Distribution and prevalence of Sin Nombre hantavirus in rodent species in eastern New Mexico.

Orthohantaviruses are diverse zoonotic RNA viruses. Small mammals, such as mice and rats are common chronic, asymptomatic hosts that transmit the virus through their feces and urine. In North America, hantavirus infection primarily causes hantavirus cardiopulmonary syndrome (HCPS), which has a mortality rate of nearly 36%. In the United States of America, New Mexico (NM) is leading the nation in the number of HCPS-reported cases (N = 129). However, no reported cases of HCPS have occurred within eastern NM. In this study, we assessed the prevalence of Sin Nombre virus (SNV) in rodent assemblages across eastern NM, using RT-qPCR. We screened for potential rodent hosts in the region, as well as identified areas that may pose significant infection risk to humans. We captured and collected blood and lung tissues from 738 rodents belonging to 23 species. 167 individuals from 16 different species were positive for SNV RNA by RT-qPCR, including 6 species unreported in the literature: Onychomys leucogaster (Northern grasshopper mouse), Dipodomys merriami (Merriam's kangaroo rat), Dipodomys ordii (Ord's kangaroo rat), Dipodomys spectabilis (Banner-tailed kangaroo rat), Perognathus flavus (Silky pocket mouse), and Chaetodipus hispidus (Hispid pocket mouse). The infection rates did not differ between sexes or rodent families (i.e., Cricetidae vs. Heteromyidae). Generalized linear model showed that disturbed habitat types positively influenced the prevalence of SNV at sites of survey. Overall, the results of this study indicate that many rodent species in east New Mexico have the potential to maintain SNV in the environment, but further research is needed to assess species specific infectivity mechanisms and potential risk to humans.

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.

Hantavirus in Panama: Twenty Years of Epidemiological Surveillance Experience.

Twenty years have passed since the emergence of hantavirus zoonosis in Panama at the beginning of this millennium. We provide an overview of epidemiological surveillance of hantavirus disease (hantavirus pulmonary syndrome and hantavirus fever) during the period 1999-2019 by including all reported and confirmed cases according to the case definition established by the health authority. Our findings reveal that hantavirus disease is a low-frequency disease, affecting primarily young people, with a relatively low case-fatality rate compared to other hantaviruses in the Americas (e.g., ANDV and SNV). It presents an annual variation with peaks every 4-5 years and an interannual variation influenced by agricultural activities. Hantavirus disease is endemic in about 27% of Panama, which corresponds to agroecological conditions that favor the population dynamics of the rodent host, Oligoryzomys costaricensis and the virus (Choclo orthohantavirus) responsible for hantavirus disease. However, this does not rule out the existence of other endemic areas to be characterized. Undoubtedly, decentralization of the laboratory test and dissemination of evidence-based surveillance guidelines and regulations have standardized and improved diagnosis, notification at the level of the primary care system, and management in intensive care units nationwide.

Modeling potential risk areas of Orthohantavirus transmission in Northwestern Argentina using an ecological niche approach.

BACKGROUND: Hantavirus Pulmonary Syndrome (HPS) is a rodent-borne zoonosis in the Americas, with up to 50% mortality rates. In Argentina, the Northwestern endemic area presents half of the annually notified HPS cases in the country, transmitted by at least three rodent species recognized as reservoirs of Orthohantavirus. The potential distribution of reservoir species based on ecological niche models (ENM) can be a useful tool to establish risk areas for zoonotic diseases. Our main aim was to generate an Orthohantavirus risk transmission map based on ENM of the reservoir species in northwest Argentina (NWA), to compare this map with the distribution of HPS cases; and to explore the possible effect of climatic and environmental variables on the spatial variation of the infection risk. METHODS: Using the reservoir geographic occurrence data, climatic/environmental variables, and the maximum entropy method, we created models of potential geographic distribution for each reservoir in NWA. We explored the overlap of the HPS cases with the reservoir-based risk map and a deforestation map. Then, we calculated the human population at risk using a census radius layer and a comparison of the environmental variables' latitudinal variation with the distribution of HPS risk. RESULTS: We obtained a single best model for each reservoir. The temperature, rainfall, and vegetation cover contributed the most to the models. In total, 945 HPS cases were recorded, of which 97,85% were in the highest risk areas. We estimated that 18% of the NWA population was at risk and 78% of the cases occurred less than 10 km from deforestation. The highest niche overlap was between Calomys fecundus and Oligoryzomys chacoensis. CONCLUSIONS: This study identifies potential risk areas for HPS transmission based on climatic and environmental factors that determine the distribution of the reservoirs and Orthohantavirus transmission in NWA. This can be used by public health authorities as a tool to generate preventive and control measures for HPS in NWA.

