Occupational Safety

Hantavirus Infection

(Hemorrhagic Fever with Renal Syndrome; Nephropathia Endemica)

Hantavirus is a highly fatal infection associated with wild rodents, especially deer mice. House mice (Mus musculus) and rats (Rattus sp.) don't appear to be a problem. While the disease in humans is not common, there are many more human deaths in the Western U.S. associated with Hantavirus infections than with rabies or plague. Hantavirus is easily the most significant health risk (PDF) associated with wild rodents.

If research work involves susceptible wild species, such as Peromyscus sp., special precautions should be in effect for the field work and for any animals returned to the vivarium. These could include specific personal protective equipment (PPE) for the researcher(s) and testing of wild rodents that will be brought into any research facility.

The hantaviruses, which can cause severe hemorrhagic disease, are widely distributed in nature among wild-rodent reservoirs. The severity of the disease produced depends on the strain involved. Strains producing hemorrhagic fever with renal syndrome are prevalent in southeastern Asia and Japan, and focally throughout Eurasia. Outbreaks of hantavirus infection characterized by a severe pulmonary syndrome resulting in numerous deaths have been recognized in the southwestern U.S. Infections associated with laboratory rodents have occurred in Russia, Scandinavia, Japan, and Belgium .

Rodents in several genera have been implicated in outbreaks of the disease in the U.S. The transmission of hantavirus infection is through the inhalation of infectious aerosols. Extremely brief exposure times (five minutes) have resulted in human infection. Rodents develop persistent, asymptomatic infections, and shed the virus in their respiratory secretions, saliva, urine, and feces for many months. Transmission of the infection can also occur by animal bite, or when dried materials contaminated with rodent excreta are disturbed, allowing wound contamination, conjunctival exposure or ingestion to occur. Recent cases that have occurred in the laboratory animal environment have involved infected laboratory rats. Person-to-person transmission apparently is not a feature of hantavirus infection.

The form of the disease known as nephropathia endemica is characterized by fever, back pain, and nephritis that causes only moderate renal dysfunction. The infection is usually self-limiting with proper treatment. The form of the disease that has been noted after laboratory animal exposure fits the classical pattern of hemorrhagic fever with renal syndrome. The infection is characterized by fever, headache, myalgia, gastrointestinal bleeding, bloody urine, severe electrolyte abnormalities, and shock.

Human hantavirus infections associated with the care and use of laboratory animals can be prevented through the isolation or elimination of infected rodents and rodent tissues before they can be introduced into the resident laboratory animal populations.