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Objective: This study employs a strengths-based approach to assess food access in remote Alaska during the COVID-19 pandemic, identifying both the negative consequences of the pandemic on store-bought and subsistence/traditional food access and compensatory strategies used. Design: As a part of a larger study on the impacts of COVID-19 on daily life remote Alaskan communities, study data presented here were collected through key informant interviews (KII) and state-wide online surveys from 21 September 2020 to 31 March 2021 among remote Alaska community members. Setting: This study was conducted with residents of remote communities in Alaska, defined as those off the road system. Remote communities often have small or no grocery stores and rely on subsistence or traditional sources of food. Participants: KII participants (n 36) were majority female (78 %) and Alaska Native (57 %). Survey participants (n 615) were also majority female, 25–54 years old and most had had some post-secondary education or training. Results: Survey and interview data revealed that the pandemic had significant negative impacts on store-bought food access in remote Alaskan communities. Individuals also shared that locally available and wild harvested foods acted as a buffer to some of the loss of access to these store-bought foods, with some people sharing that the harvesting of wild and traditional foods served as a coping strategy during times of pandemic-related stress. Conclusions: The results from this study demonstrate that the remoteness of some Alaskan communities has been both a source of vulnerability and protection in terms of food access.

Objective To assess knowledge, attitudes, and practices (KAP) of veterinary personnel and pet owners regarding ticks and tick-borne diseases in Alaska and to conduct a serosurvey for tick-borne disease pathogens among domestic animals visiting veterinary clinics for preventative care. Sample Across 8 veterinary clinics, we sampled 31 veterinary personnel, 81 pet owners, 102 client-owned dogs, and 1 client-owned cat. Procedures Information on KAP among veterinary staff and pet owners was collected via self-administered questionnaires. Tick and tick-borne disease prevalence were assessed via tick checks and benchtop ELISA antibody tests detecting Anaplasma phagocytophilum, Anaplasma platys, Erlichia canis, Erlichia ewingii, and Borrelia burgdorferi. Results The veterinary personnel KAP survey showed a low average knowledge score (53.5%) but a moderate attitude score (71.7%). In contrast, owner average knowledge score was higher (67.5%) and attitude score was comparatively low (50.6%). Both veterinary personnel and owners had low average practice scores (64.5% and 56.3%, respectively). One dog was positive for anaplasmosis (unknown species) antibody, and 1 dog was positive for B burgdorferi antibody. No ticks were found during the study. Clinical Relevance This study was the first of its kind in the state and indicated a low prevalence of ticks and tick-borne diseases in the domestic pet population and highlighted significant knowledge gaps that could be targeted by public health efforts. Our results suggest the value of a One Health approach and of the veterinary-client relationship to address ticks and tick-borne diseases.

Alaskan wildfires have major ecological, social, and economic consequences, but associated health impacts remain unexplored. We estimated cardiorespiratory morbidity associated with wildfire smoke (WFS) fine particulate matter with a diameter less than 2.5 μm (PM2.5) in three major population centers (Anchorage, Fairbanks, and the Matanuska‐Susitna Valley) during the 2015–2019 wildfire seasons. To estimate WFS PM2.5, we utilized data from ground‐based monitors and satellite‐based smoke plume estimates. We implemented time‐stratified case‐crossover analyses with single and distributed lag models to estimate the effect of WFS PM2.5 on cardiorespiratory emergency department (ED) visits. On the day of exposure to WFS PM2.5, there was an increased odds of asthma‐related ED visits among 15–65 year olds (OR = 1.12, 95% CI = 1.08, 1.16), people >65 years (OR = 1.15, 95% CI = 1.01, 1.31), among Alaska Native people (OR = 1.16, 95% CI = 1.09, 1.23), and in Anchorage (OR = 1.10, 95% CI = 1.05, 1.15) and Fairbanks (OR = 1.12, 95% CI = 1.07, 1.17). There was an increased risk of heart failure related ED visits for Alaska Native people (Lag Day 5 OR = 1.13, 95% CI = 1.02, 1.25). We found evidence that rural populations may delay seeking care. As the frequency and magnitude of Alaskan wildfires continue to increase due to climate change, understanding the health impacts will be imperative. A nuanced understanding of the effects of WFS on specific demographic and geographic groups facilitates data‐driven public health interventions and fire management protocols that address these adverse health effects., Key Points The size and frequency of wildfires in Alaska are increasing, but there are no assessments of the direct health impacts of these eventsIn Alaska, wildfire smoke is positively associated with asthma emergency room visits, and this varies by age, sex, race, and geographyAlaska Native people had a higher risk of several cardiovascular outcomes during wildfire events

