CHENNAI: H1N1, commonly known as swine flu, is seeing a rise in cases across several parts of India during the monsoon season. While most people recover without major complications, the infection can become serious in some cases. Here is everything you need to know about swine flu, including its symptoms, causes, treatment, vaccination and prevention.
Swine flu is an illness caused by influenza viruses that can infect both pigs and humans. In people, infections are most commonly associated with the H1N1 strain of influenza A. The illness primarily affects the respiratory system and can range from mild symptoms to serious complications.
The H1N1 virus found in humans shares genetic similarities with viruses that circulate among pigs. Other influenza strains, including H1N2 and H3N2, have also been detected in pigs and have occasionally infected humans.
H1N1 gained global attention in 2009 when the virus spread rapidly among people and resulted in a pandemic. Since then, H1N1 has continued to circulate as one of the viruses responsible for seasonal influenza. Because many people have developed immunity through previous infections and vaccination, health experts generally view the current H1N1 risk differently from the situation during the 2009 outbreak.
Nevertheless, influenza viruses that cross from animals to humans remain a public health concern. Researchers continue to monitor such viruses because their behaviour and impact on humans can change over time.
H1N1 infection can produce symptoms that are similar to those associated with seasonal influenza.
Common signs include:
Fever
Cough
Sore throat
Headache
Body pain
Chills
Fatigue
Some people may also experience vomiting or diarrhoea, although these symptoms are less frequent.
Serious illness can occasionally result in breathing problems, respiratory failure or death. However, most infected people experience relatively mild illness and recover without major complications.
Certain groups face a greater possibility of developing severe disease. These include young children, elderly people, pregnant women and individuals whose immune systems are weakened.
Following the 2009 H1N1 pandemic, scientists developed vaccines specifically to provide protection against the virus. Protection against H1N1 is now incorporated into seasonal influenza vaccination.
Flu vaccines are reviewed and updated regularly because the strains circulating in the population can change. Health authorities assess which influenza viruses are expected to be prevalent during the upcoming season and adjust vaccine formulations accordingly.
The US Centers for Disease Control and Prevention recommends annual influenza vaccination for most people aged six months and above, subject to certain exceptions. People with specific health concerns should consult a medical professional about vaccination.
Most people infected with H1N1 improve without requiring extensive medical treatment.
Doctors may prescribe antiviral medicines in certain situations. These medications can help reduce the length and intensity of the illness, particularly when treatment is started promptly.
Antiviral treatment may be particularly important for people who:
Develop serious symptoms or complications
Require hospitalisation
Face a higher-than-usual risk of complications
How can swine flu symptoms be managed at home?
People with mild flu symptoms can take several measures to support recovery and reduce the possibility of spreading the infection.
These include:
Getting adequate rest
Drinking sufficient fluids
Eating nutritious, balanced meals
Using appropriate over-the-counter medicines for symptom relief
Washing hands frequently
Avoiding close contact with people who are unwell
Cleaning commonly touched surfaces
Managing stress
Maintaining regular physical activity when well enough to do so
People experiencing flu symptoms should avoid attending work or school until they have recovered sufficiently.
H1N1 can spread between people through respiratory droplets released when an infected person coughs, sneezes or talks. Close contact with an infected individual can increase the likelihood of transmission.
People who work closely with pigs may also be exposed to influenza viruses circulating among animals. Infections that pass between animals and humans are known as zoonotic infections.
Certain groups are more likely to contract influenza or develop complications after infection.
They include:
Adults aged 65 and above
Children younger than five
Pregnant women
People living with diabetes, HIV, cancer or other conditions that weaken immunity
Individuals with long-term lung conditions such as asthma
People with chronic heart problems, including heart failure
Those with weakened immune systems
Children affected by neurological disorders
When influenza is suspected, a healthcare professional may recommend testing to determine whether the patient has flu.
Rapid influenza diagnostic tests can detect influenza viruses, although their accuracy can vary. A negative result does not always rule out infection.
Specialised laboratories can perform more sensitive tests when confirmation is necessary. However, many patients do not require extensive testing because the recommended treatment may remain the same regardless of the specific test result.
People with influenza can take several precautions to reduce the spread of the virus.
They should:
Minimise close contact with other people while sick
Stay away from work or school during the symptomatic period
Cover the nose and mouth while coughing or sneezing
Use a tissue when possible and dispose of it immediately after use
Wash their hands regularly
Keep frequently touched areas clean
Follow medical advice and prescribed treatment
Annual influenza vaccination can also provide protection against several circulating flu strains.
People whose occupations involve regular contact with pigs or other animals should follow recommended workplace health and safety measures. They should ensure that pigs receive appropriate vaccinations, seek veterinary assistance when an animal appears unwell and avoid handling animals showing signs of illness.
No. Swine flu is transmitted primarily through respiratory droplets and contact with contaminated surfaces. Eating pork that has been properly cooked does not cause H1N1 infection.