Our analyses revealed that the majority of the participants had heard about TB, though their knowledge about TB transmission was low. It also provided national level prevalence estimates for TB, which is comparable to routine programmatic data. The highlights of our analyses were that nearly half the population knew that TB transmission occurs through air when coughing or sneezing but only a quarter knew about correct mode of TB transmission i.e. without having any misconceptions about it. Encouragingly, the majority of participants knew that TB can be cured and this was associated with having correct knowledge about TB transmission. Among the traditional mass media, only listening to the radio was associated with correct knowledge about TB transmission. From our results, we may interpret that widespread publicity about DOTS may have improved the general awareness about TB, and specifically about the cure for TB. Our results may be useful for managers and policy makers of RNTCP and emphasized the need for evaluation of the IEC activities undertaken by RNTCP.
The strength of our analyses was the calculation of national level prevalence estimates for self-reported TB, and knowledge about transmission of TB from a large representative sample of adult men and women. Our report also includes misconceptions and the stigma about TB which are scarce in the literature. Despite these strengths, we had some limitations and our results should be interpreted with caution. The DHS questionnaire inquired mainly about the modes of transmission but not about TB symptoms and treatment availability. Respondents were not asked about the sources of information about TB. Estimates of self-reported TB in rural areas may have been flawed due to lack of awareness about TB symptoms, low education and the stigma attached with the disclosure of TB. DHS interviewers were well trained to extract such information. However, there may have been an over-estimation of self-reported TB and DHS did not have any means to verify self-reported TB by laboratory tests. Assessing the determinants of correct knowledge about TB transmission using a cross-sectional data lacks temporality to interpret a cause-effect relationship.
The prevalence of self-reported TB in our analysis was more than the estimated TB prevalence reported by WHO and from the annual reports of the Ministry of Health (MOH), Government of India (GOI) [5, 9]. It is not clear from our analysis, if there was under-reporting because the questions asked during the survey were not specific to pulmonary and extra-pulmonary TB. Moreover, extra-pulmonary TB which is less known in the general population may not have been reported by the survey respondents. Despite the skepticism regarding self-reports about health and disease status in surveys, we believe that self-reported TB in DHS is reliable [26, 27]. The data are comparable to existing reports on TB burden in India [5, 9]. The socio-economic patterning of TB was in accordance with the previous reports [28–30]. TB experts have recommended that socio-economic data should be measured during TB surveys . However we did not perform further analysis on determinants of TB using other explanatory variables since in this survey TB was a self-report. Higher prevalence of TB in rural areas and in North-Eastern and Eastern states is also in accordance with annual reports of MOH, GOI .
Several studies from different countries about awareness, perceptions, attitudes, and treatment seeking behaviors for TB have reported that awareness about TB in the general population is poor and treatment seeking behavior is not appropriate [15, 21, 23, 32–36]. However, most of these except our study and a report from Bangladesh  were small scale surveys and lacked the implications on policy making at the national level. A good knowledge about TB symptoms in the general population may help to improve health-care seeking behavior of patients . Knowledge about transmission of TB is also important to protect oneself from infection with TB by following cough etiquette and respiratory hygiene which are critical in preventing TB transmission . Our results suggest that prevention of TB transmission in the general population of India is less likely since people did not know the correcmode of TB transmission and people had misconceptions about it. In the neighboring country of Bangladesh, the proportion of women knowing correctly about TB transmission was much lower . Correct knowledge about TB transmission was associated with education and income, but among mass media, only the frequency of listening to radio was associated with correct knowledge which was similar to the results reported from Bangladesh . Inadequate knowledge about TB transmission in India may be due to lack of IEC messages about TB transmission before and during the time of DHS survey i.e. 2005–06. The IEC messages which focused on symptoms, curability and availability of treatment (DOTS) were disseminated by the RNTCP, which implements TB control activities in India. The IEC activities were meant to achieve the targets in terms of case detection rate and cure rates set by RNTCP. In pursuit of these targets, RNTCP program planners may have missed the inclusion of messages about TB transmission. However, recently, the pamphlets about facts of TB contain the message “TB is spread through coughing or sneezing of a TB patient.” While case detection and cure of TB is secondary prevention, prevention of TB transmission before infectious cases are diagnosed and treated is primary prevention. We emphasize that primary prevention cannot be overlooked considering the reports about diagnostic delays in high burden countries [11, 12].
Currently, knowledge about symptoms and transmission of TB, stigma about TB, and health seeking behavior for TB are not measured in program evaluation. Inclusion of such indicators into periodic program evaluation may serve as a guide to improve the program’s performance. Two studies about the evaluation of IEC activities of RNTCP done in New Delhi have reported about issues other than TB transmission and have called for an improvement in IEC strategies [16, 18]. Lack of association of correct knowledge about TB transmission with traditional mass media such as television, newspapers and magazines shows the need for using other means to disseminate IEC messages about TB [16, 18]. This may be due to lower levels of literacy prevailing in India. People belonging to the poorest wealth quintiles were more likely to have TB while the frequency of listening to radio was associated with knowledge about TB transmission. Since radio is more affordable to the poorest people, radio may be used to intensify IEC activities. TB control program planners should also consider primary prevention in addition to early diagnosis and treatment. The regional differences in TB prevalence and knowledge of TB transmission should be considered in program planning. Areas with high TB prevalence and lower knowledge may need advocacy, communication and social mobilization as recommended by STOP-TB initiative [13, 14, 19]. Nation-wide surveys like DHS provide a good opportunity to study further about TB knowledge and health behavior towards TB. Future DHS surveys may include questions about the knowledge of TB symptoms and treatment seeking behavior among people having cough lasting three weeks or more. As DHS surveys are not done frequently, RNTCP could consider inclusion of TB knowledge, and health-care seeking behavior for TB in their program evaluation to assess the impact of IEC activities on the diagnosis of TB .