Longitudinal assessment of anti-PGL-I serology in contacts of leprosy patients in Bangladesh.

BACKGROUND: Despite elimination efforts, the number of Mycobacterium leprae (M. leprae) infected individuals who develop leprosy, is still substantial. Solid evidence exists that individuals living in close proximity to patients are at increased risk to develop leprosy. Early diagnosis of leprosy in endemic areas requires field-friendly tests that identify individuals at risk of developing the disease before clinical manifestation. Such assays will simultaneously contribute to reduction of current diagnostic delay as well as transmission. Antibody (Ab) levels directed against the M.leprae-specific phenolic glycolipid I (PGL-I) represents a surrogate marker for bacterial load. However, it is insufficiently defined whether anti-PGL-I antibodies can be utilized as prognostic biomarkers for disease in contacts. Particularly, in Bangladesh, where paucibacillary (PB) patients form the majority of leprosy cases, anti-PGL-I serology is an inadequate method for leprosy screening in contacts as a directive for prophylactic treatment. METHODS: Between 2002 and 2009, fingerstick blood from leprosy patients' contacts without clinical signs of disease from a field-trial in Bangladesh was collected on filter paper at three time points covering six years of follow-up per person. Analysis of anti-PGL-I Ab levels for 25 contacts who developed leprosy during follow-up and 199 contacts who were not diagnosed with leprosy, was performed by ELISA after elution of bloodspots from filter paper. RESULTS: Anti-PGL-I Ab levels at intake did not significantly differ between contacts who developed leprosy during the study and those who remained free of disease. Moreover, anti-PGL-I serology was not prognostic in this population as no significant correlation was identified between anti-PGL-I Ab levels at intake and the onset of leprosy. CONCLUSION: In this highly endemic population in Bangladesh, no association was observed between anti-PGL-I Ab levels and onset of disease, urging the need for an extended, more specific biomarker signature for early detection of leprosy in this area. TRIAL REGISTRATION: ClinicalTrials.gov ISRCTN61223447.

Outcome of 6 months MBMDT in MB patients in Bangladesh- preliminary results.

Introduction: Duration of leprosy treatment remains long and difficult to complete in resource poor areas. Studies suggest that shortening duration of therapy for MB patients to 6 months may be possible. Methods: New MB patients in 2005 in two NGO projects in Bangladesh were treated with 6 months WHO MB MDT and the rate of relapse and fall in BI on slit skin smear during follow up to date were compared with a control group treated for 12 months the previous year. Results: 1612 patients were enrolled in the trial, and the average duration of follow up was over 7 years after diagnosis. During 11,425 PYAR of follow-up, no relapses were detected, by bacteriological or clinical criteria, in the 918 patients in the 6 months MB MDT group, nor in the 694 patients in the control group. Rate of decline of BI in those who were smear positive was not significantly different between groups. Conclusion: The data does not suggest that shortening duration of treatment from 2 months to 6 months MDT for MB leprosy patients leads to increased rates of relapse.

Leprosy incidence: six years follow-up of a population cohort in Bangladesh.

BACKGROUND: With approximately 250,000 new leprosy cases detected annually, transmission of M. leprae appears to be ongoing in many areas of the world. By studying prospectively the number of leprosy patients found in a population sample at the beginning of the study (prevalence) and the number of new patients found during the 6-year observation period (incidence), we aim to understand better the transmission of M. leprae and the burden of disease. METHODOLOGY: To establish the prevalence and incidence rates of leprosy in the general population of a high endemic area in Bangladesh, we followed prospectively 20,218 individuals from a random cluster sample of the population and examined them at 2-yearly intervals for 6 years. RESULTS: At intake we found 27 new leprosy cases, indicating a prevalence of previously undiagnosed leprosy of 13.3/10,000. Follow-up at 2, 4 and 6 years revealed 17, 16, and eight new cases, respectively, representing incidence rates of 4.0, 4.5 and 2.3/10,000 PYAR, respectively. The incidence rate over 6 years was 3.7/10,000 PYAR. The observed incidence rate is three times higher than the new case detection rate in the same area. Of all 68 new leprosy cases, five (7%) had MB leprosy. The proportion of children under 15 years was 24%. The proportion of female patients was 60%, but the incidence rate of leprosy was the same for males and females. CONCLUSIONS: The decline in incidence of leprosy in a general population sample is less pronounced than routine data from a control programme led us to expect.