In the western United States, Ixodes pacificus Cooley & Kohls (Acari: Ixodidae) is the primary vector of the agents causing Lyme disease and granulocytic anaplasmosis in humans. The geographic distribution of the tick is associated with climatic variables that include temperature, precipitation, and humidity, and biotic factors such as the spatial distribution of its primary vertebrate hosts. Here, we explore (1) how climate change may alter the geographic distribution of I. pacificus in California, USA, during the 21st century, and (2) the spatial overlap among predicted changes in tick habitat suitability, land access, and ownership. Maps of potential future suitability for I. pacificus were generated by applying climate-based species distribution models to a multi-model ensemble of climate change projections for the Representative Concentration Pathway (RCP) 4.5 (moderate emission) and 8.5 (high emission) scenarios for two future periods: mid-century (2026-2045) and end-of-century (2086-2099). Areas climatically-suitable for I. pacificus are projected to expand by 23% (mid-century RCP 4.5) to 86% (end-of-century RCP 8.5) across California, compared to the historical period (1980-2014), with future estimates of total suitable land area ranging from about 88 to 133 thousand km2, or up to about a third of California. Regions projected to have the largest area increases in suitability by end-of-century are in northwestern California and the south central and southern coastal ranges. Over a third of the future suitable habitat is on lands currently designated as open access (i.e. publicly available), and by 2100, the amount of these lands that are suitable habitat for I. pacificus is projected to more than double under the most extreme emissions scenario (from ~23,000 to >51,000 km2). Of this area, most is federally-owned (>45,000 km2). By the end of the century, 26% of all federal land in the state is predicted to be suitable habitat for I. pacificus. The resulting maps may facilitate regional planning and preparedness by informing public health and vector control decision-makers.

Aedes (Stegomyia) aegypti (L.) and Aedes (Stegomyia) albopictus (Skuse) are potential vectors of Zika, dengue, and chikungunya viruses in the United States. A Zika virus outbreak in Florida in the summer of 2016, driven by Ae. aegypti and resulting in > 200 locally acquired cases of human illness, underscored the need for up-to-date information on the geographic distribution of Ae. aegypti and Ae. albopictus in the United States. In early 2016, we conducted a survey and literature review to compile county records for presence of Ae. aegypti and Ae. albopictus in the United States from 1995 to 2016. Surveillance for these vectors was intensified across the United States during the summer and fall of 2016. At the end of 2016, we therefore conducted a follow-up survey of mosquito control agencies, university researchers, and state and local health departments to document new collection records for Ae. aegypti and Ae. albopictus. The repeated survey at the end of the year added Ae. aegypti collection records from 38 new counties and Ae. albopictus collection records from 127 new counties, representing a 21 and 10 percent increase, respectively, in the number of counties with reported presence of these mosquitoes compared with the previous report. Moreover, through our updated survey, 40 and 183 counties, respectively, added additional years of collection records for Ae. aegypti and Ae. albopictus from 1995 to 2016. Our findings underscore the continued need for systematic surveillance of Ae. aegypti and Ae. albopictus.

The novel coronavirus SARS-CoV-2, the causative agent of COVID-19, emerged in the human population in December 2019 and spread worldwide within a few short months. Much of the public health focus for preventing and mitigating the spread of COVID-19 has been on individual and collective behaviors, such as social distancing, mask-wearing, and hygiene. It is important to recognize that these behaviors and health outcomes occur within broader social and environmental contexts, and factors within local communities such as regional policy, historical context, cultural beliefs, and natural- and built environmental characteristics affect underlying population health and the spread of disease. For example, the COVID-19 pandemic has renewed attention to the importance of secure water and sanitation services in protecting human health; many remote Alaskan communities are particularly vulnerable to infectious disease transmission because of inadequate water and sanitation services. In addition, there are a number of socio-economic, physical, and infrastructure factors in rural Alaska (e.g., remoteness, household overcrowding, climate change impacts, limited medical facilities, and high prevalence of chronic diseases) that contribute to the potential for more severe COVID-19 disease outcomes in these predominantly Alaska Native communities., Graphical abstract Unlabelled Image

