H3N2: Respiratory Illnesses Caused By H3N2 Influenza

India has been experiencing a significant increase in H3N2 influenza cases, with an alarming increase in admissions to intensive care units.

The latest data from the Union Health Ministry indicate that up until March 9th, 2023, there have been 3038 laboratory-confirmed cases of several influenza subtypes, including H3N2.

A significant increase in ICU admissions has been observed in India as a result of the rise in H3N2 influenza cases [1].

The Union health ministry reported that approximately 92% of patients presented with fever, 86% with cough, 27% with breathlessness, 16% with wheezing, 16% with pneumonia, and 6% with seizures. About 10% of patients required oxygen, and 7% required intensive care [2].

Respiratory Illness Caused By H3N2 Influenza

A number of factors have caused experts around the world to be concerned about H3N2v, and one of the main reasons is that it can lead to severe respiratory illnesses. Below are a few of the respiratory illnesses caused by H3N2:

1. Pneumonia

Pneumonia is an infection of the air sacs in one or both lungs, which causes a cough, chills, fever, and difficulty breathing.

In some cases, seasonal influenza may result in complications such as pneumonia [3].

There is a wide spectrum of severity associated with pneumonia, ranging from mild to life-threatening. The most serious cases occur in infants, young children, seniors, and those with weakened immune systems.

2. Chronic obstructive pulmonary disease (COPD)

COPD is a chronic inflammatory lung disease that causes obstruction of airflow from the lungs. Signs and symptoms of COPD include breathing difficulties, coughs, mucus production and wheezing.

Among patients with COPD, influenza infections are associated with an increased risk of ischemic stroke, pneumonia, respiratory failure, and acute exacerbations of their condition [4].

3. Pulmonary fibrosis

When the lungs become damaged and scarred, pulmonary fibrosis occurs. This thickened, stiff tissue makes it more difficult for the lungs to function in a proper manner. As pulmonary fibrosis worsens, you become progressively more breathless.

According to numerous studies, viruses such as the influenza virus cause long-term damage to the lungs and remain risk factors for pulmonary fibrosis for many years following infection [5].

4. Asthma

When you suffer from asthma, your airways narrow and swell, producing extra mucus, which can make breathing difficult and cause coughing, wheezing (whistling) sounds when you breathe out, and shortness of breath [6].

Asthmatics are at high risk of developing complications from the influenza virus, yet most of them do not receive an annual influenza vaccination. Children and adults with asthma should also receive influenza vaccinations.

On A Final Note...

The Indian Council of Medical Research (ICMR) has advised patients to drink plenty of fluids, avoid touching their eyes and noses, and take paracetamol only for fevers and body aches.