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
Emergence or reemergence seen in which of the following organisms - 
Select and explain. 
A. Polio virus, B. Measles virus, C. Nipah virus, D. West Nile virus
C: Nipah virus
Answer: C: Nipah virus 
Explanation: <p> Nipah virus is a new infectious disease recognised in 1999. Emerging infectious diseases are those whose incidence in humans has increased during the last two decades or which threaten to increase in the near future. Reference:Park&;s textbook of preventive and social medicine,K.Park,23rd edition,page no:355-357. <\p>