Pre-treatment delay and out of pocket expenses by notified new tuberculosis patients in an Indian mega city.

BACKGROUND: Study was carried out to find out delay from onset of symptoms and out of pocket expenditure (OOPE) until initiation of anti-TB treatment (ATT) by new Tuberculosis (TB) patients registered in public health facilities in Bengaluru. METHODS: Notified patients (N = 228) selected purposively were interviewed at initiation of ATT regarding number and type of facilities visited and delay in initiating ATT. OOPE was elicited separately for in- and out-patient visits, towards consultation, purchase of medicines, diagnostic tests, transportation, hospitalization and food. Dissaving or money borrowed was ascertained. RESULTS: Two-thirds of participants were 15-44 years of age and 56% were males, mean annual household income was $4357. About 75% first visited a private health facility; 68% and 87% respectively were diagnosed and started on ATT in public sector after visiting an average of three facilities and after a mean delay of 68 days; the median delay was 44 days. Of mean OOPE of $402, 54% was direct medical expenditure, 5% non-medical direct and 41% indirect. OOPE was higher for Extra-pulmonary TB compared to PTB and when number of health facilities visited before initiating treatment was >3 compared to those who visited ≤3 and when the time interval between onset of symptoms and treatment initiation (total delay) was >28 days compared to when this interval was ≤28 days. About 20% suffered catastrophic expenditure; 34% borrowed money and 37% sold assets. CONCLUSION: Concerted efforts are needed to reduce delay and OOPE in pre-treatment period and social protection to account for indirect expenditure.

Active tuberculosis case finding in India - The way forward.

Community based active case finding (ACF) for tuberculosis (TB) has seen resurrection in the current armamentarium of many TB managers in their fight toward eliminating TB. This article explores the accuracy and approximate cost of various ACF algorithms currently in vogue in India or those which could be useful, while inputting the sensitivity and specificity of screening and diagnostic tools as estimated from recently conducted community based surveys. This analysis informs that ACF may be prioritized to higher prevalence settings and the diagnostic algorithm for specific setting may be chosen taking into account the expected prevalence, estimated accuracy of the algorithm and resource availability. Further, chest X-ray cannot be used alone as a diagnostic tool and can be relied upon for this purpose when at least one of the three sputum specimen is smear positive. Accuracy of Xpert MTB/RIF as a diagnostic tool in community situations needs to be investigated further. The review brings out significant proportions of initial default and default during treatment among cases detected through ACF thus emphasizing the need for heightened efforts toward preventing the same. The article rounds off emphasizing priority to addressing barriers to speedy scale up of more sensitive diagnostic tools for health center based case finding including in private sector and ACF in high risk clinical groups for early and efficient case detection. It concludes by putting forth certain research areas that would strengthen future efforts.

Sub-national TB prevalence surveys in India, 2006-2012: Results of uniformly conducted data analysis.

SETTING: Community based tuberculosis (TB) prevalence surveys in ten sites across India during 2006-2012. OBJECTIVE: To re-analyze data of recent sub-national surveys using uniform statistical methods and obtain a pooled national level estimate of prevalence of TB. METHODS: Individuals ≥15 years old were screened by interview for symptoms suggestive of Pulmonary TB (PTB) and history of anti-TB treatment; additional screening by chest radiography was undertaken in five sites. Two sputum specimens were examined by smear and culture among Screen-positives. Prevalence in each site was estimated after imputing missing values to correct for bias introduced by incompleteness of data. In five sites, prevalence was corrected for non-screening by radiography. Pooled prevalence of bacteriologically positive PTB was estimated using Random Effects Model after excluding data from one site. Overall prevalence of TB (all ages, all types) was estimated by adjusting for extra-pulmonary TB and Pediatric TB. RESULTS: Of 769290 individuals registered, 715989 were screened by interview and 294532 also by radiography. Sputum specimen were examined from 50 852 individuals. Estimated prevalence of smear positive, culture positive and bacteriologically positive PTB varied between 108.4-428.1, 147.9-429.8 and 170.8-528.4 per 100000 populations in different sites. Pooled estimate of prevalence of bacteriologically positive PTB was 350.0 (260.7, 439.0). Overall prevalence of TB was estimated at 300.7 (223.7-377.5) in 2009, the mid-year of surveys. Prevalence was significantly higher in rural compared to urban areas. CONCLUSION: TB burden continues to be high in India suggesting further strengthening of TB control activities.

