring the epidemiological trends in Chennai city in future.

Evaluation of different types of chest symptoms for diagnosing pulmonary tuberculosis cases in community surveys.

BACKGROUND: Prevalence of tuberculosis (TB) is an important epidemiological index to measure the load of the disease in a community. A series of disease surveys were undertaken in rural community in Tiruvallur district in Tamilnadu, south India OBJECTIVE: To investigate the yield of pulmonary tuberculosis (TB) cases by different symptoms status and suggest predominant symptoms for detection of cases in the community based surveys. METHODS: Three disease surveys were conducted during 1999-2006, in a random sample of 82,000 adults aged > or = 15 years to estimate the prevalence and incidence of pulmonary TB. All subjects were screened for chest symptoms and chest radiography. Sputum examination was done among those who were either symptomatic or abnormal on X-ray or both. Cases observed through symptom inquiry were included for analysis. RESULTS: In survey-I, 65.6% had cough of > or = 14 days and yielded 79.1% of the total cases. In surveys II and III, symptomatic subjects with cough contributed 69.5% and 69.2% of the cases respectively. In survey I, 26.8% had symptoms without cough but with at least chest pain > or = 1 month contributed 8.4% of total cases. The corresponding proportions in subsequent surveys were 29.3, 11.5%; and 23.4, 11.2% respectively. The number of symptomatics without cough and chest pain but with fever > or = 1 month was negligible. CONCLUSION: The relative importance of cough as a predominant symptom was reiterated. The yield of pulmonary TB cases from symptomatics having fever of > or = 1 month was negligible. Fever may be excluded from the definition of symptomatics for screening the population in community surveys.

Survival of tuberculosis patients treated under DOTS in a rural Tuberculosis Unit (TU), south India.

OBJECTIVE: To estimate survival probabilities and identify risk factors for death of tuberculosis (TB) patients during treatment period. METHODS: TB patients registered during May 1999 to December 2004 from a rural TB unit (TU) with a population of 580,000 in Tiruvallur district, South India, formed study population. Life table and Cox's regression methods were used. RESULTS: Of the 3818 TB patients who were initiated on treatment, 96, 94 and 97% of category--I, II and III respectively, were surviving after completion of treatment. Higher death rates were independently associated with patient's age (45 years), previous history of treatment, alcoholism and initial body weight (<35 kgs). CONCLUSION: The survival probability was found to be similar in all patients irrespective of categorization. Necessary actions need to be initiated in the programme to improve body weight and abstain from alcoholism.

Impact of improved treatment success on the prevalence of TB in a rural community based on active surveillance.

OBJECTIVE: To study the impact of improved treatment outcome of a cohort of patients treated under DOTS strategy on the prevalence of pulmonary tuberculosis (TB) in the community. DESIGN: The data from TB register of one Tuberculosis Unit (TU) in Tiruvallur district of Tamilnadu, and two TB disease surveys conducted in the same area during 1999-2003 were analysed. The successful treatment outcome was compared to the prevalence of TB in the subsequent cohort. RESULTS: The proportion of patients who completed treatment successfully was 75.3% in the first cohort period. This higher proportion of treatment success among patients treated under DOTS in the first cohort period (1999-2001) compared to the 51-55% reported during SCC, resulted in a lower prevalence of smear-positive cases, irrespective of culture results observed in the survey conducted during 2001-2003 compared to that in the survey conducted during 1999-2001 (252 vs. 323 per 100,000; annual decline of 9%). Similarly, a decline in culture-positive cases, irrespective of smear results, was also observed (443 vs. 605; annual decline 11%). CONCLUSION: The higher proportion of successful completion of treatment after DOTS implementation was associated with a substantial decline in the prevalence of TB. These findings showed that we are in the direction towards achieving the Millennium Development Goals (MDGs).

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 programme.

Status of re-registered patients for tuberculosis treatment under DOTS programme.

OBJECTIVE: To assess the proportion of patients re-registered after default, failure or successful treatment, completion and evaluate their treatment outcome. Setting: Tuberculosis patients diagnosed were registered for treatment under DOTS in rural area, South India. Patients reregistered during 1999-2004 identified from the TB register were considered for analysis. RESULTS: Among 273 Category-I patients 'defaulted' 23% and among 112 'failure' cases 68% were re-registered. After 'successful treatment completion' of 1796 cases 6.5% were re-registered as relapse. Corresponding figures for Category II were 20% of 281 defaulters; 23% of 60 failures; 12.9% of 302 'successful treatment completion' patients. Among patients re-registered as 'default', subsequent default was also high (57% vs 37%). Failure in Category II treatment was similar among patients who were re-registered for Category II and initially registered in it for treatment. Median delay for reregistration was >200 days for 'defaulters' and 18 days for 'failures'. CONCLUSION: Our findings emphasise the need for continuing motivation and prompt defaulter retrieval action to reduce default at all stages of treatment. 'Defaulters' need to be contacted so that they can be started on treatment without delay. Patients declared as 'successful treatment completion' should be encouraged to report if chest symptoms recur.

