Landscape, Environmental and Social Predictors of Hantavirus Risk in São Paulo, Brazil

Seroprevalence of Hantavirus among Manual Cane Cutters and Epidemiological Aspects of HPS in Central Brazil

Hantavirus pulmonary syndrome (HPS) is a rodent-borne zoonotic disease that is endemic throughout the Americas. Agricultural activities increase exposure to wild rodents, especially for sugarcane cutters. We carried out a survey of the epidemiological aspects of HPS and investigated the prevalence of hantavirus infection in the sugarcane cutter population from different localities in the Brazilian Midwest region. We conducted a retrospective study of all confirmed HPS cases in the state of Goiás reported to the National HPS surveillance system between 2007 and 2017, along with a seroepidemiological study in a population of sugarcane cutters working in Goiás state in 2016, using the anti-hantavirus (Andes) ELISA IgG. A total of 634 serum samples from cane cutters were tested for hantavirus antibodies, with 44 (6.9%) being IgG-reactive according to ELISA. The destination of garbage was the only statistically significant variable (p = 0.03) related to the detection of hantavirus IgG (p < 0.05). We described the epidemiological profile of reported hantavirus cases in Goiás-a highly endemic area for HPS, and where the seroepidemiological study was conducted. Our results increase our knowledge about hantavirus infections in Brazil and highlight the vulnerability of sugarcane cutters to a highly lethal disease that, to date, has no specific treatment or vaccination.

Land-cover, land-use and human hantavirus infection risk: a systematic review

Previous studies suggest that the risk of human infection by hantavirus, a family of rodent-borne viruses, might be affected by different environmental determinants such as land cover, land use and land use change. This study examined the association between land-cover, land-use, land use change, and human hantavirus infection risk. PubMed and Scopus databases were interrogated using terms relative to land use (change) and human hantavirus disease. Screening and selection of the articles were completed by three independent reviewers. Classes of land use assessed by the different studies were categorized into three macro-categories of exposure ('Agriculture', 'Forest Cover', 'Urban Areas') to qualitatively synthesize the direction of the association between exposure variables and hantavirus infection risk in humans. A total of 25 articles were included, with 14 studies (56%) conducted in China, 4 studies (16%) conducted in South America and 7 studies (28%) conducted in Europe. Most of the studies (88%) evaluated land cover or land use, while 3 studies (12%) evaluated land use change, all in relation to hantavirus infection risk. We observed that land cover and land-use categories could affect hantavirus infection incidence. Overall, agricultural land use was positively associated with increased human hantavirus infection risk, particularly in China and Brazil. In Europe, a positive association between forest cover and hantavirus infection incidence was observed. Studies that assessed the relationship between built-up areas and hantavirus infection risk were more variable, with studies reporting positive, negative or no associations.

Deforestation for oil palm increases microclimate suitability for the development of the disease vector Aedes albopictus

A major trade-off of land-use change is the potential for increased risk of infectious diseases, a.o. through impacting disease vector life-cycles. Evaluating the public health implications of land-use conversions requires spatially detailed modelling linking land-use to vector ecology. Here, we estimate the impact of deforestation for oil palm cultivation on the number of life-cycle completions of Aedes albopictus via its impact on local microclimates. We apply a recently developed mechanistic phenology model to a fine-scaled (50-m resolution) microclimate dataset that includes daily temperature, rainfall and evaporation. Results of this combined model indicate that the conversion from lowland rainforest to plantations increases suitability for A. albopictus development by 10.8%, moderated to 4.7% with oil palm growth to maturity. Deforestation followed by typical plantation planting-maturation-clearance-replanting cycles is predicted to create pulses of high development suitability. Our results highlight the need to explore sustainable land-use scenarios that resolve conflicts between agricultural and human health objectives.

Neglected tropical diseases risk correlates with poverty and early ecosystem destruction

BACKGROUND

Neglected tropical diseases affect the most vulnerable populations and cause chronic and debilitating disorders. Socioeconomic vulnerability is a well-known and important determinant of neglected tropical diseases. For example, poverty and sanitation could influence parasite transmission. Nevertheless, the quantitative impact of socioeconomic conditions on disease transmission risk remains poorly explored.

METHODS

This study investigated the role of socioeconomic variables in the predictive capacity of risk models of neglected tropical zoonoses using a decade of epidemiological data (2007-2018) from Brazil. Vector-borne diseases investigated in this study included dengue, malaria, Chagas disease, leishmaniasis, and Brazilian spotted fever, while directly-transmitted zoonotic diseases included schistosomiasis, leptospirosis, and hantaviruses. Environmental and socioeconomic predictors were combined with infectious disease data to build environmental and socioenvironmental sets of ecological niche models and their performances were compared.