The late-season extreme fire activity in Southcentral Alaska during 2019 was highly unusual and consequential. Firefighting operations had to be extended by a month in 2019 due to the extreme conditions of hot summer temperature and prolonged drought. The ongoing fires created poor air quality in the region containing most of Alaska&rsquo, s population, leading to substantial impacts to public health. Suppression costs totaled over $70 million for Southcentral Alaska. This study&rsquo, s main goals are to place the 2019 season into historical context, provide an attribution analysis, and assess future changes in wildfire risk in the region. The primary tools are meteorological observations and climate model simulations from the NCAR CESM Large Ensemble (LENS). The 2019 fire season in Southcentral Alaska included the hottest and driest June&ndash, August season over the 1979&ndash, 2019 period. The LENS simulation analysis suggests that the anthropogenic signal of increased fire risk had not yet emerged in 2019 because of the CESM&rsquo, s internal variability, but that the anthropogenic signal will emerge by the 2040&ndash, 80 period. The effect of warming temperatures dominates the effect of enhanced precipitation in the trend towards increased fire risk.

In addition to serving as vectors of several other human pathogens, the black-legged tick, Ixodes scapularis Say, and western black-legged tick, Ixodes pacificus Cooley and Kohls, are the primary vectors of the spirochete (Borrelia burgdorferi) that causes Lyme disease, the most common vector-borne disease in the United States. Over the past two decades, the geographic range of I. pacificus has changed modestly while, in contrast, the I. scapularis range has expanded substantially, which likely contributes to the concurrent expansion in the distribution of human Lyme disease cases in the Northeastern, North-Central and Mid-Atlantic states. Identifying counties that contain suitable habitat for these ticks that have not yet reported established vector populations can aid in targeting limited vector surveillance resources to areas where tick invasion and potential human risk are likely to occur. We used county-level vector distribution information and ensemble modeling to map the potential distribution of I. scapularis and I. pacificus in the contiguous United States as a function of climate, elevation, and forest cover. Results show that I. pacificus is currently present within much of the range classified by our model as suitable for establishment. In contrast, environmental conditions are suitable for I. scapularis to continue expanding its range into northwestern Minnesota, central and northern Michigan, within the Ohio River Valley, and inland from the southeastern and Gulf coasts. Overall, our ensemble models show suitable habitat for I. scapularis in 441 eastern counties and for I. pacificus in 11 western counties where surveillance records have not yet supported classification of the counties as established.

The expanding geographic ranges of tick species that are known pathogen vectors can have implications for human, domestic animal, and wildlife health. Although Alaska is home to several hard tick species, it has historically been outside of the range of the most common medically important ticks in the contiguous United States and western Canada. To assess the status of tick species establishment in the state and to provide a baseline for tracking future change in the distribution of ticks, we reviewed and compiled historical tick records and summarized recent tick occurrence records collected through the development of the Alaska Submit-A-Tick Program and through tick drag sampling at sentinel sites in southcentral Alaska. Between 1909–2019, there were 1190 tick records representing 4588 individual ticks across 15 species in Alaska. The majority of ticks were species historically found in Alaska: Haemaphysalis leporispalustris, Ixodes angustus, Ixodes auritulus, Ixodes howelli, Ixodes signatus, and Ixodes uriae. Over half of all tick records in the state were collected in the last 10 yr. During this time, the number of tick records and the number of tick species recorded in Alaska each year has increased substantially. Between 2010–2019, there were 611 tick records representing 1921 individual ticks. The most common hosts for reported ticks were domestic animals (n = 343, 56 %) followed by small wild mammals (n = 147, 24 %), humans (n = 49, 8%), and wild birds (n = 31, 5%). Less than 5% of records (n = 25) were of unattached ticks found in the environment. Since 2007, non-native tick species have been documented in the state every year, including Amblyomma americanum, Dermacentor andersoni, Dermacentor occidentalis, Dermacentor variabilis, Ixodes pacificus, Ixodes ricinus, Ixodes scapularis, Ixodes texanus, and Rhipicephalus sanguineus sensu lato (s.l.). Almost half of the records (n = 68, 48 %) of non-native tick species from 2010 to 2019 represented ticks found on a host (usually a dog or a human) that had traveled outside of Alaska in the two weeks prior to collection. However, A. americanum, D. variabilis, I. pacificus, I. texanus, and R. sanguineus s.l. have been found on humans and domestic animals in Alaska without reported recent travel. In particular, there is evidence to suggest that there is local establishment of R. sanguineus s.l. in Alaska. A tick species historically found in the state, I. angustus was frequently found on human and dogs, suggesting a potential role as a bridge vector of pathogens. Given the inconsistency of tick monitoring in Alaska over the past century, it is difficult to draw many conclusions from temporal trends in the data. Continued monitoring through the Alaska Submit-A-Tick Program will allow a more accurate assessment of the changing risk of ticks and tick-borne diseases in the state and provide information for setting clinical and public health guidelines for tick-borne disease prevention.

