This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Which of the following infection is mainly diagnosed by serological tests? 
Select and explain. 
A. Actinomycosis, B. Q Fever, C. TB, D. Leprosy
B: Q Fever
Answer: B: Q Fever 
Explanation: Ans. is 'b' i.e., Q fever The diagnosis of actinomycosis is most commonly made by microscopic identification of sulphur granules. In most instances, the diagnosis of Q-fever relies upon serology. TB is usually diagnosed by sputom microscopy and/or culture. Leprosy is diagnosed clinically which is confirmed by histological examination of skin biopsies and by the detection of acid fast bacilli in nasal discharges, scraping from nasal mucosa and slit-skin smear.