The combined effect of chemoprophylaxis with single dose rifampicin and immunoprophylaxis with BCG to prevent leprosy in contacts of newly diagnosed leprosy cases: a cluster randomized controlled trial (MALTALEP study).

BACKGROUND: Despite almost 30 years of effective chemotherapy with MDT, the global new case detection rate of leprosy has remained quite constant over the past years. New tools and methodologies are necessary to interrupt the transmission of M. leprae. Single-dose rifampicin (SDR) has been shown to prevent 57% of incident cases of leprosy in the first two years, when given to contacts of newly diagnosed cases. Immunization of contacts with BCG has been less well documented, but appears to have a preventive effect lasting up to 9 years. However, one major disadvantage is the occurrence of excess cases within the first year after immunization. The objective of this study is to examine the effect of chemoprophylaxis with SDR and immunoprophylaxis with BCG on the clinical outcome as well as on host immune responses and gene expression profiles in contacts of newly diagnosed leprosy patients. We hypothesize that the effects of both interventions may be complementary, causing the combined preventive outcome to be significant and long-lasting. METHODS/DESIGN: Through a cluster randomized controlled trial we compare immunization with BCG alone with BCG plus SDR in contacts of new leprosy cases. Contact groups of around 15 persons will be established for each of the 1300 leprosy patients included in the trial, resulting in approximately 20,000 contacts in total. BCG will be administered to the intervention group followed by SDR, 2 months later. The control group will receive BCG only. In total 10,000 contacts will be included in both intervention arms over a 2-year period. Follow-up will take place one year as well as two years after intake. The primary outcome is the occurrence of clinical leprosy within two years. Simultaneously with vaccination and SDR, blood samples for in vitro analyses will be obtained from 300 contacts participating in the trial to determine the effect of these chemo- and immunoprophylactic interventions on immune and genetic host parameters. DISCUSSION: Combined chemoprophylaxis and immunoprophylaxis is potentially a very powerful and innovative tool aimed at contacts of leprosy patients that could reduce the transmission of M. leprae markedly. The trial intends to substantiate this potential preventive effect. Evaluation of immune and genetic biomarker profiles will allow identification of pathogenic versus (BCG-induced) protective host biomarkers and could lead to effective prophylactic interventions for leprosy using optimized tools for identification of individuals who are most at risk of developing disease. TRIAL REGISTRATION: Netherlands Trial Register: NTR3087.

A qualitative exploration of social contact patterns relevant to airborne infectious diseases in northwest Bangladesh.

In South Asia, the burden of infectious diseases is high. Socioeconomically and culturally-defined social interaction patterns are considered to be an important determinant in the spread of diseases that are transmitted through person-to-person contact. Understanding of the contact patterns in this region can be helpful to develop more effective control measures. Focus group discussions were used in exploring social contact patterns in northwest Bangladesh. The patterns were assessed for perceived relevance to the spread of airborne infectious diseases, with special focus on diseases, like leprosy and tuberculosis, in which the role of social determinants is well-recognized. Highly-relevant social contact patterns inside the home and the neighbourhood, across age and sex groups, were reported in all group discussions. Outside the home, women and girls reported relevant contacts limited to the close neighbourhood while men mentioned high relevant contacts beyond. This implies that, in theory, infectious diseases can easily be transmitted across age and sex groups in and around the home. Adult men might play a role in the transmission of airborne infectious diseases from outside this confined area since only this group reported highly-relevant social contacts beyond the home. This concept needs further exploration but control programmes in the South Asian region could benefit from considering differences in social contact patterns by gender for risk assessments and planning of preventive interventions.