RESULTS

Socioeconomic variables were found to be as important as environmental variables in influencing the estimated likelihood of disease transmission across large spatial scales. The combination of socioeconomic and environmental variables improved overall model accuracy (or predictive power) by 10% on average (P < 0.01), reaching a maximum of 18% in the case of dengue fever. Gross domestic product was the most important socioeconomic variable (37% relative variable importance, all individual models exhibited P < 0.00), showing a decreasing relationship with disease indicating poverty as a major factor for disease transmission. Loss of natural vegetation cover between 2008 and 2018 was the most important environmental variable (42% relative variable importance, P < 0.05) among environmental models, exhibiting a decreasing relationship with disease probability, showing that these diseases are especially prevalent in areas where natural ecosystem destruction is on its initial stages and lower when ecosystem destruction is on more advanced stages.

CONCLUSIONS

Destruction of natural ecosystems coupled with low income explain macro-scale neglected tropical and zoonotic disease probability in Brazil. Addition of socioeconomic variables improves transmission risk forecasts on tandem with environmental variables. Our results highlight that to efficiently address neglected tropical diseases, public health strategies must target both reduction of poverty and cessation of destruction of natural forests and savannas.

[Environmental factors and cardiopulmonary syndrome due to hanta virus in Chile]

OBJECTIVE

Evaluate the relationship between ambient temperature, relative humidity and particulate matter 2,5 with the number of cases Hantavirus Cardiopulmonary Syndrome in Chile between 2015 and 2017.

METHODS

Observational, cross-sectional study in 197 cases of Hantavirus Cardiopulmonary Syndrome reported and confirmed, occurring between 2015 and 2017 in Chile.

RESULTS

Positive and significant relationship was identified between ambient temperature and number of cases of Hantavirus Cardiopulmonary Syndrome and a negative and significant relationship between the number of cases Hantavirus Cardiopulmonary Syndrome and the relative humidity. Also, ambient temperature together with particulate matter 2,5 was observed to increase significantly the number of cases of Hantavirus Cardiopulmonary Syndrome.

CONCLUSIONS

Environmental factors are related to the number of cases Hantavirus Pulmonary Syndrome in Chile between the years 2015 to 2017.

Habitat fragmentation matters more than habitat loss: The case of host-parasite interactions

While ecologists agree that habitat loss has a substantial negative effect on biodiversity it is still very much a matter of debate whether habitat fragmentation has a lesser effect and whether this effect is positive or negative for biodiversity. Here, we assess the relative influence of tropical forest loss and fragmentation on the prevalence of vector-borne blood parasites of the genera Plasmodium and Haemoproteus in six forest bird species. We also determine whether habitat loss and fragmentation are associated with a rise or fall in prevalence. We sample more than 4000 individual birds from 58 forest sites in Guadeloupe and Martinique. Considering 34 host-parasite combinations independently and a fine characterization of the amount and spatial configuration of habitat, we use partial least square regressions to disentangle the relative effects of forest loss, forest fragmentation, landscape heterogeneity, and local weather conditions on spatial variability of parasite prevalence. Then we test for the magnitude and the sign of the effect of each environmental descriptor. Strikingly, we show that forest fragmentation explains twice as much of the variance in prevalence as habitat loss or landscape heterogeneity. In addition, habitat fragmentation leads to an overall rise in prevalence in Guadeloupe, but its effect is variable in Martinique. Both habitat loss and landscape heterogeneity exhibit taxon-specific effects. Our results suggest that habitat loss and fragmentation may have contrasting effects between tropical and temperate regions and that inter-specific interactions may not respond in the same way as more commonly used biodiversity metrics such as abundance and diversity.

Population fluctuations and synanthropy explain transmission risk in rodent-borne zoonoses

Population fluctuations are widespread across the animal kingdom, especially in the order Rodentia, which includes many globally important reservoir species for zoonotic pathogens. The implications of these fluctuations for zoonotic spillover remain poorly understood. Here, we report a global empirical analysis of data describing the linkages between habitat use, population fluctuations and zoonotic reservoir status in rodents. Our quantitative synthesis is based on data collated from papers and databases. We show that the magnitude of population fluctuations combined with species' synanthropy and degree of human exploitation together distinguish most rodent reservoirs at a global scale, a result that was consistent across all pathogen types and pathogen transmission modes. Our spatial analyses identified hotspots of high transmission risk, including regions where reservoir species dominate the rodent community. Beyond rodents, these generalities inform our understanding of how natural and anthropogenic factors interact to increase the risk of zoonotic spillover in a rapidly changing world.

Synthesizing the connections between environmental disturbances and zoonotic spillover

Zoonotic spillover is a phenomenon characterized by the transfer of pathogens between different animal species. Most human emerging infectious diseases originate from non-human animals, and human-related environmental disturbances are the driving forces of the emergence of new human pathogens. Synthesizing the sequence of basic events involved in the emergence of new human pathogens is important for guiding the understanding, identification, and description of key aspects of human activities that can be changed to prevent new outbreaks, epidemics, and pandemics. This review synthesizes the connections between environmental disturbances and increased risk of spillover events based on the One Health perspective. Anthropogenic disturbances in the environment (e.g., deforestation, habitat fragmentation, biodiversity loss, wildlife exploitation) lead to changes in ecological niches, reduction of the dilution effect, increased contact between humans and other animals, changes in the incidence and load of pathogens in animal populations, and alterations in the abiotic factors of landscapes. These phenomena can increase the risk of spillover events and, potentially, facilitate new infectious disease outbreaks. Using Brazil as a study model, this review brings a discussion concerning anthropogenic activities in the Amazon region and their potential impacts on spillover risk and spread of emerging diseases in this region.

