Health officials in California have closed off parts of a National Forest after a squirrel was found infected with plague.
Visitors have been ordered to leave the Angeles National Forest near Wrightwood in the San Gabriel mountains, as a precaution against the potentially deadly disease.
No individuals are said to be affected by the plague, known as the Black Death, after the animal was trapped as part of random checks.
Officials played down the significance of the discovery in the infected ground squirrel, pointing out that there have been relatively few cases of the disease in recent years.
"It is important for the public to know that there have only been four cases of human plague in Los Angeles County residents since 1984, none of which were fatal," Dr. Jonathan Fielding, health department chief, said.
A statement on the County of Los Angeles Public Health Department website said officials closed the Broken Blade, Twisted Arrow, and Pima Loops of the Table Mountain Campgrounds for at least seven days.
"Plague is a bacterial infection that can be transmitted to humans through the bites of infected fleas, which is why we close affected campgrounds and recreational areas as a precaution while preventive measures are taken to control the flea population," Dr Fielding said, recommending that residents and visitors use insecticides to protect against fleas, mosquitoes, and ticks.
The Black Death was responsible for one of the greatest pandemics in human history. Estimates vary, but it is thought that between 75-200 million people were killed by the disease in the 14th century. The plague entered England through the port of Weymouth in 1348, killing half of the country's population.