Influenza is a viral illness that usually occurs during the late fall, winter and early spring months. There are several types of influenza viruses, with influenza A and B being the most common types that cause illness in humans. Each season, a different strain of these viruses affects people around the world.
Time Frame
The incubation period of the virus is around two to three days. It is spread by respiratory droplets, from coughing and sneezing of infected individuals, or from droplets staying on unclean surfaces.
Effects
The main signs and symptoms of influenza are fever, cough, runny nose, headache, body aches and weakness. These symptoms usually last less than a week. Patients with weakened immune systems, chronic respiratory conditions, people older than 65 and children younger than 2 years of age are at increased risk for complications of influenza infection. These complications include respiratory distress and failure, pneumonia, apnea, sepsis and death.
Identification
The diagnosis of influenza infection is often made clinically, but tests can confirm the diagnosis. The tests are most reliable if done within the first three days of symptoms. A rapid diagnostic test is available for clinics and hospitals. This test can produce results within 15 minutes. It requires a specimen of secretions from the nose and throat. The reliability of the rapid diagnostic tests varies, and they have a high rate of false-negative results. Hospitals may have a more reliable test in their labs, but it takes a few hours to produce results.
Prevention/Solution
There are several antiviral medicines available for treatment of the influenza virus. The most common ones are the neuraminidase inhibitors, oseltamivir and zanamivir. To be effective, patients must take these medicines within the first 48 hours of symptoms.
History
There have been several pandemics of influenza throughout history, usually caused by a new strain of the flu. These pandemics cause more severe illness, with worse symptoms at presentation, and lead to an increase in the number of hospitalizations and fatal cases. Frequent hand-washing, staying home when sick or diagnosed with the flu, and covering your coughs and sneezes with a sleeve are all good techniques to minimize the spread of the virus.
References
- Centers for Disease Control and Prevention: Seasonal Influenza
- Red Book: 2009 Report of the Committee on Infectious Diseases; American Academy of Pediatrics, Committee on Infectious Diseases; 2009
