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
The Leptospira interrogans complex - 
Select and explain. 
A. Causes disease in rodents which is usually fatal, B. Mostly affects the kidney and liver, C. Causes rise in 1gM antibodies which disppears after the first week of the disease, D. All
B: Mostly affects the kidney and liver
Answer: B: Mostly affects the kidney and liver 
Explanation: Ans. is 'b' i.e., Mostly affects the kidney and liver . The leptospires are generally non pathogenic in reservoir animals (e.g. rodents). . The leptospires mainly infect the kidney and liver. . Vasculitis is responsible for the most impoant manifestations of the disease. . Ig M antibodies appear after one week (not disappear). . No vaccine of leptospira is used world wide. "In pas of the world where the prevalence of human infection in ceain group is high, selective human immunization schemes may be of benifit if suitable vaccine is available"