The California Department of Public Health is reporting that a Northern California man has been diagnosed with hantavirus after rodent exposure.

The warning, posted Tuesday, reminds the public that rodents and other animals can easily contaminate food and food preparation surfaces with the hantavirus and plague.

To visit the interactive map, please click on the image.

There have been 73 hantavirus infections in California and 659 cases nationally since it was first identified in 1993. About 30 percent of hantavirus cases identified in California have been fatal.

The California Department of Public Health (CDPH) provides an interactive map of Rodent Plague Surveillance in the state. It shows “the density of plague-positive rodent collections for all collection years. Density is defined as the number of plague-positive rodents per square mile; the darker color, the more positive rodents in that location.”

Deer mice and white-footed deer mice are the animals most often responsible for infecting people with hantavirus. Both species can be easily differentiated from so-called house mice because they have white fur on their bellies and large eyes.

Hantavirus Pulmonary Syndrome (HPS) is caused by a virus that humans can contract through contact with the urine, droppings or saliva of wild rodents, primarily deer mice and white-footed deer mice. Breathing in small particles of mouse urine or droppings that have been stirred up into the air is the most common route of exposure.

“The chances of getting the virus are greatest when entering or cleaning buildings, or other closed spaces, where wild rodents are present,” CDPH Director and State Public Health Officer Dr. Karen Smith said in the warning notice.

Owners of buildings and closed spaces used for manufacturing or storage and shipping of food products are urged to be aware of the potential for food to become contaminated with hantavirus or plague.

Health officials have performed routine plague surveillance and control in California since the 1930s. The CDPH published the California Compendium of Plague Control to aid the diagnosis, treatment, and prevention of the plague, including the discussion of surveillance and control, and plague preventative measures.

The CDPH notes that Hantavirus illness begins with fever, headache, and muscle aches and progresses rapidly to severe difficulty breathing and, in some cases, death. Most people with Plague develop fever and swollen lymph nodes. Plague is treatable with antibiotics, but can progress to severe and sometimes fatal illness if diagnosis and treatment are delayed.

To prevent people and food from being contaminated with hantavirus, CDPH recommends the following:

  • Avoid contact with all wild rodents, their droppings, and nesting materials.
  • Before entering an enclosed area that may be infested with rodents, allow it to air out for at least 30 minutes.
  • Do not dry sweep or vacuum areas that rodents have potentially contaminated.
  • Surfaces that rodents may have contaminated with urine or droppings should be made wet with a 10% bleach solution or a commercial disinfectant following label directions before mopping up.
  • Promptly dispose of all cleaning materials when done, and thoroughly wash hands and clothes.
  • Examine the outside of all buildings and seal any holes or other areas that would let rodents get inside.
  • Store all food items securely in rodent-proof containers.

More information about HPS and Plague can be found on the CDPH’s website.

(To sign up for a free subscription to Food Safety News, click here.)