Spatial clustering and local risk of leprosy in São Paulo, Brazil.

BACKGROUND: Although the detection rate is decreasing, the proportion of new cases with WHO grade 2 disability (G2D) is increasing, creating concern among policy makers and the Brazilian government. This study aimed to identify spatial clustering of leprosy and classify high-risk areas in a major leprosy cluster using the SatScan method. METHODS: Data were obtained including all leprosy cases diagnosed between January 2006 and December 2013. In addition to the clinical variable, information was also gathered regarding the G2D of the patient at diagnosis and after treatment. The Scan Spatial statistic test, developed by Kulldorff e Nagarwalla, was used to identify spatial clustering and to measure the local risk (Relative Risk-RR) of leprosy. Maps considering these risks and their confidence intervals were constructed. RESULTS: A total of 434 cases were identified, including 188 (43.31%) borderline leprosy and 101 (23.28%) lepromatous leprosy cases. There was a predominance of males, with ages ranging from 15 to 59 years, and 51 patients (11.75%) presented G2D. Two significant spatial clusters and three significant spatial-temporal clusters were also observed. The main spatial cluster (p = 0.000) contained 90 census tracts, a population of approximately 58,438 inhabitants, detection rate of 22.6 cases per 100,000 people and RR of approximately 3.41 (95%CI = 2.721-4.267). Regarding the spatial-temporal clusters, two clusters were observed, with RR ranging between 24.35 (95%CI = 11.133-52.984) and 15.24 (95%CI = 10.114-22.919). CONCLUSION: These findings could contribute to improvements in policies and programming, aiming for the eradication of leprosy in Brazil. The Spatial Scan statistic test was found to be an interesting resource for health managers and healthcare professionals to map the vulnerability of areas in terms of leprosy transmission risk and areas of underreporting.

Spatial heterogeneity in projected leprosy trends in India.

BACKGROUND: Leprosy is caused by infection with Mycobacterium leprae and is characterized by peripheral nerve damage and skin lesions. The disease is classified into paucibacillary (PB) and multibacillary (MB) leprosy. The 2012 London Declaration formulated the following targets for leprosy control: (1) global interruption of transmission or elimination by 2020, and (2) reduction of grade-2 disabilities in newly detected cases to below 1 per million population at a global level by 2020. Leprosy is treatable, but diagnosis, access to treatment and treatment adherence (all necessary to curtail transmission) represent major challenges. Globally, new case detection rates for leprosy have remained fairly stable in the past decade, with India responsible for more than half of cases reported annually. METHODS: We analyzed publicly available data from the Indian Ministry of Health and Family Welfare, and fit linear mixed-effects regression models to leprosy case detection trends reported at the district level. We assessed correlation of the new district-level case detection rate for leprosy with several state-level regressors: TB incidence, BCG coverage, fraction of cases exhibiting grade 2 disability at diagnosis, fraction of cases in children, and fraction multibacillary. RESULTS: Our analyses suggest an endemic disease in very slow decline, with substantial spatial heterogeneity at both district and state levels. Enhanced active case finding was associated with a higher case detection rate. CONCLUSIONS: Trend analysis of reported new detection rates from India does not support a thesis of rapid progress in leprosy control.

Analysis of the detection coefficient for the association between leprosy and pregnancy in the integration region of Carajas, State of Para, Brazil

Introduction The association between leprosy and pregnancy is currently poorly understood and has been linked to serious clinical consequences. Methods A retrospective study between 2007 and 2009 was performed in the integration region of Carajás, Brazil on a population of pregnant lepers, with non-lepers of ages 12-49 years serving as the reference population. Results Twenty-nine pregnant lepers were studied during the study period. The detection rates (DRs) for the studied association were 4.7 in 2007, 9.4 in 2008, and 4.3 in 2009. Conclusions The Carajás region presented a medium pattern of endemicity during most of the study period, with a high DR found in 2008. .

Analysis of the detection coefficient for the association between leprosy and pregnancy in the integration region of Carajás, State of Pará, Brazil.

INTRODUCTION: The association between leprosy and pregnancy is currently poorly understood and has been linked to serious clinical consequences. METHODS: A retrospective study between 2007 and 2009 was performed in the integration region of Carajás, Brazil on a population of pregnant lepers, with non-lepers of ages 12-49 years serving as the reference population. RESULTS: Twenty-nine pregnant lepers were studied during the study period. The detection rates (DRs) for the studied association were 4.7 in 2007, 9.4 in 2008, and 4.3 in 2009. CONCLUSIONS: The Carajás region presented a medium pattern of endemicity during most of the study period, with a high DR found in 2008.

