With the increasingly global nature of our society, and mutations that allow pathogens to infect new hosts, there is a rise in cases of human infections with pathogens like re emerging diseases, and ailment previously only seen in birds. new, mutated of the virus have been seen in humans since 1997. birds are not the only animals spreading their infectious diseases to humans. h1n1, also called , has also been a recent cause for concern. in fact, new and/or increased exposure to animals is identified as a possible source of a few new diseases, including , which is believed to stem from humans consuming infected cats in china.

Viral infection by consuming animal diet is very common these days. These generally cause global pandemic. Most of the pandemic virus are influenza virus, which causes flu like symptoms in humans as well animals including birds, and poultry animals.

The H1N1 virus, which a Influenza A virus causes many type of infections, which includes Swine flu, Cat flu etc. The cat flu is a flu, which is known to be caused by eating cats. The viruses are well known to evolve and mutate easily and cause the changes in the subtype. The mutations in subtypes of viruses makes it difficult to make a vaccine for these types of flu.

Hence, the first blank can be filled with Subtypes, second blank can be filled with Influenza A and the third blank can be filled with Cat Flu.

i thinking chemical change