Sensitivity and specificity of screening tools and smear microscopy in active tuberculosis case finding.

SETTING: Community based five pulmonary tuberculosis (PTB) surveys among adults. OBJECTIVES: Estimate sensitivity and specificity of screening tools for PTB and sputum microscopy. METHODS: For each survey site, we estimated sensitivity and specificity of different screening criteria and microscopy against culture; pooled estimates were obtained using Random Effects Model. RESULTS: Sensitivity of cough alone, screening for any symptom (persistent cough ≥2 weeks, fever or chest pain ≥1 month, hemoptysis), any symptom or history of anti-TB treatment (h/o ATT) were 56.2%, 66% and 71.2% respectively; specificities were 95.3%, 93.8% and 92.7% respectively. X-ray when used alone for primary screening had sensitivity and specificity of 76.6% and 97.3% respectively. When used along with screening for cough, these figures were 94.3% and 93.1%, and 100% and 97.3% when used with any symptom and h/o ATT. When used for secondary screening, sensitivity and specificity of X-ray was 66.8% and 87.8% respectively after primary screening for cough, 65.0% and 89.8% after screening for any symptom, and 67.1% and 86.7% when used after screening for any symptom or h/o ATT. Pooled sensitivity and specificity of smear was 46.2% and 99.3% respectively. CONCLUSION: Program managers may use these estimates while evaluating algorithms for active case finding.

Tuberculosis diagnostic and treatment practices in private sector: Implementation study in an Indian city.

SETTING: Implementation study in private health facilities in an Indian metropolis. OBJECTIVES: Improve Tuberculosis (TB) care by private practitioners (PPs). METHODS: PPs from a defined city area were imparted short training in TB care and linkages made with public facilities; subsequent practices were recorded. RESULTS: Of 364 presumptive TB patient records, 70 (19.3%) did not conform to its definition. Of the conforming, 174 (59.2%) had presumptive pulmonary TB (PTB), 53 (18%) presumptive extra-pulmonary (EPTB) and 67 (24%) had both. Of conforming presumptive PTB, most underwent Chest X-ray and sputum examination in private laboratories. Tissue based diagnostics were not advised for most presumptive EPTB patients. Of 101 cases diagnosed with TB, 82% were new, 23% known diabetic and 4.7% human immune deficiency virus (HIV) reactive out of 64 tested. Most were notified and initiated treatment within 15 days of diagnosis. One-fourth was prescribed standard treatment regimen and treatment was not directly observed for most. One third was initial defaulters or lost during treatment; 62% of PTB and 46% EPTB cases initiated on treatment in private were successfully treated. Of successfully treated PTB cases, 61% had undergone follow-up sputum examination. CONCLUSION: Much intensified support mechanisms are needed to improve TB care in private sector.

Knowledge of private practitioners of Bangalore city in diagnosis, treatment of pulmonary tuberculosis and compliance with case notification.

One hundred and twenty-nine qualified private practitioners (PPs) were assessed on their knowledge in diagnosis of pulmonary tuberculosis (PTB), treatment of a new drug sensitive PTB case and practices of case notification, using semi-structured questionnaire. About 20% had adequate knowledge of diagnosis, 29% of treatment regimen, 54% the need for Direct Observation Treatment and 57% about role of sputum smear examination in monitoring treatment response. Of 85 (68%) PPs who had diagnosed any TB case during last two years, 54 (64%) had practised notification. These findings suggest the need for upgrading knowledge of PPs in TB diagnosis, treatment and notification.

Integration and decentralisation of TB-HIV services increases HIV testing of TB cases in Rajasthan, India.

