Influenza, also known as the flu, is a contagious viral infection that attacks the nose, throat, and lungs. The flu virus is extremely small and can only be seen under an electronic microscope. The genetic material present inside the virus contains information needed to replicate and make more viruses. A protein shell provides a hard, protective enclosure for the genetic material as it travels between other living things.
An outer envelope allows the virus to infect other cells by merging into the targeted cell’s outer membrane. Projecting out of the envelope are spikes. The flu virus uses its H spikes like a key to enter the cell and then N spike proteins to allow copies of the virus to break away from the infected cell, which will then go on to infect more cells.
There are 17 known types of H spikes and 9 types of N spikes that scientists use to name different flu viruses, such as the H5N1. The flu is caught by touching an object that has the virus or being exposed to body fluids from infected people or animals.
When an infected person talks, coughs, or sneezes, droplets carrying the influenza virus may land in your mouth or nose and then move into the lungs. Once the virus enters the body, the virus comes in contact with cells in the nose, throat, or lungs. The H spike on the virus inserts into a healthy cell membrane like a lock and key. Next, the virus travels inside a sack made from the cell membrane towards the cell’s nucleus.
The viral envelope and the cell membrane sack combine, allowing the viral genetic material to leave the sack and enter the cell’s nucleus. The viral genetic material hijacks the energy and nutrients in the cell’s nucleus to make thousands of copies of itself. Some of the genetic material moves out of the nucleus and then attaches to ribosomes. The ribosomes end up making more viral proteins, like the H and N spikes. The Golgi apparatus carries the spikes in vesicles, which then merge into the cell membrane. All the particles needed to create a virus gather beneath the cell membrane and new virus particles begin to form and leave out of the cell membrane. These new influenza viruses now infect more cells and cause the body to develop the symptoms of the flu.
Types of Flu
There are three types of flu viruses: namely A, B, and C. They belong to the family Orthomyxoviridae. Type A and B cause epidemics and are more serious diseases, while type C causes mild illness.
- High fever (38°C or 100.4°F)
- Sore throat
- Runny nose
- Muscle pains
Though it usually improves within a week, sometimes people get so ill that they require hospitalization and even end up in the ICU. A person may be contagious, too, a day before their symptoms begin and up to 2 weeks post-recovery from the illness.
If you are otherwise healthy and fit, there is no need to see a healthcare provider. The best way to cope with flu symptoms is to rest, keep warm, and drink plenty of water. If you have a high fever or body aches, paracetamol or ibuprofen would be advisable to take. Avoid going to work or school if you have the flu to prevent spreading it.
When Do I See a Doctor?
- Above the age of 65
- Have any underlying medical conditions like diabetes, heart disease, lung disease, kidney disease, or a neurological disease
- Have HIV or are undergoing chemotherapy. The immune system is already in a compromised state so it is best to see a doctor as soon as possible.
- Symptoms worsen with time and haven’t gone away even after a week
Preventing The Spread
One can prevent the flu from spreading by practicing good hygienic techniques such as:
- Always wash your hands with soap and warm water
- Clean surfaces that are used regularly (e.g. computer keyboards, telephones, and door handles)
- Cover your mouth with tissue paper while coughing and sneezing
- Avoid unnecessary contact with other people while you have an infection
- Getting an annual flu vaccine or antiviral medication at the beginning of flu season
- When is flu season? While flu viruses are detected year-round in the US, it’s most common during fall or winter.
- Why are flu vaccinations important? Vaccinations prevent people from being infected with the disease. The vaccine protects you and helps to protect other people around you who cannot get vaccinated, such as children below 6 months of age. Every year, the seasonal flu vaccine is developed and it protects us against the four types of flu.
Healthier Me Today is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Never ignore professional medical advice in seeking treatment, always consult with your healthcare professional. Stay healthy!