Spatial distribution and temporal trends of tuberculosis case notifications, Uganda: a ten-year retrospective analysis (2013-2022).

BACKGROUND: Uganda has a high incidence and prevalence of tuberculosis (TB). Analysis of spatial and temporal distribution of TB is an important tool for supporting spatial decision-making, planning, and policy formulations; however, this information is not readily available in Uganda. We determined the spatial distribution and temporal trends of tuberculosis notifications in Uganda, 2013-2022. METHODS: We conducted a retrospective analysis of routinely-generated program data reported through the National TB and Leprosy Programme (NTLP) surveillance system. We abstracted data on all TB cases diagnosed from 2013 to 2022 by district and region. We drew choropleth maps for Uganda showing the TB case notification rates (CNR) per 100,000 and calculated the CNR using the cases per district as the numerator and individual district populations as the denominators. Population estimates were obtained from the 2014 National Population and Housing Census, and a national growth rate of 3% was used to estimate the annual population increase. RESULTS: Over the entire study period, 568,957 cases of TB were reported in Uganda. There was a 6% annual increase in TB CNR reported from 2013 (134/100,000) to 2022 (213/100,000) (p-value for trend p < 0.00001). Cases were reported from all 12 Ministry of Health regions during the entire period. The distribution of CNR was heterogeneous throughout the country and over time. Moroto, Napak and Kampala districts had consistently high CNR throughout the ten years. Kalangala district had lower CNR from 2013 to 2018 but high CNR from 2019 to 2022. Moroto region, in the northeast, had consistently high CNR while Mbale and Soroti regions in Eastern Uganda had the lowest CNR throughout the ten years. CONCLUSION: There was an overall increasing trend in TB CNR from 2013 to 2022. We recommend that the National TB program institutes intensified measures aided by more funding to mitigate and reverse the negative impacts of the COVID-19 pandemic on TB.

Private practitioners' practices for tuberculosis management in a city largely served by the private health sector in Uganda.

BACKGROUND: Globally, tuberculosis (TB) remains a significant cause of morbidity and mortality having caused 1.6 million deaths in 2021. Uganda is a high TB burden country with a large private sector that serves close to 60% of the urban population. However, private for-profit health facilities' involvement with the National TB and Leprosy Program (NTLP) activities remains poor. This study evaluated the practices of diagnosis and treatment of pulmonary tuberculosis (PTB) and associated factors among practitioners in private for-profit (PFP) healthcare facilities in Kampala, Uganda. METHODS: We conducted a cross-sectional study among randomly selected private practitioners in Uganda's largest city, Kampala. A structured questionnaire was used for data collection. Descriptive statistics and generalized linear models with log Poisson link were used to analyze data. Practices were graded as standard or substandard. RESULTS: Of the 630 private practitioners studied, 46.2% (95% confidence interval (CI): 26.6 to 67.1) had overall standard practices. Being a laboratory technician (prevalence ratio (PR) = 2.7, p< 0.001) or doctor (PR = 1.2, p< 0.001), a bachelor's degree level of qualification (PR = 1.1, p = 0.021), quarterly supervision by the national TB program (PR = 1.3, p = 0.023), and acceptable knowledge of the practitioner about TB (PR = 1.8, p<0.001) were significantly associated with standard practices. CONCLUSIONS: The practices of TB management for practitioners from the PFP facilities in Kampala are suboptimal and this poses a challenge for the fight against TB given that these practitioners are a major source of primary health care in the city.

Wanda Blenska and the program of leprosy treatment in Uganda.

Wanda Blenska (1911-2014), a Polish physician, established a leprosy treatment center in the village of Buluba in Uganda in 1951, which lasted until 1993. Through her efforts, the village for lepers in Buluba, established in 1934, which had previously been a place of isolation conducted by the Little Sisters of St. Francis in Uganda, became such an important leprosy treatment and research center that eventually the facility was able to cooperate with similar centers in India and South Africa. It then became affiliated with research institutes in London and Amsterdam; the Borstel Research Institute near Hamburg, Germany; and the World Health Organization. Blenska developed a working relationship with the government of Uganda and contributed to changes in the government provision of health care for lepers by creating a network of leprosy treatment stations throughout the country. Through her efforts, public health education and leprosy prophylaxis became available for thousands of people, effectively changing the national attitude toward this disease. In 1994, one of the buildings of the St. Francis hospital complex in Buluba was named in her honor (The Wanda Blenska Training Centre).