Hantavirus in humans: a review of clinical aspects and management.

Hantavirus infections are part of the broad group of viral haemorrhagic fevers. They are also recognised as a distinct model of an emergent zoonotic infection with a global distribution. Many factors influence their epidemiology and transmission, such as climate, environment, social development, ecology of rodent hosts, and human behaviour in endemic regions. Transmission to humans occurs by exposure to infected rodents in endemic areas; however, Andes hantavirus is unique in that it can be transmitted from person to person. As hantaviruses target endothelial cells, they can affect diverse organ systems; increased vascular permeability is central to pathogenesis. The main clinical syndromes associated with hantaviruses are haemorrhagic fever with renal syndrome (HFRS), which is endemic in Europe and Asia, and hantavirus cardiopulmonary syndrome (HCPS), which is endemic in the Americas. HCPS and HFRS are separate clinical entities, but they share several features and have many overlapping symptoms, signs, and pathogenic alterations. For HCPS in particular, clinical outcomes are highly associated with early clinical suspicion, access to rapid diagnostic testing or algorithms for presumptive diagnosis, and prompt transfer to a facility with critical care units. No specific effective antiviral treatment is available.

Emerging Maripa Hantavirus as a Potential Cause of a Severe Health Threat in French Guiana.

We describe the clinical parameters and management of nine confirmed cases of hantavirus pulmonary syndrome reported in French Guiana since 2008. All patients were admitted to Cayenne Hospital. Seven patients were men and the mean age was 48 years (range, 19-71 years). Two phases characterized the disease. The prodromal phase was characterized by fever (77.8%), myalgia (66.7%), and gastrointestinal symptoms (vomiting and diarrhea; 55.6%) starting, on average, 5 days before the illness phase, which was characterized by respiratory failure in all patients. Five patients died (55.6%) and the length of stay in the intensive care unit was 19 days (range, 11-28 days) for survivors. Detection of two back-to-back recent cases highlights the reason to screen for hantavirus infection during the nonspecific phase of the disease, in particular when concomitant pulmonary infection and digestive disorders are observed. Specific longitudinal serological surveys must also be used to identify other potential clinical forms of the disease in French Guiana.

Hantavirus Pulmonary Syndrome: 1993-2018.

OBJECTIVES: From 1993 to 2018, hantavirus infections were reported in 39 states, with hantavirus pulmonary syndrome (HPS) as the most common and fatal manifestation. To identify differences in the presentation of HPS between children and adults, we hypothesized that children with HPS would be diagnosed later in their illness course given the nonspecific clinical features of HPS. METHODS: This was an evaluation of the clinical and demographic characteristics of national HPS cases from 1993 to 2018. Data were from the Centers for Disease Control and Prevention database and 1 state department of health, comprising 97% of US cases. We compared children (0 to 12 years), adolescents (13 to 18 years), and adults using nonparametric and parametric analyses, with additional exploratory analyses to identify clinical variables associated with mortality. RESULTS: Among 719 HPS patients, 22 (3.0%) were aged ≤12 years, 47 (6.5%) were 13 to 18 years old, and the remaining 650 (90.4%) were adults. Overall mortality was 35.4% and did not differ between age groups (P = .8). The time between symptom onset and death differed by age group, with children living a median of 2 days (interquartile range [IQR] 2 to 3), adolescents 4 days (IQR 3 to 5), and adults 5 days (IQR 4 to 8; P = .001). The mean highest hematocrit and median highest creatinine level were significantly associated with mortality in those 0 to 18 years old but not adults. CONCLUSIONS: In our dataset representing the largest study of HPS in the United States, we found that children with HPS died more quickly than adults and that highest hematocrit and creatinine levels were associated with death only among those <19 years old.