Ixodes pacificus Cooley & Kohls (Acari: Ixodidae), the primary vector of Lyme disease spirochetes to humans in the far-western United States, is broadly distributed across Pacific Coast states, but its distribution is not uniform within this large, ecologically diverse region. To identify areas of suitable habitat, we assembled records of locations throughout California where two or more I. pacificus were collected from vegetation from 1980 to 2014. We then employed ensemble species distribution modeling to identify suitable climatic conditions for the tick and restricted the results to land cover classes where these ticks are typically encountered (i.e., forest, grass, scrub-shrub, riparian). Cold-season temperature and rainfall are particularly important abiotic drivers of suitability, explaining between 50 and 99% of the spatial variability across California among models. The likelihood of an area being classified as suitable increases steadily with increasing temperatures >0°C during the coldest quarter of the year, and further increases when precipitation amounts range from 400 to 800 mm during the coldest quarter, indicating that areas in California with relatively warm and wet winters typically are most suitable for I. pacificus. Other consistent predictors of suitability include increasing autumn humidity, temperatures in the warmest month between 23 and 33°C, and low-temperature variability throughout the year. The resultant climatic suitability maps indicate that coastal California, especially the northern coast, and the western Sierra Nevada foothills have the highest probability of I. pacificus presence.

Contemporary ecological models of health prominently feature the natural environment as fundamental to the ecosystem services that support human life, health, and well-being. The natural environment encompasses and permeates all other spheres of influence on health. Reviews of the natural environment and health literature have tended, at times intentionally, to focus on a limited subset of ecosystem services as well as health benefits stemming from the presence, and access and exposure to, green infrastructure. The sweeping influence of green infrastructure on the myriad ecosystem services essential to health has therefore often been underrepresented. This survey of the literature aims to provide a more comprehensive picture—in the form of a primer—of the many simultaneously acting health co-benefits of green infrastructure. It is hoped that a more accurately exhaustive list of benefits will not only instigate further research into the health co-benefits of green infrastructure but also promote consilience in the many fields, including public health, that must be involved in the landscape conservation necessary to protect and improve health and well-being.

The mosquitoes Aedes (Stegomyia) aegypti (L.)(Diptera:Culicidae) and Ae. (Stegomyia) albopictus (Skuse) (Diptera:Culicidae) transmit dengue, chikungunya, and Zika viruses and represent a growing public health threat in parts of the United States where they are established. To complement existing mosquito presence records based on discontinuous, non-systematic surveillance efforts, we developed county-scale environmental suitability maps for both species using maximum entropy modeling to fit climatic variables to county presence records from 1960–2016 in the contiguous United States. The predictive models for Ae. aegypti and Ae. albopictus had an overall accuracy of 0.84 and 0.85, respectively. Cumulative growing degree days (GDDs) during the winter months, an indicator of overall warmth, was the most important predictive variable for both species and was positively associated with environmental suitability. The number (percentage) of counties classified as environmentally suitable, based on models with 90 or 99% sensitivity, ranged from 1,443 (46%) to 2,209 (71%) for Ae. aegypti and from 1,726 (55%) to 2,329 (75%) for Ae. albopictus. Increasing model sensitivity results in more counties classified as suitable, at least for summer survival, from which there are no mosquito records. We anticipate that Ae. aegypti and Ae. albopictus will be found more commonly in counties classified as suitable based on the lower 90% sensitivity threshold compared with the higher 99% threshold. Counties predicted suitable with 90% sensitivity should therefore be a top priority for expanded mosquito surveillance efforts while still keeping in mind that Ae. aegypti and Ae. albopictus may be introduced, via accidental transport of eggs or immatures, and potentially proliferate during the warmest part of the year anywhere within the geographic areas delineated by the 99% sensitivity model.

