Viral Diseases - HEMORRHAGIC FEVER WITH RENAL SYNDROME [HFRS]

(Korean Hemorrhagic Fever, Nephropathia Epidemica, Epidemic Hemorrhagic Fever, Hemorrhagic Nephrosonephritis)

AGENT:

Bunyaviridae family, Hantaan virus genus.

RESERVOIR AND INCIDENCE:

Recognized originally in troops serving in the Korean war. Named Hantaan after river in endemic area of Korea. Isolated in 1978 in Apodemus agrarius, then adapted to tissue culture and laboratory rats. Serologic mapping indicates that Hantaviruses have infected large numbers of people in the region from Japan across central and north Asia to the Scandinavian Peninsula, and southward in Europe to the Balkans. Other Hantaviruses have been identified in urban rats captured in major Asian and Western cities, including the USA and Brazil. Hosts of hantavirus are wild Rodents Several antigenic subtypes exist, each associated with a single rodent species: Apodemus species (striped field mouse - A. agrarius) (Korea) associated with KHF. Domestic Rattus norvegicus and Rattus rattus in Korea and Domestic Rattus norvegicus in the U.S. had virus similar to prototype Hantaan virus yet distinct from it. Microtus pennsylvanicus: the meadow vole. Reservoir for Prospect Hill virus, most recently isolated Hantavirus. Isolated at NIH and named for Prospect Hill in Frederick, MD where the vole was captured that yielded the first isolate. No human disease associated with this so far but antibody has been identified among mammalogists in the U.S.(1982). Cletheronomys glareolus: the bank vole. Reservoir for Puumala virus, cause of Nephropathia epidemica (NE), a mild form of HFRS found in Scandinavia, Western Soviet Union and much of Europe.

TRANSMISSION:

Aerosol transmission from rodent excreta is presumed. Virus is present in urine, feces and saliva of persistently infected asymptomatic rodents; highest virus concentration is found in the lungs. Human to human transmission does not occur.

DISEASE IN RODENTS:

Chronic, ASYMPTOMATIC infection. Following infection, rodent is viremic for about 1 week when virus is disseminated throughout the body. After viremia antigen is usually abundant in the lungs, spleen and kidneys. Antibody is produced and persists but does not diminish the abundance of antigen expressed in organs.

DISEASE IN MAN:

Symptoms begin with the sudden onset of fever which lasts 1-2 weeks, accompanied by prostration, anorexia, generalized pains, conjunctivitis, proteinuria and hypotension, possibly followed by hemorrhages and hematuria with renal failure. Case fatality rate is 7%.

DIAGNOSIS:

Serology using indirect immunofluorescence or ELISA.

TREATMENT:

IV Ribavirin

PREVENTION/CONTROL:

Although most US commercial animal breeders have eliminated these viruses through barrier breeding and caesarean derivation, small suppliers and producers of select inbred strains may be at risk of infection. Be aware of potentially infected animals when receiving shipments from Japan, Belgium or other countries which may have the agent present in lab. animals (where virus-free certification cannot be provided). Animals should be serologically tested in advance of shipment. Test all rodent tissues, tumors, cell lines received from source that cannot provide virus free certification. Education and awareness of potential problem. Exclude rodents from housing and other buildings in endemic areas.