Exposure to urban greenspace and pathways to respiratory health: An exploratory systematic review

BACKGROUND/OBJECTIVE

Urban greenspace may have a beneficial or adverse effect on respiratory health. Our objective was to perform an exploratory systematic review to synthesise the evidence and identify the potential causal pathways relating urban greenspace and respiratory health.

METHODS

We followed PRISMA guidelines on systematic reviews and searched five databases for eligible studies during 2000-2021. We incorporated a broad range of urban greenspace and respiratory health search terms, including both observational and experimental studies. Screening, data extraction, and risk of bias, assessed using the Navigation Guide criteria, were performed independently by two authors. We performed a narrative synthesis and discuss suggested pathways to respiratory health.

RESULTS

We identified 108 eligible papers (n = 104 observational, n = 4 experimental). The most common greenspace indicators were the overall greenery or vegetation (also known as greenness), green land use/land cover of physical area classes (e.g., parks, forests), and tree canopy cover. A wide range of respiratory health indicators were studied, with asthma prevalence being the most common. Two thirds (n = 195) of the associations in these studies were positive (i.e., beneficial) with health, with 31% (n = 91) statistically significant; only 9% (n = 25) of reported associations were negative (i.e., adverse) with health and statistically significant. The most consistent positive evidence was apparent for respiratory mortality. There were n = 35 (32%) 'probably low' and n = 73 (68%) 'probably high' overall ratings of bias. Hypothesised causal pathways for health benefits included lower air pollution, more physically active populations, and exposure to microbial diversity; suggested mechanisms with poorer health included exposure to pollen and other aeroallergens.

CONCLUSION

Many studies showed positive association between urban greenspace and respiratory health, especially lower respiratory mortality; this is suggestive, but not conclusive, of causal effects. Results underscore the importance of contextual factors, greenspace metric employed, and the potential bias of subtle selection factors, which should be explored further.

A Review of Mammarenaviruses and Rodent Reservoirs in the Americas

In the Americas, infectious viral diseases caused by viruses of the genus Mammarenavirus have been reported since the 1960s. Such diseases have commonly been associated with land use changes, which favor abundance of generalist rodent species. In the Americas-where the rates of land use change are among the highest worldwide-at least 1326 of all 2277 known rodent species have been reported. We conducted a literature review of studies between 1960 and 2020, to establish the current and historical knowledge about genotypes of mammarenaviruses and their rodent reservoirs in the Americas. Our overall goal was to show the importance of focusing research efforts on the American continent, since the conditions exist for future viral hemorrhagic fever (VHF) outbreaks caused by rodent-borne viruses, in turn, carried by widely distributed rodents. We found 47 species identified down to the species level, and one species identified only down to the genus level (Oryzomys sp.), reported in the Americas as reservoirs of mammarenaviruses, most these are ecological generalists. These species associate with 29 genotypes of Mammarenavirus, seven of which have been linked to VHFs in humans. We also highlight the need to monitor these species, in order to prevent viral disease outbreaks in the region.

Biodiversity and public health interface

Abstract Alongside modernity, the human activity has been a key factor in global environmental risks, with worldwide anthropic modification being the cause of the emergence of diseases for wild and livestock animals, and even humans. In special, the increase in the spatial distribution and in the incidence of some emerging infectious diseases (EID) are directly associated to deforestation and global climate changes. Moreover, the arise of new EID agents, such as the SARS-COV-2 have been reported for the last 30 years. On the other hand, biodiversity has been shown to be a key indicator for ecosystem health, and to pose a role to increase the promotion of human public health. In neotropical regions, and in special, in Brazil, several infectious diseases have been demonstrated to be directly affected for the biodiversity loss, such as malaria, hantavirus pulmonary syndrome, yellow fever, urban arboviruses, spotted fever, amongst other. To better understand the ecosystem capacity of regulation of infectious diseases, FAPESP BIOTA program have supported researchers and research projects to increase knowledge about Brazilian biodiversity and the ecosystems, such as diversity of bird bioagents, venomous animals biodiversity, diversity of mosquitos species in forest patches inside urban areas, propagation of the yellow fever virus over fragmented forest territories, loss of ecological corridors and occurrence of spotted fever and malaria, amongst others. It is noteworthy that FAPESP BIOTA is a successful program and must be expanded as an important tool for present and future public health promotion.

