Tuberculin Survey Research Articles

Tuberculin skin test surveys and the Annual Risk of Tuberculous Infection in school children in Northern KwaZulu-Natal.

Tuberculin skin test surveys in primary school children can be used to quantify Mycobacterium tuberculosis transmission at community level. KwaZulu-Natal province, South Africa, is home to 11.5 million people and suffers a burden of tuberculosis disease that is among the highest in the world. The last tuberculin survey in the province was undertaken in 1979. We performed a tuberculin skin test survey nested within a demographic and health household surveillance programme in Northern KwaZulu-Natal. We enrolled children aged between six and eight years of age attending primary schools in this community. Mixture analysis was used to determine tuberculin skin test thresholds and the Annual Risk of Tuberculous Infection derived from age at testing and infection prevalence. The Community Infection Ratio, a measure of the relative importance of within-household and community transmission, was calculated from data on tuberculin positivity disaggregated by household tuberculosis contact. Between June and December 2013, we obtained tuberculin skin test results on 1240 children. Mixture analysis proved unstable, suggesting two potential thresholds for test positivity. Using a threshold of ≥10mm or treating all non zero reactions as positive yielded estimates of the Annual Risk of Tuberculous Infection of 1.7% (1.4-2.1%) or 2.4% (2.0-3.0%). Using the same thresholds and including children reported to be receiving TB treatment as cases, resulted in estimates of 2.0% (1.6-2.5%) or 2.7% (2.2-3.3%). The Community Infection Ratio was 0.58 (0.33-1.01). The force of infection in this community is lower than that observed in Western Cape province, South Africa, but higher than that observed in community settings in most other parts of the world. Children in this community are commonly infected with Mycobacterium tuberculosis outside the home. Interventions to interrupt transmission are urgently needed.

Disease Transmission by Patients With Subclinical Tuberculosis.

Subclinical tuberculosis has been increasingly recognized as a separate state in the spectrum of the disease. However, evidence on the transmissibility of subclinical tuberculosis is still inconclusive. We re-analyzed the data from the 2007 combined tuberculosis prevalence and tuberculin surveys in Vietnam. Poisson regression with robust standard errors was conducted to assess the effect of clinical presentation of individuals with tuberculosis in the household on tuberculin skin test (TST) positivity among children aged 6-14 years who participated in the tuberculin survey, adjusting for child's age, smear status of the index patient, and other covariates. In the multivariate analysis, we found significantly increased risks for TST positivity in children living with patients with clinical, smear-positive tuberculosis, compared with those living with individuals without tuberculosis (adjusted risk ratio [aRR]: 3.04; 95% confidence interval [CI]: 2.00-4.63) and with those living with patients with subclinical tuberculosis, adjusting for index smear status (aRR: 2.26; 95% CI: 1.03-4.96). Among children aged 6-10 years, those living with patients with clinical, smear-positive tuberculosis and those living with patients with subclinical, smear-positive tuberculosis had similarly increased risks of TST positivity compared with those living with individuals without tuberculosis (aRRs [95% CI] of 3.56 [1.91-6.62] and 3.11 [1.44-6.72], respectively). Our findings support the hypothesis that smear-positive subclinical tuberculosis contributes to Mycobacterium tuberculosis transmission. To eliminate tuberculosis in 2035, control strategies need to address subclinical presentations of the disease.

A Measure of Transmission of Tuberculosis Infection among Children in Household Contact

