Why is the flu suddenly high in summer?

Speaking of flu, I believe everyone is familiar with it. General influenza viruses are easy to break out in autumn and winter, such as influenza A, influenza B and swine flu. This time is often referred to as the flu season, mainly because the air is dry in autumn and winter, and people prefer to stay indoors at this time, which is easy to cause the spread of flu. Generally, it begins in autumn and then spreads rapidly, and the following year is 65438+ 10 and February.

Summer flu usually occurs in May and September, which is rare, but it does exist.

Recently, many southern provinces have entered a rare summer flu peak, and many people can't understand this phenomenon. It stands to reason that influenza virus is not easy to survive in the high temperature in summer. Why did it suddenly break out in summer?

According to the statement in the Technical Guide for Influenza Vaccination in China (202 1-2022) issued by CDC, the annual periodicity of influenza A in China generally increases with the increase of latitude. Especially in southern provinces south of 27 degrees north latitude, April-June is a single-year peak, while in mid-latitude areas,1-February and June-August are double-cycle peaks every year.

This sudden outbreak of influenza is still traceable.

In addition to the annual periodic trend mentioned above, the influenza virus itself also presents a variation trend. In mid-May, 2022, Hainan influenza virus quickly changed from Bv subtype to A(H3N2) subtype, which spread quickly and was highly contagious, and the number of influenza patients naturally increased.

In addition, due to the continuous epidemic prevention and control measures in the past two years, the implementation of measures such as wearing masks and gathering less has led to a sharp decline in influenza and other diseases. I don't know if you feel this way, but there have been very few colds in the past two years. I feel this way anyway.

With the decrease of influenza infection rate, the original immune level decreases, leading to the accumulation of susceptible people.

In addition, don't forget that this time period is the peak of summer return trip, and people are more susceptible to influenza virus.

Regarding protection, I think everyone must know the daily protective measures for epidemic breeding. But more importantly, I think it is necessary to get the flu vaccine. The general influenza vaccination season is September to June, 165438+ 10. Generally, the relevant departments will inform you during the vaccination season. Because of the different policies in each region, I personally suggest that it is best to consult the local vaccination clinic.

At present, the epidemic situation in COVID-19 has not completely subsided, and the influenza virus is on the rise this summer. This domestic influenza outbreak may be caused by small-scale population movement. After the temperature drops, everyone's outdoor activities will be reduced, which should gradually ease.