The number of patients with the bacterial disease scrub typhus has increased eightfold over the past three weeks, prompting health authorities to urge caution.

According to the Korea Disease Control and Prevention Agency(KDCA) on Friday, the number of scrub typhus patients jumped from 58 between October 13 and 19 to 264 between October 20 and 26, then 459 between October 27 and November 2.

The density index of chiggers, the microscopic mites that carry the Orientia tsutsugamushi bacteria, which cause the disease, has more than tripled over the cited period.

Symptoms include fever, chills, headache, sore muscles and rashes. 

The disease has a relatively low fatality rate of zero-point-one to zero-point-three percent and can be treated with antibiotics.

The KDCA forecast an increase in the number of patients over the next three to four weeks, as more than half of all cases are typically reported in November. 

Agency chief Jee Young-mee urged people to take extra care during outdoor activities to avoid chigger bites.