Health officials in California are investigating a human plague case in an Los Angeles County child.

Oriental rat flea, Xenopsylla cheopis/CDC

They say a the child became ill and was hospitalized after visiting the Stanislaus National Forest and camping at Crane Flat Campground in Yosemite National Park in mid-July.

No other members of the camping party reported symptoms and health officials are continuing to monitor the child’s family and treatment providers. The child is recovering.

This is the third human plague case reported since yesterday. Colorado health officials reported on two plague cases, one fatal on Wednesday.

The California Department of Public Health (CDPH) is working closely with the Los Angeles County Department of Public Health (LACDPH), U.S. Centers for Disease Control and Prevention, Yosemite National Park and the U. S. Forest Service to investigate the source of the infection, and the patient’s travel history and activities during the incubation period.

CDPH Director and State Health Officer Dr. Karen Smith said, “Human cases of plague are rare, with the last reported human infection in California occurring in 2006.

“Although this is a rare disease, people should protect themselves from infection by avoiding any contact with wild rodents. Never feed squirrels, chipmunks, or other rodents in picnic or campground areas, and never touch sick or dead rodents. Protect your pets from fleas and keep them away from wild animals.”

As a precaution, Yosemite National Park will provide additional information to visitors about steps to prevent plague exposure, and post caution signs at the Crane Flat campground and nearby campgrounds. Steps the public can take to avoid exposure to human plague include:

  • Never feed squirrels, chipmunks or other rodents and never touch sick or dead rodents
  • Avoid walking, hiking or camping near rodent burrows
  • Wear long pants tucked into socks or boot tops to reduce exposure to fleas
  • Spray insect repellent containing DEET on socks and pant cuffs to reduce exposure to fleas
  • Keep wild rodents out of homes, trailers, and outbuildings and away from pets.

The last reported cases of human plague in California occurred in 2005 and 2006 in Mono, Los Angeles and Kern counties and all three patients survived following treatment with antibiotics. Since 1970, 42 human cases of plague have been confirmed in California, of which nine were fatal.

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