Microbiology:-
Coxiella burnetii—the etiologic agent of Q fever—is a small, pleomorphic
coccobacillus with a gram-negative cell wall that exists intracellularly.
A worldwide disease, Q fever is a zoonosis. Cattle, sheep, and goats are responsible for most cases of human infection; many other animals can serve as vectors of transmission or as reservoirs of disease.
The specific presentation of acute Q fever differs geographically (e.g., pneumonia in Nova Scotia and granulomatous hepatitis in Marseille); chronic
Q fever almost always implies endocarditis.
with flulike syndromes, prolonged fever, pneumonia, hepatitis, pericarditis, myocarditis, meningoencephalitis, and infection during pregnancy.
Symptoms are often nonspecific (e.g., fever, fatigue, headache, chills, sweats, nausea, vomiting, diarrhea, cough, and occasionally rash).
– Multiple rounded opacities on CXR in pts in endemic areas are highly suggestive of Q fever pneumonia.
– The WBC count is usually normal, but thrombocytopenia occurs. During recovery, reactive thrombocytosis can develop.
– Prolonged fatigue, along with a constellation of nonspecific symptoms (e.g., headaches, myalgias, arthralgias), can follow Q fever (post–Q fever fatigue syndrome).
– Fever is absent or low grade; pts may be ill for >1 year before diagnosis.
– Valvular vegetations are best seen with transesophageal echocardiography rather than transthoracic echocardiography, which identifies vegetations in only 12% of cases. The vegetations differ from those in bacterial endocarditis of other etiologies and manifest as endothelium-covered nodules on the valve.
– The disease should be suspected in all pts with culture-negative endocarditis.
– Although C. burnetii can be isolated by a shell-vial technique, most laboratories are not permitted to attempt isolation because of the organism’s highly contagious nature. PCR testing of tissue or biopsy specimens can be used, but serology is the most common diagnostic tool; IFA is the method of choice.
The medicines that can be thought of use are:-