Scrub Typhus Scrub typhus is a disease caused by Orientia tsutsugamushi. It is spread to people through bites of infected chiggers (larval mites). The most common symptoms of include fever, headache, body ache, dark, scab-like region at the site of the chigger bite (also known as eschar), mental changes, ranging from confusion to coma. Antibiotics are most effective if given soon after symptoms begin. People who are treated early with doxycycline usually recover quickly.