A Weil-Felix test was performed on serial dilutions from a patient bitten by a tick. The results obtained were positive for OX-19 and negative for OX-2 and OX-K. Based on these findings, the organism can be identified as:
a. R. rickettsii.
b. O. tsutsugamushi.
c. Rickettsia prowazekii.
d. Rickettsia typhi.
A
Patients with R. prowazekii (epidemic typhus), R. typhi (murine typhus), and R. rickettsii (Rocky Mountain spotted fever) will be positive for OX-19 and negative for OX-2 and OX-K. However, R. prowazekii is transmitted via lice, and R. typhi is transmitted via fleas. R. rickettsii is trans-mitted via ticks. O. tsutsugamushi (scrub typhus) will be positive for OX-K and negative for OX-19 and OX-2 and is transmitted by chiggers.
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