The Annual Report of National Tuberculosis Program (2014) shows that the case notification rate (CNR) of all forms of TB has remained stagnant for last 10 years in Nepal even when each layered and analyzed in the regional/ eco-terrain level. So, the Government of Nepal needs to know the reality of TB prevalence in the country instead of being based on estimates of it by WHO. This is very important for Nepal so that evidence based TB control program and activities can be designed and implemented to move the country towards “End TB” strategy. Therefore, understanding the actual burden of TB in Nepal by National TB Prevalence Survey (NTPS) is considered to be very important for developing appropriate strategies/plans for effective TB control program in Nepal. The prevalence of TB is the number of TB cases that exist in the population at a given point in time. It is usually reported as the total number of prevalent cases in a country, or as the number of prevalent cases for a given unit of population e.g. the number of cases per 100000« population. The survey is cross-sectional and population-based study to identify number of people with TB disease among the sample population.
In this survey, all survey participants will be screened using interviews and chest Xrays. Sputum samples are then taken from all those with abnormal chest X-rays suggestive to TB and/or symptoms suggestive of pulmonary TB and are tested in laboratories to identify individuals with bacteriologically-positive pulmonary TB (that is, Xpert MTB/RIF detected pulmonary TB, smear positive TB and/or culture-positive TB). A Case for NTPS is when an eligible survey participant has at least one Xpert MTB/RIF+ve (GX+) result, given that the result is not regarded as cross contaminated, among any of the two specimens tested (Spot and Morning). The survey focuses on the measurement of pulmonary TB among adults. Yet, it cannot meaure the prevalence of extra-pulmonary TB among adults or the prevalence of TB disease in children.
Gen Xpert has been used as a main tool in this survey which has been identified as an innovative and useful system for rapid detection of TB and identification of Rifampicin (RIF) resistance. The results are found to be superior to smear microscopy and comparable to culture. NTPS will be mainly based on Xpert/MTB testing through Gen Xpert machine rather than culture because country‟s lab capacity is limited to carry out huge volumes of culture at the time of survey and Xpert/MTB testing has proven to be useful in other countries carrying out prevalence survey.
Cross sectional population based study will be conducted for thissurvey in 99 clusters. Sampling population will be people with age ≥ 15 years of selected clusters and total sample size is 57610.
Goal and objectives of survey
The goal of survey is to gain a better understanding of the burden of disease caused by TB in the community of Nepal.
- To measure the prevalence of overall Xpert MTB/RIF detected pulmonary TB among 15 years population in Nepal in 2017.
- To extrapolate prevalence of bacteriologically confirmed TB prevalence based on the results of culture and Xpert MTB/RIF tests.
- To describe the health seeking behaviour of people with TB symptoms.
- To describe the health service (TB services) utilization practices of participants who have or had TB disease.
Timeline of National TB Prevalence Survey
Timeline of NTPS
|Final Protocol||Jan, 2017|
|Ethical clearance from Nepal Health Research Council (NHRC)||By June, 2017|
|Data management software for PS developed by||By end of June or mid- July|
|The outsource agency for field work selected by||By end of May, 2017|
|Pretesting of Tools||By end of July 2017|
|Training completed (central and field staffs)||By August 2017|
|Piloting (also include pre-visit)||By September, 2017|
|*From Sept 19 to October 27- National Festival and public holiday in most of those days|
|Pre-visit I||By November 2017 (50 clusters)|
|Field work I||December 2017- June 2018 (1 month of mid-term review in between)|
|Mid Term review||March 2018 (RIT and WHO)|
|Pre-visit II||July 2018 (49 clusters)|
|Field work II||August 2018 – March 2019|
|* Tentatively from Sept 19 to October 27- National Festival and public holiday in most of those days.|
|Data analysis, report write up and dissemination||Aug-19|
Based on the timeline set, NTPS Protocol is expected to be finalized and endorsed by Ministry of Health by Jan 2017. In order to conduct the survey, ethical approval by National Health Research Council is expected by June, 2017. The NTPS is a paperless survey, so, an outsource agency (OSA) will be recruited to develop forms/ formats in software form and data management system to be used in survey. Similarly, an OSA for field operation will be selected. All the tools that will be used in survey, will be pre-tested before going for training of NTPS staffs. By September 2017, piloting of NTPS will be done in three clusters. Pre-visit and field operation has been planned into two phases for the study. In first phase, pre-visit will be done in 50 clusters followed by field operation in those clusters. Mid-term review of NTPS will be done in March, 2018. Pre-visit and field operations of remaining 49 clusters are expected to complete by March 2019. After that, data analysis will be done and report will be written. The NTPS report is expected to be disseminated by August, 2019.