"Most of the animals that spread the disease are cold-blooded, so when it's warmer, they're more active," explained Brian Brannon with Orange County Mosquito and Vector Control.
"It's spread by the actual flea dirt or the excrement of the fleas, so when you scratch yourself, that dirt gets into your bloodstream."
There have been five confirmed cases of flea-borne typhus in Orange County this year. The most recent case was reported in Fountain Valley earlier this month. A case was in reported in Santa Ana in January and again in June.
Another case was found in Anaheim in July and a fourth case was reported in Garden Grove earlier this month.
"We can always find typhus through dead animals that we test and we take them and we test the fleas for the presence of the disease," said Brannon.
While typhus cannot spread person-to-person, officials warn pets can carry fleas that carry the disease.
"Possums are a big source of flea-borne typhus," said Brannon. "Cats can also carry it, so we really recommend that don't feed feral cats. Don't pet feral cats. You're looking for trouble if you do that."
Typhus symptoms include fever, rash and severe headache. Most cases are mild, but some may require hospitalization.
"Typhus can be a deadly disease, so it's really something that we need to be on the watch for," said Brannon.
No deaths have been reported in the cases found in Orange County.
OC Vector encourages people to stay up to date on their pet's flea medication, wear insect repellent outdoors, and clean up trash and food waste around your home that may attract animals.
Anyone who sees a dead animal in their area is urged to call animal control.