Geographic distribution, age pattern and sites of lesions in a cohort of Buruli ulcer patients from the Mapé Basin of Cameroon.

Buruli ulcer (BU), a neglected tropical disease of the skin, caused by Mycobacterium ulcerans, occurs most frequently in children in West Africa. Risk factors for BU include proximity to slow flowing water, poor wound care and not wearing protective clothing. Man-made alterations of the environment have been suggested to lead to increased BU incidence. M. ulcerans DNA has been detected in the environment, water bugs and recently also in mosquitoes. Despite these findings, the mode of transmission of BU remains poorly understood and both transmission by insects or direct inoculation from contaminated environment have been suggested. Here, we investigated the BU epidemiology in the Mapé basin of Cameroon where the damming of the Mapé River since 1988 is believed to have increased the incidence of BU. Through a house-by-house survey in spring 2010, which also examined the local population for leprosy and yaws, and continued surveillance thereafter, we identified, till June 2012, altogether 88 RT-PCR positive cases of BU. We found that the age adjusted cumulative incidence of BU was highest in young teenagers and in individuals above the age of 50 and that very young children (<5) were underrepresented among cases. BU lesions clustered around the ankles and at the back of the elbows. This pattern neither matches any of the published mosquito biting site patterns, nor the published distribution of small skin injuries in children, where lesions on the knees are much more frequent. The option of multiple modes of transmission should thus be considered. Analyzing the geographic distribution of cases in the Mapé Dam area revealed a closer association with the Mbam River than with the artificial lake.

Mycobacterium leprae in Colombia described by SNP7614 in gyrA, two minisatellites and geography.

New cases of leprosy are still being detected in Colombia after the country declared achievement of the WHO defined 'elimination' status. To study the ecology of leprosy in endemic regions, a combination of geographic and molecular tools were applied for a group of 201 multibacillary patients including six multi-case families from eleven departments. The location (latitude and longitude) of patient residences were mapped. Slit skin smears and/or skin biopsies were collected and DNA was extracted. Standard agarose gel electrophoresis following a multiplex PCR-was developed for rapid and inexpensive strain typing of Mycobacterium leprae based on copy numbers of two VNTR minisatellite loci 27-5 and 12-5. A SNP (C/T) in gyrA (SNP7614) was mapped by introducing a novel PCR-RFLP into an ongoing drug resistance surveillance effort. Multiple genotypes were detected combining the three molecular markers. The two frequent genotypes in Colombia were SNP7614(C)/27-5(5)/12-5(4) [C54] predominantly distributed in the Atlantic departments and SNP7614 (T)/27-5(4)/12-5(5) [T45] associated with the Andean departments. A novel genotype SNP7614 (C)/27-5(6)/12-5(4) [C64] was detected in cities along the Magdalena river which separates the Andean from Atlantic departments; a subset was further characterized showing association with a rare allele of minisatellite 23-3 and the SNP type 1 of M. leprae. The genotypes within intra-family cases were conserved. Overall, this is the first large scale study that utilized simple and rapid assay formats for identification of major strain types and their distribution in Colombia. It provides the framework for further strain type discrimination and geographic information systems as tools for tracing transmission of leprosy.

[Geostatistical analysis of leprosy cases in the State of São Paulo, 1991-2002]. / Análise geoestatística de casos de hanseníase no Estado de São Paulo, 1991-2002.

OBJECTIVE: To analyze the spatial pattern of leprosy case occurrences in order to identify areas with a probability of disease transmission risks. METHODS: This was an ecological study in which the analysis units were municipalities in the State of São Paulo that were georeferenced at their centroids. The data source was the electronic database of notified leprosy cases at the Epidemiological Surveillance Center of the State of São Paulo, from 1991 to 2001. Geostatistical techniques were used for detecting areas with a probability of leprosy risk, and for quantifying the spatial dependency of cases. RESULTS: The spatial dependence detected extended outwards to 0.55 degrees from the georeferenced coordinates, which corresponded to approximately 60 km. The main areas identified as presenting a probability of risk were the northeastern, northern and northwestern regions of the State. CONCLUSIONS: Verification of areas with the probability of leprosy risk using spatial dependence analysis may be a useful tool for assessing health conditions and planning budget allocations.