Patient-related factors predicting the effectiveness of rifampicin chemoprophylaxis in contacts: 6 year follow up of the COLEP cohort in Bangladesh.

OBJECTIVES: The COLEP trial in Bangladesh showed a 57% reduction in leprosy incidence among contacts of newly diagnosed patients in the first 2 years after chemoprophylaxis with single dose rifampicin (SDR). We assessed the impact of this intervention after 6 years and identified characteristics of the leprosy index patients predicting the effectiveness of this intervention. DESIGN: The cohort of 1037 patients and their 28 092 contacts that participated in the randomised placebo controlled field trial with single dose rifampicin was followed for 6 years. The leprosy status of contacts was established at 2, 4 and 6 years after the intervention. We assessed the association between characteristics of the index leprosy patients and the development of clinical leprosy among their contacts using logistic regression. RESULTS: The protective effect of SDR was seen only in the first 2 years, with no additional effect after 4 and 6 years. However, the total impact of the intervention was still statistically significant (P = 0.025) after 6 years and no excess cases were observed in the SDR arm at a later stage. The intervention prevented leprosy in contacts that actually received SDR, but did not offer protection to members of the same contact group who did not take chemoprophylaxis. The intervention was most effective in contact groups of female index patients, an enhanced effect was also observed in contact groups of patients belonging to a cluster of two or more leprosy patients at intake as well. CONCLUSION: These easy to recognise patient characteristics indicate a possible enhanced risk of transmission of Mycobacterium leprae to contacts in the vicinity of patients and are useful for deciding about preventive measures, such as early detection or chemoprophylaxis.

Acceptability of chemoprophylaxis for household contacts of leprosy patients in Bangladesh: a qualitative study.

OBJECTIVES: Chemoprophylaxis with single dose rifampicin is a promising intervention to prevent leprosy in close contacts of patients. However, application in control programmes often requires disclosure of the leprosy diagnosis, which is still a stigmatised disease in many countries. Promoting control and treatment of stigmatised diseases without contributing towards stigma of the individuals involved can be very difficult. The objective of this study was to assess the social acceptability of disclosure of the diagnosis and the attitude towards taking prophylactic medicines in a leprosy endemic area in Bangladesh. DESIGN: Qualitative study through focus group discussions with 136 healthy men and women from different age groups and religions, coming from two rural villages and an urban area in northwest Bangladesh, and 14 health workers with extensive experience with leprosy patients. RESULTS: The participants would not object to disclosure of the diagnosis to household members and nearby family if they were diagnosed with leprosy. However, many participants were not willing to share this information with their neighbours and other social contacts due to stigma of the disease. All healthy participants were willing to take chemoprophylaxis if any of their close contacts were diagnosed with leprosy, even after explaining that full protection against leprosy was not guaranteed. CONCLUSION: It can be concluded that chemoprophylaxis for household contacts of leprosy patients is an effective and socially acceptable addition to the current leprosy control programme. Chemoprophylaxis for other categories of contacts likely to benefit would only be feasible, without disclosure of patient information, if given in the form of mass campaigns for the whole population in the area.

Recent food shortage is associated with leprosy disease in Bangladesh: a case-control study.

BACKGROUND: Leprosy is remaining prevalent in the poorest areas of the world. Intensive control programmes with multidrug therapy (MDT) reduced the number of registered cases in these areas, but transmission of Mycobacterium leprae continues in most endemic countries. Socio-economic circumstances are considered to be a major determinant, but uncertainty exists regarding the association between leprosy and poverty. We assessed the association between different socio-economic factors and the risk of acquiring clinical signs of leprosy. METHODS AND FINDINGS: We performed a case-control study in two leprosy endemic districts in northwest Bangladesh. Using interviews with structured questionnaires we compared the socio-economic circumstances of recently diagnosed leprosy patients with a control population from a random cluster sample in the same area. Logistic regression was used to compare cases and controls for their wealth score as calculated with an asset index and other socio-economic factors. The study included 90 patients and 199 controls. A recent period of food shortage and not poverty per se was identified as the only socio-economic factor significantly associated with clinical manifestation of leprosy disease (OR 1.79 (1.06-3.02); p = 0.030). A decreasing trend in leprosy prevalence with an increasing socio-economic status as measured with an asset index is apparent, but not statistically significant (test for a trend: OR 0.85 (0.71-1.02); p = 0.083). CONCLUSIONS: Recent food shortage is an important poverty related predictor for the clinical manifestation of leprosy disease. Food shortage is seasonal and poverty related in northwest Bangladesh. Targeted nutritional support for high risk groups should be included in leprosy control programmes in endemic areas to reduce risk of disease.