The proportion of tuberculosis (TB) patients tested for the human immunodeficiency virus (HIV) in the state of Ra-jasthan, India, is limited by the availability of HIV testing facilities. Rajasthan implemented a policy of initiating TB-HIV diagnosis at all health institutions in July 2013. The number of TB diagnostic facilities increased from 33 to 63 in Banswara District and from 22 to 68 in Jhunjhunu District, while the number of HIV testing facilities in these districts increased from 1 to 53 and from 10 to 81, respectively, after the policy implementation. The proportion of TB patients tested for HIV increased by respectively 27% and 19%.

La proportion de patients tuberculeux (TB) testés pour le virus de l'immunodéficience humaine (VIH) dans l'état du Rajasthan, Inde, est limitée par la disponibilité de lieux de tests du VIH. Le Rajasthan a mis en œuvre une politique d'initiation du diagnostic TB dans toutes les structures de santé en juillet 2013. Le nombre de lieux de diagnostic TB a augmenté de 33 à 63 dans le district de Banswara et de 22 à 68 dans le district de Jhunjhunu, tandis que le nombre de lieux de test du VIH a augmenté de 1 à 53 et de 10 à 81, respectivement, après la mise en œuvre de cette politique. La proportion de patients TB testés pour le VIH a augmenté de 27% et 19%, respectivement, dans les deux districts.

La proporción de pacientes con tuberculosis (TB) que cuentan con la prueba del virus de la inmunodeficiencia humana (VIH) en el estado de Rajastán en la India se ve limitada por la escasez de establecimientos que la practican. En julio del 2013 se introdujo en Rajastán una política de iniciar el diagnóstico de la TB y el VIH en todos los establecimientos de atención de salud. Después de la introducción de la política, el número de centros de diagnóstico de la TB en el distrito de Banswara aumentó de 33 a 63 y en el distrito Jhunjhunu aumentó de 22 a 68 y la progresión de centros con diagnóstico de la infección por el VIH en Banswazra fue de 1 a 53 centros y en Jhunjhunu de 10 a 81. La proporción de pacientes con TB que cuentan con una prueba del VIH en estos distritos aumentó un 27% y un 19%, respectivamente.

Estimating tuberculosis incidence from primary survey data: a mathematical modeling approach.

BACKGROUND: There is an urgent need for improved estimations of the burden of tuberculosis (TB). OBJECTIVE: To develop a new quantitative method based on mathematical modelling, and to demonstrate its application to TB in India. DESIGN: We developed a simple model of TB transmission dynamics to estimate the annual incidence of TB disease from the annual risk of tuberculous infection and prevalence of smear-positive TB. We first compared model estimates for annual infections per smear-positive TB case using previous empirical estimates from China, Korea and the Philippines. We then applied the model to estimate TB incidence in India, stratified by urban and rural settings. RESULTS: Study model estimates show agreement with previous empirical estimates. Applied to India, the model suggests an annual incidence of smear-positive TB of 89.8 per 100 000 population (95%CI 56.8-156.3). Results show differences in urban and rural TB: while an urban TB case infects more individuals per year, a rural TB case remains infectious for appreciably longer, suggesting the need for interventions tailored to these different settings. CONCLUSIONS: Simple models of TB transmission, in conjunction with necessary data, can offer approaches to burden estimation that complement those currently being used.

Cost analysis of different diagnostic algorithms for pulmonary tuberculosis varying in placement of Xpert MTB/RIF.

