The long-term impact of the Leprosy Post-Exposure Prophylaxis (LPEP) program on leprosy incidence: A modelling study.

BACKGROUND: The Leprosy Post-Exposure Prophylaxis (LPEP) program explored the feasibility and impact of contact tracing and the provision of single dose rifampicin (SDR) to eligible contacts of newly diagnosed leprosy patients in Brazil, India, Indonesia, Myanmar, Nepal, Sri Lanka and Tanzania. As the impact of the programme is difficult to establish in the short term, we apply mathematical modelling to predict its long-term impact on the leprosy incidence. METHODOLOGY: The individual-based model SIMCOLEP was calibrated and validated to the historic leprosy incidence data in the study areas. For each area, we assessed two scenarios: 1) continuation of existing routine activities as in 2014; and 2) routine activities combined with LPEP starting in 2015. The number of contacts per index patient screened varied from 1 to 36 between areas. Projections were made until 2040. PRINCIPAL FINDINGS: In all areas, the LPEP program increased the number of detected cases in the first year(s) of the programme as compared to the routine programme, followed by a faster reduction afterwards with increasing benefit over time. LPEP could accelerate the reduction of the leprosy incidence by up to six years as compared to the routine programme. The impact of LPEP varied by area due to differences in the number of contacts per index patient included and differences in leprosy epidemiology and routine control programme. CONCLUSIONS: The LPEP program contributes significantly to the reduction of the leprosy incidence and could potentially accelerate the interruption of transmission. It would be advisable to include contact tracing/screening and SDR in routine leprosy programmes.

The long-term impact of the leprosy post-exposure prophylaxis (LPEP) program on leprosy incidence: a modelling study

The Leprosy Post-Exposure Prophylaxis (LPEP) program explored the feasibility and impact of contact tracing and the provision of SDR to eligible contacts of newly diagnosed leprosy patients in states or districts of Brazil, India, Indonesia, Myanmar, Nepal, Sri Lanka and Tanzania. This study investigated the long-term impact of the LPEP program on the leprosy new case detection rate (NCDR). Our results show that LPEP could reduce the NCDR beyond the impact of the routine leprosy control programme and that many new cases could be prevented. The benefit of LPEP increases gradually over time. LPEP could accelerate the time of reaching predicted NCDR levels of 2040 under routine program by up to six years. Furthermore, we highlighted how the impact varies between countries due to differences in the number of contacts per index patient screened and differences in leprosy epidemiology and national control programme. Generally, including both household contacts and neighbours (> 20 contacts per index patient) would yield the highest impact.

A Review on Dapsone Hypersensitivity Syndrome Among Chinese Patients with an Emphasis on Preventing Adverse Drug Reactions with Genetic Testing.

AbstractDapsone is a bactericidal and bacteriostatic against Mycobacterium leprae, a causative agent of leprosy. Dapsone is also applied in a range of medical fields because of its anti-inflammatory and immunomodulatory effects. Dapsone hypersensitivity syndrome (DHS) is a rare yet serious adverse drug reaction (ADR) caused by dapsone involving multiple organs. We performed a systematic review of published articles describing dapsone-induced hypersensitivity syndrome, including all Chinese articles and the latest literature available in online databases published between October 2009 and October 2015. We determined the prevalence, clinical characteristics, and mortality rate of DHS. Importantly, we also summarized the recent advances in genetic testing allowing prediction of ADRs. In an initial systematic electronic search, we retrieved 191 articles. Subsequently, these articles were further filtered and ultimately 84 articles (60 Chinese case reports, 21 non-Chinese articles, and three epidemiological studies) were selected, which included 877 patients. The prevalence of DHS among Chinese patients was 1.5% with a fatality rate of 9.6%. Early withdrawal of dapsone and appropriate treatment reduced the fatality rate. Most importantly, genetic screening for the HLA-B*13:01 allele among high-risk populations showed a significant utility as a useful genetic marker to DHS. In conclusion, this review discusses the epidemiological and clinical characteristics of DHS among Chinese patients, which may help physicians to understand this syndrome.

The pathway to foot ulceration in diabetes.