The distribution of I. scapularis, the tick vector of the bacteria that cause Lyme disease, has been expanding over the last two decades in the north-central United States in parallel with increasing incidence of human cases of Lyme disease in that region. However, assessments of residential risk for exposure to ticks are lacking from this region. Here, we measured the density of host-seeking I. scapularis nymphs in two suburban and two rural public recreational sites located in Washington County, Minnesota as well as in nearby residential properties. We sought to compare tick densities across land use types and to identify environmental factors that might impact nymphal density. We also assessed the prevalence of infection in the collected ticks with Lyme disease spirochetes (Borrelia burgdorferi sensu stricto, B. mayonii), and other I. scapularis-borne pathogens including B. miyamotoi, Babesia microti and Anaplasma phagocytophilum. Similar to studies from the eastern United States, on residential properties, I. scapularis nymphal densities were highest in the ecotonal areas between the forest edge and the lawn. Residences with the highest densities of nymphs were more likely to have a higher percentage of forest cover, log piles, and signs of deer on their property. In recreational areas, we found the highest nymphal densities both in the wooded areas next to trails as well as on mowed trails. Among the 303 host-seeking I. scapularis nymphs tested for pathogens, B. burgdorferi sensu stricto, A. phagocytophilum and B. miyamotoi were detected in 42 (13.8%), 14 (4.6%), and 2 (0.6%) nymphs, respectively.

In addition to serving as vectors of several other human pathogens, the black-legged tick, Ixodes scapularis Say, and western black-legged tick, Ixodes pacificus Cooley and Kohls, are the primary vectors of the spirochete (Borrelia burgdorferi) that causes Lyme disease, the most common vector-borne disease in the United States. Over the past two decades, the geographic range of I. pacificus has changed modestly while, in contrast, the I. scapularis range has expanded substantially, which likely contributes to the concurrent expansion in the distribution of human Lyme disease cases in the Northeastern, North-Central and Mid-Atlantic states. Identifying counties that contain suitable habitat for these ticks that have not yet reported established vector populations can aid in targeting limited vector surveillance resources to areas where tick invasion and potential human risk are likely to occur. We used county-level vector distribution information and ensemble modeling to map the potential distribution of I. scapularis and I. pacificus in the contiguous United States as a function of climate, elevation, and forest cover. Results show that I. pacificus is currently present within much of the range classified by our model as suitable for establishment. In contrast, environmental conditions are suitable for I. scapularis to continue expanding its range into northwestern Minnesota, central and northern Michigan, within the Ohio River Valley, and inland from the southeastern and Gulf coasts. Overall, our ensemble models show suitable habitat for I. scapularis in 441 eastern counties and for I. pacificus in 11 western counties where surveillance records have not yet supported classification of the counties as established.

The Earth's ecosystems have been altered by anthropogenic processes, including land use, harvesting populations, species introductions and climate change. These anthropogenic processes greatly alter plant and animal communities, thereby changing transmission of the zoonotic pathogens they carry. Biodiversity conservation may be a potential win–win strategy for maintaining ecosystem health and protecting public health, yet the causal evidence to support this strategy is limited. Evaluating conservation as a viable public health intervention requires answering four questions: (i) Is there a general and causal relationship between biodiversity and pathogen transmission, and if so, which direction is it in? (ii) Does increased pathogen diversity with increased host biodiversity result in an increase in total disease burden? (iii) Do the net benefits of biodiversity conservation to human well-being outweigh the benefits that biodiversity-degrading activities, such as agriculture and resource utilization, provide? (iv) Are biodiversity conservation interventions cost-effective when compared to other options employed in standard public health approaches? Here, we summarize current knowledge on biodiversity–zoonotic disease relationships and outline a research plan to address the gaps in our understanding for each of these four questions. Developing practical and self-sustaining biodiversity conservation interventions will require significant investment in disease ecology research to determine when and where they will be effective. This article is part of the themed issue ‘Conservation, biodiversity and infectious disease: scientific evidence and policy implications’.