Impact of BCG vaccination on tuberculin surveys to estimate the annual risk of tuberculosis infection in south India.

BACKGROUND AND OBJECTIVES: Annual risk of tuberculosis infection (ARTI) computed from prevalence of infection measures the extent of tuberculosis transmission in the community and it is used to monitor the tuberculosis control programme. This is usually derived from tuberculin surveys among children not vaccinated with BCG. This study explores whether the estimated ARTI among BCG vaccinated children is comparable to that of unvaccinated children. METHODS: Three tuberculin surveys were undertaken among children aged >10 yr as part of assessing the impact of DOTS implemented in Tiruvallur district, south India. The prevalence of infection was estimated using the anti-mode method among vaccinated and unvaccinated children. The ARTI was computed separately and compared in all the three surveys. RESULTS: The prevalence of infection among unvaccinated and vaccinated children in the first survey were 7.8 per cent (95% CI: 7.1-8.6) and 7.9 per cent (95% CI: 7.1-8.8) respectively (ARTI was estimated to be 1.6 per cent in both groups) and the difference was not statistically significant. The corresponding figures for children test read in the second and third surveys were 6.9 per cent (95% CI: 6.2-7.6) and 6.8 per cent (6.0-7.5) and; 6.0 per cent (5.2-6.7) and 6.0 per cent (5.5-6.5) respectively. The computed ARTI was respectively 1.4 and 1.2 per cent among unvaccinated children in the second and third surveys; and 1.4 and 1.2 per cent among vaccinated children in the second and third rounds. INTERPRETATION AND CONCLUSION: There was no difference in the infection with Mycobacterium tuberculosis among vaccinated and unvaccinated children. BCG vaccinated children may thus be included for estimation of infection to assess the extent of transmission in the community as well as for monitoring purpose.

Influence of drug susceptibility on treatment outcome and susceptibility profile of failures to category II regimen.

Objective: To assess the influence of drug resistance on treatment outcome among patients treated with Category-II regimen and document drug susceptibility pattern of “Failures” to this regimen. Design: A retrospective analysis of patients registered from May 1999 through December 2004. Results: Treatment success was 42% among 572 patients and was similar among patients with fully susceptible or resistant but non-MDR organisms (41% of 254 and 40% of 128 patients, respectively). Among 49 MDR-TB patients, 27% had successful treatment outcome. The failure rates among patients with fully susceptible, resistant but non-MDR and MDR bacilli, were 6%, 12% and 27% respectively. Default was significantly higher among males (53% vs. 34%: p<0.01) smokers (57% vs. 36%: p <0.001), alcoholics (58% vs. 39%: p <0.001) and patients with higher initial smear grading (2+ or 3+, 56% vs. scanty or 1+, 44%: p <0.01). DST results were available for 60% (31 of 52) of failures and 10 had MDR-TB. Conclusion: The low success rate to the re-treatment regimen was mainly due to non-compliance. Failure was observed among 9% of patients and MDR-TB was 32% among Category II failures. The currently recommended Category II regimen appears to be adequate for majority of re-treatment cases.

Performance of a DOTS programme: Administrative and Technical Challenges - A field report from a district in south India.

Background: Performance of tuberculosis (TB) control programme depends on the functioning of health facilities (HFs). TB control programmes have been evaluated based on the programme indicators of conversion and cure. We have attempted to correlate the programme performance based on the availability of staff and their performance at the HF level. Objective: To correlate the performance of HFs to programme indicators, conversion and cure of patients treated under DOTS, in a district of south India. Design: Analysis of the data on new sputum smear-positive cases registered in 17 HFs during 1999-2003 was undertaken using TB register. The HFs with a low conversion or cure rates were identified and the reasons for the same were analysed. A scoring system was designed for the functioning of the HFs based on staff availability, supervision and review meetings which was correlated with programme performance. Univariate and multivariate analyses were performed. Results: Of 1893 new smear-positive patients registered during the study period, conversion was 1582 (83.6%) with cure rate of 76.4% (1447 of 1893), 254 (13.4%) default, 94 (5.0%) failure and 85 (4.5%) death. The conversion rates increased from 76% in 1999 to 87% in 2003; a statistically significant trend (c2 = 15.9; P<0.001). Similarly, a significant increase in trend (c2 = 4.0; P < 0.05) was observed in cure rates also (71 to 80%). The HFs were broadly classified into four groups namely; poor, fair, good and very good based on functioning scores .Correlation co-efficient was 0.77 between functioning of the HFs and conversion, and 0.76 between functioning and cure (P<0.01). Lack of regular review meetings was found to be independently associated with poor programme performance. Conclusion: Availability of staff such as Medical Officer, Laboratory Technician, and regular supervisory visits and review meetings are essential for a well functioning of programme. There is significant impact on DOTS with good functioning of HFs.

