Spatial distribution pattern of new leprosy cases under 15 years of age and their contacts in Sobral, Ceará, Brazil.

This study's objective was to analyze the spatial distribution pattern of new leprosy cases under 15 years and their contacts. A cross-sectional descriptive study covering sociodemographic characteristics and spatial analysis was carried out. The participants were from the city of Sobral, Ceará and the study was conducted between August 2014 and September 2015. Contacts were identified by the persons responsible for the children. Seropositivity was determined with the NDO-LID antigen, and positive cases were plotted on Voronoi polygons. Nine new cases of leprosy under 15 years of age have been found. The average number of people living with the cases was higher than the number of people living with non-household contacts. All household contacts were aware of other leprosy cases and had a higher rate of seropositive tests than non-household contacts. The index cases lived in the poorest regions of the municipality and hyper-endemic areas. Spatial analysis revealed a cluster of subclinical infection within a radius of 102 meters, suggesting that non-household transmission is related to proximity with seropositive individuals. In conclusion, the search for new leprosy cases cannot be restricted to household contacts.

Spatial distribution pattern of new leprosy cases under 15 years of age and their contacts in Sobral, Ceará, Brazil / Distribuição espacial de novos casos de hanseníase em menores de 15 anos e de seus contatos em Sobral, Ceará, Brasil

Abstract This study's objective was to analyze the spatial distribution pattern of new leprosy cases under 15 years and their contacts. A cross-sectional descriptive study covering sociodemographic characteristics and spatial analysis was carried out. The participants were from the city of Sobral, Ceará and the study was conducted between August 2014 and September 2015. Contacts were identified by the persons responsible for the children. Seropositivity was determined with the NDO-LID antigen, and positive cases were plotted on Voronoi polygons. Nine new cases of leprosy under 15 years of age have been found. The average number of people living with the cases was higher than the number of people living with non-household contacts. All household contacts were aware of other leprosy cases and had a higher rate of seropositive tests than non-household contacts. The index cases lived in the poorest regions of the municipality and hyper-endemic areas. Spatial analysis revealed a cluster of subclinical infection within a radius of 102 meters, suggesting that non-household transmission is related to proximity with seropositive individuals. In conclusion, the search for new leprosy cases cannot be restricted to household contacts.

Resumo O objetivo deste estudo foi analisar o padrão de distribuição espacial de novos casos de hanseníase em menores de 15 anos e seus contatos. Estudo transversal, descritivo, abrangendo características sociodemográficas e análise espacial. Os participantes eram de Sobral, Ceará e o estudo foi realizado entre agosto de 2014 e setembro de 2015. Os contatos foram identificados pelos responsáveis pelas crianças. A soropositividade foi determinada com o antígeno NDO-LID e os casos positivos foram plotados em polígonos de Voronoi. Nove novos casos de hanseníase em menores de 15 anos foram encontrados. O número médio de pessoas que conviviam com os casos foi superior ao número de pessoas que conviviam com contatos não domiciliares. Todos os contatos domiciliares sabiam de outros casos de hanseníase e apresentaram maior taxa de testes soropositivos do que os contatos não domiciliares. Os casos índice residiam nas regiões mais pobres do município e em áreas hiperendêmicas. A análise espacial revelou um agrupamento de infecção subclínica em um raio de 102 metros, sugerindo que a transmissão não domiciliar está relacionada à proximidade com indivíduos soropositivos. Concluindo, a busca por novos casos de hanseníase não pode se restringir aos contatos domiciliares.

A social network approach for the study of leprosy transmission beyond the household.

BACKGROUND: Mycobacterium leprae was the first microorganism directly associated with a disease, however, there are still important gaps in our understanding of transmission. Although household contacts are prioritized, there is evidence of the importance of extrahousehold contacts. The goal of this article is to contribute to our understanding of the transmission of leprosy ex-household. METHODS: We compare co-location data of 397 leprosy cases and 211 controls drawn from the Centro de Dermatologia Sanitária D. Libânia in Fortaleza, Brazil. We collected lifetime geolocation data related to residence, school attendance and workplace and developed novel methods to establish a critical distance (Rc) for exposure and evaluated the potential for transmission for residence, school and workplace. RESULTS: Our methods provide different threshold values of distance for residence, school and workplace. Residence networks demonstrate an Rc of about 500 m. Cases cluster in workplaces as well. Schools do not cluster cases. CONCLUSIONS: Our novel network approach offers a promising opportunity to explore leprosy transmission. Our networks confirm the importance of coresidence, provide a boundary and suggest a role for transmission in workplaces. Schools, on the other hand, do not demonstrate a clustering of cases. Our findings may have programmatic relevance.

