RESUMO
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.
Assuntos
Infecções por Hantavirus , Síndrome Pulmonar por Hantavirus , Orthohantavírus , Vírus Sin Nombre , Humanos , Animais , Camundongos , Roedores , Dipodomys , Vírus Sin Nombre/genética , New Mexico/epidemiologia , Prevalência , Infecções por Hantavirus/epidemiologia , Infecções por Hantavirus/veterinária , Orthohantavírus/genética , Arvicolinae , Síndrome Pulmonar por Hantavirus/epidemiologia , Síndrome Pulmonar por Hantavirus/veterináriaRESUMO
BACKGROUND: Rodent-borne hantaviruses (genus Orthohantavirus) are the etiologic agents causing two human diseases: hemorrhagic fever with renal syndrome (HFRS) in Euroasia; and hantavirus pulmonary syndrome (HPS) in North and South America. In South America fatality rates of HPS can reach up to 35%-50%. The transmission of pathogenic hantaviruses to humans occurs mainly via inhalation of aerosolized excreta from infected rodents. Thus, the epidemiology of HPS is necessarily linked to the ecology of their rodent hosts and the contact with a human, which in turn may be influenced by climatic variability. Here we examined the relationship between climatic variables and hantavirus transmission aim to develop an early warning system of potential hantavirus outbreaks based on ecologically relevant climatic factors. METHODOLOGY AND MAIN FINDINGS: We compiled reported HPS cases in northwestern Argentina during the 1997-2017 period and divided our data into biannual, quarterly, and bimestrial time periods to allow annual and shorter time delays to be observed. To evaluate the relationship of hantavirus transmission with mean temperature and precipitation we used dynamic regression analysis. We found a significant association between HPS incidence and lagged rainfall and temperature with a delay of 2 to 6 months. For the biannual and quarterly models, hantavirus transmission was positively associated with lagged rainfall and temperature; whereas the bimestrial models indicate a direct relationship with the rainfall but inverse for temperature in the second lagged period. CONCLUSIONS/SIGNIFICANCE: This work demonstrates that climate variability plays a significant role in the transmission of hantavirus in northwestern Argentina. The model developed in this study provides a basis for the forecast of potential HPS outbreaks based on climatic parameters. Our findings are valuable for the development of public health policies and prevention strategies to mitigate possible outbreaks. Nonetheless, a surveillance program on rodent population dynamics would lead to a more accurate forecast of HPS outbreaks.
Assuntos
Clima , Surtos de Doenças/estatística & dados numéricos , Síndrome Pulmonar por Hantavirus/epidemiologia , Argentina/epidemiologia , Síndrome Pulmonar por Hantavirus/transmissão , Humanos , Chuva , Vírus Sin Nombre , TemperaturaRESUMO
Hantavirus pulmonary syndrome (HPS) is a severe disease characterized by a rapid onset of pulmonary edema followed by respiratory failure and cardiogenic shock. The HPS associated viruses are members of the genus Hantavirus, family Bunyaviridae. Hantaviruses have a worldwide distribution and are broadly split into the New World hantaviruses, which includes those causing HPS, and the Old World hantaviruses [including the prototype Hantaan virus (HTNV)], which are associated with a different disease, hemorrhagic fever with renal syndrome (HFRS). Sin Nombre virus (SNV) and Andes virus (ANDV) are the most common causes of HPS in North and South America, respectively. Case fatality of HPS is approximately 40%. Pathogenic New World hantaviruses infect the lung microvascular endothelium without causing any virus induced cytopathic effect. However, virus infection results in microvascular leakage, which is the hallmark of HPS. This article briefly reviews the knowledge on HPS-associated hantaviruses accumulated since their discovery, less than 20 years ago.