Nipah virus has caused recurring outbreaks in central and northwest Bangladesh (the “Nipah Belt”). Little is known about roosting behavior of the fruit bat reservoir, Pteropus giganteus, or factors driving spillover. We compared human population density and ecological characteristics of case villages and control villages (no reported outbreaks) to understand their role in P. giganteus roosting ecology and Nipah virus spillover risk. Nipah Belt villages have a higher human population density (P < 0.0001), and forests that are more fragmented than elsewhere in Bangladesh (0.50 versus 0.32 patches/km2, P < 0.0001). The number of roosts in a village correlates with forest fragmentation (r = 0.22, P = 0.03). Villages with a roost containing Polyalthia longifolia or Bombax ceiba trees were more likely case villages (odds ratio [OR] = 10.8, 95% confidence interval [CI] = 1.3–90.6). This study suggests that, in addition to human population density, composition and structure of the landscape shared by P. giganteus and humans may influence the geographic distribution of Nipah virus spillovers.

Aedes (Stegomyia) aegypti (L.) and Aedes (Stegomyia) albopictus (Skuse) transmit arboviruses that are increasing threats to human health in the Americas, particularly dengue, chikungunya, and Zika viruses. Epidemics of the associated arboviral diseases have been limited to South and Central America, Mexico, and the Caribbean in the Western Hemisphere, with only minor localized outbreaks in the United States. Nevertheless, accurate and up-to-date information for the geographical ranges of Ae. aegypti and Ae. albopictus in the United States is urgently needed to guide surveillance and enhance control capacity for these mosquitoes. We compiled county records for presence of Ae. aegypti and Ae. albopictus in the United States from 1995-2016, presented here in map format. Records were derived from the Centers for Disease Control and Prevention ArboNET database, VectorMap, the published literature, and a survey of mosquito control agencies, university researchers, and state and local health departments. Between January 1995 and March 2016, 183 counties from 26 states and the District of Columbia reported occurrence of Ae. aegypti, and 1,241 counties from 40 states and the District of Columbia reported occurrence of Ae. albopictus. During the same time period, Ae. aegypti was collected in 3 or more years from 94 counties from 14 states and the District of Columbia, and Ae. albopictus was collected during 3 or more years from 514 counties in 34 states and the District of Columbia. Our findings underscore the need for systematic surveillance of Ae. aegypti and Ae. albopictus in the United States and delineate areas with risk for the transmission of these introduced arboviruses.

We developed the Livelihood Vulnerability Index (LVI) to estimate climate change vulnerability in the Mabote and Moma Districts of Mozambique. We surveyed 200 households in each district to collect data on socio-demographics, livelihoods, social networks, health, food and water security, natural disasters and climate variability. Data were aggregated using a composite index and differential vulnerabilities were compared. Results suggest that Moma may be more vulnerable in terms of water resources while Mabote may be more vulnerable in terms of socio-demographic structure. This pragmatic approach may be used to monitor vulnerability, program resources for assistance, and/or evaluate potential program/policy effectiveness in data-scarce regions by introducing scenarios into the LVI model for baseline comparison.

Brown dog ticks morphologically identifiable as Rhipicephalus sanguineus sensu lato, are distributed world-wide and their systematics is controversial. Results of genetic and reproductive compatibility studies of geographically distinct populations of R. sanguineus s.l. indicate that the R. sanguineus complex is paraphyletic. To further elucidate systematic relationships within R. sanguineus s.l. and geographic boundaries of its lineages, we conducted a phylogeographical study of 136 tick specimens from 23 countries. Voucher specimens were morphologically identified. A phylogenetic tree was constructed using concatenated partial mitochondrial 12S and 16S rDNA gene sequences and analyzed by the Neighbor-Joining method. A set of 19 bioclimatic variables within the WorldClim dataset were extracted and analyzed to assess correlations between distribution of R. sanguineus s.l. lineages and climatic variables. The following four branches are clearly recognized on the phylogenetic tree: R. sanguineus s.l.-tropical and temperate clades, R. leporis, and R. turanicus. DNA sequences of Rhipicephalus ticks from Israel differ from those of other groups. Strong association between geographical locations of major clades of R. sanguineus s.l. and temperature was identified. The tropical clade of R. sanguineus s.l. occupies areas with the annual mean temperature >20 °C, whereas the temperate clade is present in areas with the annual mean temperature