Addressing the drug-resistant tuberculosis challenge through implementing a mixed model of care in Uganda.

Worldwide, Drug-resistant Tuberculosis (DR-TB) remains a big problem; the diagnostic capacity has superseded the clinical management capacity thereby causing ethical challenges. In Sub-Saharan Africa, treatment is either inadequate or lacking and some diagnosed patients are on treatment waiting lists. In Uganda, various health system challenges impeded scale-up of DR-TB care in 2012; only three treatment initiation facilities existed, with only 41 of the estimated 1010 RR-TB/MDR-TB cases enrolled on treatment yet 300 were on the waiting list and there was no DR-TB treatment scale-up plan. To scale up care, the National TB and leprosy Program (NTLP) with partners rolled out a DR-TB mixed model of care. In this paper, we share achievements and outcomes resulting from the implementation of this mixed Model of DR-TB care. Routine NTLP DR-TB program data on treatment initiation site, number of patients enrolled, their demographic characteristics, patient category, disease classification (based on disease site and human immunodeficiency virus (HIV) status), on co-trimoxazole preventive therapy (CPT) and antiretroviral therapy (ART) statuses, culture results, smear results and treatment outcomes (6, 12, and 24 months) from 2012 to 2017 RR-TB/MDR-TB cohorts were collected from all the 15 DR-TB treatment initiation sites and descriptive analysis was done using STATA version 14.2. We presented outcomes as the number of patient backlog cleared, DR-TB initiation sites, RR-TB/DR-TB cumulative patients enrolled, percentage of co-infected patients on the six, twelve interim and 24 months treatment outcomes as per the Uganda NTLP 2016 Programmatic Management of drug-resistant Tuberculosis (PMDT) guidelines (NTLP, 2016). Over the period 2013-2015, the RR-TB/MDR-TB Treatment success rate (TSR) was sustained between 70.1% and 74.1%, a performance that is well above the global TSR average rate of 50%. Additionally, the cure rate increased from 48.8% to 66.8% (P = 0.03). The Uganda DR-TB mixed model of care coupled with early application of continuous improvement approaches, enhanced cohort reviews and use of multi-disciplinary teams allowed for rapid DR-TB program expansion, rapid clearance of patient backlog, attainment of high cumulative enrollment and high treatment success rates. Sustainability of these achievements is needed to further reduce the DR-TB burden in the country. We highly recommend this mixed model of care in settings with similar challenges.

Adherence to the MDR-TB intensive phase treatment protocol amongst individuals followed up at central and peripheral health care facilities in Uganda - a descriptive study.

BACKGROUND: Following initiation of MDR-TB treatment, patients have a choice to receive follow up DOT supervision at either the central initiating facility or at a peripheral facility. OBJECTIVES: We describe the adherence patterns of MDR-TB patients undergoing DOT supervision at the two health facility categories during intensive phase of treatment. METHODS: We used a retrospective cohort of patients initiated on MDR TB treatment at Mulago National Referral Hospital between 2014 and 2016. We extracted data from the National Tuberculosis and Leprosy Program records and analysed these using STATA V14. RESULT: Majority (84.01%) of the patients received their DOT supervision from the peripheral facilities. Males made up 62.1% of patients, and 91.2% had had their household contacts screened for MDR-TB. 26.5% of the patients on peripheral DOT supervision had good adherence to treatment protocol compared to 0% among patients on central initiating health facility DOT supervision. Among the patients with good adherence, 24.1% had contacts screened for MDR-TB as compared to 3.6% with poor adherence. CONCLUSION: More patients preferred MDR-TB DOT supervision at peripheral facilities, which had better adherence to the treatment protocol compared to the central initiating facility. Younger people and those with household contacts screened had better adherence to the treatment protocol, highlighting areas for targeted interventional programs for MDR-TB in resource limited settingsMore patients preferred MDR-TB DOT supervision at peripheral facilities, which had better adherence to the treatment protocol compared to the central initiating facility. Younger people and those with household contacts screened had better adherence to the treatment protocol, highlighting areas for targeted interventional programs for MDR-TB in resource limited settings.

Spatial distribution and temporal trends of leprosy in Uganda, 2012-2016: a retrospective analysis of public health surveillance data.

