Xenopsylla cheopis, the rat flea, is shown here.

Long Beach health officials said Tuesday they have seen more than double the number of cases of flea-borne typhus this year compared to the average of prior years.

So far this year, the Long Beach Health Department has reported 10 cases of typhus compared to the year-to-date average of four cases.

Typhus is caused by a bacteria that enters the skin through scratching following a bite from an infected flea, which can be carried by rats, raccoons, opossums, and household pets like cats and dogs.

In a statement Tuesday, health officials did not speculate on a reason for the increase, but they urged the public to take protective measures, including treating pets with flea control and keeping food and other debris that might attract wild animals away from their homes.

Typhus, which is endemic to Long Beach, can cause high fever, chills, headache and rash. It can be treated with antibiotics; left untreated it can cause severe illness.