Evaluation of activity limitation and social participation, and the effects of reconstructive surgery in people with disability due to leprosy: a prospective cohort study.

PURPOSE: To assess how activity limitation and social participation of individuals with leprosy-related disability change over time, and to quantify the effect of reconstructive surgery. METHOD: Individuals with disability due to leprosy who accepted invitations for assessment at a leprosy clinic between March and July 2007 were interviewed using the SALSA Scale (measuring activity limitation) and the Participation Scale (assessing social participation). All participants were offered reconstructive surgery. Follow-up interviews were done 1 year after the first interview or 1 year after surgery. The main outcomes were changes in SALSA score and Participation score. We used analysis of variance to identify the effects of independent factors on mean SALSA and Participation scores. RESULTS: We interviewed 222 participants, 15 of whom took up the offer of surgery and 207 who did not. Comparison of SALSA Scale scores at baseline and 1 year revealed that activity limitation did not significantly change over time in individuals who declined surgery; however, participants who had surgery showed a significant improvement at 1 year (p < 0.001). Social participation improved over time in both groups, but the difference was significant only in the non-surgery group (p < 0.001). CONCLUSIONS: The findings suggest that reconstructive surgery has beneficial effects on functioning. Evaluation of the need for, and effect of, surgery in larger studies is recommended.

Cost-effectiveness of a chemoprophylactic intervention with single dose rifampicin in contacts of new leprosy patients.

BACKGROUND: With 249,007 new leprosy patients detected globally in 2008, it remains necessary to develop new and effective interventions to interrupt the transmission of M. leprae. We assessed the economic benefits of single dose rifampicin (SDR) for contacts as chemoprophylactic intervention in the control of leprosy. METHODS: We conducted a single centre, double blind, cluster randomised, placebo controlled trial in northwest Bangladesh between 2002 and 2007, including 21,711 close contacts of 1,037 patients with newly diagnosed leprosy. We gave a single dose of rifampicin or placebo to close contacts, with follow-up for four years. The main outcome measure was the development of clinical leprosy. We assessed the cost effectiveness by calculating the incremental cost effectiveness ratio (ICER) between the standard multidrug therapy (MDT) program with the additional chemoprophylaxis intervention versus the standard MDT program only. The ICER was expressed in US dollars per prevented leprosy case. FINDINGS: Chemoprophylaxis with SDR for preventing leprosy among contacts of leprosy patients is cost-effective at all contact levels and thereby a cost-effective prevention strategy. In total, $6,009 incremental cost was invested and 38 incremental leprosy cases were prevented, resulting in an ICER of $158 per one additional prevented leprosy case. It was the most cost-effective in neighbours of neighbours and social contacts (ICER $214), slightly less cost-effective in next door neighbours (ICER $497) and least cost-effective among household contacts (ICER $856). CONCLUSION: Chemoprophylaxis with single dose rifampicin given to contacts of newly diagnosed leprosy patients is a cost-effective intervention strategy. Implementation studies are necessary to establish whether this intervention is acceptable and feasible in other leprosy endemic areas of the world.

Protective effect of the combination BCG vaccination and rifampicin prophylaxis in leprosy prevention.

