Q. Consider the following:

1. H5N1
2. Nipah Virus
3. Chikungunya
4. Scrub Typhus

Which of the above are caused by viruses?
Answer: Only 1, 2 and 3
Notes: H5N1, Nipah Virus, and Chikungunya are diseases caused by viruses. H5N1 is an avian influenza virus, Nipah Virus is a zoonotic virus, and Chikungunya is a mosquito-borne viral disease. Scrub Typhus, however, is not caused by a virus; it is a rickettsial disease transmitted by mites. Therefore, the correct answer is Only 1, 2 and 3.