Influenza virus type A positive

Influenza virus, also known as flu virus, is generally divided into three types: A (A), B (B), and C (C). Human influenza is mainly caused by influenza A virus and influenza B virus. The typical clinical symptoms of these diseases are acute high fever, body pain, significant fatigue and respiratory symptoms. If the influenza virus type A test is positive, it means you have been infected with influenza and need to take medicine. We must strengthen protection during the peak influenza season.

Influenza, the full name of influenza, is an acute respiratory infectious disease caused by influenza viruses that are highly susceptible to mutation. The virus belongs to the Orthomyxoviridae family, is an enveloped virus, and is highly contagious. Medically, the virus is divided into three types: A (A), B (B), and C (C) according to the different antigenicity of the nucleoprotein (NP) and matrix protein (MP) inside the virus. Among them, type A virus is the most susceptible to mutation and is highly contagious. The peak influenza season is from November to March of the following year, with an incubation period of 1 to 3 days, and it is prevalent in groups.

All three types of influenza viruses can cause infection in humans, but the degree to which they occur varies.

Influenza A virus: It has a wide range of prevalence and can infect humans and a variety of animals. It is the culprit that has caused global influenza many times.

Influenza B virus: Found only in humans and seals, usually of low pathogenicity, occasionally causing local outbreaks.

Influenza C virus: It mostly appears in the form of sporadic cases, generally does not cause epidemics, and the symptoms after infection are relatively mild.

According to statistics, 5% to 10% of adults and 20% to 30% of children worldwide suffer from influenza every year, and most influenza patients can recover on their own. However, high-risk groups such as infants and young children, especially babies under 2 years old, are more likely to develop laryngitis, tracheitis, bronchitis, bronchiolitis, pneumonia and gastrointestinal symptoms; pregnant women, women within 2 weeks after delivery, and the elderly (age ≥ 65 years) may also develop serious complications such as pneumonia, encephalitis or myocarditis, so these people should start antiviral treatment as soon as possible when they are diagnosed with or suspected of influenza.

The reason why influenza is so lethal is that it is extremely contagious. A healthy person can excrete the virus 3 to 5 hours after being infected with the influenza virus. The peak period of virus emission in influenza patients is between 24 and 48 hours after onset of illness.

Influenza patients and asymptomatic carriers are the main sources of infection. It is mainly transmitted through droplets in the air, and can also be transmitted through direct or indirect contact with mucous membranes such as the mouth, nose, and eyes. It is also possible to become infected through contact with the patient's respiratory secretions, body fluids, and contaminants.

However, not every individual infected with the influenza virus will develop influenza symptoms. Whether or not one develops the disease depends on the interaction between each person's immunity and the virus. Influenza viruses enter the human respiratory tract through droplets. Normal people have secretory IgA antibodies on their respiratory mucosa that can eliminate the virus. When the body's immunity decreases, the level of secretory IgA will decrease, the ability to clear viruses will decrease, and symptoms of influenza may appear.