BCG vaccination and rifampicin chemoprophylaxis are both strategies for leprosy prevention. While the combined effect is unknown, the combination may give the desired push to halt leprosy transmission. Secondary analysis was done on results from a single centre, double blind, cluster randomized, and placebo-controlled trial. Individually, BCG (given at infancy) and rifampicin showed to protect against leprosy (57% [95% CI: 24-75%] and 58% [95% CI: 30-74%], respectively). The combined strategies showed a protective effect of 80% (95% CI: 50-92%). This is the first time that the additive effect of BCG and rifampicin are shown; the combined strategies can possibly lower leprosy incidence.

Polymorphism N248S in the human Toll-like receptor 1 gene is related to leprosy and leprosy reactions.

We investigated the association between a polymorphism of a key innate immunity receptor, Toll-like receptor 1 (TLR1) N248S, and susceptibility to leprosy and its clinical presentation. TLR1 N248S has been shown elsewhere to diminish TLR1 signaling and subsequent leprosy disease. The homozygous genotype SS was more frequent (P=.012) and the heterozygous SN genotype was less frequent (P=.015) in patients with leprosy than in control subjects. Additional observed differences in allelic frequency in patients who experienced reversal reactions and/or erythema nodosum leprosum reactions indicates that altered TLR1 function, or at least a TLR1 N248S-linked trait, may affect the progression from infection to disease as well as the disease course and the risk of debilitating reactional episodes in this population.

Preventing nerve function impairment in leprosy: validation and updating of a prediction rule.

BACKGROUND: To validate and update a prediction rule for estimating the risk of leprosy-related nerve function impairment (NFI). METHODOLOGY/PRINCIPAL FINDINGS: Prospective cohort using routinely collected data, in which we determined the discriminative ability of a previously published rule and an updated rule with a concordance statistic (c). Additional risk factors were analyzed with a Cox proportional hazards regression model. The population consisted of 1,037 leprosy patients newly diagnosed between 2002 and 2003 in the health care facilities of the Rural Health Program in Nilphamari and Rangpur districts in northwest Bangladesh. The primary outcome was the time until the start of treatment. An NFI event was defined as the decision to treat NFI with corticosteroids after diagnosis. NFI occurred in 115 patients (13%; 95% confidence interval 11%-16%). The original prediction rule had adequate discriminative ability (c = 0.79), but could be improved by substituting one predicting variable: 'long-standing nerve function impairment at diagnosis' by 'anti-PGL-I antibodies'. The adjusted prediction rule was slightly better (c = 0.81) and identified more patients with NFI (80%) than the original prediction rule (72%). CONCLUSIONS/SIGNIFICANCE: NFI can well be predicted by using the risk variables 'leprosy classification' and 'anti-PGL-I antibodies'. The use of these two variables that do not include NFI offer the possibility of predicting NFI, even before it occurs for the first time. Surveillance beyond the treatment period can be targeted to those most likely to benefit from preventing permanent disabilities.

Effectiveness of single dose rifampicin in preventing leprosy in close contacts of patients with newly diagnosed leprosy: cluster randomised controlled trial.

OBJECTIVE: To determine the effectiveness of chemoprophylaxis using a single dose of rifampicin to prevent leprosy in close contacts. DESIGN: Single centre, double blind, cluster randomised, placebo controlled trial. SETTING: Leprosy control programme in two districts of northwest Bangladesh with a population of more than four million. PARTICIPANTS: 28,092 close contacts of 1037 patients with newly diagnosed leprosy. 21,711 contacts fulfilled the study requirements. INTERVENTIONS: A single dose of rifampicin or placebo given to close contacts in the second month of starting the index patient's treatment, with follow-up for four years. MAIN OUTCOME MEASURE: Development of clinical leprosy. RESULTS: 18,869 of the 21,711 contacts (86.9%) were followed-up at four years. Ninety one of 9452 contacts in the placebo group and 59 of 9417 in the rifampicin group had developed leprosy. The overall reduction in incidence of leprosy using a single dose of rifampicin in the first two years was 57% (95% confidence interval 33% to 72%). The groups did not differ between two and four years. The overall number needed to treat (NNT) to prevent a single case of leprosy among contacts was 297 (95% confidence interval 176 to 537). Differences were found between subgroups at two years, both in reduction of incidence and in NNT. CONCLUSION: A single dose of rifampicin given to contacts of patients with newly diagnosed leprosy is effective at preventing the development of clinical leprosy at two years. The effect was maintained, but no difference was seen between the placebo and rifampicin groups beyond two years. TRIAL REGISTRATION: Current Controlled Trials ISRCTN61223447 [controlled-trials.com].

