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H3N2 Flu: Symptoms, Diagnosis, Treatment & Prevention

Home > Blogs > H3N2 Flu: Symptoms, Diagnosis, Treatment & Prevention

H3N2 Flu: Symptoms, Diagnosis, Treatment & Prevention

Internal Medicine | Posted on 04/28/2023 by Dr. Rahul Mathur

Whenever weather and climate come, they bring countless illnesses along with them and H3N2 is one of them. Cold, fever, and flu are the first ones to arrive. H3N2 also known as the influenza virus was first found in pings over a decade ago. Since then numerous sporadic outbreaks have been reported, but all of them were because of the transmission from pigs to humans. It has happened for the first time ever that H3N2 has been reported in various countries like India. 

In India, there are a few reasons like low vaccination rates and heavy pollution. The country has two main seasons for the outbreak of flu which is November and February including monsoon season as well. According to a study, it is discovered that H3N2 causes serious infection and disease in individuals who are over 65 and children below five years. 

We will discuss in detail about H3N2 symptoms, diagnosis, treatment, and precautions in this write-up. So, make sure you read till the end. However, kindly note that the information we are providing in this blog is completely for informational purposes only and doesn’t rule out consulting a healthcare professional in any way. Get in touch with an internal medicine expert if you face any medical issues.

What is H3N2?

The H3N2 is an influenza virus also known as Hong Kong flu causing respiratory diseases in people. It has already created havoc in the past because of its outbreak. India has reported a significant increase in the number of H3N2 cases. It is causing symptoms like coughing, prolonged sickness, and many other symptoms. It is a contagious disease and spreads because of droplet infections such as Covid-19 and other seasonal flu. One can catch the virus by coming in contact with an infected surface and touching the eyes, mouth, nose, or face. Since it is a contagious illness, one can catch it by coming in contact with an infected person. After the symptoms develop, they might last for around five to seven days. 

What are the H3N2 symptoms?

The H3N2 symptoms are very much similar to those of the influenza virus. One must get in touch with the doctor immediately if the following symptoms are experienced:

  • Fever 
  • Severe chills 
  • Stuffy nose
  • Body pain 
  • Severe cough 
  • Sneezing 
  • Headaches

Is there a vaccine for H3N2 flu?

Flu vaccines are useful in preventing illnesses and symptoms in people. However, it is unfortunate that for H3N2 no vaccination is available at present. 

How long does the H3N2 virus last?

Firstly, one must know that he/she is contagious if they have the H3N2 flu from the day it starts to five days and after the symptoms begin to appear. The virus stays in the body for around 5-7 days and in some cases, one might begin to feel better within five days but it can go up as well in severe cases.

How is the H3N2 virus diagnosed?

There are certain signs of the H3N2 virus which are similar to other respiratory illnesses such as cold. It can be difficult to detect the virus by just looking at the physical signs as a lot of illnesses pose similar symptoms like Covid-19. Hence, the only way to diagnose H3N2 disease is through a blood test. An expert will order the test and once the results are out, the doctor will determine whether the person is infected with influenza H3N2 or any other illness. However, in case, if someone is exhibiting flu-like symptoms, then the doctor might make a diagnosis of the disease even without a lab test.

How is the H3N2 virus treated?

The H3N2 treatment entirely depends on an individual’s symptoms and their severity. Any seasonal flu or H3N2 virus caused by the influenza virus can be easily treated by managing the symptoms. There are various ways that will be included by the doctor for H3N2 treatment such as:

  • Including plenty of liquids
  • Getting enough sleep
  • Taking OTC or over-the-counter medications for relieving the symptoms like body pain, headache, fever, and chills.

In certain cases of H3N2, there are antivirals such as peramivir, baloxavir, and oseltamivir which are recommended by the doctor. After including antiviral medications within 48 hours of developing flu-like symptoms, they can help in shortening the disease and preventing complications.

It is recommended to seek immediate medical help if someone is falling into high-risk categories like:

  • Pregnant females
  • Adults who are above 65 years of age
  • Children under five years of age
  • People have conditions such as asthma, heart conditions, pneumonia, diabetes, and a weak immune system. 

What are the tips for H3N2 prevention?

If you want to safeguard yourself, then here are some tips for H3N2 prevention:

  • Make sure to get yourself vaccinated for the influenza virus
  • Make sure to wash your face, hands, eyes, and nose often or after using the washroom
  • Don’t visit crowded places where the virus can spread quickly like public transportation, offices, schools, etc.
  • Keep your distance from ill people as much as possible
  • Always cover your face while coughing or sneezing 


H3N2 is one of the most serious viral infections causing significant morbidity and mortality, specifically in susceptible populations like children and elderly people. The best way for preventing the flu and complications related to it is to use preventative measures such as hand washing regularly, avoiding contact with infected people, etc. since there is no vaccination available for H3N2. One can test themselves if they have contracted H3N2. 

If you are diagnosed with H3N2 and aren’t certain about which internal medicine doctor to consult, then Rukmani Birla Hospital, Jaipur, one of the best multispeciality hospitals, is your one-stop solution. With the assistance of talented and experienced healthcare professionals, you will not only receive the treatment that’s suitable for you, but they will also ensure that they offer the best patient care.


Can you get h3n2 twice?

Yes, it is possible to get the H3N2 virus twice because there are two types of influenza i.e. influenza A and influenza B. 

How long does h3n2 flu last?

H3N2 lasts for around five days to seven days. 

Is h3n2 swine flu?

It is sometimes called swine flu because it is contracted through pigs and is a type of influenza A virus.