Modelling relative abundance of Oligoryzomys flavescens, an Orthohantavirus reservoir, in an endemic hantavirus pulmonary syndrome zone.

Hantavirus pulmonary syndrome (HPS) is a zoonotic emerging infectious disease caused by New World orthohantaviruses (family Hantaviridae) hosted by rodents of the family Cricetidae. In Argentina, one of its main hosts is the sigmodontine rodent Oligoryzomys flavescens, a widely distributed mouse of the Pampas, Delta and Espinal ecoregions of central-east Argentina. Because the abundance of the reservoir and its proportion in the rodent community affects both virus prevalence and human exposure risk, its estimation throughout its known geographical distribution is of key importance for the design of public health strategies to prevent HPS. The aim of this study was therefore to model the relative abundance of O. flavescens in most of the Pampas ecoregion within Buenos Aires Province, Argentina, where hantavirus pulmonary syndrome is endemic. To do this we used owl-pellet samples collected between 2006 and 2008 from 51 sites distributed throughout most of Buenos Aires province. Mammalian prey in each pellet was identified to the lowest possible taxonomic level by examination of the skulls, dentaries and molars. We modelled the frequency of O. flavescens found in each sample as a function of climatic, environmental, and topographic data of each site. The two best models were applied to a Geo referential Information System to build maps of estimated frequency (as a proxy of relative abundance) within Buenos Aires province. Estimated relative abundance of O. flavescens in Buenos Aires province was significantly associated with annual mean temperature, annual precipitation and presence of freshwater bodies, and varied among sub-regions, with the Inland and Rolling Pampas being the regions with highest frequencies. Knowing in which areas O. flavescens abundance is expected to be higher can be used to concentrate limited sanitary efforts in those areas that are most needed in order to reduce transmission and increase detection.

Modeling of hantavirus cardiopulmonary syndrome. / Modelamiento del síndrome cardiopulmonar por hantavirus.

Introduction: Hantavirus cardiopulmonary syndrome is an infection caused by rodents of the Bunyanvirales family towards humans. This disease in Chile is considered endemic, which has a high fatality rate. At present, some studies show the contagion between people of the Andes virus, whose locality is concentrated in Argentina and Chile. Objectives: Analyze the possibility of hantavirus transmission between humans using an SEIR-type mathematical model. Methods: An SEIR (Susceptible, Exposed, Infectious and Recovered) mathematical model to express the dynamics of hantavirus disease is proposed, including the possibility of human-to-human transmission and the perception of risk. Results: The peak of human-to-human contagion decreases by about 25% after increasing peoples perception of risk by reducing the rate of resistance to changeand increasing the speed of peoples reaction. Conclusions: It is urgent to review risk communication strategies and prevention measures in the face of this possibility of massive human-tohuman infections, in addition to strengthening research and planning the development of a vaccine to protect populations exposed to this disease with a high fatality rate.

Introducción: El síndrome cardiopulmonar por hantavirus es una enfermedad causada por un virus perteneciente al orden bunyanvirales, y transmitida hacia los humanos a través de roedores. Esta enfermedad en Chile es considerada endémica, la cual tiene una alta tasa de letalidad. En la actualidad existen estudios que evidencian el contagio entre personas del virus Andes, cuya localidad se concentra en los países de Argentina y Chile. Objetivos: Analizar la posibilidad de transmisión de hantavirus entre humanos, mediante un modelo matemático tipo SEIR. Métodos: Se plantea un modelo matemático tipo SEIR (susceptible, expuesto, infeccioso y recuperado) para expresar la dinámica de la enfermedad por hantavirus, incluyendo la posibilidad de transmisión entre humanos y la percepción del riesgo. Resultados: El máximo de contagio entre humanos disminuye cerca de 25% tras aumentar la percepción de riesgo de las personas, mediante la reducción de la tasa de resistencia al cambio y aumento la velocidad de reaccionar de las personas. Conclusiones: Es urgente revisar las estrategias de comunicación de riesgo y medidas de prevención ante esta posibilidad de contagios masivos entre humanos, además de fortalecer la investigación y proyectar el desarrollo de una vacuna para proteger las poblaciones expuestas a esta enfermedad con alta tasa de letalidad.