BACKGROUND: We undertook cost analysis for diagnosis of pulmonary tuberculosis (PTB) using present algorithm under Revised National Tuberculosis Control programme and using Xpert MTB/RIF (Xpert) as frontline test or in conjunction with smear microscopy and/or chest radiography. METHODS: Costs were estimated for different strategies: (A) present algorithm involving sputum smear examination followed by antibiotic trial in smear negative patients, repeat smear examination (RE) if symptoms continue and chest radiography if RE negative; (B) direct Xpert; (C) smear microscopy followed by Xpert in smear negative patients; (D) radiography followed by Xpert in those having abnormal pulmonary shadows; and (E) smear examination followed by radiography among smear negative patients and Xpert in presence of abnormal pulmonary shadow. RESULTS: Cost to program was estimated lowest with Strategy A and highest with Strategy B. Compared to the latter, program cost reduces by 7%, 4.5%, and 17.4% by strategies C, D, and E, respectively. Cost to the group of individuals with presumptive PTB and their attendants is significantly higher for Strategy A compared to other four strategies. Among the latter, the patients' cost was minimum with Strategy B and maximum with Strategy C. Program cost per case diagnosed was lowest by Strategy A and highest by Strategy B. Patient cost per case diagnosed was highest by Strategy A and lowest by Strategy B. Using Xpert, Strategy E had the lowest program as well as overall cost per case diagnosed. CONCLUSION: Strategy E may be chosen for diagnosis of PTB. When resources would no longer be a constraint, direct Xpert would reduce costs incurred by the patients.

Tuberculosis case notification by private practitioners in Pune, India: how well are we doing?

SETTING: Pimpri Chinchwad Municipal Corporation area, Pune, India. OBJECTIVE: To assess the proportion of private practitioners (PPs) who notified tuberculosis (TB) patients during February-April 2013 and their contribution to the overall number notified, and to determine their perceived challenges in reporting TB cases. DESIGN: Mixed-method study including an analysis of notification data, followed by in-depth interviews with PPs. Interviews were transcribed and inductive content analysis was performed to derive themes. RESULTS: Of 831 PPs, 533 (64%) participated in case notification; of these 87 (16%) notified at least one TB case during the study period. In all, 138 TB cases were notified by PPs, accounting for 20% of the total TB cases notified. Emerging themes among perceived challenges and barriers were lack of complete knowledge about TB notification, fear of a breach of patient confidentiality, lack of a simplified operational mechanism of notification, and lack of trust and coordination with the government health system. CONCLUSION: About two thirds of PPs participated in case notification and contributed significantly to the overall TB cases notified. India's national TB programme should focus on training PPs and targeted media communication campaigns, and establish alternative mechanisms for notification, such as the internet and mobile telephones, to overcome perceived barriers.

Cadre : Zone de la Corporation Municipale de Chinchwad, Pune, Inde.Objectif : Evaluer la proportion de praticiens privés (PP) qui ont déclaré des patients ayant la tuberculose (TB) entre février et avril 2013 et leur contribution au total de cas déclarés, et déterminer les défis perçus en matière de déclaration des cas de TB.Schéma : Etude reposant sur plusieurs méthodes, notamment une analyse des données de déclaration suivie d'entretiens approfondis avec des PP. Ces entretiens ont été transcrits et leur contenu a été analysé pour en dériver des thèmes.Résultats : Sur 831 PP, 533 (64%) ont participé à la notification, et parmi eux 87 (16%) ont déclaré au moins un cas de TB pendant la période d'étude. Au total, 138 cas de TB ont été déclarés par les PP, ce qui constitue 20% du total de cas de TB notifiés. Les thèmes qui ont émergé parmi les défis et contraintes perçus ont été la connaissance incomplète du système de notification de la TB, la peur d'enfreindre la confidentialité des patients, l'absence de système opérationnel simplifié de déclaration et le manque de confiance envers le système de santé gouvernemental et le manque de coordination avec ce dernier.Conclusion : Près de deux tiers des PP ont participé à la notification et ont apporté une contribution significative à l'ensemble des cas de TB déclarés. Le programme national TB devrait se concentrer sur la formation des PP, sur des campagnes de communication ciblées auprès des media et sur la mise en place de mécanismes alternatifs de notification (par exemple, par internet et par téléphone portable) pour vaincre les obstacles perçus.