Introduction: Tuberculosis (TB) is transmitted through droplets from patients having pulmonary TB, Young children living in the same household are at higher risk Tuberculosis, with great potential to benefit from screening and preventive treatment. This study was conducted with the objectives to estimate the prevalence of TB infection among under five years old children in household contact with pulmonary tuberculosis patients, and assess the factors associated with transmission of TB.
 Methods: Pulmonary TB patients receiving treatment from the DOTS Centres in Sunsari District (Index Case-IC) were visited in their household to identify and assess contacts below five years of age. Transverse induration greater than10 mm was defined as a positive Mantoux test suggestive of tubercular infection.
 Results: Among 190 household contacts, Mantoux was positive in 13.7% (95%CI: 11.2-16.2). Higher sputum bacillary load (adjusted OR=3.03; 95% CI 1.01-9.1) and spitting habits of Index Cases (aOR=3.1; 95% CI 1.2-7.7), first-degree relationship (aOR=3.5; 95%CI 1.4-8.7) and longer duration of contact (aOR- 6.7; 95% CI 1.4-32.2), were factors significantly associated with positive Mantoux test in the under-five years old household contact.
 Conclusion: The prevalence of tuberculosis infection among under-five children in contact with pulmonary tuberculosis patients was 13.7%, which is nearly double than the results of first national tuberculin survey (7%), conducted by National Tuberculosis Centre. This highlights the need for a competent & functioning contact tracing mechanism to halt the chain of transmission of infection. Social and behavioral factors existing in the household were significantly associated with the transmission of Tuberculosis infection.

Tuberculin survey in Bangladesh, 2007–2009: prevalence of tuberculous infection and implications for TB control

To assess the prevalence of tuberculous infection and the annual risk of tuberculous infection (ARTI) for 2007-2009 in Bangladesh, approximately 45 years after the first tuberculin survey in 1964-1966. A tuberculin survey was conducted along with the National Tuberculosis Disease Prevalence Survey in 2007-2009. This was a multistaged community-based, cross-sectional survey, including 17,718 children aged 5-14 years. The prevalence of tuberculous infection was estimated using the mixture method and a cut-off point of ≥ 8 mm. The prevalence of infection was 10.0% (interquartile range [IQR] 8.6-12.2) in children aged 5-9 years and 17.9% (IQR 15.4-20.2) in those aged 10-14 years using the mixture analysis. Prevalence was 12.4% (95% confidence interval [CI] 11.7-13.1) in children aged 5-9 years and 22.6% (95%CI 21.6-23.4) in those aged 10-14 years using a cut-off point of ≥ 8 mm. The estimated ARTI was respectively 1.5% and 1.7% in 5-9 and 10-14 year olds using the mixture method and respectively 1.9% and 2.1% using the cut-off method. The moderate reduction in the prevalence of infection and slow decline of the ARTI after two decades of DOTS implementation indicates considerable ongoing transmission.

First national tuberculin survey in Viet Nam: characteristics and association with tuberculosis prevalence

To estimate the prevalence of infection with Mycobacterium tuberculosis and the annual risk of tuberculous infection (ARTI) and to compare this with the prevalence of tuberculosis (TB) over study clusters and households. A nationwide, stratified cluster sample survey was carried out in 2006-2007 in Viet Nam to assess the prevalence of infection with M. tuberculosis. A representative sample of children aged 6-14 years underwent a tuberculin skin test (TST) using the Mantoux method. Of 23,160 children registered, 21,487 (92.8%) were tested and read and available for analysis. Using a cut-off point of 10 mm, the estimated prevalence of TST positivity was 16.7%, and the ARTI was 1.7% (95%CI 1.5-1.8). Higher infection rates were found in urban than in rural and remote areas, and infection rates increased with age. There was significant association between the prevalence of TB disease and infection at the cluster level (regression coefficient 0.54, 95%CI 0.06-1.01, P = 0.027, correlation coefficient R(2) 0.120). Children with a (recent) case of TB in the household were 1.6 times more likely to be TST-positive than children in households with no recent cases (P < 0.05). The estimated nationwide ARTI was 1.7%. TST positivity was associated with the presence of a TB case in the household.

Mycobacterium tuberculosisComplex in Remains of 18th–19th Century Slaves, Brazil

<i>Mycobacterium tuberculosis</i>Complex in Remains of 18th–19th Century Slaves, Brazil