BACKGROUND: Leprosy is a neglected disease that poses a significant challenge to public health in Uganda. The disease is endemic in Uganda, with 40% of the districts in the country affected in 2016, when 42 out of 112 districts notified the National Tuberculosis and Leprosy Program (NTLP) of at least one case of leprosy. We determined the spatial and temporal trends of leprosy in Uganda during 2012-2016 to inform control measures. METHODS: We analyzed quarterly leprosy case-finding data, reported from districts to the Uganda National Leprosy Surveillance system (managed by NTLP) during 2012-2016. We calculated new case detection by reporting district and administrative regions of treatment during this period. New case detection was defined as new leprosy cases diagnosed by the Uganda health services divided by regional population; population estimates were based on 2014 census data. We used logistic regression analysis in Epi-Info version 7.2.0 to determine temporal trends. Population estimates were based on 2014 census data. We used QGIS software to draw choropleth maps showing leprosy case detection rates, assumed to approximate the new case detection rates, per 100,000 population. RESULTS: During 2012-2016, there was 7% annual decrease in reported leprosy cases in Uganda each year (p = 0.0001), largely driven by declines in the eastern (14%/year, p = 0.0008) and central (11%/year, p = 0.03) regions. Declines in reported cases in the western (9%/year, p = 0.12) and northern (4%/year, p = 0.16) regions were not significant. The combined new case detection rates from 2012 to 2016 for the ten most-affected districts showed that 70% were from the northern region, 20% from the eastern, 10% from the western and 10% from the central regions. CONCLUSION: There was a decreasing trend in leprosy new case detection in Uganda during 2012-2016; however, the declining trends were not consistent in all regions. The Northern region consistently identified more leprosy cases compared to the other regions. We recommend evaluation of the leprosy surveillance system to ascertain the leprosy situation.

Explaining the successes and failures of tuberculosis treatment programs; a tale of two regions in rural eastern Uganda.

BACKGROUND: Optimally performing tuberculosis (TB) programs are characterized by treatment success rate (TSR) of at least 90%. In rural eastern Uganda, and elsewhere in sub Saharan Africa, TSR varies considerably across district TB programs and the reasons for the differences are unclear. This study explored factors associated with the low and high TSR across four districts in rural eastern Uganda. METHODS: We interviewed District TB and Leprosy Supervisors, Laboratory focal persons, and health facility TB focal persons from four districts in eastern Uganda as key informants. Interviews were audio recorded, transcribed verbatim, and imported into ATLAs.ti where thematic content analysis was performed and results were summarized into themes. RESULTS: The emerging themes were categorized as either facilitators of or barriers to treatment success. The emerging facilitators prevailing in the districts with high rates of treatment success were using data to make decisions and design interventions, continuous quality improvement, capacity building, and prioritization of better management of people with TB. The barriers common in districts with low rates of treatment success included lack of motivated and dedicated TB focal persons, scarce or no funding for implementing TB activities, and a poor implementation of community-based directly observed therapy short course. CONCLUSION: This study shows that several factors are associated with the differing rates of treatment success in rural eastern Uganda. These factors should be the focus for TB control programs in Uganda and similar settings in order to improve rates of treatment success.

Strengthening the Tuberculosis Specimen Referral Network in Uganda: The Role of Public-Private Partnerships.

BACKGROUND: Diagnosis of multidrug-resistant tuberculosis and prompt initiation of effective treatment rely on access to rapid and reliable drug-susceptibility testing. Efficient specimen transport systems and appropriate training on specimen referral contribute to optimal and timely access to tuberculosis diagnostic services. METHODS: With support and technical assistance from a public-private partnership (PPP) between Becton Dickinson and the US President's Emergency Plan for AIDS Relief, the Uganda National TB Reference Laboratory (NTRL) and National TB and Leprosy Program redesigned the tuberculosis specimen transport network and trained healthcare workers with the goal of improving multidrug-resistant tuberculosis detection. RESULTS: Between 2008 and 2011, the PPP mapped 93% of health facilities and trained 724 healthcare and postal staff members covering 72% of districts. Strengthening the tuberculosis specimen referral system increased referrals from presumptive multidrug-resistant tuberculosis cases by >10-fold, with 94% of specimens reaching the NTRL within the established target transport time. CONCLUSIONS: This study demonstrates the potential of PPP collaborations with ministries of health to positively influence patient care by strengthening laboratory systems through increased access to drug-susceptibility testing in Uganda. Ongoing efforts to integrate specimen transport networks will maximize resources and improve patient management.