Summary 1. Flying foxes Pteropus spp. play a key role in forest regeneration as seed dispersers and are also the reservoir of many viruses, including Nipah virus in Bangladesh. Little is known about their habitat requirements, particularly in South Asia. Identifying Pteropus habitat preferences could assist in understanding the risk of zoonotic disease transmission broadly and, in Bangladesh, could help explain the spatial distribution of human Nipah virus cases. 2. We analysed characteristics of Pteropus giganteus roosts and constructed an ecological niche model to identify suitable habitat in Bangladesh. We also assessed the distribution of suitable habitat in relation to the location of human Nipah virus cases. 3. Compared to non-roost trees, P. giganteus roost trees are taller with larger diameters and are more frequently canopy trees. Colony size was larger in densely forested regions and smaller in flood-affected areas. Roosts were located in areas with lower annual precipitation and higher human population density than non-roost sites. 4. We predicted that 2–17% of Bangladesh’s land area is suitable roosting habitat. Nipah virus outbreak villages were 26 times more likely to be located in areas predicted as highly suitable habitat for P. giganteus compared to non-outbreak villages. 5. Synthesis and applications. Habitat suitability modelling may help identify previously undocumented Nipah outbreak locations and improve our understanding of Nipah virus ecology by highlighting regions where there is suitable bat habitat but no reported human Nipah virus. Conservation and public health education is a key component of P. giganteus management in Bangladesh due to the general misunderstanding and fear of bats that are a reservoir of Nipah virus. Affiliation between Old World fruit bats (Pteropodidae) and people is common throughout their range, and in order to conserve these keystone bat species and prevent emergence of zoonotic viruses, it is imperative that we continue to improve our understanding of Pteropus resource requirements and routes of virus transmission from bats to people. Results presented here can be utilized to develop land management strategies and conservation policies that simultaneously protect fruit bats and public health.

We respond to Valle and Clark,1 who assert that “conservation efforts may increase malaria burden in the Brazilian Amazon,” because the relationship between forest cover and malaria incidence was stronger than the effect of the deforestation rate.1 We contend that their conclusion is flawed because of limitations in their methodology that we discuss in detail. Most important are the exclusion of one-half the original data without a discussion of selection bias, the lack of model adjustment for either population growth or migration, and the crude classifications of land cover and protected areas that lead to aggregation bias.1 Of greater significance, we stress the need for caution in the interpretation of data that could have profound effects on regional land use decisions.

Department of Population Health Sciences, Nelson Institute for Environmental Studies, Center for Sustainability and the Global Environment (SAGE), University of Wisconsin–Madison, 1710 University Avenue, Madison, WI 53726 Robert Wood Johnson Foundation Health & Society Scholars Program, UCSF Center for Health & Community and UC Berkeley School of Public Health, 3333 California Street, STE 465, San Francisco, CA 94118 Consortium for Health and Ecology, School of Natural Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027, Australia

Nelson Institute. Center for Sustainability and the Global Environment. University of Wisconsin-Madison, Madison, WI, United States of America Department of Population Health Sciences. School of Medicine and Public Health. Madison, WI, United States of America Fundação Oswaldo Cruz. Instituto de Comunicação e Informação Científica e Tecnológica em Saúde. Rio de Janeiro, RJ, Brasil Department of Global Ecology, Carnegie Institution for Science. Stanford University. California, CA, United States of America Nelson Institute. Center for Sustainability and the Global Environment. University of Wisconsin-Madison, Madison, WI, United States of America/ Department of Population Health Sciences, School of Medicine and Public Health. Madison, WI, United States of America Malaria is a significant public health threat in the Brazilian Amazon. Previous research has shown that deforestation creates breeding sites for the main malaria vector in Brazil, Anopheles darlingi, but the influence of selective logging, forest fires, and road construction on malaria risk has not been assessed. To understand these impacts, we constructed a negative binomial model of malaria counts at the municipality level controlling for human population and social and environmental risk factors. Both paved and unpaved roadways and fire zones in a municipality increased malaria risk. Within the timber production states where 90% of deforestation has occurred, compared with areas without selective logging, municipalities where 0–7% of the remaining forests were selectively logged had the highest malaria risk (1.72, 95% CI 1.18–2.51), and areas with higher rates of selective logging had the lowest risk (0.39, 95% CI 0.23–0.67). We show that roads, forest fires, and selective logging are previously unrecognized risk factors for malaria in the Brazilian Amazon and highlight the need for regulation and monitoring of sub-canopy forest disturbance