[Prognostic factors for cardio-pulmonary syndrome and death by hantavirus Andes Sur: cohort study in San Carlos de Bariloche and health influence area]. / Factores pronósticos de síndrome cardiopulmonar y muerte por hantavirus Andes Sur: Estudio de cohorte en San Carlos de Bariloche y su zona de influencia sanitaria.

Hantavirus infections occur through the inhalation of aerosols from the excreta of infected rodents. These viruses cause a cardiopulmonary syndrome in the case of the Andes Sur variant, with a mortality that can reach 50%. It occurs in sporadic cases or in small clusters, in which interhuman contagion predominates. In this historical cohort-type observational study, in people infected with Andes Sur hantavirus during the years 2009 to 2019 who was assisted in the public health subsector of San Carlos de Bariloche (Argentina), it was sought to identify factors that could predict poor evolution (cardiopulmonary syndrome and death). For this, the risk for each of the variables was characterized and, to obtain key information about the relationships between them, a multiple correspondence analysis was also applied. During the study period, 38 people were included. The mean age was 35 years. Person-to-person contagion was suspected in 10/38 (26.8%) cases. 21.1% (8/28) presented a hantavirus pulmonary syndrome at the time of diagnosis, while 55.3% (21/38) developed it during their evolution, and 44.7% (17/38) of those infected died during hospitalization. Age over 15 years and thrombocytopenia were associated with a higher risk of clinical progression, while mild forms or asymptomatic people, person-to-person transmission, or during an epidemiological outbreak, were associated with a lower risk of death.

Las infecciones por hantavirus, ocurren a través de la inhalación de aerosoles provenientes de excretas de roedores infectados. Estos virus causan síndrome cardiopulmonar en el caso de la variante Andes Sur, con una mortalidad que puede alcanzar el 50%. Se presenta como casos esporádicos o en pequeños conglomerados, en los que predomina el contagio interhumano. En este estudio observacional de tipo cohorte histórica, en personas infectadas con hantavirus Andes Sur durante los años 2009 a 2019 que fueron asistidas en el subsector público de salud de San Carlos de Bariloche(Argentina), se buscó identificar factores que pudieran predecir mala evolución (síndrome cardiopulmonar y muerte). Para ello se caracterizó el riesgo para cada una de las variables y, para obtener información clave sobre las relaciones entre las mismas, se aplicó además un análisis de correspondencias múltiples. Durante el período de estudio, 38 personas fueron incluidas. La edad media fue de 35 años. Se sospechó contagio de persona a persona en 10/38 (26.8%) casos. El 21.1% (8/28) tuvo al momento del diagnóstico un síndrome pulmonar por hantavirus. Mientras que, 55.3% (21/38) lo desarrolló durante su evolución y 44.7% (17/38) de los infectados fallecieron durante la internación. La edad mayor a 15 años y la plaquetopenia, se asociaron con un mayor riesgo de progresión clínica, mientras que las formas de leves o las personas asintomáticas, el contagio persona a persona o durante un brote epidemiológico, se asociaron con un menor riesgo de muerte.

Modelamiento del síndrome cardiopulmonar por hantavirus / Modeling of hantavirus cardiopulmonary syndrome

INTRODUCCIÓN: El síndrome cardiopulmonar por hantavirus es una enfermedad causada por un virus perteneciente al orden bunyanvirales, y transmitida hacia los humanos a través de roedores. Esta enfermedad en Chile es considerada endémica, la cual tiene una alta tasa de letalidad. En la actualidad existen estudios que evidencian el contagio entre personas del virus Andes, cuya localidad se concentra en los países de Argentina y Chile. OBJETIVOS: Analizar la posibilidad de transmisión de hantavirus entre humanos, mediante un modelo matemático tipo SEIR. MÉTODOS: Se plantea un modelo matemático tipo SEIR (susceptible, expuesto, infeccioso y recuperado) para expresar la dinámica de la enfermedad por hantavirus, incluyendo la posibilidad de transmisión entre humanos y la percepción del riesgo. Resultados: El máximo de contagio entre humanos disminuye cerca de 25% tras aumentar la percepción de riesgo de las personas, mediante la reducción de la tasa de resistencia al cambio y aumento la velocidad de reaccionar de las personas. CONCLUSIONES: Es urgente revisar las estrategias de comunicación de riesgo y medidas de prevención ante esta posibilidad de contagios masivos entre humanos, además de fortalecer la investigación y proyectar el desarrollo de una vacuna para proteger las poblaciones expuestas a esta enfermedad con alta tasa de letalidad.

