Harmful viruses attack the cells of human body and multiply in them. Many of them cause contagious diseases. In bio-terrorism, viruses can be used for mass destruction purposes. Hence threat of any viral bio-attack has become a national security as well as public health issue at present....

Human race has been affected with parasite infections since the time immemorial. The mouth is the entry port for many parasites. Parasitic infections are commonly seen in tropics. It is commonly seen among people with poor living conditions and where personal hygiene is commonly ignored....