Association of conversion & cure with initial smear grading among new smear positive pulmonary tuberculosis patients treated with Category I regimen.

BACKGROUND & OBJECTIVES: Early diagnosis of tuberculosis (TB) is important for initiating treatment to gain cure. The present investigation was undertaken to study the association of conversion and cure with initial smear grading among pulmonary tuberculosis (TB) patients registered in a directly observed treatment - short course (DOTS) programme in Tiruvallur district, south India. METHODS: All new smear positive cases registered from May, 1999 to December, 2002 were analysed for conversion and cure related to initial smear grading. RESULTS: Of the 1463 patients, 1206(82.4%) were converted at the end of the intensive phase and 1109 (75.8%) were declared 'cured' after the completion of treatment. The cure rate decreased as the initial smear grading increased and the decrease in trend was statistically significant (P=0.01). Similarly, a significant decrease in conversion rate was also observed with increase in initial smear grading (P<0.001). In multivariate analysis, lower cure rate was significantly associated with patient's age (AOR=1.5, 95% CI=1.1-2.1), alcoholism (AOR=1.7, 95% CI 1.2- 2.4) and conversion at the end of intensive phase (AOR=3.5, 95% CI= 2.6-4.8). INTERPRETATION & CONCLUSION: Cure and conversion rates were linearly associated with initial smear grading. High default and death rates were responsible for low cure and conversion. The proportion of patients who required extension of treatment and those who had an unfavourable treatment outcome were significantly higher among patients with a 3+ initial smear grading. This reiterates the need to pay more attention in motivating these patients to return to regular treatment and sustained commitment in the control of tuberculosis. There is a need to extend the treatment for one more month in the intensive phase of treatment.

Sputum examination at 2-months into continuation phase - How much does it contribute to define treatment outcome.

Objective: To assess the usefulness of sputum examination at 2-months into Continuation Phase (CP) to declare treatment outcome. Methodology: It is a retrospective study conducted in one tuberculosis unit, Tiruvallur district of Tamilnadu among smear positive patients treated with Category I and Category II regimens from May, 1999 – December, 2003. Results: Sputum was collected at 2-months into CP from 70% of 1551 Category I and 74% of 292 Category II patients declared cure, failed or treatment completed. Result at 2-months CP was used for giving outcome in 112 (10.3%) of 1088 Category I patients and 37 (17%) of 217 Category II patients. Conclusion: In practice, sputum needs to be collected for 7.8% of the patients with smear positive at the end of Intensive Phase. By doing so, there will be a delay of 1 month for 3.6% of the patients in declaring ‘failure’. By deferring the sputum examination at 2 months into CP, workload of laboratory technicians can be reduced by about 30%.

Estimation of annual risk of tuberculosis infection among children irrespective of BCG scar in the south zone of India.

Objective: To estimate the proportion infected and compute Annual Risk of Tuberculosis Infection (ARTI) among children irrespective of BCG scar and compare with that among children without BCG scar. Methodology: Tuberculin survey was conducted in south zone of India as a part of the nation-wide survey to estimate the ARTI in different parts of the country and ARTI was computed among children without BCG scar excluding children with BCG scar. In this exercise, the tuberculin test results of children with BCG scar and irrespective of BCG scar were considered for analysis and the results were compared. Results: The prevalence of infection and ARTI estimated among children irrespective of BCG scar aged 1-9 years were 5.7% and 1.0% (95% C.I: 0.8-1.3) respectively. The corresponding figures among unvaccinated children were 5.9% and 1.0% (95% C.I: 0.7-1.4) respectively. The ARTI among children irrespective of BCG scar were similar to that among unvaccinated children. Conclusion: Estimation of proportion of children infected and computation of ARTI using mirror-image technique could be undertaken among children irrespective of BCG scar among children aged either from 1-9 years or 5-9 years.

Is it worth treating Category I failure patients with Category II regimen.