INTRODUCTION: Hantavirus cardiopulmonary syndrome is an infection caused by rodents of the Bunyanvirales family towards humans. This disease in Chile is considered endemic, which has a high fatality rate. At present, some studies show the contagion between people of the Andes virus, whose locality is concentrated in Argentina and Chile. OBJECTIVES: Analyze the possibility of hantavirus transmission between humans using an SEIR-type mathematical model. METHODS: An SEIR (Susceptible, Exposed, Infectious and Recovered) mathematical model to express the dynamics of hantavirus disease is proposed, including the possibility of human-to-human transmission and the perception of risk. RESULTS: The peak of human-to-human contagion decreases by about 25% after increasing people's perception of risk by reducing the rate of resistance to changeand increasing the speed of people's reaction. CONCLUSIONS: It is urgent to review risk communication strategies and prevention measures in the face of this possibility of massive human-tohuman infections, in addition to strengthening research and planning the development of a vaccine to protect populations exposed to this disease with a high fatality rate.

Global Comprehensive Outlook of Hantavirus Contagion on Humans: A Review.

Hantaviruses are rodent viruses that have been identified as etiologic agents of 2 diseases in humans: Hemorrhagic Fever with Renal Syndrome (HFRS) and Nephropathiaepidemica (NE) in the Old World and Hantavirus Pulmonary Syndrome (HPS) in the New World. Orthohantavirus is a genus of single-stranded, enveloped, negative-sense RNA viruses in the family Hantaviridae of the order Bunyavirales. The important reservoir of Hantaviruses is rodents. Each virus serotype has its unique rodent host species and is transmitted to human beings with the aid of aerosolized virus, which is shed in urine, faeces and saliva and hardly by a bite of the contaminated host. Andes virus is the only Hantavirus identified to be transmitted from human-to-human and its major signs and symptoms include fever, headache, muscle aches, lungs filled with fluid, etc. In early 1993, this viral syndrome appeared in the Four Corner location in the southwestern United States. The only accepted therapeutics for this virus is Ribavirin. Recently, serological examinations to identify Hantavirus antibodies have become most popular for investigation among humans and rodent reservoirs.

Case Report: Hantavirus Cardiopulmonary Syndrome Diagnostic in the Face of the COVID-19 Pandemic.

Hantavirus cardiopulmonary syndrome (HCPS) is an emerging rodent-borne disease in the Americas. The most common initial symptoms of HCPS are similar to those of COVID-19 and other respiratory infections that evolve rapidly to respiratory failure, resulting from pulmonary edema and shock in about 40% of cases. We describe a fatal case of HCPS in a 24-year-old man who was hospitalized with fever, hemoconcentration, thrombocytopenia, leukocytosis, dry cough and a bilateral diffuse alveolar pulmonary infiltrate during the emergence of the COVID-19 pandemic in Brazil. HCPS needs to be ruled out in patients with clinical manifestations compatible with respiratory infections such as influenza and COVID-19.

Hantavirus Disease and COVID-19.

OBJECTIVES: Navajo Nation is disproportionately affected by hantavirus cardiopulmonary syndrome (HCPS), a severe respiratory disease that can quickly progress to respiratory failure and cardiogenic shock. The initial signs and symptoms of HCPS are indistinguishable from coronavirus disease 2019 (COVID-19). However, this distinction is critical, as the disease course differs greatly, with most patients with COVID-19 experiencing mild to moderate illness. We set out to determine if the evaluation of peripheral blood smears for five hematopathologic criteria previously identified as hallmarks of hantavirus infection, or "the hantavirus 5-point screen," could distinguish between COVID-19 and HCPS. METHODS: The hantavirus 5-point screen was performed on peripheral blood smears from 139 patients positive for COVID-19 seeking treatment from Tséhootsooí Medical Center and two Emory University hospitals. RESULTS: Of these 139 individuals, 136 (98%) received a score of 3/5 or below, indicating low suspicion for HCPS. While thrombocytopenia, one of the key signs of HCPS, was seen in the patients with COVID-19, it was generally mild and remained stable on repeat specimens collected 12 to 24 hours later. CONCLUSIONS: Given these findings, the 5-point screen remains a useful rapid screening tool for potential HCPS cases and may be useful to distinguish early HCPS from COVID-19 in HCPS endemic regions.

