Child contracts the plague at Yosemite Park, California

A child has contracted the plague on a camping trip to Yosemite National Park and Stanislaus National Forest.

Responding to the first case of the bacterial disease reported in California since 2006, state health officials announced Thursday they had opened an emergency investigation, performed an environmental evaluation to determine the breadth of the malady and started warning campers in the mountainous paradise to take precautions.

In mid-July, the child from Los Angeles County became ill and was hospitalised following a family camping trip to Crane Flat Campground in Yosemite and the Stanislaus forest, officials said.

Tests on the child conducted by the state Public Health Laboratory came back positive for plague on Wednesday, officials said.

The case comes in the same week Colorado health officials announced that a second victim of the plague had died in the state in three months.

California officials have consulted with the Centres for Disease Control and Prevention in Atlanta and the state Department of Public Health as they search for the source of the child’s infection, as well as review the child’s travel history and activities.

The name, age and gender of the child were not released. The plague is an infectious bacterial disease usually carried by squirrels, chipmunks, other wild rodents and fleas that inhabit their hides.

The ominous history of the plague dates to medieval times when it wiped out tens of thousands of people in Europe.

Although there are several types of plague, including bubonic plague, officials were not specific on the strand contracted by the young camper.

National Park Service officials were posting signs Thursday at the Crane Flat Campground and other nearby camping areas advising visitors to take precautions, such as covering their arms and legs to reduce exposure to fleas and avoiding direct contact with rodents and their burrows.

“Although this is a rare disease, people should protect themselves from infection by avoiding any contact with wild rodents,’’ said Dr Karen Smith, director of the Department of Public Health and the state’s health officer.

“Never feed squirrels, chipmunks, or other rodents in picnic or campground areas, and never touch sick or dead rodents.’’

Smith also advised campers to protect their pets from fleas and keep them away from wild animals. “When an infected rodent becomes sick and dies, its fleas can carry the infection to other warm-blooded animals or humans,’’ reads a statement put out Thursday by the state Department of Public Health.

Officials urged calm, saying it is extremely unlikely the plague can be transmitted from person to person, unless the individual infected is coughing due to severe respiratory illness. They said the infected child did not exhibit such symptoms.

“There have been no known cases of human-to-human infection in California since 1924,’’ the state health officials’ statement reads.

The child is recovering at a undisclosed hospital. Others family members in the camping party did not report any symptoms.

Symptoms of human plague include fever, nausea, chills and swollen lymph nodes in the neck, armpits or groin.

Officials warned the disease can be fatal if not treated. "Plague is a very rare disease,'' said Dr Danielle Buttke, a health official for the National Park Service. "We typically have an average of seven cases in the United States every year.'' On Tuesday, officials announced that an adult in Colorado had died from human plague after likely getting it from fleas.

It was the second fatal case of plague in Colorado in less than three months.

In June, a 16-year-old boy died in Larimer County, Colorado, from the disease, which wasn’t detected until after he died.

Officials said there has not been a case of human infection in California since three patients were diagnosed in Mono, Los Angeles and Kern counties from 2005 to 2006.

All survived after being treated with antibiotics. In one 2006 case, a 28-year-old woman contracted the plague by handling raw meat from an infected Kern County rabbit, officials said.

New York Times