Annual risk of tuberculous infection among schoolchildren in Bhutan

School-based survey in the mountainous nation of Bhutan. To estimate the annual risk of tuberculous infection (ARTI) among children aged 6-8 years. A national-level tuberculin survey was carried out among children attending 64 schools selected by two-stage cluster sampling. The study population was comprised of children without and with bacille Calmette-Guérin (BCG) scar. Tuberculin testing was performed using 2 tuberculin units of purified protein derivative RT23. The maximum transverse diameter of induration was measured at 48-72 h. Of 6087 satisfactorily test-read children, 82% had a BCG scar. The frequency distribution of tuberculin reaction sizes in all children (with and without BCG scar) did not reveal the mode for tuberculous reactions. The mode seen at 17 mm among children without BCG scar was applied to estimate the prevalence of infection among all children using the mirror-image method. Estimation was also undertaken by shifting the mode by 1 mm on either side. The ARTI computed from the prevalence thus estimated varied between 0.2% and 0.7%. There was no difference in the prevalence of infection by BCG scar status, implying that the estimated ARTI was not influenced by BCG-induced tuberculin sensitivity. The ARTI has declined in Bhutan compared to the 1991 survey estimate of 1.9%.

Annual risk of tuberculosis infection in Sri Lanka: a low prevalent country with a high BCG vaccination coverage in the South-East Asia Region.

Despite its simplicity, efficiency and reliability, Sri Lanka has not used the Annual Risk of Tuberculosis Infection (ARTI) to assess the prevalence and efficiency of tuberculosis (TB) control. Hence, a national tuberculin survey was conducted to estimate the ARTI. A school-based, cross-sectional tuberculin survey of 4352 children aged 10 years irrespective of their BCG vaccination or scar status was conducted. The sample was selected from urban, rural and estate strata using two-stage cluster sampling technique. In the first stage, sectors representing three strata were selected and, in the second stage, participants were selected from 120 clusters. Using the mode of the tuberculin reaction sizes (15 mm) and the mirror-image technique, the prevalence and the ARTI were estimated. The prevalence of TB estimated for urban, rural and estate sectors were 13.9%, 2.2% and 2.3%, respectively. The national estimate of the prevalence of TB was 4.2% (95% CI = 1.7-7.2%). ARTI for the urban, rural and estate sectors were 1.4%, 0.2% and 0.2%, respectively, and the national estimate was 0.4% (95% CI = 0.2-0.7%). The estimated annual burden of newly infected or re-infected TB cases with the potential of developing into the active disease (400/100 000 population) was nearly 10-fold higher than the national new case detection rate (48/100 000 population). The national estimate of ARTI was lower than the estimates for many developing countries. The high-estimated risk for the urban sector reflected the need for intensified, sector-specific focus on TB control activities. This underscores the need to strengthen case detection. Repeat surveys are essential to determine the annual decline rate of infection.

Tuberculosis score chart signs and symptoms in children with positive tuberculin skin tests

Background The Indonesian Pediatrics Respirology WorkingGroup (IPRWG) developed the tuberculosis (TB) scorechart to assist in diagnosing TB in community health centers(Puskesmas).Objectives To document signs and symptoms of the IPRWG TBscore chart, to analyze various combinations of these signs andsymptoms, and to compare these combinations in children withTB to those without TB, based on a TB score chart.Methods We performed a cross-sectional study from July toOctober 2008, in Padang, Bukittinggi and Pasaman. We recruitedchildren with known positive tuberculin skin tests (TST) from a2006 tuberculin survey. Questionnaires on signs and symptoms(IPRWG TB score chart) were completed and chest radiographswere obtained for all children. Subjects fulfilling a total score ofsix or more were considered to have a diagnosis of TB.Results We diagnosed TB in 78/285 (27.3%) subjects. A scorevalue of3 for the category of household contact (HHC) positivesmears was added in 21/78 subjects. However, the highest risk forTB disease was found in those diagnosed with no clear history ofHHC (58.9%; OR 192, 95% CI 22 to 1679). The highest riskfactors for TB were suggestive chest X-ray (34.6%; OR 9.2, 95%CI 3.6 to 23 .4) and fever lasting &gt; 2 weeks (17.9%; OR 8, 95%CI 2.2 to 29.1), respectively. Of 46 children with TB diagnosisbut without HHC, the combination of undernourishment, lymphnode enlargement and suggestive chest X-ray was highest (28.2%).Individual or dual combination signs and symptoms were alsofound in children without TB diagnosis.Conclusion Various combinations of signs and symptoms couldlead to fulfillment of scoring for TB diagnosis. [Paediatr lndones.2012;5 2: 78-85].