Hantavirus.

Hantaviruses are tri-segmented lipid-enveloped RNA viruses belonging to the Bunyaviridae family. Human infection corresponds to a zoonosis associated with two different clinical syndromes: hemorrhagic fever with renal syndrome that occurs in Asia and Europe and hantavirus cardiopulmonary syndrome (HCPS) that occurs in the North America, Central America and South America. The major pathogenic mechanisms in HCPS include (1) direct microvascular endothelial injury leading to increased capillary permeability and the development of noncardiogenic pulmonary edema and acute respiratory distress syndrome, and (2) exaggerated host immune response leading to secondary organ damage. The incubation period for this disease is quite long (6-39 days, median: 18 days); however, rapid progression to respiratory failure and shock can occur highlighting the importance of high index of clinical suspicion. Management revolves around high-quality supportive care. Various management and preventative strategies are currently being explored and warrant further examination to improve the overall outlook following infection with hantavirus.

First Evidence of Akodon-Borne Orthohantavirus in Northeastern Argentina.

Orthohantaviruses (genus Orthohantavirus, family Hantaviridae) are the etiologic agents of Hantavirus Pulmonary Syndrome in the Americas. In South America, orthohantaviruses are highly diverse and are hosted by sigmodontine rodents (subfamiliy Sigmodontinae, family Cricetidae), an also diverse group of rodents. The aims of this work were to (1) identify orthohantavirus hosts and (2) to study the spatial and temporal variations in the prevalence of infection and their associations with community, environmental and individual characteristics, in different environments of Misiones province, northeastern Argentina. Live-capture sessions were carried out during two years in different land uses, with a trapping effort of 31,653 trap nights. We captured 719 individuals from the species Akodon montensis, Rattus rattus, Mus musculus, Calomys tener, Thaptomys nigrita, Oligoryzomys nigripes, Euryoryzomys russatus, Oligoryzomys flavescens, Brucepattersonius sp., and Juliomys pictipes. Antibodies against orthohantavirus were detected in Akodon montensis in one natural protected and one periurban areas, and it was the most abundant species in almost every study sites. We observed the presence of spatial focality of orthohantavirus infection and a positive association with host abundance suggesting the existence of a threshold density. At the individual level, large, reproductively active, and male individuals were more likely to have antibodies against orthohantavirus. This is the first record of orthohantavirus infection in A. montensis in Argentina, which shows the importance of investigations about emerging diseases.

Impact of Predator Exclusion and Habitat on Seroprevalence of New World Orthohantavirus Harbored by Two Sympatric Rodents within the Interior Atlantic Forest.

Understanding how perturbations to trophic interactions influence virus-host dynamics is essential in the face of ongoing biodiversity loss and the continued emergence of RNA viruses and their associated zoonoses. Herein, we investigated the role of predator exclusion on rodent communities and the seroprevalence of hantaviruses within the Reserva Natural del Bosque Mbaracayú (RNBM), which is a protected area of the Interior Atlantic Forest (IAF). In the IAF, two sympatric rodent reservoirs, Akodon montensis and Oligoryzomys nigripes, harbor Jaborá and Juquitiba hantavirus (JABV, JUQV), respectively. In this study, we employed two complementary methods for predator exclusion: comprehensive fencing and trapping/removal. The goal of exclusion was to preclude the influence of predation on small mammals on the sampling grids and thereby potentially reduce rodent mortality. Following baseline sampling on three grid pairs with different habitats, we closed the grids and began predator removal. By sampling three habitat types, we controlled for habitat-specific effects, which is important for hantavirus-reservoir dynamics in neotropical ecosystems. Our six-month predator exclusion experiment revealed that the exclusion of terrestrial mammalian predators had little influence on the rodent community or the population dynamics of A. montensis and O. nigripes. Instead, fluctuations in species diversity and species abundances were influenced by sampling session and forest degradation. These results suggest that seasonality and landscape composition play dominant roles in the prevalence of hantaviruses in rodent reservoirs in the IAF ecosystem.