Marco de referencia: La región de la Corporación Municipal de Pimpri Chinchwad de Pune, en la India.Objetivo: Evaluar la proporción de médicos del sector privado (PP) que notificaban pacientes con diagnóstico de tuberculosis (TB) durante el período del febrero a abril del 2013 y su contribución al número global de casos notificados, y determinar las dificultades que encontraron los profesionales con respecto a la notificación de casos.Método: La presente investigación adoptó un diseño de métodos mixtos, que incluyó el análisis de los datos de notificación seguido de entrevistas exhaustivas a los PP. Las entrevistas se transcribieron y se llevó a cabo un análisis de contenido de tipo inductivo con el fin de derivar los temas.Resultados: De los 831 PP, 533 participaban en la notificación (64%) y de ellos 87 notificaron como mínimo un caso de TB durante el período del estudio (16%). En total, los PP notificaron 138 casos de TB, que correspondieron al 20% de todos los casos notificados. Los temas que surgieron sobre las dificultades y las barreras a la notificación fueron la falta de un conocimiento completo sobre la notificación de la TB, el temor a infringir la confidencialidad del paciente, la carencia de un mecanismo operativo simplificado de notificación y la falta de confianza y coordinación con el sistema de salud gubernamental.Conclusión: Cerca de dos tercios de los PP participaban en la notificación y su contribución fue considerable con respecto a la totalidad de casos de TB notificados. El programa nacional contra la TB debe centrar su interés en la formación de los PP, llevar a cabo campañas dirigidas en los medios de comunicación y establecer mecanismos alternos de notificación (por ejemplo, en internet o por conducto de los teléfonos móviles), con el fin de superar las barreras percibidas en el estudio.

A descriptive study of tuberculosis case finding in private health care facilities in a South Indian district.

SETTING: A South Indian district providing anti-tuberculosis services through the Revised National TB Control Programme (RNTCP) and private health care facilities. OBJECTIVE: To ascertain the profile of tuberculosis (TB) patients diagnosed and/or treated in private health care facilities. METHODS: Data on TB cases diagnosed and/or treated in all clinical departments of the medical college, 83 nursing homes and RNTCP health care facilities were collected prospectively. RESULTS: About 83% of new TB cases recorded in the private medical college, 47% in nursing homes and 24.5% in RNTCP TB registers were extra-pulmonary. The proportion of retreatment cases was respectively 5.5%, 9.6% and 19.8%. The proportion of males and those in the economically productive age group were similar in the three data sources. About 94% of cases diagnosed in the medical college and 55% in nursing homes were registered for treatment under the RNTCP. About 11% of the smear-positive patients diagnosed in RNTCP were initial defaulters. CONCLUSION: The proportion of extra-pulmonary cases was higher in the medical college and nursing homes and that of retreatment cases was lower than in the RNTCP.

Are registered sputum smear-negative tuberculosis patients in Karnataka, India, diagnosed by national algorithm?

SETTING: Four districts of Karnataka State, India, that have implemented the National Tuberculosis Control Programme (RNTCP). OBJECTIVE: To assess the proportion of patients diagnosed according to the nationally recommended algorithm among new smear-negative (NSN) PTB cases registered under the RNTCP. METHODS: Information on 201 registered NSN-PTB patients as regards date of initial sputum examination, repeat sputum examination and chest X-ray (CXR) if undertaken, treatment initiation and number of days of antibiotic treatment after initial sputum examination, were collected through record review and patient interviews. In patients with negative or unknown human immunodeficiency virus (HIV) status, the algorithm was considered completed if the patient underwent initial sputum examination, antibiotic trial for ⩾10 days, repeat sputum examination ⩾10 days after initial sputum examination, CXR after repeat sputum examination and anti-tuberculosis treatment ⩾10 days after initial sputum examination. In HIV-positive patients, the algorithm was considered completed if CXR was performed after or at the same time as initial sputum examination. RESULTS: Complete information was available for 170 patients. Of these, the algorithm was completed in 14 (8.2%, 95%CI 0.9-15.5): 1/140 patients with negative or unknown HIV status and 13/30 HIV-positive patients. CONCLUSION: The algorithm was not completed in most patients registered for treatment. Measures are needed to improve the diagnostic process for smear-negative PTB.

