Many people have been affected by the recent flu in Tamilnadu. The increase in fever cases in Tamilnadu is because of the influenza A(H3N2) virus and other subtypes. Normally, the fever cases will come down in January month. Let’s see the flu in detail in this blog.
Reason for flu:
The primary cause of the current outbreak is because of influenza A(H3N2) and not covid 19 and swine flu. Based on sample testing conducted in 2023, the influenza A(H3N2) virus is the most common cause of flu-like illness followed by respiratory syncytial virus and adenovirus. The respiratory syncytial virus A/B is also common in the community and causes a self-limiting flu-like illness
An overview of the influenza virus:
There are three distinct types of influenza virus(RNA virus) A, B, and C. They have 2 major surface proteins namely Hemagglutinin (HA) and Neuraminidase (NA) which project as spikes through the viral envelope (the outermost layer of the virus). Influenza type A mainly affects birds and mammals while types B and C affect mainly humans causing an epidemic outbreak. Pigs, horses, birds, and bats are just a few of the species that are affected by the influenza virus. These animals act as the viruses’ reservoirs.
How a pandemic is created by this virus:
Viral recombination (process producing variation in the majority of viruses) could result in minor changes in the virus (viral drift). Moreover, if there are any major changes in the virus because of viral recombination then it is called a viral shift. A virus with novel and serologically distinct HA or NA enters the population and affects the innocent non-immune population causing a disease pandemic.
Seasonal influenza outbreaks are caused by the virus’s ability to escape human immune response due to the occurrence of virus drift (minor changes in the virus due to recombination of the virus). The type B influenza virus doesn’t cause seasonal flu. Humans are commonly infected with H1, H2, H3, and N1 or N2 viruses.
Symptoms of recent flu:
Children are more badly affected by this flu than adults. The symptoms of this flu are
- Fever
- Sore throat
- Body pain
- Tiredness
- Cough lasting for at least 3 weeks
The majority of flu symptoms are mild and only last a few days. The symptoms can be clinically classified as
*Mild(A)
*Moderate (B)
*Severe (C)
Patients in category C (having severe symptoms) who are elderly and have comorbidities with respiratory distress can be treated with Tamiflu (oseltamivir) tablets.
Who are all exposed to this virus:
* Children are particularly vulnerable due to their high viral infection levels and prolonged shedding.
*Pregnant women will also have severe complications due to their altered immune and physiological status
Effects of infections in pregnancy:
During the previous influenza pandemic, it was found that pregnant women are at higher risk of complications. Even during the inter-pandemic periods (the period between influenza pandemics), they are at higher risk of hospitalization especially if they get infected in the later stage of pregnancy. Pregnant women with co-morbid conditions like obesity, asthma, diabetes, renal or cardiac diseases, and immune suppressive disorders are at higher risk if they get an influenza infection at any stage of pregnancy.
Effects of infection on pregnancy outcome:
Influenza fever in pregnant mothers will have the following risks
*Preterm delivery
*Stillbirth (death or loss of a baby before or during delivery)
*Infant death
*Low birth weight
Although maternal antibodies which are transferred from mother to child give protection to the newborn in the initial month of life, severe maternal influenza infection may have detrimental effects. These infants have a high risk of pneumonia and ICU care.
To conclude:
To avoid these influenza infections follow the necessary preventive measures for flu and protect yourself and your family from infections. Elderly people, children, pregnant women, and adults with decreased immunity should avoid crowded places to safeguard them from infections. Additionally, protect yourself from seasonal flu in Tamilnadu by getting vaccinated.
