Flea-Borne Typhus: Causes, Symptoms, Prevention and Treatment

Flea-borne typhus — also called murine or endemic typhus — is caused by the bacterium Rickettsia typhi. People catch it through contact with infected fleas, most often the Oriental rat flea and the cat flea. Fleas become infected by biting infected animals such as rats, cats or opossums, and stay infected for life.

The Oriental rat flea, one of the main carriers of flea-borne typhus. Image from CDC's page.

How it spreads

When an infected flea bites, it breaks the skin. Fleas defecate as they feed, and their droppings ("flea dirt") carry the bacteria, which can be rubbed into the bite or other wounds. People can also breathe in infected flea dirt or rub it into their eyes. Fewer than 5% of patients remember a flea bite or exposure in the week or two before falling ill. The disease does not spread from person to person.

Where it occurs

Flea-borne typhus occurs in tropical, subtropical and temperate regions worldwide, including parts of Southeast Asia, Africa, Central and South America, southern Europe and the Middle East. In the United States, most cases are reported in southern California, Hawaii and southern Texas, though cases likely occur elsewhere. In the few states that report it, cases have risen significantly since 2008, suggesting it may be re-emerging in some areas.

Symptoms

Symptoms begin 3 to 14 days after contact with infected fleas or flea dirt, though people often do not know they were exposed. Spending time outdoors and contact with rats, opossums or free-roaming cats raise the risk. Symptoms can include:

• fever and chills;
• body aches and muscle pain;
• headache;
• loss of appetite, nausea, vomiting and stomach pain;
• cough; and
• rash, in about half of patients, usually starting around the fifth day.

Almost everyone recovers fully with the right antibiotics, and deaths are rare (under 1% of cases). Without prompt treatment, some people need hospital care, and the disease can cause severe illness, organ damage and death.

Prevention

There is no vaccine. To avoid fleas:

• Protect pets: animals that go outside can bring fleas in, so ask a veterinarian about flea control such as collars, oral medicines or topical products. Do not use permethrin on cats.
• Keep rodents and wildlife away: store food, including pet food, in sealed containers; clear brush, rock piles, junk and clutter; seal holes where rodents can enter; and keep compost and trash bins closed.
• Protect yourself: don't feed or pet wild or stray animals, wear gloves when handling sick or dead animals, and use EPA-registered insect repellent on skin and clothing outdoors, following the label.

Diagnosis and treatment

In the first week, flea-borne typhus looks like many other illnesses. See a health care provider if symptoms appear, and mention any contact with fleas, rats or mice, stray cats or wildlife such as opossums. Blood tests can look for the bacteria or for antibodies, but results can take weeks, so treatment may start before they arrive.

Flea-borne typhus is treated with the antibiotic doxycycline, which can be used at any age and works best when started soon after symptoms begin.

Sources

• Centers for Disease Control and Prevention, "About Flea-borne Typhus": https://www.cdc.gov/typhus/about/murine.html
• The source spells the Oriental rat flea's scientific name two ways (Xenopsylla cheopsis and X. cheopis); this page uses the common name.