Background: Very little information is available on the drug susceptibility profile among patients who are treated with standardized short-course chemotherapy regimens under programme conditions. Methods: Sputum samples were collected from new sputum smear-positive patients declared ‘failure’ after treatment with Category I regimen under tuberculosis control programme using DOTS strategy from a rural area of Tamil Nadu. Results: Of 1463 patients started on Category I regimen between May1999 and December 2002, 74 cases were declared as ‘failures’ (smear positive at 5/6 months of treatment). We collected sputum samples from 60 (81%) of 74 ‘failures’ and 27% (16 of 60) of them were culture-negative for M tuberculosis and 17% (10 of 60) had organisms resistant to Isoniazid and Rifampicin (MDR TB). Conclusion: Based on the drug susceptibility profile at the time of ‘failure’, treating Category I ‘failures’ with Category II regimen with close monitoring appears to be justified.

Default during the intensive phase of treatment under DOTS programme.

Objective: To study default and its associated risk factors during the intensive phase of treatment among new sputum smear positive patients registered under a Directly Observed Treatment- Short Course (DOTS) programme in Tiruvallur district, Tamil Nadu. Design: Analysis of data collected from the Tuberculosis Register, treatment cards and interview schedules during May 1999 to December 2002. Results: Of the 1463 patients registered, drug regularity results were available for 1406 patients. The cure rate was 76% with an overall default rate of 15%, of which nearly three-fourth occurred during the intensive phase. The potential risk factors were identified by multivariate analysis. A higher likelihood of default was associated with age > 45 years (AOR=1.9; 95% CI=1.2-3.0), illiteracy (1.6; 1.0-2.4), alcoholism (2.7; 1.8-4.2), DOTS inconvenience (1.9; 1.1-3.4) and cases identified and referred by the community survey (1.8; 1.1-3.0). Of the 75 defaulters from two cohort periods visited separately, 53 defaulted during the intensive phase. Among these, only 31 patients were interviewed since 17 (32%) migrated, three died, one was untraceable at the address provided while another had treatment elsewhere. Drug related (84%) and work related (32%) problems were the other reasons for default reported by the patients interviewed. Conclusion: The majority of defaults occurred during intensive phase of treatment. All efforts should be made to retrieve these patients and return them to treatment to achieve the expected goal of the RNTCP.

Estimation of burden of tuberculosis in India for the year 2000.

BACKGROUND AND OBJECTIVE: Data on the burden of tuberculosis (TB) in India are vital for programme planners to plan the resource requirements and for monitoring the nation-wide TB control programme. There was a need to revise the earlier estimate on the burden of TB in India based on the increase in population and current epidemiological data. This study estimates the burden of disease for the year 2000 based on recent prevalence of TB and annual risk of tuberculosis infection (ARTI) estimates. METHODS: Data on prevalence generated among adults by the Tuberculosis Research Centre (TRC), Chennai, among children by National Tuberculosis Institute (NTI), Bangalore, and the ARTI estimates from the nation-wide sample survey by NTI and TRC were used for the estimation. The prevalence of disease corresponding to 1 per cent ARTI was extrapolated to different parts of the country using the estimates of ARTI and the population in those areas and added together to get the total cases. Abacillary cases that required treatment were estimated from X-ray abnormals. The estimates of bacillary, abacillary and extrapulmonary cases were then combined to get the national burden. RESULTS: The estimated number of bacillary cases was 3.8 million (95% CI: 2.8-4.7). The number of abacillary cases was estimated to be 3.9 million and that for extrapulmonary cases was 0.8 million giving a total burden of 8.5 million (95% CI: 6.3-10.4) for 2000. INTERPRETATION AND CONCLUSION: The present estimate differs from the earlier estimates because we have included the disease burden of X-ray cases that are likely to breakdown to bacillary cases in a one year period, and extrapulmonary TB cases. The current estimates provided baseline information for advocacy and planning resource allocation for TB control activities. Also, these estimates can be compared with that in future years to measure the long term impact of TB control activities in India.

Failure to initiate treatment for tuberculosis patients diagnosed in a community survey and at health facilities under a dots programme in a district of south India.

We studied the proportion and fate of tuberculosis patients who were not initiated on treatment (initial defaulters) in Tiruvallur district of Tamilnadu, where DOTS strategy was implemented. These patients were visited to find out the reason for default. Treatment was not initiated in 57 (23.5%) of the 243 sputum positive cases diagnosed in a community survey and 156 (14.9%) of 1049 patients diagnosed in health facility. Men were more likely not to have treatment initiated. The common reasons stated for initial default were unwillingness, symptoms being mild, personal reasons and dissatisfaction. There is an urgent need to improve the patient’s perception of treatment and strengthen the health systems’ capabilities to reduce initial default.