The Black Creek Canal virus, carried by the cotton rat (Sigmodon hispidus) and the Bayou virus, hosted by the rice rat (Oryzomys palustris).
Through January 30, 2002, a total of 289 cases of hantavirus pulmonary syndrome have been reported in the United States. This case count started when the disease was first recognized in May 1993. Thirty-eight percent of all reported cases have resulted in death. Of these 289 cases, 60% have been male and 40% female. The average age of confirmed case patients was 37 years old. Whites currently account for 78% of all cases. American Indians account for about 19% of cases, African Americans for 2% of cases, and Asians for 1% of cases. Cases have been reported in 31 states, including most of the western half of the country and some eastern states as well. Over half of the confirmed cases have been reported from areas outside the Four Corners area where it originally started. (CDC).
Available evidence indicates that the most frequent mechanism of infection for humans is the inhalation of infectious aerosols produced by the rodents. There are several ways these aerosols are distributed. The rodents shed the virus continuously in their urine and droppings. They also shed it in their saliva, which dries on anything they've chewed, including their nesting material. The shed virus can live for several days in the environment. (RN 16) As mentioned, the most common way of transmission is for these aerosols to become airborne. When the rodent's urine, excrement, or nesting material is disturbed, the tiny viral particles are aerosolized or become airborne. Humans can then inadvertently inhale the particles, particularly if the aerosolization has occurred in closed, poorly ventilated areas. (RN 16) .
Who is at risk? Anything that puts you in contact with rodent droppings, urine or nesting materials can place you at risk for infection. These include such activities as opening up cabins and sheds or cleaning outbuildings that have been closed during the winter "such as barns, garages or storage facilities.
