Influenza and its different types

• May 6, 2024

Every year, at the beginning of the cold season, we hear about influenza. It is not an exotic name to qualify a simple cold , but of a acute respiratory disease what is necessary to know.

The nomenclature to describe the type of virus of influenza is expressed in this order: (1) type of virus , (2) geographic location where it was first isolated, (3) number of strain , (4) year of isolation, and (5) subtype of virus .

A little history

1. The first major epidemic of flu , caused by an outbreak of influenza virus A of the subtype H1N1 which is known, is known as "Influenza or Spanish Influenza "Of 1918, which killed between 50 and 100 million people around the world.
2. Pandemic 1957-58: "Asian flu "H2N2 . It was first identified in China, with 1-2 million deaths worldwide. Since this strain has not circulated in humans since 1968, nobody under 40 has immunity To her.
3. Pandemia 1968-69: "Hong Kong flu "H3N2 . It was first detected in Hong Kong, with 700,000 deaths worldwide. The virus H3N2 still circulating in our days.
4. New human strain 1977: "Russian flu "H1N1 .
5. New human strain 2009: H1N1 . Detected in Mexico .

Types of influenza viruses

According to the Mexican health authorities, influenza viruses are divided into three types, called A, B and C, but their manifestations are similar.

Influenza A

Wild waterfowl are the natural hosts of a variety of the influenza A . Sometimes, viruses are transmitted to other species and can cause devastating outbreaks in poultry or result in pandemics of flu human

The virus of type A are the most virulent human pathogens among the three types of influenza and causes more serious ailments.

It can be subdivided into different serotypes based on the response from antibodies to these virus : H1N2, endemic in humans and pigs, H9N2, H7N2, H7N3, H10N7 and up to 144 combinations, from H1N1 to H16N9, because 16 hemagglutinins (H) and 9 neuroaminidases (N) have been detected.

Influenza B

East virus It affects especially humans and is less common than influenza A. The only animals known to be susceptible to B infection are the seal and the ferret.

Influenza C

Eastvirus usually produces respiratory diseases mild that present symptoms that do not cause great discomfort or even cause epidemics . It infects humans, dogs and pigs.

The virus of influenza they mutate or change continuously, allowing them to "cheat" the immune system , que ha creado antibodies for the virus of the flu presented previously.