Tuberculosis retreatment 'others' in comparison with classical retreatment cases; a retrospective cohort review.

BACKGROUND: Many of the countries in sub-Saharan Africa are still largely dependent on microscopy as the mainstay for diagnosis of tuberculosis (TB) including patients with previous history of TB treatment. The available guidance in management of TB retreatment cases is focused on bacteriologically confirmed TB retreatment cases leaving out those classified as retreatment 'others'. Retreatment 'others' refer to all TB cases who were previously treated but with unknown outcome of that previous treatment or who have returned to treatment with bacteriologically negative pulmonary or extra-pulmonary TB. This study was conducted in 11 regional referral hospitals (RRHs) serving high burden TB districts in Uganda to determine the profile and treatment success of TB retreatment 'others' in comparison with the classical retreatment cases. METHODS: A retrospective cohort review of routinely collected National TB and Leprosy Program (NTLP) facility data from 1 January to 31 December 2010. This study uses the term classical retreatment cases to refer to a combined group of bacteriologically confirmed relapse, return after failure and return after loss to follow-up cases as a distinct group from retreatment 'others'. Distribution of categorical characteristics were compared using Chi-squared test for difference between proportions. The log likelihood ratio test was used to assess the independent contribution of type of retreatment, human immunodeficiency virus (HIV) status, age group and sex to the models. RESULTS: Of the 6244 TB cases registered at the study sites, 733 (11.7%) were retreatment cases. Retreatment 'others' constituted 45.5% of retreatment cases. Co-infection with HIV was higher among retreatment 'others' (70.9%) than classical retreatment cases (53.5%). Treatment was successful in 410 (56.2%) retreatment cases. Retreatment 'others' were associated with reduced odds of success (AOR = 0.44, 95% CI 0.22,0.88) compared to classical cases. Lost to follow up was the commonest adverse outcome (38% of adverse outcomes) in all retreatment cases. Type of retreatment case, HIV status, and age were independently associated with treatment success. CONCLUSION: TB retreatment 'others' constitute a significant proportion of retreatment cases, with higher HIV prevalence and worse treatment success. There is need to review the diagnosis and management of retreatment 'others'.

High mortality associated with retreatment of tuberculosis in a clinic in Kampala, Uganda: a retrospective study.

The World Health Organization recommends for tuberculosis retreatment a regimen of isoniazid (H), rifampicin (R), ethambutol (E), pyrazinamide (Z), and streptomycin (S) for 2 months, followed by H, R, E, and Z for 1 month and H, R, and E for 5 months. Using data from the National Tuberculosis and Leprosy Program registry, this study determined the long-term outcome under programmatic conditions of patients who were prescribed the retreatment regimen in Kampala, Uganda, between 1997 and 2003. Patients were traced to determine their vital status; 62% (234/377) patients were found dead. Having ≤ 2 treatment courses and not completing retreatment were associated with mortality in adjusted analyses.

Analysis of the leprosy agents Mycobacterium leprae and Mycobacterium lepromatosis in four countries.

OBJECTIVES: To differentiate the leprosy agents Mycobacterium leprae and Mycobacterium lepromatosis and correlate them with geographic distribution and clinicopathologic features. METHODS: Species-specific polymerase chain reactions were used to detect each bacillus in archived skin biopsy specimens from patients with leprosy from Brazil (n = 52), Malaysia (n = 31), Myanmar (n = 9), and Uganda (n = 4). Findings were correlated with clinical and pathologic data. RESULTS: Etiologic species was detected in 46 of the 52 Brazilian patients, including 36 patients with M leprae, seven with M lepromatosis, and three with both bacilli. The seven patients with sole M lepromatosis all had tuberculoid leprosy, whereas only nine of the 36 patients infected with M leprae exhibited this type, and the rest were lepromatous (P < .001). All patients with dual infections had lepromatous leprosy. Of the nine patients from Myanmar, six were test positive: four with M leprae and two with M lepromatosis. Of the Malaysian and Ugandan patients, only M leprae was detected in 27 of the 31 Malaysians and two of the four Ugandans. CONCLUSIONS: The leprosy agents vary in geographic distribution. Finding M lepromatosis in Brazil and Myanmar suggests wide existence of this newly discovered species. The leprosy manifestations likely vary with the etiologic agents.

