Virus sin Nombre
Encyclopedia
The Sin Nombre virus (SNV) is the prototypical etiologic agent of hantavirus cardiopulmonary syndrome (HCPS).
Its original name was "Four Corners virus" or "Navajo Flu", but the name was changed after local residents raised objections.
carrier, (the deer mouse Peromyscus maniculatus
) is found, which includes essentially the entire United States
except for the far southeastern region from eastern Texas
through Florida
. SNV and HCPS are especially common in western states; peak incidences for HCPS has been reported in regions in which there is a lot of contact between humans and mice (New Mexico
, Arizona
) and in states with exceptionally large rural populations such as California
. All of the western provinces of Canada
have also reported cases. SNV can be contracted through the inhalation of virus-contaminated deer mouse excreta.
The case fatality ratio of SNV-induced HCPS in the USA was reported to be about 66.7% (CDC, 1993). However, since that time the case fatality ratio has steadily declined as more mild cases came to be recognized. By 2007 the CFR had declined to about 35%.
extracted from autopsy material as well as RNA extracted from cell culture-adapted virus. The L RNA is 6562 nucleotides (nt) in length; the M RNA is 3696 nt long; and the S RNA is 2059 to 2060 nt long. Interestingly, when the prototype sequence (NMH15) of SNV detected in tissues from an HPS case was compared with the sequence of the SNV isolate (NMR11; isolated in Vero E6 cells from Peromyscus maniculatus
trapped in the residence of the same case), only 16 nucleotide changes were found, and none of these changes resulted in alterations in amino acid sequences of viral proteins. It had been assumed that in the process of adaptation to cell culture, selection of SNV variants which grow optimally in cell culture would occur, and selected variants would differ genetically from the parental virus. Though NMH10 and NMR11 are identical in protein sequence, nucleotide substitutions in nontranslated regions of the genome could be responsible for altered viral phenotypes, as could changes in protein glycosylation or virus membrane components.
The nested RT-PCR assay developed during the initial HCPS outbreak provided a rapid method for the genetic characterization of novel hantaviruses that did not require a virus isolate. Numerous new hantaviruses have been detected by RT-PCR in rodent tissues but have yet to be associated with human disease. These include El Moro Canyon virus associated with the western harvest mouse, Reithrodontomys megalotis, Tula virus with Microtus arvalis and M. rossiaemeridionalis, Rio Segundo virus with the Mexican harvest mouse, R. mexicanus, Isla Vista virus with the California vole, M. californicus, and Prospect Hill-like viruses in Microtus
species.
Its original name was "Four Corners virus" or "Navajo Flu", but the name was changed after local residents raised objections.
History
It was first isolated from rodents collected near the home of one of the initial patients with hantavirus pulmonary syndrome (HPS) in the Four Corners region of the western United States. Isolation was achieved through blind passage in Peromyscus maniculatus (deer mouse) and subsequent adaptation to growth in Vero E6 cells. Additional viral strains have also been isolated from P. maniculatus associated with a fatal case in California and P. leucopus from the vicinity of probable infection of a New York case. Black Creek Canal virus was isolated from S. hispidus collected near the residence of a human case in Dade County, Florida. Another etiologic agent of HCPS, Bayou virus, was first isolated from the vicinity of Monroe, Louisiana.Epidemiology
SNV occurs wherever its reservoir rodentRodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
carrier, (the deer mouse Peromyscus maniculatus
Peromyscus maniculatus
Peromyscus maniculatus is a rodent native to North America. It is most commonly called the Deer Mouse, although that name is common to most species of Peromyscus and is fairly widespread across the continent, with the major exception being the southeast United States and the far north.Like other...
) is found, which includes essentially the entire United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
except for the far southeastern region from eastern Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
through Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
. SNV and HCPS are especially common in western states; peak incidences for HCPS has been reported in regions in which there is a lot of contact between humans and mice (New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
, Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
) and in states with exceptionally large rural populations such as California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. All of the western provinces of Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
have also reported cases. SNV can be contracted through the inhalation of virus-contaminated deer mouse excreta.
The case fatality ratio of SNV-induced HCPS in the USA was reported to be about 66.7% (CDC, 1993). However, since that time the case fatality ratio has steadily declined as more mild cases came to be recognized. By 2007 the CFR had declined to about 35%.
Virus Sequencing
The entire genomic sequence of SNV has subsequently been determined by using RNARNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
extracted from autopsy material as well as RNA extracted from cell culture-adapted virus. The L RNA is 6562 nucleotides (nt) in length; the M RNA is 3696 nt long; and the S RNA is 2059 to 2060 nt long. Interestingly, when the prototype sequence (NMH15) of SNV detected in tissues from an HPS case was compared with the sequence of the SNV isolate (NMR11; isolated in Vero E6 cells from Peromyscus maniculatus
Peromyscus maniculatus
Peromyscus maniculatus is a rodent native to North America. It is most commonly called the Deer Mouse, although that name is common to most species of Peromyscus and is fairly widespread across the continent, with the major exception being the southeast United States and the far north.Like other...
trapped in the residence of the same case), only 16 nucleotide changes were found, and none of these changes resulted in alterations in amino acid sequences of viral proteins. It had been assumed that in the process of adaptation to cell culture, selection of SNV variants which grow optimally in cell culture would occur, and selected variants would differ genetically from the parental virus. Though NMH10 and NMR11 are identical in protein sequence, nucleotide substitutions in nontranslated regions of the genome could be responsible for altered viral phenotypes, as could changes in protein glycosylation or virus membrane components.
The nested RT-PCR assay developed during the initial HCPS outbreak provided a rapid method for the genetic characterization of novel hantaviruses that did not require a virus isolate. Numerous new hantaviruses have been detected by RT-PCR in rodent tissues but have yet to be associated with human disease. These include El Moro Canyon virus associated with the western harvest mouse, Reithrodontomys megalotis, Tula virus with Microtus arvalis and M. rossiaemeridionalis, Rio Segundo virus with the Mexican harvest mouse, R. mexicanus, Isla Vista virus with the California vole, M. californicus, and Prospect Hill-like viruses in Microtus
Microtus
The genus Microtus is a group of voles found in North America, Europe and northern Asia. The genus name refers to the small ears of these animals. There are 62 species in the genus....
species.
External links
- www.cdc.gov -- Virology -- CDC Hantaviruses
- http://hsc.unm.edu/som/pathology/emergingvirus/mepidemiology.shtml - Clinical and Lab Recognition and other info