Flu is a common name for influenza, an infectious disease found in mammals and birds, caused by the RNA viruses. Its symptoms include sore throat, runny nose, headache, fever, coughing, and chills. The two modes of transmission for flu include the air through sneezes or coughs, and direct contact through touching contaminated surfaces or nasal secretions and bird droppings. Disinfectants, sunlight and detergents can inactivate the flu virus. Occasionally, pneumonia may develop as a result of flu, either viral pneumonia that is direct or bacterial pneumonia that is secondary. A common sign that flu is developing into pneumonia in both children and adults is when the flu patient seems to be recovering but starts having trouble in breathing or with high fever. However, sometimes flu is confused with an illness like common cold.
Flu spreads in seasonal epidemics leading to severe illnesses and deaths every year. Three flu epidemics occurred in the 20th Century, having been caused by a new virus strain in humans leading to millions of deaths. Most commonly, the strain occurs when the virus spreads form animals to humans. It occurs when new genes from pigs’ or birds’ virus are picked up by human strains. However, there are three common types of influenza that include influenzavirus A, influenzavirus B, and influenzavirus C. Each of these genus have on species, influenza A virus, influenza B virus, and influenza C virus.
Picture of ducks (Source: commons.wikimedia.org)
Influenzavirus A is naturally hosted by wild aquatic birds but the same is spread to other bird species causing a severe outbreak in domesticated poultry. This may be subdivided into serotypes depending on the response of antibodies to the virus. In humans, the confirmed serotypes that cause deaths include H1N1, H2N2, H3N2, H5N1, H7N7, H1N2, H9N2, H7N2, H7N3, H10N7, and H7N9. Influenzavirus B is not as common as influenzavirus A and it infects humans exclusively. However, the only animals known to be susceptible to this flu virus include the ferret and the seal. Influenzavirus B mutates twice to thrice slower than influenzavirus A. Also, it has less genetic diversification, with one influenza serotype. Influenzavirus C is found in pigs, humans and dogs and sometimes causes local epidemics and severe illnesses. It is not as common as other types of influenza viruses with a mild cause of the disease among children.
CDC scientist transferring H7N9 (Source: commons.wikimedia.org)
Therefore, since the modes of transmission for the flu virus include the air through sneezes or coughs, and direct contact through touching contaminated surfaces or nasal secretions and bird droppings, it is advisable that good personal hygiene should be maintained. The hygiene habits include frequent washing of hands, avoidance of touching the mouth, nose and eyes, avoiding contact with patients, avoiding spiting, the use of gloves and face masks when taking care of patients, avoiding smoking as it raises risks of infection, and surface sanitizing.