Implementation efficiency of a diagnostic algorithm in sputum smear-negative presumptive tuberculosis patients.

BACKGROUND: For the diagnosis of smear-negative pulmonary tuberculosis (PTB), India's Revised National Tuberculosis Control Programme (RNTCP) recommends a course of broad-spectrum antibiotics after negative smear on initial sputum examination, followed by repeat sputum examination and chest X-ray (CXR). OBJECTIVES: 1) To ascertain the proportion of presumptive PTB patients smear-negative on initial sputum examination who completed the diagnostic algorithm, and 2) to investigate barriers to the completion of the algorithm. METHODS: In Karnataka State, India, 256 study participants were interviewed in 2012 to ascertain the number of days antibiotics had been prescribed and consumed, the number of re-visits to health centre(s), whether repeat sputum examinations had been performed, whether or not CXR had been performed and when, and whether PTB had been diagnosed. In-depth interviews were conducted with 19 medical officers. RESULTS: The diagnostic algorithm was completed in 13 (5.1%) of 256 participants; three were diagnosed with PTB without completing the algorithm. Most medical officers were unaware of the algorithm, had trained 5-10 years previously, prescribed antibiotics for <10 days and advised CXR without repeat sputum examination, irrespective of the number of days of antibiotic treatment. Other main reasons for non-completion of algorithm were patients not returning to the health centres and a proportion switching to the private sector. CONCLUSION: Refresher training courses, raising patient awareness and active follow-up of patients to complete the algorithm are suggested.

Role of pre-Xpert® screening using chest X-ray in early diagnosis of smear-negative pulmonary tuberculosis.

In a sub-district level hospital in South India, the proportion of patients with abnormal chest X-ray (CXR) was evaluated among smear-negative, Xpert® MTB/RIF (Xpert) positive individuals with pulmonary tuberculosis (PTB) symptoms; 384 smear-negative PTB individuals with PTB symptoms and without a history of anti-tuberculosis treatment underwent CXR and Xpert testing of one sputum specimen. Of 378 individuals with both Xpert and CXR results available, 14 were positive for Mycobacterium tuberculosis. Of these, 13 (92.9%) had an abnormal CXR and one was normal. This study highlights the usefulness of CXR before Xpert testing, which needs further validation.

Treatment outcome of tuberculosis patients in a clinic of Bangalore.

A total of 112 cases (New = 101, previously treated = 11) were diagnosed as suffering from tuberculosis (TB) at a private clinic in Bangalore city. The clinic identified TB suspects, established diagnosis of TB, administered direct observation of treatment (DOT), maintained treatment cards and undertook defaulter retrieval actions as and when required. The Revised National Tuberculosis Control Programme (RNTCP) provided support in terms of sputum microscopy supply of patient-wise drug boxes and registration of patients. Ninety six (95.1%) of new cases and 10 (90.9%) of previously treated cases had successful treatment outcome. Most patients completed treatment within the prescribed period. No TB deaths were reported during the period of treatment.

Impact of awareness drives and community-based active tuberculosis case finding in Odisha, India.

India's Revised National Tuberculosis Control programme employs passive case detection. The new sputum smear-positive case detection rate is less than 70% in Odisha State. During April-June 2012, active case finding (ACF) was conducted through awareness drives and field-based tuberculosis (TB) screening in select communities with the lowest case detection rates. During the campaign, 240 sputum smear-positive TB cases were detected. The number of smear-positive cases detected increased by 11% relative to April-June 2011 in intervention communities compared to an 0.8% increase in non-intervention communities. ACF brought TB services closer to the community and increased TB case detection.

Tobacco smoking: a major risk factor for pulmonary tuberculosis--evidence from a cross-sectional study in central India.