Prevalence and annual risk of tuberculosis infection in rural Mysore

We carried out a tuberculin survey among 5-10 years old children in rural Mysore (n=1026) to estimate the annual risk of tuberculosis infection (ARTI). 90.8% of them had BCG scar. The prevalence of infection was estimated as 13.3% with 95% CI of 11.4-15.5 and ARTI as 1.38%. These figures are comparatively higher than what is reported from other places in India.

Annual risk of tuberculosis infection among the tribal children of Jhabua, Madhya Pradesh

A cross sectional tuberculin survey was undertaken to estimate the Annual Risk of Tuberculosis Infection (ARTI) amongst tribal children aged 1-9 years in Jhabua district, Madhya Pradesh, India. Of the 1056 test-read children, 774 (73.3%) had no BCG scar. The prevalence of infection was estimated as 6.3% (95% CI: 4.8-7.7) and ARTI as 1.2% (95% CI: 0.9-1.5). The findings suggest that the tuberculosis situation in the tribal population of Jhabua district is not that different from the situation among the non-tribal population in the country. However, there is a need to further intensify tuberculosis control measures in the area.

A tuberculin skin test survey among Ghanaian school children

BackgroundGhana has not conducted a national tuberculin survey or tuberculosis prevalence survey since the establishment of the National Tuberculosis Control Programme. The primary objective of this study was therefore to determine the prevalence of tuberculin skin sensitivity in Ghanaian school children aged 6-10 years in 8 out of 10 regions of Ghana between 2004 and 2006.MethodsTuberculin survey was conducted in 179 primary schools from 21 districts in 8 regions. Schools were purposively selected so as to reflect the proportion of affluent private and free tuition public schools as well as the proportion of small and large schools.ResultsOf the 24,778 children registered for the survey, 23,600 (95.2%) were tested of which 21,861 (92.6%) were available for reading. The age distribution showed an increase in numbers of children towards older age: 11% of the children were 6 years and 25%, 10 years. Females were 52.5% and males 47.5%. The proportion of girls was higher in all age groups (range 51.4% to 54.0%, p < 0.001). BCG scar was visible in 89.3% of the children. The percentage of children with a BCG scar differed by district and by age. The percentage of children with a BCG scar decreased with increasing age in all districts, reflecting increasing BCG vaccination coverage in Ghana in the last ten years. The risk of tuberculosis infection was low in the northern savannah zones compared to the southern coastal zones. Using a cut-off of 15 mm, the prevalence of infection ranged from 0.0% to 5.4% and the Annual Risks of Tuberculosis Infection 0.0% to 0.6%. There was an increase in the proportion of infected children after the age of 7 years. Children attending low and middle-class schools had a higher risk of infection than children attending upper-class schools.ConclusionTuberculosis infection is still a public health problem in Ghana and to monitor the trend, the survey needs to be repeated at 5 years interval.

Prevalence of Mycobacterium tuberculosis infection in children in western Uttar Pradesh

This study was conducted to estimate the prevalence of tubercular infection and compute the Annual risk of tuberculosis infection (ARTI) in Bijnor district of western Uttar Pradesh through a hospital-based tuberculin survey conducted at a pediatric hospital. A total of 1085 children below 18 years (0-4 years 866, 5-17 years 219), attending the out-patient department during October 2007 through September 2008 were included. Tuberculin skin test using standard PPD RT23 with Tween 80 was performed on every 4th child attending the out-patient department and induration was measured after 48 to 72 hours. Using a cut-off of 15 mm among 0-4 y aged children, the average prevalence rate was 7.4%, and using cut-off of 10 mm in 5-17 y age group the average prevalence rate was 26.9%. ARTI was 4.11% (95% CI 3.09-5.14) and 3.50 % (2.46-4.48), respectively in the two age groups.

Annual risk of tuberculosis infection among tribal population of central India

To estimate the annual risk of tuberculosis infection (ARTI) among tribal children of Madhya Pradesh, central India. 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. 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. 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.