Influence of Climatic Factors on Human Hantavirus Infections in Latin America and the Caribbean: A Systematic Review

BACKGROUND

With the current climate change crisis and its influence on infectious disease transmission there is an increased desire to understand its impact on infectious diseases globally. Hantaviruses are found worldwide, causing infectious diseases such as haemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS)/hantavirus pulmonary syndrome (HPS) in tropical regions such as Latin America and the Caribbean (LAC). These regions are inherently vulnerable to climate change impacts, infectious disease outbreaks and natural disasters. Hantaviruses are zoonotic viruses present in multiple rodent hosts resident in Neotropical ecosystems within LAC and are involved in hantavirus transmission.

METHODS

We conducted a systematic review to assess the association of climatic factors with human hantavirus infections in the LAC region. Literature searches were conducted on MEDLINE and Web of Science databases for published studies according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) criteria. The inclusion criteria included at least eight human hantavirus cases, at least one climatic factor and study from > 1 LAC geographical location.

RESULTS

In total, 383 papers were identified within the search criteria, but 13 studies met the inclusion criteria ranging from Brazil, Chile, Argentina, Bolivia and Panama in Latin America and a single study from Barbados in the Caribbean. Multiple mathematical models were utilized in the selected studies with varying power to generate robust risk and case estimates of human hantavirus infections linked to climatic factors. Strong evidence of hantavirus disease association with precipitation and habitat type factors were observed, but mixed evidence was observed for temperature and humidity.

CONCLUSIONS

The interaction of climate and hantavirus diseases in LAC is likely complex due to the unknown identity of all vertebrate host reservoirs, circulation of multiple hantavirus strains, agricultural practices, climatic changes and challenged public health systems. There is an increasing need for more detailed systematic research on the influence of climate and other co-related social, abiotic, and biotic factors on infectious diseases in LAC to understand the complexity of vector-borne disease transmission in the Neotropics.

Human development, greenhouse gas emissions and sub-national mitigation burdens: a Brazilian perspective

International frameworks for greenhouse gas (GHG) mitigation usually disregard country-specific inequalities for the allocation of mitigation burdens. This may hinder low developed regions in a country from achieving development in a socioeconomic perspective, such as the Sustainable Development Goals (SDGs) of eradicating poverty (SDG1) and hunger (SDG2). We use observed data (1991–2010) of carbon dioxide equivalent (CO₂eq) emissions and a sub-national human development index (MicroHDI, range [0, 1]) for Brazilian microregions to design a framework where regional mitigation burdens are proportional to the MicroHDI, without compromising national mitigation pledges. According to our results, the less developed Brazilian regions have not been basing their development in emission-intensive activities; instead, the most developed regions have. Between 2011 and 2050, Brazilian cumulative emissions from the sectors most correlated with MicroHDI are expected to be 325 Gt CO₂eq, of which only 50 Gt are associated with regions of MicroHDI < 0.8. Assuming a national GHG mitigation target of 56.5% in 2050 over 2010 (consistent with limiting global warming to 2 ºC), Brazil would emit 190 Gt CO₂eq instead of 325 Gt and the 135 Gt reduction is only accounted for by regions after reaching MicroHDI ≥ 0.8. Allocating environmental restrictions to the high-developed regions leaves ground for the least developed ones to pursue development with fewer restrictions. Our heterogeneous framework represents a fairer allocation of mitigation burdens which could be implemented under the concepts of green economy. This work could be an international reference for addressing both environmental and socioeconomic development in developing countries at sub-national level as emphasized by the SDGs.

Association between predator species richness and human hantavirus infection emergence in Brazil

Hantavirus infection is a rodent-borne disease (RBD) transmitted by urine or feces (as the natural reservoirs) with an annual estimated worldwide incidence of ~150,000 cases. Previous ecological studies suggested that higher species richness of rodents could decrease the risk of RBDs in humans, because the regulatory pressure of predators could reduce contact among rodents, and between humans and rodents. Using surveillance data, we investigated the association of predator species richness with hantavirus infection emergence in 5562 Brazilian inland municipalities between 2007 and 2017. Multivariable logistic regression models were used for the analyses. Diurnal and non-diurnal predator species were independent explanatory variables in the models. Rodent species richness and demographic, socioeconomic, and environmental factors were used as covariates. During the study period, 1084 cases were reported in 429 municipalities. The results showed a reverse-U-shaped association between diurnal predator species richness and hantavirus infection emergence (odds ratio [OR] 0.463, 0.688, and 0.553 for the first [lowest], third, and fourth [highest] quartiles, respectively, using the second quartile as a reference), while higher non-diurnal predator species richness tended to be associated with higher emergence risk (OR 0.134, 1.065, and 2.708 for the first, third, and fourth quartiles, respectively). The difference in these associations illustrates the complexity of the effects of predator species richness on human RBDs, which require further investigation in follow-up studies. The results showed a close link between environmental factors and public health, emphasizing that the One Health concept should be employed to understand the dynamics of RBDs.

