Pankoj
Pankoj
Blog Article
Seasonal flu is caused by influenza viruses that primarily affect the respiratory system. There are four types of influenza viruses: A, B, C, and D, but types A and B are responsible for the annual flu epidemics in human populations. These viruses are highly contagious and spread through respiratory droplets when an infected person coughs, sneezes, or talks. They can also spread by touching surfaces contaminated with the virus and then touching the face, particularly the mouth, nose, or eyes.
The flu virus tends to change or mutate over time, making it difficult for the immune system to recognize and protect the body from subsequent infections. This is one of the reasons why seasonal flu occurs annually, with different strains of the virus circulating each year. In Bangladesh, the flu season typically begins in the cooler months, from December to February, though outbreaks can occur throughout the year.