The prevalence of previously undiagnosed leprosy in the general population of northwest bangladesh.

BACKGROUND: The prevalence of previously undiagnosed leprosy (PPUL) in the general population was determined to estimate the background level of leprosy in the population and to compare this with registered prevalence and the known PPUL in different levels of contacts of leprosy patients. METHODOLOGY AND PRINCIPAL FINDINGS: Multistage cluster sampling including 20 clusters of 1,000 persons each in two districts with over 4 million population. Physical examination was performed on all individuals. The number of newly found leprosy cases among 17,862 people above 5 years of age from the cluster sample was 27 (19 SLPB, 8 PB2-5), giving a PPUL rate of 15.1 per 10,000. CONCLUSIONS AND SIGNIFICANCE: PPUL in the general population is six times higher than the registered prevalence, but three times lower than that in the most distant subgroup of contacts (neighbour of neighbour and social contacts) of leprosy patients in the same area. Full village or neighbourhood surveys may be preferable to contact surveys where leprosy is highly endemic.

Physical distance, genetic relationship, age, and leprosy classification are independent risk factors for leprosy in contacts of patients with leprosy.

BACKGROUND: Close contacts of patients with leprosy have a higher risk of developing leprosy. Several risk factors have been identified, including genetic relationship and physical distance. Their independent contributions to the risk of developing leprosy, however, have never been sufficiently quantified. METHODS: Logistic-regression analysis was performed on intake data from a prospective cohort study of 1037 patients newly diagnosed as having leprosy and their 21,870 contacts. RESULTS: Higher age showed an increased risk, with a bimodal distribution. Contacts of patients with paucibacillary (PB) leprosy with 2-5 lesions (PB2-5) and those with multibacillary (MB) leprosy had a higher risk than did contacts of patients with single-lesion PB leprosy. The core household group had a higher risk than other contacts living under the same roof and next-door neighbors, who again had a higher risk than neighbors of neighbors. A close genetic relationship indicated an increased risk when blood-related children, parents, and siblings were pooled together. CONCLUSIONS: Age of the contact, the disease classification of the index patient, and physical and genetic distance were independently associated with the risk of a contact acquiring leprosy. Contact surveys in leprosy should be not only focused on household contacts but also extended to neighbors and consanguineous relatives, especially when the patient has PB2-5 or MB leprosy.

Association between anti-pGL-I IgM and clinical and demographic parameters in leprosy.

OBJECTIVE: To determine the risk factors and clinical significance of anti-PGL-I seropositivity. DESIGN: A large-scale sero-epidemiological study (COLEP) was carried out in northwest Bangladesh. Blood on filter paper from 1025 newly diagnosed patients was collected before treatment was started and tested with an anti-PGL-I ELISA; the relation between patient determinants and seropositivity was calculated using logistic regression. RESULTS: The median age was 30 years and the male:female ratio 1.9. Overall, 342 patients (33.4%) were seropositive. The following determinants showed a significant correlation with seropositivity (P < 0-05) in multivariate analysis: sex, age, disability grade, bacterial index and classification according to the World Health Organization (WHO) system. The number and extent of clinical signs correlated with seropositivity, except for the presence of satellite lesions. People with or without a BCG vaccination scar had a similar risk to be seropositive. CONCLUSION: Serology is a marker for a higher systemic bacterial load and may identify potential infectious sources among patients with few clinical signs. The size of skin lesions was positively correlated with seropositivity. We did not find different levels of seropositivity among patients with one or two skin lesions, neither did we find different levels among patients with or without satellite