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 11 mm and a mode at 18 mm 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.

Tuberculin survey among school-aged children in Ahvaz, Iran, 2006

The tuberculin test is widely used for the diagnosis of tuberculosis (TB) in children, as it is the only one to provide evidence of infection with Mycobacterium tuberculosis. Our objective was to estimate the prevalence of TB infection, the annual risk of infection (ARI), and the incidence of active TB in school children. A cross-sectional study was carried out in Ahvaz, a city of southern Iran, in 2006. A questionnaire was used to collect information, including demographic characteristics, bacillus Calmette-Guérin (BCG) vaccination history, and household contact with active TB. Tuberculin testing was performed. Reactivity that measured < 5 mm was considered negative, between 5 and 9 mm was considered doubtful, and > or = 10mm was considered positive. Chest radiographs were obtained as part of the evaluation for children with a positive result. A total of 3906 children with a mean+/-standard deviation (SD) age of 10.59+/-2.63 years (51% female, 49% male) were entered into our study. Of these, 3338 children (85.5%) did not develop a reaction (0mm), 243 (6.2%) had reactivity of 1-4mm, 238 (6.1%) had reactivity of 5-9 mm, and 87 (2.2%) had reactivity of > or = 10 mm. More than 90% of the children had received the BCG vaccine in the first week of life. The ARI rate was 0.5% and the estimated case of smear-positive TB was approximately 25 per 100000 population. Only three children were diagnosed with active TB, a prevalence of 75 per 100000 population. Tuberculin testing using 5TU-PPD (5 tuberculin units of purified protein derivative) is a valuable diagnostic test for latent TB and active TB in childhood. BCG vaccination has no remarkable effect on the interpretation of tuberculin reactivity. The incidence rate of active pulmonary TB in children in the region of study is of concern.

Tuberculin Survey to Estimate the Prevalence of Tuberculosis Infection of the Elementary Schoolchildren under High BCG Vaccination Coverage

Background: Although the prevalence of tuberculosis infections (PTBI) is one of the basic epidemiologic indices, no survey has been carried out since 1995 because the nation-wide tuberculosis prevalence survey was changed to a surveillance system. Subjects without a BCG scar are examined in a tuberculin survey. However, it is very difficult to select these subjects under high vaccination coverage. It is important to evaluate the impact of BCG vaccinations on the tuberculin response and estimate the PTBI regardless of the BCG vaccination status. Methods: A nation-wide, school-based cross-sectional tuberculin survey was carried out among first graders in elementary school in 2006. A total of 5,148 children in 40 schools were selected by quota sampling. Tuberculin testing with 0.1 ml of two tuberculin units of PPD RT23 was carried out on 4,018 children. The maximum transverse diameter of induration was measured 48 to 72 hours later. The presence of a BCG scar was checked separately. Results: There were no BCG scars in 6.3% of the subjects. The mean induration size of tuberculin testing was , which included 1,882 (46.8%) subjects with an induration size of 0 mm. The PTBI was 10.9% (439 subjects) using a cut-off point of (conventional method). The annual risk of tuberculosis infections (ARTI) was 1.9% when the mean age of the subjects was assumed to be 6 years. There was no difference in the PTBI according to the presence or absence of a BCG scar [11.2% vs 7.6% (OR: 1.54, 95% CI: 0.98~2.43)]. Using a mirror image technique with 16 mm as the cut-off point, the PTBI and ARTI had decreased to 2.4% and 0.4% respectively. Conclusion: PTBI and ARTI, as estimated by conventional methods, appear to be high among BCG vaccinated children. A mirror image technique is more suitable for estimating the indices in a country with an intermediate burden of tuberculosis than the conventional method.