Assuntos
Genoma Viral , Vírus Hantaan/fisiologia , Síndrome Pulmonar por Hantavirus/virologia , Febre Hemorrágica com Síndrome Renal/virologia , Pulmão/virologia , Orthohantavírus/fisiologia , Insuficiência Respiratória/virologia , Choque Cardiogênico/virologia , Vírus Sin Nombre/fisiologia , Animais , Antivirais/administração & dosagem , Cricetinae , Europa (Continente) , Orthohantavírus/patogenicidade , Síndrome Pulmonar por Hantavirus/complicações , Síndrome Pulmonar por Hantavirus/tratamento farmacológico , Síndrome Pulmonar por Hantavirus/epidemiologia , Síndrome Pulmonar por Hantavirus/patologia , Febre Hemorrágica com Síndrome Renal/tratamento farmacológico , Febre Hemorrágica com Síndrome Renal/epidemiologia , Febre Hemorrágica com Síndrome Renal/patologia , Humanos , Pulmão/patologia , América do Norte , Filogeografia , Insuficiência Respiratória/tratamento farmacológico , Insuficiência Respiratória/epidemiologia , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/patologia , Ribavirina/administração & dosagem , Choque Cardiogênico/tratamento farmacológico , Choque Cardiogênico/epidemiologia , Choque Cardiogênico/etiologia , Choque Cardiogênico/patologia , Vírus Sin Nombre/patogenicidade , América do SulRESUMO
The objective of this study was to document persistent pulmonary symptoms and pulmonary function abnormalities in adults surviving hantavirus pulmonary syndrome (HPS). Acute infection by most hantaviruses result in mortality rates of 25-35%, while in Panama the mortality rate of 10% is contrasted by an unusually high incidence. In all types of HPS, the viral prodrome, cardiopulmonary phase due to massive pulmonary capillary leak syndrome, and spontaneous diuresis are followed by a convalescent phase with exertional dyspnea for 3-4 weeks, but the frequency of persistent symptoms is not known. In this observational study of a convenience sample, 14 survivors of HPS caused by Choclo virus infection in Panama and 9 survivors of HPS caused by Sin Nombre virus infection in New Mexico completed a questionnaire and pulmonary function tests up to 8 years after infection. In both groups, exertional dyspnea persisted for 1-2 years after acute infection in 43% (Panama) and 77% (New Mexico) of survivors surveyed. Reduction in midexpiratory flows (FEF(25-75%)), increased residual volume (RV), and reduced diffusion capacity (D(L)CO/VA) also were common in both populations; but the severity of reduced expiratory flow did not correlate with exertional dyspnea. Symptoms referable to previous hantavirus infection had resolved within 3 years of acute infection in most but not all patients in the Panama group. Temporary exertional dyspnea and reduced expiratory flow are common in early convalescence after HPS but resolves in almost all patients.
Assuntos
Convalescença , Síndrome Pulmonar por Hantavirus/fisiopatologia , Síndrome Pulmonar por Hantavirus/reabilitação , Doença Aguda , Adulto , Anticorpos Antivirais/análise , Feminino , Seguimentos , Síndrome Pulmonar por Hantavirus/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Panamá/epidemiologia , Vírus Sin Nombre/isolamento & purificação , Estados Unidos/epidemiologiaRESUMO
BACKGROUND: All viruses in the family Bunyaviridae possess a tripartite genome, consisting of a small, a medium, and a large RNA segment. Bunyaviruses therefore possess considerable evolutionary potential, attributable to both intramolecular changes and to genome segment reassortment. Hantaviruses (family Bunyaviridae, genus Hantavirus) are known to cause human hemorrhagic fever with renal syndrome or hantavirus pulmonary syndrome. The primary reservoir host of Sin Nombre virus is the deer mouse (Peromyscus maniculatus), which is widely distributed in North America. We investigated the prevalence of intramolecular changes and of genomic reassortment among Sin Nombre viruses detected in deer mice in three western states. METHODS: Portions of the Sin Nombre virus small (S) and medium (M) RNA segments were amplified by RT-PCR from kidney, lung, liver and spleen of seropositive peromyscine rodents, principally deer mice, collected in Colorado, New Mexico and Montana from 1995 to 2007. Both a 142 nucleotide (nt) amplicon of the M segment, encoding a portion of the G2 transmembrane glycoprotein, and a 751 nt amplicon of the S segment, encoding part of the nucleocapsid protein, were cloned and sequenced from 19 deer mice and from one brush mouse (P. boylii), S RNA but not M RNA from one deer mouse, and M RNA but not S RNA from another deer mouse. RESULTS: Two of 20 viruses