Broad and potently neutralizing monoclonal antibodies isolated from human survivors of New World hantavirus infection

New World hantaviruses (NWHs) are endemic in North and South America and cause hantavirus cardiopulmonary syndrome (HCPS), with a case fatality rate of up to 40%. Knowledge of the natural humoral immune response to NWH infection is limited. Here, we describe human monoclonal antibodies (mAbs) isolated from individuals previously infected with Sin Nombre virus (SNV) or Andes virus (ANDV). Most SNV-reactive antibodies show broad recognition and cross-neutralization of both New and Old World hantaviruses, while many ANDV-reactive antibodies show activity for ANDV only. mAbs ANDV-44 and SNV-53 compete for binding to a distinct site on the ANDV surface glycoprotein and show potently neutralizing activity to New and Old World hantaviruses. Four mAbs show therapeutic efficacy at clinically relevant doses in hamsters. These studies reveal a convergent and potently neutralizing human antibody response to NWHs and suggest therapeutic potential for human mAbs against HCPS.

Engdahl et al. show that monoclonal antibodies isolated from human survivors of New World hantavirus infection display broad and potent neutralization across hantavirus species and recognize distinct sites on the glycoprotein spike. Multiple antibodies demonstrate potential therapeutic candidates for New World hantavirus infection. Some antibodies also neutralized Old World hantaviruses.

Key Factors That Enable the Pandemic Potential of RNA Viruses and Inter-Species Transmission: A Systematic Review

Viruses play a primary role as etiological agents of pandemics worldwide. Although there has been progress in identifying the molecular features of both viruses and hosts, the extent of the impact these and other factors have that contribute to interspecies transmission and their relationship with the emergence of diseases are poorly understood. The objective of this review was to analyze the factors related to the characteristics inherent to RNA viruses accountable for pandemics in the last 20 years which facilitate infection, promote interspecies jump, and assist in the generation of zoonotic infections with pandemic potential. The search resulted in 48 research articles that met the inclusion criteria. Changes adopted by RNA viruses are influenced by environmental and host-related factors, which define their ability to adapt. Population density, host distribution, migration patterns, and the loss of natural habitats, among others, have been associated as factors in the virus-host interaction. This review also included a critical analysis of the Latin American context, considering its diverse and unique social, cultural, and biodiversity characteristics. The scarcity of scientific information is striking, thus, a call to local institutions and governments to invest more resources and efforts to the study of these factors in the region is key.

Moving to healthier landscapes: Forest restoration decreases the abundance of Hantavirus reservoir rodents in tropical forests

Hantavirus Cardiopulmonary Syndrome (HCPS) is a disease with high human lethality rates, whose transmission risk is directly related to the abundance of reservoir rodents. In the Brazilian Atlantic forest, the main reservoirs species, Oligoryzomys nigripes and Necromys lasiurus, are thought to increase in abundance with deforestation. Therefore, forest restoration may contribute to decrease HCPS transmission risk, a topic still unexplored, especially in tropical regions. Aiming at filling this research gap, we quantified the potential of forest restoration, as required by the current environmental legislation, to reduce the abundance of Hantavirus reservoir rodents in the Brazilian Atlantic Forest. Using a dataset on small mammal communities sampled at 104 sites, we modeled how the abundance of these two rodent species change with the percentage of forest cover and forest edge density. From the best model, we extrapolated rodent abundance to the entire Atlantic Forest, considering two scenarios: current and restored forest cover. Comparing the estimated abundance between these two scenarios, we show that forest restoration can reduce the abundance of O. nigripes up to 89.29% in 43.43% of Atlantic forest territory. For N. lasiurus, abundance decreased up to 46% in 44% of the Atlantic forest. To our knowledge, this is the first study linking forest restoration and zoonotic diseases. Our results indicate that forest restoration would decrease the chance of HCPS transmission in ~45% of the Atlantic forest, making the landscape healthier to ~2,8 million people living within this area. This positive effect of restoration on disease regulation should be considered as an additional argument to encourage and promote forest restoration in tropical areas around the world.

Prediction of hot spot areas of hemorrhagic fever with renal syndrome in Hunan Province based on an information quantity model and logistical regression model

Background

China’s “13^th 5-Year Plan” (2016–2020) for the prevention and control of sudden acute infectious diseases emphasizes that epidemic monitoring and epidemic focus surveys in key areas are crucial for strengthening national epidemic prevention and building control capacity. Establishing an epidemic hot spot areas and prediction model is an effective means of accurate epidemic monitoring and surveying. Objective: This study predicted hemorrhagic fever with renal syndrome (HFRS) epidemic hot spot areas, based on multi-source environmental variable factors. We calculated the contribution weight of each environmental factor to the morbidity risk, obtained the spatial probability distribution of HFRS risk areas within the study region, and detected and extracted epidemic hot spots, to guide accurate epidemic monitoring as well as prevention and control. Methods: We collected spatial HFRS data, as well as data on various types of natural and human social activity environments in Hunan Province from 2010 to 2014. Using the information quantity method and logistic regression modeling, we constructed a risk-area-prediction model reflecting the epidemic intensity and spatial distribution of HFRS. Results: The areas under the receiver operating characteristic curve of training samples and test samples were 0.840 and 0.816. From 2015 to 2019, HRFS case site verification showed that more than 82% of the cases occurred in high-risk areas.

