Deadly typhus spread by mite bites now found in US

A potentially deadly form of typhus that’s spread by chiggers has been detected in the United States for the first time.

Scientists from the CDC discovered that chiggers — also called trombiculid mites — in North Carolina parks are infected with the bacteria that causes scrub typhus.

Scrub typhus can cause severe multi-organ failure if not treated promptly.

The illness has a fatality rate of up to 70% without medical attention, according to a report in PLOS Neglected Tropical Diseases.

The disease was formerly seen only in the “Tsutsugamushi Triangle,” an area of the Asia-Pacific region named for the Orientia tsutsugamushi bacteria that causes the illness.

“This is the first time that [scrub typhus] has been detected in the free-living chigger [mites] in the US,” Dr. Kaiying Chen, an entomologist at North Carolina State University, told the Daily Mail.

Mites carrying the O. tsutsugamushi bacteria were found throughout North Carolina, from the coastal area at Merchant Millpond State Park to the Piedmont region in Morrow Mountain State Park.


Adult and larval chiggers are small enough to fit on the head of a pin.
CDC

A chigger bite can look like a small cigarette burn.
CDC

“Clinicians in this region should be alert for possible human cases of illness resulting from Orientia spp. infection,” according to the CDC dispatch, published in Emerging Infectious Diseases.

In addition to North Carolina, the disease has recently been discovered in Chile, Africa and the Middle East.

Scrub typhus spreads to people through the bites of infected chiggers, which are the larval form of mites. The bite mark can look like a small cigarette burn.

Symptoms of scrub typhus typically show up within 10 days of being bitten and can include fever, headache, body aches and rash.


chigger on finger
A chigger can spread scrub typhus, a potentially lethal disease.
Universal Images Group via Getty Images

The infection can often be misdiagnosed as flu, or sometimes as a tick-borne disease like Rocky Mountain spotted fever, according to Becker’s Clinical Leadership & Infection Control.

When caught early, scrub typhus can be easily treated with the antibiotic doxycycline, according to the CDC.

The spread of scrub typhus follows the trend of other tropical diseases spreading into more temperate climates: Five new US cases of malaria are alarming officials because they were locally acquired, meaning a mosquito in the US was carrying the disease.