A. Rickettsia typhi.
B. Rickettsia rickettsiae.
C. Rickettsia prowazekii.
D. Rickettsia akari.
Ans:C. Rickettsia prowazekii.
The parasite shown in the picture above represent Louse.
History of a louse bite with rashes all over the body and vasculitis is suggestive of epidemic typhus, caused by Rickettsia prowazekii.
- Epidemic typhus (also called “Epidemic louse-borne typhus,”and “louse-borne typhus”) is a form of typhus so named because the disease often causes epidemics following wars and natural disasters.
- The causative organism is Rickettsia prowazekii, transmitted by the human body louse.
- Rickettsia parasitize the endothelial cells of the small venous, arterial, and capillary vessels. The organisms proliferate and cause endothelial cellular enlargement with resultant multiorgan vasculitis.
- The incubation period for the disease is 10 to 14 days, on average.
- Fever is characterized by abrupt onset and high grade.
- Headache is characterized by abrupt onset and is unremitting.
- A maculopapular/petechial rash occurs on days 4-7 and may begin on the axilla and trunk and spread peripherally. Other symptoms may include rigors, myalgias, malaise, and CNS symptoms (ranging from mental dullness to coma).
- The infection is treated with antibiotics like Tetracycline, Chloramphenicol, and Doxycycline.