Tracing Transmission of Sin Nombre Virus and Discovery of Infection in Multiple Rodent Species.

Sin Nombre orthohantavirus (SNV), a negative-sense, single-stranded RNA virus that is carried and transmitted by the North American deer mouse Peromyscus maniculatus, can cause infection in humans through inhalation of aerosolized excreta from infected rodents. This infection can lead to hantavirus cardiopulmonary syndrome (HCPS), which has an ∼36% case-fatality rate. We used reverse transcriptase quantitative PCR (RT-qPCR) to confirm SNV infection in a patient and identified SNV in lung tissues in wild-caught rodents from potential sites of exposure. Using viral whole-genome sequencing (WGS), we identified the likely site of transmission and discovered SNV in multiple rodent species not previously known to carry the virus. Here, we report, for the first time, the use of SNV WGS to pinpoint a likely site of human infection and identify SNV simultaneously in multiple rodent species in an area of known host-to-human transmission. These results will impact epidemiology and infection control for hantaviruses by tracing zoonotic transmission and investigating possible novel host reservoirs. IMPORTANCE Orthohantaviruses cause severe disease in humans and can be lethal in up to 40% of cases. Sin Nombre orthohantavirus (SNV) is the main cause of hantavirus disease in North America. In this study, we sequenced SNV from an infected patient and wild-caught rodents to trace the location of infection. We also discovered SNV in rodent species not previously known to carry SNV. These studies demonstrate for the first time the use of virus sequencing to trace the transmission of SNV and describe infection in novel rodent species.

Proteinuria in Hantavirus Cardiopulmonary Syndrome: A Frequent Finding Linked To Mortality.

OBJECTIVES: To determine the relative frequency and prognosis value of proteinuria in hantavirus cardiopulmonary syndrome (HCPS) due to Andes virus. METHODS: This observational analytical study prospectively obtained data from patients admitted to 12 health centers in nine Chilean cities between 2001 and 2018. Only patients with confirmed Andes virus HCPS and laboratory characterization that included qualitative proteinuria determination at admission were considered. RESULTS: The database involved 175 patients, 95 of them had a measurement of urine protein at the time of hospital admission. They were mainly male (71%) and the median age was 35 [22-47] years. Median duration of the febrile prodromal time was 5 [4-7] days. Hospital length of stay and hospital mortality rate were 10 [7-14] days and 21.1%, respectively. Seventy-three patients (77%) were identified with proteinuria at admission, which was associated with increased mortality rate (26% versus 5%, p=0.036) and the relative risk was 1.3 [1.1-1.6], p=0.002. CONCLUSIONS: Proteinuria is a frequent finding in patients with HCPS, which is associated with a higher mortality rate.

Continuing Orthohantavirus Circulation in Deer Mice in Western Montana.

Hantavirus pulmonary syndrome (HPS) is an often-fatal disease caused by New World hantaviruses, such as Sin Nombre orthohantavirus (SNV). In the US, >800 cases of HPS have been confirmed since it was first discovered in 1993, of which 43 were reported from the state of Montana. The primary cause of HPS in the US is SNV, which is primarily found in the reservoir host Peromyscus maniculatus (deer mouse). The reservoir host covers most of the US, including Montana, where multiple studies found SNV in local deer mouse populations. This study aimed to check the prevalence of SNV in the deer mice at popular recreation sites throughout the Bitterroot Valley in Western Montana as compared to previous studies in western Montana. We found high prevalence (up to 20%) of deer mice positive for SNV RNA in the lungs. We were unable to obtain a SNV tissue culture isolate from the lungs but could passage SNV from lung tissue into naïve deer mice. Our findings demonstrate continuing circulation of SNV in western Montana.