were found to be reassortants. Within virus sequences from different rodents, the average rate of synonymous substitutions among all pair-wise comparisons (pis) was 0.378 in the M segment and 0.312 in the S segment sequences. The replacement substitution rate (pia) was 7.0 x 10-4 in the M segment and 17.3 x 10-4 in the S segment sequences. The low pia relative to pis suggests strong purifying selection and this was confirmed by a Fu and Li analysis. The absolute rate of molecular evolution of the M segment was 6.76 x 10-3 substitutions/site/year. The absolute age of the M segment tree was estimated to be 37 years. In the S segment the rate of molecular evolution was 1.93 x 10-3 substitutions/site/year and the absolute age of the tree was 106 years. Assuming that mice were infected with a single Sin Nombre virus genotype, phylogenetic analyses revealed that 10% (2/20) of viruses were reassortants, similar to the 14% (6/43) found in a previous report. CONCLUSION: Age estimates from both segments suggest that Sin Nombre virus has evolved within the past 37-106 years. The rates of evolutionary changes reported here suggest that Sin Nombre virus M and S segment reassortment occurs frequently in nature.
Assuntos
Reservatórios de Doenças , Evolução Molecular , Síndrome Pulmonar por Hantavirus/veterinária , RNA Viral/genética , Vírus Sin Nombre/classificação , Vírus Sin Nombre/genética , Sequência de Aminoácidos , Substituição de Aminoácidos/genética , Estruturas Animais/virologia , Animais , Sequência de Bases , Análise por Conglomerados , Colorado , Síndrome Pulmonar por Hantavirus/virologia , Camundongos , Dados de Sequência Molecular , Montana , New Mexico , Peromyscus , Filogenia , Vírus Reordenados/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Análise de Sequência de DNA/métodos , Homologia de Sequência , Vírus Sin Nombre/isolamento & purificaçãoRESUMO
Prevalence of antibody reactive with Sin Nombre hantavirus (SNV) was evaluated from rodents captured over 31 months (March 1988 to September 1990) from six mark-recapture grids on the central Argentine Pampa. The most frequently infected rodents were: Akodon azarae (31/459), Necromys benefactus (8/141), and Oligoryzomys flavescens (10/281), which are known hosts of Pergamino, Maciel, and Lechiguanas hantaviruses, respectively. Relative population density and antibody prevalence varied seasonally and from year to year, population densities were highest in fall and prevalences were highest in spring. A positive association between antibody prevalence and body weight corroborated findings from other studies suggesting that hantaviruses are maintained in reservoir populations by horizontal transmission. In two of three host species, transmission was more frequent among male than among female mice. We found no evidence for a detrimental effect of hantavirus infection on host body weight, growth, longevity, movement, or reproductive preparedness. This analysis, based on cryopreserved specimens, represents the earliest conducted longitudinal, mark-recapture study of the dynamics of infection of autochthonous American hantaviruses in their sigmodontine host populations.
Assuntos
Anticorpos Antivirais/sangue , Reservatórios de Doenças/veterinária , Infecções por Hantavirus/veterinária , Orthohantavírus/imunologia , Doenças dos Roedores/epidemiologia , Animais , Argentina/epidemiologia , Peso Corporal , Feminino , Geografia , Orthohantavírus/isolamento & purificação , Infecções por Hantavirus/epidemiologia , Infecções por Hantavirus/transmissão , Síndrome Pulmonar por Hantavirus/epidemiologia , Síndrome Pulmonar por Hantavirus/transmissão , Síndrome Pulmonar por Hantavirus/veterinária , Humanos , Estudos Longitudinais , Masculino , Densidade Demográfica , Doenças dos Roedores/transmissão , Roedores , Estações do Ano , Estudos Soroepidemiológicos , Fatores Sexuais , Vírus Sin Nombre/imunologia , Vírus Sin Nombre/isolamento & purificação , Especificidade da EspécieAssuntos
Anticorpos Antivirais/sangue , Infecções por Hantavirus/epidemiologia , Orthohantavírus/imunologia , Vírus Sin Nombre/imunologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Guiana Francesa/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Estudos SoroepidemiológicosRESUMO
We evaluated titers of homotypic and heterotypic neutralizing antibodies (NAbs) to Andes and Sin Nombre hantaviruses in plasma samples from 20 patients from Chile and the United States. All but 1 patient had high titers of NAb. None of the plasma samples showed high titers against the heterologous virus.
