Environmental factors affecting ecological niche of Coccidioides species and spatial dynamics of valley fever in the United States.

Coccidioidomycosis is an understudied infectious disease acquired by inhaling fungal spores of Coccidioides species. While historically connected to the southwestern United States, the endemic region for this disease is not well defined. This study's objective was to estimate the impact of climate, soil, elevation and land cover on the Coccidioides species' ecological niche. This research used maximum entropy ecological niche modeling based on disease case data from 2015 to 2016. Results found mean temperature of the driest quarter, and barren, shrub, and cultivated land covers influential in characterizing the niche. In addition to hotspots in central California and Arizona, the Columbia Plateau ecoregion of Washington and Oregon showed more favorable conditions for fungus presence than surrounding areas. The identification of influential spatial drivers will assist in future modeling efforts, and the potential distribution map generated may aid public health officials in watching for potential hotspots, assessing vulnerability, and refining endemicity

The role of age, ethnicity and environmental factors in modulating malaria risk in Rajasthali, Bangladesh

Background: Malaria is endemic in the Rajasthali region of the Chittagong Hill Tracts in Bangladesh and the Rajasthali region is the most endemic area of Bangladesh. Quantifying the role of environmental and socioeconomic factors in the local spatial patterns of malaria endemicity can contribute to successful malaria control and elimination. This study aimed to investigate the role of environmental factors on malaria risk in Rajasthali and to quantify the geographical clustering in malaria risk unaccounted by these factors

Future Lyme disease risk in the southeastern United States based on projected land cover

Lyme disease is the most significant vector-borne disease in the United States, and its southward advance over several decades has been quantified. Previous research has examined the potential role of climate change on the disease’s expansion, but no studies have considered the role of future land cover upon its distribution. This research examines Lyme disease risk in the south-eastern U.S. based on projected land cover developed under four Intergovernmental Panel on Climate Change Scenarios: A1B, A2, B1, and B2. Land cover types and edge indices significantly associated with Lyme disease in Virginia were incorporated into a spatial Poisson regression model to quantify potential land cover suitability for Lyme disease in the south-eastern U.S. under each scenario. Our results indicate an intensification of potential land cover suitability for Lyme disease under the A scenarios and a decrease of potential land cover suitability under the B scenarios. The decrease under the B scenarios is a critical result, indicating that Lyme disease risk can be decreased by making different land cover choices. Additionally, health officials can focus efforts in projected high incidence areas

Spatial Epidemiology in an Appalachian Context

Once only spoken of by physicians and epidemiologists, exotic tropical diseases have recently become household names. Chikungunya, Ebola, SARS, Zika, even the local evening news talks about them. But for all the attention we give to each tropical menace, we seem willfully ignorant of home-grown epidemics. This is especially true of diseases which prey upon residents of disadvantaged rural areas. Appalachia is no exception; in fact it is burdened by several such diseases. With almost no news coverage, it may surprise some to learn that Hepatitis C kills more Americans than any other infectious disease including HIV. The Hepatitis C outbreak is inexorably intertwined with the ongoing heroin and opioid-abuse epidemic, and sadly, Appalachia serves as hot spots for both. For all the talk of Zika-carrying mosquitoes, it is easy to lose track of the fact that tick-borne Lyme disease is the most significant vector-borne agent in the country. Lyme continues its slow southerly advance, and has found Appalachian farming communities to be particularly hospitable. Through the use of spatiotemporal analysis, we investigate the impact of Hepatitis C and Lyme disease on rural Appalachia. In addition to describing the where and the when of each epidemic, we also investigate why Appalachia, in particular, is so vulnerable to these intractable threats

Local perceptions of measures to control Aedes mosquitoes and mosquito-borne diseases in Puntarenas and San José, Costa Rica

