In this review, the most important viruses associated with human and animal influenza are reported. These include Influenza A,B and C. Influenza viruses are members of the family Orthomyxoviridae. Influenza A virus being the most pathogenic and wide spread with many subtypes has constantly cause epidemics in several regions of the world. Epidemiology and mechanism of infection were revealed from molecular basis. Classification of influenza A into subtypes are based on the type of hemaglutinin (HA) and Neuraminidase (NA) proteins present on the outer surface of the virus. The mode of transmission is through the air, contact with body fluids and surfaces contaminated with the virus. Clinical manifestation include a rise in the body temperature, cough pains through out the body and ruffled features in mild infections, myalgia and pneumonia are also presented in severe infections. Laboratory diagnosis of influenza are virus isolation, immunoflouresence and serological methods. In this review, the most effective treatment of influenza is by multidrug antiviral therapy (M2 and NI inhibitors). Vaccination plays a major role in prevention though some have no or less safety guards such as the live attenuated influenza vaccine (LAIV) while the trivalent influenza vaccine (TIV) is more preferable.
Key words: Viruses, influenza, humans, animals, safety.