Chemoprophylaxis is effective in the prevention of leprosy in endemic countries: a systematic review and meta-analysis. MILEP2 Study Group. Mucosal Immunology of Leprosy.

OBJECTIVE: To quantify the efficacy of chemoprophylaxis against leprosy. METHOD: Literature searching of Medline and Embase databases, hand-searching of references and correspondence with investigators. STUDY SELECTION: published papers relating to the prevention of leprosy and the use of chemotherapy in leprosy were identified for critical appraisal. Trials were selected and grouped into three categories according to study design and control groups. DATA ANALYSIS: the relative risks (RR) with 95% confidence intervals were calculated from the original data using a random effects model. To assess the cost-effectiveness of chemoprophylaxis, a further analysis of the rates of disease in the trial and control groups was done based on the numbers needed to be treated (NNT) to prevent one new case of leprosy. RESULTS: A total of 14 trials were identified from 127 published papers on chemoprophylaxis of leprosy. The trials were categorized into randomized controlled trials, non-randomized controlled trials, and uncontrolled trials. The overall results of the meta-analysis shows that chemoprophylaxis gives around 60% protection against leprosy. The NNT are low in trials of household contacts. CONCLUSIONS: The evidence shows that chemoprophylaxis against leprosy is an effective way to reduce the incidence of leprosy, particularly in household contacts. The role of chemoprophylaxis needs to be re-examined using newer drugs given the continuing case detection rates globally.

World leprosy in relation to climatic stimulation and bodily vigor

As with other infectious diseases over thhe world, leprosy tends to be more severe and rapidly progressive in the regions of lesser climatic stimulation. It is almost universally true that those areas of the earth with a stimulation index of less than 3.0 are cursed with leprosy as a major public health problem. With an index above 6.0 the disease becomes distinctly more mild and less prevalent, while above 12.0 it continues to exist only by important of cases. Where the stimulation rises to 18.0 or above, there seems to occur a spontaneous cessation of the disease as a public health problem. Leprosy, imported from the tropics into cooler portions of the earth, persists only in those regions of benumbing cold where the real index of climatic stimulation falls to subtropical levels. Scandinavia and the maritime provinces of Canada, with their long cold winters, exemplify this depressing effect of prolonged cold on body vitality. The last wave of leprosy in Norway coincided to a remarkable degree with a world-wide period of subnormal temperatures and increased storminess. On the other hand there is considerable evidence that, when the disease spread with such virulence over Europe in the Middle Ages, the earth was under the influence of a major heat wave that sapped the vigor and vitality of population masses in temperate zones...

A field study of leprosy in Cebu

In the municipality of Cordova, Mactan Island, Province of Cebu, Philippine Islands, a field study of leprosy was found to be entirely practicable. At the commencement of the study certain questions were propounded on which it was hoped to gain information. Certain of these were very definitely answered, and the data collected indicate that most of the others could be satisfactorily settled in a more extensive study. In a population of 6,063 persons, 104 cases of leprosy were found, including 43 that were already in segregation and 16 others on parole. Of the remaining 45 cases, 15 were "closed" cases already on the register of the Cebu Skin Dispensary. The total incidence was 17.2 per thousand, but excluding 23 cases regarded as "arrested" or "quiescent" the rate is reduced to 13.4 per thousand. If the same ratio between segregated and nonsegregated cases be assumed to hold throughout the Philippines, on the basis of the total number now in segregation (approximately 8,500), the total number of all cases of leprosy of all varities, active and quiescent, would be 20,000 more or less. Of the 30 newly discovered cases, only three were of the bacteriologically positive cutaneous type. Contact with an antecedent case, at least as intimate as sleeping in the same house, could be established in 38.5 per cent. Excluding those with such a history who were not members of the same families as the antecedent cases, it was found that 27, or 26 per cent, gave a history of family contact. To obtain these histories with accuracy and in sufficient detail is costly and time consuming, particularly in an area where the disease is frequent. Studies of these and other families are being continued and it is probable that thse percentages will be materially raised. In a high proportion of a limited series of patients the primary lesions were situated on those parts of the body most exposed to injury. The incidence of leprosy in the area studied was not associated with an unusual incidence of any other infectious disease, save that yaws and certain parasitic skin diseases are highly prevalent. There was no obvious deficiency of diet in Cordova, but on this matter no definite opinion can be expressed without further study. A suggestive association was found between the occurrence of leprosy and overcrowding of the home. Detailed findings on paroled patients will be given in a later report.