What is swine flu?

Technically, the term ‘swine flu’ refers to influenza in pigs. Occasionally, pigs transmit influenza viruses to people, mainly to hog farmers and veterinarians. Less often, someone infected passes the infection to others.

The human respiratory infection caused by a particular influenza virus H1N1 strain — popularly known as swine flu — was first recognised in spring 2009. A few months after the first swine flu cases were reported, rates of confirmed H1N1-related illness were increasing in much of the world. As a result, the World Health Organisation declared the infection a global pandemic.

The pandemic was declared over in August 2010. Currently, H1N1 is still circulating in humans as a seasonal flu virus and is included in the seasonal flu vaccine.

An outbreak of the virus has claimed more than 1,200 lives in India in recent weeks.

What are the symptoms?

Swine flu signs and symptoms in humans are similar to those of other flu strains:

•Fever

•Cough

•Sore throat

•Runny or stuffy nose

•Body aches

•Headache

•Chills

•Fatigue

•Diarrhoea

•Vomiting

Swine flu symptoms develop about one to three days after you’re exposed to the virus and continue for about seven days.

When to see a doctor

It’s not necessary to see a doctor if you’re generally healthy and develop flu signs and symptoms, such as fever, cough and body aches. Call your doctor, however, if you have flu symptoms and you’re pregnant or you have a chronic disease, such as emphysema or a heart condition.

Causes of swine flu

Influenza viruses infect the cells lining your nose, throat and lungs. The virus enters your body when you inhale contaminated droplets or transfer live virus from a contaminated surface to your eyes, nose or mouth.

You can’t catch swine flu from eating meat.

Risk factors

If you’ve travelled to an area where many people are affected by swine flu (H1N1 flu), you may have been exposed to the virus, particularly if you spent time in large crowds in areas where the virus is active.

Complications from swine flu

Influenza complications include:

•Worsening of chronic conditions, such as heart disease, diabetes and asthma

•Pneumonia

•Neurological signs and symptoms, ranging from confusion to seizures

•Respiratory failure

Treatment and drugs

Most cases of flu, including H1N1 flu, require only symptom relief. If you have a chronic respiratory disease, your doctor may prescribe additional medication to help relieve your symptoms.

The antiviral drugs oseltamivir (Tamiflu) and zanamivir (Relenza) are sometimes prescribed to reduce the severity of symptoms, but flu viruses can develop resistance to them. Some researchers recommend further study on both of these drugs due to uncertainty about their effects beyond the initial reduction in symptoms.

To make development of resistance less likely and maintain supplies of these drugs for those who need them most, antivirals are reserved for people at high risk of complications.

At high risk

High-risk groups are those who:

•Are hospitalised

•Are younger than 5 years of age, particularly children younger than 2 years

•Are 65 years and older

•Are pregnant or within two weeks of delivery, including women who have had pregnancy loss

•Are younger than 19 years of age and are receiving long-term aspirin therapy, because of an increased risk for Reye’s syndrome, a rare but potentially fatal disease

•Have certain chronic medical conditions, including asthma, emphysema, heart disease, diabetes, neuromuscular disease, obesity, and kidney, liver or blood disease

•Are immuno-suppressed due to certain medications

Home remedies

If you develop any type of flu, these measures may help ease your symptoms:

•Drink plenty of liquids. Choose water, juice and warm soups to prevent dehydration. Drink enough so that your urine is clear or pale yellow.

•Rest. Get more sleep to help your immune system fight infection. • Consider pain relievers. Use an over-the-counter pain reliever, such as acetaminophen or ibuprofen, cautiously. Also, use caution when giving aspirin to children or teenagers.

Remember, pain relievers may make you more comfortable, but they won’t make your symptoms go away faster and may have side effects.

— Mayo Clinic