Microbiology – MCQ 54 – Weil felix reaction

An army jawan posted in a remote forest area had fever and headache. His fever was 104°F and pulse was 70 per min. He had an erythematous lesion of about 1 cm on the leg surrounded by small vesicles, along with generalized lymphadenopathy at the time of presentation to the referral hospital. His blood sample was collected to perform serology for the diagnosis of Rickettsial disease. Which one of the following results in Weil felix reaction will be diagnostic in this clinical setting:
A. High OX-2
B. High OX-19
C. High OX-K
D. High OX-19 and OX-2

Correct answer : C. High OX-K

The history and clinical features described are suggestive of scrub typhus. OX-K is specific for scrub typhus.