Discussion

This research method could accurately predict HFRS hot spot areas and provided an evaluation model for Hunan Province. Therefore, this method could accurately detect HFRS epidemic high-risk areas, and effectively guide epidemic monitoring and surveyance.

Hunan, the main epidemic area of HRFS in China. Hunan has had a cumulative incidence of 117,000 cases since 1963. During this time Hunan experienced two high incidence periods in the 1980s and 1990s. We used an Information quantity + Logistic regression model (I+LR model) to predict high-incidence and potential epidemic HFRS areas. Normalized difference vegetation index(NDVI)contributed most to HFRS risk. Per capita GDP, population size, land-use type, rainfall, elevation, and soil type were all factors found to influence HFRS risk. Our study is useful for risk prediction, prevention, and control of HFRS.

Epidemiologic Characteristics of Domestic Patients with Hemorrhagic Fever with Renal Syndrome in Taiwan: A 19-Year Retrospective Study

Background: Hemorrhagic fever with renal syndrome (HFRS) is an illness caused by hantaviruses. Numerous factors modify the risk of hantavirus transmission. This study explored the epidemiological characteristics, differences, and trends in terms of gender, age, season, and living areas of those diagnosed with domestically acquired HFRS in Taiwan from 2001 to 2019. Methods: We examined publicly available annual summary data on the domestic cases with HFRS from 2001 to 2019; these data were obtained from the web database of Taiwan’s Centers for Disease Control (CDC). Results: This study analyzed 21 domestic cases with HFRS from Taiwan’s CDC databases. In this study of the cases of HFRS in Taiwan, a gradual increase in the cases of those aged ≥40 years acquiring the disease was noted, and a distinct pattern of seasonal variation (spring) was observed. Furthermore, more men had domestically acquired HFRS, and living in Taipei metropolitan area (6 cases [28.6%]) and the rural areas (Gao-Ping region, 9 cases [42.9%]) was identified as a potential risk factor. This study represents the first report of confirmed cases of domestically acquired HFRS from surveillance data from Taiwan’s CDC, 2001–2019. Conclusion: This study highlights the importance of longitudinal studies covering a wide geographical area, particularly for highly fluctuating pathogens, to understanding the implications of the transmission of zoonotic diseases in human populations. Important data were identified to inform future surveillance and research efforts in Taiwan.

Spatiotemporal Dynamics of Hantavirus Cardiopulmonary Syndrome Transmission Risk in Brazil

BACKGROUND

Hantavirus disease in humans is rare but frequently lethal in the Neotropics. Several abundant and widely distributed Sigmodontinae rodents are the primary hosts of Orthohantavirus and, in combination with other factors, these rodents can shape hantavirus disease. Here, we assessed the influence of host diversity, climate, social vulnerability and land use change on the risk of hantavirus disease in Brazil over 24 years.

METHODS

Landscape variables (native forest, forestry, sugarcane, maize and pasture), climate (temperature and precipitation), and host biodiversity (derived through niche models) were used in spatiotemporal models, using the 5570 Brazilian municipalities as units of analysis.

RESULTS

Amounts of native forest and sugarcane, combined with temperature, were the most important factors influencing the increase of disease risk. Population at risk (rural workers) and rodent host diversity also had a positive effect on disease risk.

CONCLUSIONS

Land use change-especially the conversion of native areas to sugarcane fields-can have a significant impact on hantavirus disease risk, likely by promoting the interaction between the people and the infected rodents. Our results demonstrate the importance of understanding the interactions between landscape change, rodent diversity, and hantavirus disease incidence, and suggest that land use policy should consider disease risk. Meanwhile, our risk map can be used to help allocate preventive measures to avoid disease.

Hantavirus Pulmonary Syndrome Risk in Entre Ríos, Argentina

Hantavirus pulmonary syndrome (HPS) is a severe emerging endemic disease of the Americas. Because hantavirus reservoirs are sylvatic rodents, HPS risk has been associated with occupational and recreational activities in natural and rural environments. The aim of this study was to analyze the risk of HPS in an endemic province of Argentina. For this, we explored the relationship between HPS cases occurring in Entre Ríos province between 2004 and 2015 and climate, vegetation, landscape, reservoir population, and rodent community characteristics by means of generalized linear models. We modeled HPS occurrence at each site, and both the incidence and number of cases grouped by department. The resulting best model of each analysis was applied in a GIS to build HPS risk maps. Risk of occurrence of HPS increased with tree cover and decreased with distance to rivers. We identified the south of Entre Ríos as the area with higher HPS risk, and therefore, where HPS prevention measures should be more urgently applied. Risk maps based on data available in the public domain are a useful tool that should be used by decision makers to concentrate surveillance and control efforts in those areas with highest HPS risk.

