Epidemiology Corner

January 17, 2002

Hantavirus

In early January, the Bureau of Epidemiology confirmed the identification of the first case of hantavirus infection in Houston. The 30-year-old man was hospitalized in late December 2001 and is now fully recovered. The location of his exposure is still under investigation but includes areas outside the city of Houston.

Hantavirus infection became reportable in Texas in February 1994, following national attention to the disease during an outbreak in New Mexico, Arizona, Colorado and Utah (an area referred to as the four corners) from April-May, 1993. This outbreak represented the first identification of the disease in the United States. Hantaviruses are negative-stranded RNA viruses that infect wild rodents. The rodents shed the virus in their urine, feces and saliva. Transmission to humans occurs when dried urine or feces becomes aerosolized and is inhaled. The current case was caused by the Bayou strain, which is carried by Oryzomys palustric, or rice rat, which is found in Texas and Louisiana.

Hantavirus cases are very rare. All suspected cases reported since 1994 occurred during Houston’s cooler months (November – April). Early symptoms are similar to the flu, occurring an average of two weeks following exposure. Symptoms include fever chills, body aches and headache. There may also be dizziness and/or abdominal problems, such as nausea, vomiting, diarrhea and abdominal pain, dry cough and rapid onset of severe respiratory failure.

Do’s and don’ts with regard to hantavirus:

• If you must open up cabins and sheds or clean outbuildings that have been closed during the winter—such as barns, garages or storage facilities for farm and construction equipment, avoid directly touching rodents or their droppings. Avoid "stirring up the dust" when cleaning. Use a household bleach solution to wet down and disinfect the environment before you go in to clean.

• Don’t camp or sleep in infested trail shelters or in other rodent habitats.

• Avoid working in crawl spaces under houses or in vacant buildings that may have a rodent population. If you must work in this environment, be sure to decontaminate it first with a household bleach solution.

• Sanitize an old dusty attic or basement with a bleach solution before you start spring-cleaning. Remember that many homes can expect to shelter a few rodents, especially when the weather turns cold.

For more information call the Bureau of Epidemiology at 713-794-9181 or visit the web cite for the CDC @ http://www.cdc.gov/health/diseases.htm

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