It should now be possible to achieve a reduction in the incidence of foot ulceration and amputations as knowledge about pathways that result in both these events increases. However, despite the universal use of patient education and the hope of reducing the incidence of ulcers in high-risk patients, there are no appropriately designed large, randomized controlled trials actually confirming that education works. It has been recognized for some years that education as part of a multidisciplinary approach to care of the diabetic foot can help to reduce the incidence of amputations in certain settings. Ultimately, however, a reduction in neuropathic foot problems will only be achieved if we remember that the patients with neuropathic feet have lost their prime warning signal­pain­that ordinarily brings patients to their doctor. Very little training is offered to health care professionals as to how to deal with such patients. Much can be learned about the management of such patients from the treatment of individuals with leprosy: if we are to succeed, we must realize that with loss of pain there is also diminished motivation in the healing of and prevention of injury.

Cryptic exposure to arsenic.

Arsenic is an odorless, colorless and tasteless element long linked with effects on the skin and viscera. Exposure to it may be cryptic. Although human intake can occur from four forms, elemental, inorganic (trivalent and pentavalent arsenic) and organic arsenic, the trivalent inorganic arsenicals constitute the major human hazard. Arsenic usually reaches the skin from occupational, therapeutic, or environmental exposure, although it still may be employed as a poison. Occupations involving new technologies are not exempt from arsenic exposure. Its acute and chronic effects are noteworthy. Treatment options exist for arsenic-induced pathology, but prevention of toxicity remains the main focus. Vitamin and mineral supplementation may play a role in the treatment of arsenic toxicity.

Adverse events of standardized regimens of corticosteroids for prophylaxis and treatment of nerve function impairment in leprosy: results from the 'TRIPOD' trials.

Reactions in leprosy causing nerve function impairment (NFI) are increasingly treated with standardized regimens of corticosteroids, often under field conditions. Safety concerns led to an assessment of adverse events of corticosteroids, based on data of three trials studying prevention of NFI (the TRIPOD study). A multicentre, randomized, double-blind placebo-controlled trial was conducted in leprosy control programmes in Nepal and Bangladesh. Treatment was with prednisolone according to fixed schedules for 16 weeks, starting in one trial with 20 mg/day (prophylactic regimen: total dosage 1.96 g) and in the other two trials with 40 mg/day (therapeutic regimen: total dosage 2.52 g). Minor adverse events were defined as moon face, fungal infections, acne, and gastric pain requiring antacid. Major adverse events were defined as psychosis, peptic ulcer, glaucoma, cataract, diabetes and hypertension. Also, the occurrence of infected plantar, palmar, and corneal ulceration was monitored, together with occurrence of TB. Considering all three trials together, minor adverse events were observed in 130/815 patients (16%). Of these, 51/414 (12%) were in the placebo group and 79/401 (20%) in the prednisolone group. The relative risk for minor adverse events in the prednisolone group was 1.6 (P = 0.004). Adverse events with a significantly increased risk were acne, fungal infections and gastric pain. Major adverse events were observed in 15/815 patients (2%); 7/414 (2%) in the placebo group and 8/401 (2%) in the prednisolone group. No major adverse events had a significantly increased risk in the prednisolone arm of the trials. No cases of TB were observed in 300 patients who could be followed-up for 24 months. Standardized regimens of corticosteroids for both prophylaxis and treatment of reactions and NFI in leprosy under field conditions in developing countries are safe when a standard pre-treatment examination is performed, treatment for minor conditions can be carried out by field staff, referral for specialized medical care is possible, and sufficient follow-up is done during and after treatment.

Prophylaxis--scope and limitations.

Attempts to prevent leprosy by one or another prophylactic method began with the use of dapsone as a chemoprophylaxis. Following early, small-scale studies, which were promising, large-scale studies with dapsone and acedapsone, both among contacts and in the general population, demonstrated that it is possible to prevent the occurrence of leprosy to a modest extent. With regard to immunoprophylaxis, BCG had long been considered a possibility, particularly in view of its potential to convert the skin test reaction to lepromin. Over the years, major, large-scale field trials of BCG had been carried out in Uganda, Burma, Papua New Guinea and India. All of the studies demonstrated that BCG was capable of preventing leprosy. However, protective efficacy varied from around 20% to greater than 80%. Killed Mycobacterium leprae mixed with BCG has also given varying results. Other vaccines based on cultivable mycobacteria have also been tried, and at least one of them appears promising. An approach to prophylaxis must take into account (a) the level of risk addressed and the perception of risk by the community; (b) the level of efficacy of the method of prophylaxis; (c) the possibility of easily identifying high-risk groups; (d) the operational feasibility; and (e) the focus of the prophylaxis, whether the individual or the community, or both. However, in view of the enormous progress being made towards elimination of leprosy by the widespread application of MDT, prophylaxis is becoming less and less relevant and less and less cost-effective, except in very special situations.