Hantavirus host assemblages and human disease in the Atlantic Forest

Several viruses from the genus Orthohantavirus are known to cause lethal disease in humans. Sigmodontinae rodents are the main hosts responsible for hantavirus transmission in the tropical forests, savannas, and wetlands of South America. These rodents can shed different hantaviruses, such as the lethal and emerging Araraquara orthohantavirus. Factors that drive variation in host populations may influence hantavirus transmission dynamics within and between populations. Landscape structure, and particularly areas with a predominance of agricultural land and forest remnants, is expected to influence the proportion of hantavirus rodent hosts in the Atlantic Forest rodent community. Here, we tested this using 283 Atlantic Forest rodent capture records and geographically weighted models that allow us to test if predictors vary spatially. We also assessed the correspondence between proportions of hantavirus hosts in rodent communities and a human vulnerability to hantavirus infection index across the entire Atlantic Forest biome. We found that hantavirus host proportions were more positively influenced by landscape diversity than by a particular habitat or agricultural matrix type. Local small mammal diversity also positively influenced known pathogenic hantavirus host proportions, indicating that a plasticity to habitat quality may be more important for these hosts than competition with native forest dwelling species. We found a consistent positive effect of sugarcane and tree plantation on the proportion of rodent hosts, whereas defaunation intensity did not correlate with the proportion of hosts of potentially pathogenic hantavirus genotypes in the community, indicating that non-defaunated areas can also be hotspots for hantavirus disease outbreaks. The spatial match between host hotspots and human disease vulnerability was 17%, while coldspots matched 20%. Overall, we discovered strong spatial and land use change influences on hantavirus hosts at the landscape level across the Atlantic Forest. Our findings suggest disease surveillance must be reinforced in the southern and southeastern regions of the biome where the highest predicted hantavirus host proportion and levels of vulnerability spatially match. Importantly, our analyses suggest there may be more complex rodent community dynamics and interactions with human disease than currently hypothesized.

The ecological dynamics of hantavirus diseases: From environmental variability to disease prevention largely based on data from China

Hantaviruses can cause hantavirus pulmonary syndrome (HPS) in the Americas and hemorrhagic fever with renal syndrome (HFRS) in Eurasia. In recent decades, repeated outbreaks of hantavirus disease have led to public concern and have created a global public health burden. Hantavirus spillover from natural hosts into human populations could be considered an ecological process, in which environmental forces, behavioral determinants of exposure, and dynamics at the human–animal interface affect human susceptibility and the epidemiology of the disease. In this review, we summarize the progress made in understanding hantavirus epidemiology and rodent reservoir population biology. We mainly focus on three species of rodent hosts with longitudinal studies of sufficient scale: the striped field mouse (Apodemus agrarius, the main reservoir host for Hantaan virus [HTNV], which causes HFRS) in Asia, the deer mouse (Peromyscus maniculatus, the main reservoir host for Sin Nombre virus [SNV], which causes HPS) in North America, and the bank vole (Myodes glareolus, the main reservoir host for Puumala virus [PUUV], which causes HFRS) in Europe. Moreover, we discuss the influence of ecological factors on human hantavirus disease outbreaks and provide an overview of research perspectives.

The Impact of Global Environmental Changes on Infectious Disease Emergence with a Focus on Risks for Brazil

Environmental changes have a huge impact on the emergence and reemergence of certain infectious diseases, mostly in countries with high biodiversity and serious unresolved environmental, social, and economic issues. This article summarizes the most important findings with special attention to Brazil and diseases of present public health importance in the country such as Chikungunya, dengue fever, yellow fever, Zika, hantavirus pulmonary syndrome, leptospirosis, leishmaniasis, and Chagas disease. An extensive literature review revealed a relationship between infectious diseases outbreaks and climate change events (El Niño, La Niña, heatwaves, droughts, floods, increased temperature, higher rainfall, and others) or environmental changes (habitat fragmentation, deforestation, urbanization, bushmeat consumption, and others). To avoid or control outbreaks, integrated surveillance systems and effective outreach programs are essential. Due to strong global and local influence on emergence of infectious diseases, a more holistic approach is necessary to mitigate or control them in low-income nations.

Spatial heterogeneity of hemorrhagic fever with renal syndrome is driven by environmental factors and rodent community composition