Dengue has become an increasingly significant risk to global health. With up to 400 million cases annually, dengue constitutes the fastest growing vector-borne disease globally. In the western hemisphere, dengue, and more recently chikungunya and Zika, exist throughout much of Latin America. These diseases are spread by Aedes mosquitoes, which have been present in the region for centuries. While perceptions of mosquito-borne disease have been studied in Latin America, such qualitative literature on Costa Rica is relatively scarce. Therefore, this study uses qualitative methods to critically investigate the prevention of Aedes mosquito-borne diseases in Puntarenas and San José, Costa Rica. Specifically, this study examines local perceptions of policies and programs to combat Aedes mosquitoes and their associated diseases. Data were collected via household interviews (n=80); semi-structured interviews with public health officials, researchers, nonprofit organizations, and community leaders (n=22); and a focus group discussion in each of two study areas (Puntarenas and San José). Results are presented as place-specific narratives on mosquito and disease control among at-risk communities. Varying degrees of local knowledge on mosquitoes and mosquito-borne diseases exist both within and across the study areas. These differences include conflicting perceptions of mosquito control techniques (e.g., fumigation, education campaigns) as well as disease source, habitat, and risk. Local narratives may inform public health actors on the perspectives of communities who confront, cope with, and manage issues of mosquito-borne disease. El dengue se ha convertido en un riesgo cada vez más importante para la salud mundial. Con un máximo de 400 millones de casos anuales, el dengue constituye de la enfermedad transmitida por vectores más rápido que el crecimiento al nivel mundial. En el hemisferio occidental, el dengue, y lo más reciente chikungunya, y el Zika, existen por casi todo Latino América. Estas enfermedades son transmitidas por los mosquitos llamados Aedes, cuales han sido presente en la región por mucho tiempo. Mientras que la percepción de la enfermedad transmitida por mosquitos se han estudiado en América Latina, este tipo de literature cualitativa en Costa Rica es relativamente escaso. Por lo tanto, este estudio utiliza métodos cualitativos para investigar críticamente la prevención de Aedes enfermedades transmitidas por mosquitos en Puntarenas y San José, Costa Rica. En concreto, este estudio examina las percepciones locales de las políticas y los programas de lucha contra los mosquitos Aedes y sus enfermedades asociadas. Los datos fueron recolectados a través de entrevistas en los hogares (n=80); entrevistas semi-estructuradas con funcionarios de salud pública, investigadores, organizaciones sin fines de lucro, y líderes de la comunidad (n=22), y un grupo de discusión en cada una de dos áreas de estudio (Puntarenas y San José). Los resultados se presentan como narrativas específicas de lugar sobre el control de mosquitos y enfermedades entre las comunidades en riesgo. Existen diversos grados de conocimiento local sobre los mosquitos y las enfermedades transmitidas por mosquitos dentro y fuera de las áreas de estudio. Estas diferencias incluyen las percepciones contradictorias de las técnicas de control de mosquitos (p.ej. fumigación y campañas de educación) así como la fuente de la enfermedad, hábitat, y el riesgo. Las narrativas locales pueden mejorar a los actores de salud pública en las perspectivas de las comunidades que confrontan, enfrentan y manejan los problemas de las enfermedades transmitidas por mosquitos

The potential for emergence of Chagas disease in the United States

To determine the risk for Chagas disease (American trypanosomiasis) in the United States, the characteristics that make the triatomine vector effective and the areas most at risk for transmission were delineated. In addition, the status of Chagas disease awareness among physicians in areas with a potential risk for the disease was determined. A geographical information system (GIS) was used to analyze three triatomine species within the United States known to harbor Trypanosoma cruzi and that exhibit qualities of domesticity. An analysis of the minimum temperature threshold for increased triatomine activity delineates the current population at increased risk, and by incorporating temperature predictions for 2030, the population at risk under a future climate scenario was also delineated. Considering both environmental and social factors, a vignette-based physician survey, based on the results of the GIS analysis, was used to gauge the level of awareness of Chagas disease within the delineated higher risk range. The current area at increased risk for Chagas disease includes much of the southern United States, and the higher risk range is expected to expand into the central United States based upon the 1°C (1.8°F) increase in temperature predicted by the Intergovernmental Panel on Climate Change (IPCC) by the year 2030. Survey results indicate a limited consideration of Chagas disease during differential diagnosis, illustrating that the low number of Chagas disease cases discovered in the United States may be attributable to a lack of disease awareness as opposed to a lack of disease threat. This study combines GIS and survey analyses to evaluate the role that temperature variability and disease awareness among physicians play in the potential emergence of Chagas disease in the United States. This approach indicates that there is a potential for Chagas disease to emerge in the United State

Reduced death rates from cyclones in Bangladesh: what more needs to be done?

Tropical storms, such as cyclones, hurricanes and typhoons, present major threats to coastal communities. Around two million people worldwide have died and millions have been injured over the past two centuries as a result of tropical storms. Bangladesh is especially vulnerable to tropical cyclones, with around 718 000 deaths from them in the past 50 years. However, cyclone-related mortality in Bangladesh has declined by more than 100-fold over the past 40 years, from 500 000 deaths in 1970 to 4234 in 2007. The main factors responsible for these reduced fatalities and injuries are improved defensive measures, including early warning systems, cyclone shelters, evacuation plans, coastal embankments, reforestation schemes and increased awareness and communication. Although warning systems have been improved, evacuation before a cyclone remains a challenge, with major problems caused by illiteracy, lack of awareness and poor communication. Despite the potential risks of climate change and tropical storms, little empirical knowledge exists on how to develop effective strategies to reduce or mitigate the effects of cyclones. This paper summarizes the most recent data and outlines the strategy adopted in Bangladesh. It offers guidance on how similar strategies can be adopted by other countries vulnerable to tropical storms. Further research is needed to enable countries to limit the risks that cyclones present to public health