Question
What is the etiological agent in an 8 year old boy presenting with a history of tick bite,fever and rash as shown in the figure?
A. Rickettsia rickettsii.
B. Rochalimaea quintana.
C. Rickettsia tsutsugamushi.
D. Coxiella burnetii.
Show Answer
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Correct Answer » A
Explanation
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Ans: A. Rickettsia rickettsii.
The condition as shown in the photograph above represents Rocky Mountain spotted fever (RMSF)
Rocky Mountain spotted fever
- It is a tickborne disease caused by the bacterium Rickettsia rickettsii.
- This organism is a cause of potentially fatal human illness in North and South America, and is transmitted to humans by the bite of infected Dermacentor tick species.
- The male-to-female ratio for RMSF is 1.7:1.
The incidence of Rocky Mountain spotted fever is highest among adults aged 60-69 years and children aged 5-9 years.
- Initial signs and symptoms of the disease include sudden onset of fever, headache, and muscle pain, followed by development of rash.
- A classic case of RMSF involves a rash that first appears 2-5 days after the onset of fever as small, flat, pink, non-itchy spots (macules) on the wrists, forearms, and ankles and spreads to include the trunk and sometimes the palms and soles.
- The classic triad of findings for this disease are fever, rash, and history of tick bite.
- Appropriate antibiotic treatment should be started immediately when there is a suspicion of Rocky Mountain spotted fever on the basis of clinical and epidemiological findings. Treatment should not be delayed until laboratory confirmation is obtained.
- Doxycycline is the drug of choice.