"Home is where the patient is": a qualitative analysis of a patient-centred model of care for multi-drug resistant tuberculosis.

BACKGROUND: Ambulatory, community-based care for multi-drug resistant tuberculosis (MDR-TB) has been found to be effective in multiple settings with high cure rates. However, little is known about patient preferences around models of MDR-TB care. Médecins Sans Frontières (MSF) has delivered home-based MDR-TB treatment in the rural Kitgum and Lamwo districts of northern Uganda since 2009 in collaboration with the Ministry of Health and the National TB and Leprosy Programme. We conducted a qualitative study examining the experience of patients and key stakeholders of home-based MDR-TB treatment. METHODS: We used semi-structured interviews and focus-group discussions to examine patients' perceptions, views and experiences of home-based treatment and care for MDR-TB versus their perceptions of care in hospital. We identified how these perceptions interacted with those of their families and other stakeholders involved with TB. Participants were selected purposively following a stakeholder analysis. Sample size was determined by data saturation being reached within each identified homogenous category of respondents: health-care receiving, health-care providing and key informant. Iterative data collection and analysis enabled adaptation of topic guides and testing of emerging themes. The grounded theory method of analysis was applied, with data, codes and categories being continually compared and refined. RESULTS: Several key themes emerged: the perceived preference and acceptability of home-based treatment and care as a model of MDR-TB treatment by patients, family, community members and health-care workers; the fear of transmission of other infections within hospital settings; and the identification of MDR-TB developing through poor adherence to and inadequate treatment regimens for DS-TB. CONCLUSIONS: Home-based treatment and care was acceptable to patients, families, communities and health-care workers and was seen as preferable to hospital-based care by most respondents. Home-based care was perceived as safe, conducive to recovery, facilitating psychosocial support and allowing more free time and earning potential for patients and caretakers. These findings could contribute to development of an adaptation of treatment approach strategy at national level.

Using a clinic based creativity initiative to reduce HIV related stigma at the Infectious Diseases Institute, Mulago National Referral Hospital, Uganda.

BACKGROUND: Stigma has been associated with chronic health conditions such as HIV/AIDS, leprosy, tuberculosis, Mental illness and Epilepsy. Different forms of stigma have been identified: enacted stigma, perceived stigma, and self stigma. Stigma is increasingly regarded as a key driver of the HIV/AIDS epidemic and has a major impact on public health interventions. OBJECTIVES: The initiative was to provide activities in the clinic while patients waited to be seen by healthcare professionals. It was envisaged this would contribute to reduction of clinic based stigma felt by clients. METHODS: This was a repeated cross-sectional survey (October-November 2005 and March-April 2007) that was conducted at the Infectious Diseases Institute clinic (IDC) at Mulago, the national referral hospital in Uganda. We utilized quantitative (survey) and qualitative (key informants, focus group discussions) methods to collect the data. Data were collected on stigma before the creativity initiative intervention was implemented, and a second phase survey was conducted to assess effectiveness of the interventions. RESULTS: Clients who attended the IDC before the creativity intervention were about twice as likely to fear catching an infection as those who came after the intervention. The proportion that had fears to be seen by a friend or relative at the clinic decreased. Thus during the implementation of the Creativity intervention, HIV related stigma was reduced in this clinic setting. CONCLUSIONS: The creativity intervention helped to build self esteem and improved communication among those attending the clinic; there was observed ambiance at the clinic and clients became empowered, with creative, communication and networking skills. Improved knowledge and communication are key in addressing self stigma among HIV positive individuals.

A study on inclusion of leprosy in the curricula of pre-service health training institutions in Uganda.

