Widely known as the â€˜flu', influenza is a viral infection that typically affects your upper respiratory tract which comprises of nose and throat, sometimes involving the lungs too. For clarification, this is not the â€˜stomach flu' responsible for vomiting and loose stools. This common infection affecting 5 to 20 percent of US population each year is caused by an influenza virus and lasts about 5 to 6 days, occasionally lasting up to two weeks.
This flu commonly results from exposure to respiratory droplets (by air) from an infected individual containing influenza viruses A, B, and C which are RNA viruses. Among the three, type A is considered the most virulent as it causes a comparatively severe infection. Person to person spread occur through sneezing and coughing but also by touching the contaminated surfaces (fomites) then touching their own nose or mouth as viruses can survive outside for some time. It is crucial to know the affected individuals can transmit the infection a day before the onset of symptoms up to 1 week of onset unknowingly.
People get sick more often at certain times of the year, usually during the fall and winter. According to studies, October marks the start of the season peaking in December and January, declining afterward. However, this applies only to the States and most European countries. Many theories are out there in explaining the reason behind flu season and one is that people spend more times indoors during the â€˜cold' season making them breathe each other expired air containing infected droplets.
Usual onset is sudden with fever with or without chills, body ache, sore throat, cough, runny nose, and headaches. Though rare in adults, vomiting and diarrhea are frequent in children. Occasionally, the infection can progress without fever only presenting body ache and a runny nose. The severity of these symptoms depends on the viral strain, individuals age, and overall body physique.
According to biology 101, we know viral infections are self-limiting and usually do not need antimicrobial treatments. The Same rule applies here, as mentioned earlier, the flu will be limited to a maximum of one week in most. So what you can do is drinking plenty of water, using an antipyretic for fever (aspirin, ibuprofen) and stopping tobacco and alcohol use while taking a good rest. Aspirin should not be given to children due to the risk of life-threatening â€˜Reye's syndrome' and instead, â€˜acetaminophen' is a good alternative for them.
Typical complications include pneumonia, ear infections, sinus infections and dehydration due to fluid loss and pneumonia being more frequent. It is not caused by the virus itself but by secondary infections due to the lowered immunity by the virus. Occasionally flu can result in worsening of already existing medical conditions (exacerbations) like chronic lung infections resulting perilous outcomes.
Nevertheless, it is important to know that complications are rare and can affect individuals belong in certain categories like elderly age, pregnant mothers, people with lowered immunity (steroid induced or with HIV) and children and they should take extra measures in personal hygiene to prevent such illnesses.
The best available option is getting the yearly flu vaccine designed to combat most common strains of influenza viruses witnessed through research. It is recommended that everybody older than 6 months should get the vaccine by end of October ideally, though not so practical. However, vaccination can prevent, reduce the intensity, number of doctor visits, and hospitalization to a greater degree. Other measures for prevention include avoiding contact with the infected and maintaining a good personal hygiene, eg. Frequent hand washing, cover your mouth and nose if already infected, avoid touching your mouth nose and eyes and importantly, staying at home when sick.