Viewpoint: do we have enough data to estimate the current burden of tuberculosis? The example of Bangladesh

National tuberculosis (TB) programmes need accurate estimates of the burden of TB in order to assess case detection, and progress towards the millennium development goals (MDGs). We reviewed nationwide epidemiological data on TB burden in Bangladesh to decide whether additional information is needed, in order to assess the current burden of TB. We collected all nationwide epidemiological information: notification data for the period 1995-2004; reports of TB prevalence surveys in 1964-1966 and 1987-1988 and a tuberculin survey in 1964-1966. Data were evaluated for usefulness to provide information about the current burden of TB. The TB prevalence surveys from 1964 to 1966 and 1987 to 1988 provide very different results, respectively, 127/100 000 and 471/100 000 smear positives. In 1964-1966, the annual risk of infection was 0.6% in the 5- to 9-year age group and 1.2% in those aged between 10 and 14 years. The notification data show an increase from 18/100 000 in 1995 to 46/100 000 smear positives in 2004. Interpretation and extrapolation of the existing epidemiological data of Bangladesh to estimate the current burden of TB is difficult. Many of the 22 high-burden countries have as few or even less survey data than Bangladesh. To enable the evaluation of progress towards the MDGs and to be able to assess the global burden of TB, epidemiological surveys are needed.

The impact of the HIV epidemic on tuberculosis transmission in Tanzania

To assess the impact of the HIV epidemic on tuberculosis transmission in Tanzania by estimating the trend in annual risk of tuberculosis infection (ARTI) over the period 1983-2003. Tuberculin survey among school children aged 6-14 years, randomly selected by cluster sampling. Primary outcome was the ARTI among children without a BCG vaccination scar. To obtain time trends, data were reanalysed from three previous surveys carried out at intervals of 5 years since 1983, using identical methods and definitions. Of 96,226 children included in the analysis (74% of those enrolled), 10,239 (11%) had no BCG scar. The ARTI was 0.68% (95% confidence interval 0.55-0.81). Despite a doubling of notification rates of smear-positive tuberculosis since 1983, this represents an average annual decline since the first survey of 2.7% (P < 0.001). The declining trend in ARTI was observed in 17 of 20 regions, with no association between this trend and region-specific prevalence of HIV infection among patients with tuberculosis (P = 0.575). A similar decline in ARTI was observed among children with a BCG scar and for various ways of estimating the prevalence of tuberculosis infection from the distribution of skin test reactions. Despite substantial increases in tuberculosis incidence, the overall population-level effect of the HIV epidemic on tuberculosis transmission in Tanzania has been limited. This suggests that in the presence of a strong control programme, the HIV epidemic has limited impact on tuberculosis transmission.

Tuberculin Survey in Government High School of Dharan Municipality

This survey was done in 682 out of 1672 children tested with Batch of Tuberculin used for Testing (PPD RT 23 with Tween 80) in Jan. 1997 with financial research grant of B.P. Koirala Institute of Health Sciences, Dharan. Dharan City is situated in Eastern Development Region (EDR) of Nepal where a high percentage of migrated population is residing with very high number of sputum positive cases. The majority of population are from high hills and mountain region where the Annual Risk of Infection (ARI) is less. This survey was done to know the epidemiological situation of Tuberculosis (TB) in Dharan. Tuberculin survey was done in Eastern Development Region (EDR) (1994) by National Tuberculosis Centre (NTC)/Japan International Cooperation Agency (JICA) in Saptari and Morang. The reported result of average Annual Risk of Infection (ARI) is 2.49% and 2.38% respectively. The mean age of surveyed population was 14.8 yrs. The Bacilli Calmette Guerin (BCG) coverage (scar rate) was 38.3% and BCG 4-8 age group 83.3% was highest and it gradually decreased to 37.5% in 12 + age group. The average 23 Tween-8-Batch of Tuberculin used for Testing (PPD) positive is 33.6% with 10 mm induration as cutoff line. Annual Risk of Infection (ARI) based on above was 2.7% in 9-11 age group and 1.31% in 12 + age group. This survey is suggestive of tuberculosis being highly prevalent in Dharan. The survey also showed average ARI to be 2.44% in Dharan in 10-15 yrs age group. The finding is suggestive of high ARI although the populations has migrated from hill and mountain. Previous report of average ARI in this area was 2.5% (Morang and Saptari). The survey result suggests that high priority, effective tuberculosis program is necessary and intensive control program can only give impact to control of tuberculosis in Dharan.