This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
Drug of choice for chemoprophylaxis in meningococcal meningitis is - 
Select and explain. 
A. Tetracycline, B. Rifampicin, C. Streptomycin, D. Erythromycin
B: Rifampicin
Answer: B: Rifampicin 
Explanation: <p>chemoprophylaxis of meningococcal meningitis:- Close contacts of persons with confirmed meningococcal disease are at an increased risk of developing meningococcal illness. Antibiotics are effective in preventing additional cases through eradicating carriage of invasive strain. In outbreaks involving limited population,those with direct prolonged contact with a case of meningococcal disease may also be offered clearance treatment. Ideally treatment should sta within 24 hours of identification of index case. Antibiotics effective for this purpose include rifampicin, ciprofloxacin, ceftriaxone or azithromycin. Mass chemoprophylaxis: Mass medication of total population some of which are not infected. Mass treatment causes an immediate drop in incidence of meningitis and in the propoion of carriers. The drugs of choice are ciprofloxacin, minocycline, spiramycin and ceftriaxone. {Reference: park&;s textbook of preventive and social medicine, 23rd edition, pg no.167}</p>