Hemorrhagic fever with renal syndrome (HFRS) is a rodent-borne disease caused mainly by two hantaviruses in China: Hantaan virus and Seoul virus. Environmental factors can significantly affect the risk of contracting hantavirus infections, primarily through their effects on rodent population dynamics and human-rodent contact. We aimed to clarify the environmental risk factors favoring rodent-to-human transmission to provide scientific evidence for developing effective HFRS prevention and control strategies. The 10-year (2006-2015) field surveillance data from the rodent hosts for hantavirus, the epidemiological and environmental data extracted from satellite images and meteorological stations, rodent-to-human transmission rates and impacts of the environment on rodent community composition were used to quantify the relationships among environmental factors, rodent species and HFRS occurrence. The study included 709 cases of HFRS. Rodent species in Chenzhou, a hantavirus hotspot, comprise mainly Rattus norvegicus, Mus musculus, R. flavipectus and some other species (R. losea and Microtus fortis calamorum). The rodent species played different roles across the various land types we examined, but all of them were associated with transmission risks. Some species were associated with HFRS occurrence risk in forest and water bodies. R. norvegicus and R. flavipectus were associated with risk of HFRS incidence in grassland, whereas M. musculus and R. flavipectus were associated with this risk in built-on land. The rodent community composition was also associated with environmental variability. The predictive risk models based on these significant factors were validated by a good-fit model, where: cultivated land was predicted to represent the highest risk for HFRS incidence, which accords with the statistics for HFRS cases in 2014-2015. The spatial heterogeneity of HFRS disease may be influenced by rodent community composition, which is associated with local environmental conditions. Therefore, future work should focus on preventing HFRS is moist, warm environments.

Abundance of impacted forest patches less than 5 km2 is a key driver of the incidence of malaria in Amazonian Brazil

The precise role that deforestation for agricultural settlements and commercial forest products plays in promoting or inhibiting malaria incidence in Amazonian Brazil is controversial. Using publically available databases, we analyzed temporal malaria incidence (2009–2015) in municipalities of nine Amazonian states in relation to ecologically defined variables: (i) deforestation (rate of forest clearing over time); (ii) degraded forest (degree of human disturbance and openness of forest canopy for logging) and (iii) impacted forest (sum of deforested and degraded forest patches). We found that areas affected by one kilometer square of deforestation produced 27 new malaria cases (r² = 0.78; F1,10 = 35.81; P < 0.001). Unexpectedly, we found both a highly significant positive correlation between number of impacted forest patches less than 5 km² and malaria cases, and that these patch sizes accounted for greater than ~95% of all patches in the study area. There was a significantly negative correlation between extraction forestry economic indices and malaria cases. Our results emphasize not only that deforestation promotes malaria incidence, but also that it directly or indirectly results in a low Human Development Index, and favors environmental conditions that promote malaria vector proliferation.

Landscape, Climate and Hantavirus Cardiopulmonary Syndrome Outbreaks

We performed a literature review in order to improve our understanding of how landscape and climate drivers affect HCPS outbreaks. Anthropogenic landscape changes such as forest loss, fragmentation and agricultural land uses are related with a boost in hantavirus reservoir species abundance and hantavirus prevalence in tropical areas, increasing HCPS risk. Additionally, higher precipitation, especially in arid regions, favors an increase in vegetational biomass, which augments the resources for reservoir rodents, also increasing HCPS risk. Although these relationships were observed, few studies described it so far, and the ones that did it are concentrated in few places. To guide future research on this issue, we build a conceptual model relating landscape and climate variables with HCPS outbreaks and identified research opportunities. We point out the need for studies addressing the effects of landscape configuration, temperature and the interaction between climate and landscape variables. Critical landscape thresholds are also highly relevant, once HCPS risk transmission can increase rapidly above a certain degree of landscape degradation. These studies could be relevant to implement preventive measures, creating landscapes that can mitigate disease spread risk.

Climate change and sugarcane expansion increase Hantavirus infection risk

Hantavirus Cardiopulmonary Syndrome (HCPS) is a disease caused by Hantavirus, which is highly virulent for humans. High temperatures and conversion of native vegetation to agriculture, particularly sugarcane cultivation can alter abundance of rodent generalist species that serve as the principal reservoir host for HCPS, but our understanding of the compound effects of land use and climate on HCPS incidence remains limited, particularly in tropical regions. Here we rely on a Bayesian model to fill this research gap and to predict the effects of sugarcane expansion and expected changes in temperature on Hantavirus infection risk in the state of São Paulo, Brazil. The sugarcane expansion scenario was based on historical data between 2000 and 2010 combined with an agro-environment zoning guideline for the sugar and ethanol industry. Future evolution of temperature anomalies was derived using 32 general circulation models from scenarios RCP4.5 and RCP8.5 (Representative greenhouse gases Concentration Pathways adopted by IPCC). Currently, the state of São Paulo has an average Hantavirus risk of 1.3%, with 6% of the 645 municipalities of the state being classified as high risk (HCPS risk ≥ 5%). Our results indicate that sugarcane expansion alone will increase average HCPS risk to 1.5%, placing 20% more people at HCPS risk. Temperature anomalies alone increase HCPS risk even more (1.6% for RCP4.5 and 1.7%, for RCP8.5), and place 31% and 34% more people at risk. Combined sugarcane and temperature increases led to the same predictions as scenarios that only included temperature. Our results demonstrate that climate change effects are likely to be more severe than those from sugarcane expansion. Forecasting disease is critical for the timely and efficient planning of operational control programs that can address the expected effects of sugarcane expansion and climate change on HCPS infection risk. The predicted spatial location of HCPS infection risks obtained here can be used to prioritize management actions and develop educational campaigns.