Hayley Scarano
Period 2
Influenza
The influenza virus, caused by the orthomyxorviridae microorganism, is a leading illness that hits millions of people each year resulting in severe discomfort, pneumonia, and potentially even death. The orthomyxoviruses are a family of RNA viruses consisting of six strains: Influenza A, influenza B, influenza C, isavirus, thogotovirus, and the recently discovered but undefined genus. The first three strains, influenza A, B and C are those that cause influenza in vertebrates. The RNA genomes of influenza A and B are single stranded and occur as eight separate segments. Influenza C, however, is made up of seven RNA segments. The virions consist of five parts: an envelope, a matrix protein, a nucleoprotein complex, a nucleocapsid and a polymerase complex. One virion of the microorganism has a diameter of 80-120 nm and a length of 200-300 nm. They are typically spherical, however filamentous forms occasionally occur. The virus itself is typically green. The replication of an orthomyxovirus usually takes about six hours, and it kills its host cell in the replication process. Before killing it, however, the virions obtain an envelope and mature as they make their way through the host cell membrane.
The influenza virus is passed from person to person in droplets that are released, most typically, through an infectious sneeze or cough. It can also be passed through saliva, feces, blood and nasal secretions. Direct contact with these bodily fluids or contact with surfaces infected by such fluids are common causes of infection. While the virus has a relatively short lifespan, it can live in mucus for up to six hours, leaving plenty of time for germs to be transmitted via an infected surface. More serious types of the virus, such as the Avian Influenza, are capable of staying alive for up to 100 days. These lifespans are perhaps why the influenza is such a prevalent illness throughout the world.
Symptoms of influenza vary from person...