Multiplex Competition, Collaboration, and Funding Networks Among Health and Social Organizations: Toward Organization-based HIV Interventions for Young Men Who Have Sex With Men.

BACKGROUND: Young men who have sex with men (YMSM) have the highest rates of human immunodeficiency virus (HIV) infection in the United States. Decades into the HIV epidemic, the relationships that YMSM-serving health and social organizations have with one another has not been studied in depth. OBJECTIVES: The aim of this study was to examine the competition, collaboration, and funding source structures of multiplex organization networks and the mechanisms that promote fruitful relationships among these organizations. RESEARCH DESIGN: The study data collection method was a survey of health and social organizations from 2013-2014 in 2 cities, Chicago, IL and Houston, TX. SUBJECTS: Study participants were representatives from 138 health and social organizations. MEASURES: Responses to survey questions were used to reconstruct competition, collaboration, and combined competition-collaboration networks. RESULTS: While taking into consideration the collaborative relationships among organizations, we provide statistical evidence that organizations of similar type, similar social media use patterns, comparable patterns of funding, and similar network contexts tended to compete with one another. This competition was less likely to be accompanied by any sort of collaboration if the organizations shared common funding sources. CONCLUSIONS: Competition that excludes potential collaboration may be detrimental to mobilizing the collective efforts that serve local YMSM communities. System-level interventions may provide promising approaches to scaling-up HIV prevention and treatment efforts so as to encourage organizations to form partnerships with otherwise competing providers.

An investigation of concurrent sex partnering in two samples of drug users having large numbers of sex partners.

The objective of this study was to quantitatively measure the nature of concurrent sex partnering in two samples of drug users having large numbers of sex partners. The purpose of this study was to measure concurrent sex partnering and overlap in concurrent sex partners in two samples of drug users in which some or all participants were trading sex-for-money. Two samples having large numbers of sex partners were used to conduct the analyses: drug-using male sex workers (MSW) and male and female crack cocaine smokers (CS) having vaginal sex. To reflect the quality of concurrent partnering, three measures were used: the proportion of the samples having concurrent partners; the proportions of the samples having intimate, casual, and sex-for-money of partners; and overlap in concurrent partners. Proportions of each sample having concurrent partners were essentially the same. However, the kinds of concurrent partners and overlap in concurrent partners were significantly different. Concurrent partners in the MSW sample were mostly sex-for-money or sex-for-drugs partners. Most concurrent partners in the CS sample were initimate or casual sex partners. Overlap in concurrent partners was also significantly different. The measure of overlap for the CS sample was three times higher than that of the MSW sample. These data suggest that concurrent sex partnering in the two samples, beyond the proportion having concurrent partners, was different. The patterns of concurrent sex partners in each sample may reflect different reasons for engaging in concurrent partnering. Different reasons for engaging in concurrent partnering may also be reflected in different overlap scores between the two samples. Efforts should be made in future studies to better capture the complexities of concurrent partnering and to examine the implications of these for disease spread and control.

Spatial bridging in a network of drug-using male sex workers.

This study sought to determine whether drug-using male sex workers (MSWs) spatially bridge sexual networks across cities and to determine whether the behaviors of MSWs who bridge differ from the behaviors of those who do not. Data were collected from 42 MSWs in Houston, Texas, between May 2003 and February 2004. Spatial bridging was defined as having traded sex for money in another city before traveling to and trading in Houston. Cities bridged by MSWs were geographically plotted and were primarily located in the Gulf Coast and in Florida. Slightly less than half of MSWs were identified as spatially bridging from one city to another. A significantly higher proportion of MSWs who bridged cities were homosexual (55% vs. 23%) and HIV positive (31% vs. 5%). Those who bridged cities used marijuana and injected drugs more frequently and had significantly more male sex partners than MSWs who did not bridge cities. Despite the small sample size, this study found that many drug-using MSWs spatially bridge sexual networks in cities where they trade sex for money.