Assuntos
Anticorpos Antivirais/imunologia , Síndrome Pulmonar por Hantavirus/imunologia , Orthohantavírus/imunologia , Vírus Sin Nombre/imunologia , Sobreviventes , Anticorpos Antivirais/sangue , Chile/epidemiologia , Síndrome Pulmonar por Hantavirus/sangue , Síndrome Pulmonar por Hantavirus/epidemiologia , Síndrome Pulmonar por Hantavirus/virologia , Humanos , Testes de Neutralização , Estados Unidos/epidemiologiaRESUMO
PURPOSE OF REVIEW: This article focuses on recent developments in knowledge about hantavirus infections and hantavirus cardiopulmonary syndrome in children. We highlight clinical characterization, epidemiology, pathogenesis, diagnostic techniques, and current alternatives for treatment and prevention. RECENT FINDINGS: After the first description of hantavirus pulmonary syndrome (HPS) in 1993 in the United States, new cases of HPS and new hantavirus species have been described throughout the Americas. The factors involved in the expression of hantavirus disease have, in part, been recognized, but there have been descriptions of newer viruses and newer rodent reservoirs. Several seroprevalence studies suggest that the virus-host interaction has been taking place for many years, and changes in human behavior and wild rodent ecology, sometimes secondary to industrial progress, facilitate the clinical recognition of disease. Sin nombre virus (SNV) and Andes virus (ANDV) are examples of the same disease with differences in the virus virulence and in the host response. The North American syndrome and the Southern HPS differ in epidemiologic patterns and in the spectrum of disease. SUMMARY: Currently, no Food and Drug Administration (FDA)-approved antiviral drugs, vaccines, or immunotherapeutic agents are available for treatment of the disease, and therapy is primarily supportive. Intensive care medicine has played an outstanding role in decreasing the lethality of HPS. A ribavirin trial in the United States did not support the use of the drug in fully developed HCPS. Recently published data suggest that a strong neutralizing antibody response may be a predictor of effective clearance of and recovery from SNV infection. This has raised the possibility that passive immunotherapy may be useful in HCPS. Extensive work has been done to develop a hantavirus vaccine, but at present it seems unlikely that a vaccine will be in commercial development in the near future.
Assuntos
Infecções por Hantavirus/diagnóstico , Infecções por Hantavirus/terapia , Criança , Orthohantavírus/isolamento & purificação , Humanos , Imunização Passiva , Vírus Sin Nombre/isolamento & purificação , VacinaçãoRESUMO
In 1995, an outbreak of hantavirus pulmonary syndrome occurred in the central Paraguayan chaco. The primary reservoir of the virus, Laguna Negra virus, was identified as the vesper mouse, Calomys laucha. Over a 15-month period, we collected 1,090 small mammals at 12 locations representing 4 habitats common in the central Paraguayan chaco. Calomys laucha was common in agricultural habitats and uncommon in the native forest habitat. Populations of C. laucha were greater during the dry season months and declined during the wet season. A total of 643 small mammals were tested for antibodies cross-reactive to Sin Nombre virus. All of the antibody-positive animals were C. laucha (crude antibody prevalence ratio 12.1% [25 of 206]). Antibody prevalence ratio increased with body size and was more common among male (18%; n = 115) than among female (4%; n = 96) vesper mice. Antibody prevalence ratio was highest among animals from cropland habitats (18%; n = 72), followed by thorn scrub (13%; n = 46) and pastureland (7%; n = 81) and may be positively correlated to the proportion of C. laucha in the small mammal community. These data suggest that community-level dynamics, in addition to population-level dynamics, may be involved in the transmission of the virus through natural populations of vesper mice.