OBJECTIVE: To establish the categories of pre-service health training institutions in Uganda that still maintain leprosy in their curricula and how leprosy training is organised. MATERIALS AND METHODS: A structured questionnaire was administered to the heads of 42 health training institutions including universities, paramedical and nurses' training schools. RESULTS: Leprosy was included in the curricula of 33 (78%) of the institutions studied but only 50% of them had organised leprosy training in the 2 years prior to the study. In 48% of cases the training was implemented by in-house trainers; the rest depended on external trainers and staff of a leprosy training centre. Course evaluation using a variety of methods was practiced by 80% of the institutions. CONCLUSIONS: Inclusion of leprosy in the curricula of pre-service health training institutions was not always followed by actual training. It is possible and acceptable to organise leprosy training within the confines of the institutions provided arrangements are made to include interaction with patients. Local leprosy control supervisors and dermatologists can be engaged to support pre-service training. In order to derive optimal benefit from this opportunity, the National Tuberculosis and Leprosy Control Programme should develop a national plan for leprosy training, organise training of trainers and assure access to appropriate teaching and learning materials. There is a need for more comprehensive evaluation of the ongoing leprosy training in pre-service institutions.

Incidence and predictors of mortality and the effect of tuberculosis immune reconstitution inflammatory syndrome in a cohort of TB/HIV patients commencing antiretroviral therapy.

BACKGROUND: Tuberculosis-HIV (TB-HIV) coinfection remains an important cause of mortality in antiretroviral therapy (ART) programs. In a cohort of TB-HIV-coinfected patients starting ART, we examined the incidence and predictors of early mortality. METHODS: Consecutive TB-HIV-coinfected patients eligible for ART were enrolled in a cohort study at the Mulago National Tuberculosis and Leprosy Program clinic in Kampala, Uganda. Predictors of mortality were assessed using Cox proportional hazards analysis. RESULTS: Three hundred and two patients [median CD4 count 53 cells/µL (interquartile range, 20-134)] were enrolled. Fifty-three patients died, 36 (68%) of these died within the first 6 months of TB diagnosis. Male sex [hazard (HR): 2.19; 95% confidence interval (CI): 1.19 to 4.03; P = 0.011], anergy to tuberculin skin test [HR: 2.59 (1.10 to 6.12); P = 0.030], a positive serum cryptococcal antigen result at enrollment (HR: 4.27; 95% CI: 1.50 to 12.13; P = 0.006) and no ART use (HR: 4.63; 95% CI: 2. 37 to 9.03; P < 0.001) were independent predictors of mortality by multivariate analysis. Six (10%) patients with TB immune reconstitution inflammatory syndrome died, and in most, an alternative contributing cause of death was identified. CONCLUSIONS: Mortality among these TB-HIV-coinfected patients was high particularly when presenting with advanced HIV disease and not starting ART, reinforcing the need for timely and joint treatment for both infections. Screening for a concomitant cryptococcal infection and antifungal treatment for patients with cryptococcal antigenemia may further improve clinical outcome.

Potential role of dermatologists and dermatological services in developing and sustaining the leprosy control referral system in resource constrained settings.

General Health Services that pay due attention to the management of skin conditions are opportune for suspecting and diagnosing early leprosy. In many developing countries, patients with dermatological conditions can only access specialist services in the larger cities and university hospitals; unaffordable costs make the services even less accessible if they can only be provided in the private sector. The high profile of dermatologists in the health services, gives them the opportunity to facilitate the development and implementation of a referral system that includes leprosy. This potential benefit for leprosy control must be initiated by current National Leprosy Programme Managers through establishing formal relationships with the dermatologists and involving them and other partners in the re-designing of leprosy control strategies to keep them in tandem with changing epidemiological patterns, national policies and on -going health sector reforms. The same health service managers should avail of the opportunities from the dermatologists (both in public and private sectors) about the current knowledge on the management and control of leprosy.

Detection and quantification of Mycobacterium leprae in tissue samples by real-time PCR.

Real-time PCR technology has improved molecular diagnostics of many pathogens, but no such test is available for Mycobacterium leprae. In this report we describe the establishment and the pre-clinical evaluation of such an assay. The test achieved a theoretical analytical sensitivity limit of 194 M. leprae cells per skin biopsy specimen and facilitated quantification of mycobacteria in tissue over a range of 54-54,000,000 cells per sample. In punch skin biopsies from 39 untreated Ugandan patients with newly diagnosed leprosy, the clinical diagnosis could be confirmed in 88.9% of multibacillary and 33.3% of paucibacillary (microscopically negative) patients. Real-time detection thus did not increase the clinical sensitivity of PCR as compared to conventional protocols, in spite of its evidently high analytical sensitivity. On the other hand, as still no culture system exists for M. leprae, the assay appears to be a robust tool for detection of the bacterium in selected clinical situations, as well as for quantitation in experimental settings.