BACKGROUND: This paper provides information on the association of tobacco smoking and alcohol consumption with pulmonary TB (PTB) in central India. METHODS: A community based cross-sectional TB prevalence survey was conducted in Jabalpur district of the central Indian state of Madhya Pradesh. The information on tobacco smoking and alcohol consumption was collected from individuals aged ≥15 years. Using logistic regression analysis, the risk factors for PTB were identified. RESULTS: A total of 94 559 individuals provided information on tobacco smoking and alcohol consumption. Persons aged 35-54 years and 55 years and above had, respectively, a 2.19 (95% CI 1.57-3.07) and a 3.26 (95% CI 2.23-4.77) times higher risk of developing PTB compared to persons aged below 35 years. Males had a 2.35 (95% CI 1.66-3.32) times higher risk than females. Tribals (indigenous population) had a 2.32 (95% CI 1.68-3.21) times higher risk than non-tribal population. The adjusted prevalence odds ratio for mild, moderate and heavy tobacco smokers were 2.28, 2.51 and 2.74 respectively as compared to non-smokers. Alcohol consumption was not found to be a risk factor on multivariate analysis. CONCLUSION: Tobacco smoking is significantly associated with PTB in this central Indian district. Smoking cessation services need to be integrated into the activities of the TB control programme.

Annual risk of tuberculous infection among schoolchildren in Bhutan.

SETTING: School-based survey in the mountainous nation of Bhutan. OBJECTIVE: To estimate the annual risk of tuberculous infection (ARTI) among children aged 6-8 years. DESIGN: 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. RESULTS: 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. CONCLUSION: The ARTI has declined in Bhutan compared to the 1991 survey estimate of 1.9%.

Trends in the annual risk of tuberculous infection in India.

SETTING: Twenty-four districts in India. OBJECTIVES: To evaluate trends in annual risk of tuberculous infection (ARTI) in each of four geographically defined zones in the country. STUDY DESIGN: Two rounds of house-based tuberculin surveys were conducted 8-9 years apart among children aged 1-9 years in statistically selected clusters during 2000-2003 and 2009-2010 (Surveys I and II). Altogether, 184,992 children were tested with 1 tuberculin unit (TU) of purified protein derivative (PPD) RT23 with Tween 80 in Survey I and 69,496 children with 2TU dose of PPD in Survey II. The maximum transverse diameter of induration was measured about 72 h after test administration. ARTI was computed from the prevalence of infection estimated using the mirror-image method. RESULTS: Estimated ARTI rates in different zones varied between 1.1% and 1.9% in Survey I and 0.6% and 1.2% in Survey II. The ARTI declined by respectively 6.1% and 11.7% per year in the north and west zones; no decline was observed in the south and east zones. National level estimates were respectively 1.5% and 1.0%, with a decline of 4.5% per year in the intervening period. CONCLUSION: Although a decline in ARTI was observed in two of the four zones and at national level, the current ARTI of about 1% in three zones suggests that further intensification of TB control activities is required.

High risk of tuberculous infection in North Sulawesi Province of Indonesia.

SETTING: Of all the provinces in Indonesia, the highest tuberculosis (TB) case notification rates are reported from North Sulawesi Province. OBJECTIVE: To estimate the annual risk of tuberculous infection (ARTI) among schoolchildren in the 6-9 year age group. METHODS: A cross-sectional survey was carried out in 99 schools selected by a two-stage sampling process. Children attending grades 1-4 in the selected schools were administered intradermally with 2 tuberculin units (TUs) of purified protein derivative RT23 with Tween 80, and the maximum transverse diameter of induration was measured about 72 h later. A total of 6557 children in the 6-9 year age group were satisfactorily test-read, irrespective of their bacille Calmette-Guérin (BCG) vaccination status. RESULTS: Based on the frequency distribution of reaction sizes obtained among satisfactorily test-read children (without and with BCG scar), the estimated ARTI rates when estimated by different methods (anti-mode, mirror-image and mixture model) varied between 1.9% and 2.5%. BCG-induced tuberculin sensitivity was not found to influence the ARTI estimates, as the differences in estimates between children without and with BCG scar were not statistically significant. CONCLUSION: TB control efforts should be further intensified to reduce the risk of tuberculous infection.