While the number of people being diagnosed with swine flu continues to rise steadily around the globe and in South Africa, Dr Pete Vincent of Netcare Travel Clinics maintains that there is still no need to panic as most people who contract this H1N1 virus recover fairly quickly.

"Although we have seen fewer confirmed cases of swine flu in our country than most countries around the world the number of people infected with the virus is gaining momentum.

"For example, a number of school groups in the Western Cape that have travelled abroad during the July holidays have returned with the virus thereby introducing it into their communities. This is probably equally true elsewhere in the country where travellers continue to be the main carriers of the H1N1 virus," says Vincent.

Learning about the virus

The upside of the evolution of the flu is that the more the virus spreads, the more our understanding of the disease evolves.

Every time a new country is added to the list and as community level spread extends in impacted countries, this information is shared globally and we continue to learn more about this virus.

The World Health Organisation is placing increasingly more emphasis on monitoring people with the H1N1 virus and is actively reporting trends in the activity of the disease.

According to the World Health Organisation (WHO), the average age of people who contract the H1N1 virus is also showing a slight increase. The average age of people reported is 12 to 17 years. However, there have been global reports that persons who require hospitalisation and patients, who do die from the virus, may be slightly older.

This differs from the usual seasonal influenza pattern, where fatal disease occurs most often in people older than 65 years.

No final answers

"We do however not have the final answers on this virus as it is still relatively early in its development," adds Vincent while pointing out that the risk factors for contracting a serious case of swine flu have now definitely been determined by the WHO.

"Illnesses such as existing cardiovascular disease, respiratory disease, diabetes and cancer are currently considered risk factors. Asthma and other forms of respiratory disease have been consistently reported as underlying conditions associated with an augmented risk of severe pandemic disease in several countries."

According to the WHO, recent reports suggest obesity may be another risk factor for severe H1N1 infection. Pregnant women also seemed to be at higher risk for more severe disease. The more information the WHO accumulates on the disease, the better are their chances of developing an effective vaccine against the H1N1 virus.

"Work has also commenced to manufacture a H1N1 vaccine which should be available overseas around September," says Vincent.

South Africans affected by the disease with severe symptoms have been treated with oseltamivir (brand name Tamiflu and Cipla Oseltamivir) and zanamivir (brand name Relenza) with great success.

"If you have severe flu-like symptoms, it's recommended you see your doctor as soon as possible. Depending on the severity of your symptoms, you should be tested for swine flu," he adds.

How the H1N1 flu works

Influenza is an infectious disease caused by viruses which affect birds and mammals (common reservoirs of flu strains are ducks and pigs ? which is why some virulent strains have arisen in the Far East, where humans often live in close contact with their animals like ducks and pigs).

Flu is spread by contact with bodily fluids containing the virus (it spreads through the air when someone sneezes, or you can be infected by touching a surface someone with flu has touched, for instance in a bathroom or hand rail).

"Strictly speaking we shouldn't be calling this swine flu at all," says Vincent.

"Because of the misguided threats to pigs it is officially been called Novel H1N1 flu virus. It's a strain which appears to have human, avian and swine elements."

New strains of flu are constantly evolving, and each year we are likely to encounter a strain that differs slightly from the one we had the previous year.

Medical scientists create flu vaccines using the strains which are prevalent in the opposite hemisphere: so, for instance, they assume that we in our South African winter will be infected by the same strain that the Europeans have just battled in their winter, and they create vaccines containing the European flu strains.

Flu kills people every year

Scientists and epidemiologists have long known that flu can be a dangerous illness ? every year it kills a number of people, usually the elderly, infants or people with compromised immune systems.

History has shown that periodically a mutation will arise, making a flu strain more deadly.

The facts:

• The pandemic A(H1N1) influenza (flu) virus (germ) is a new member of the influenza virus family. Different influenza viruses cause the annual seasonal (winter) flu and, every few decades, a global pandemic.
• Seasonal human influenza results in 6000 to 10 000 deaths every winter in South Africa and between 250 000 to 500 000 deaths globally, mostly in people over 65 and those with certain chronic medical conditions.
• During pandemic influenza many of the deaths occur in younger and apparently healthy individuals. The number of deaths during an influenza pandemic varies greatly, depending mostly on the virulence of the virus, but also on factors like crowding, individual health, access to healthcare, and preventive measures.

How does the flu virus spread?

Influenza viruses are very infectious. It is almost impossible to stop influenza viruses, whether seasonal or pandemic, from spreading from person to person mainly through coughing or sneezing by infected people.

Touching surfaces such as counters and doorknobs with influenza viruses on them can also infect people and afterwards their mouth, nose or eyes. This is why handwashinghelps. However influenza viruses are very infectious and all precautions can only decrease, but not eliminate, risk.

How can the spread be limited?

You can reduce the risk of getting or spreading flu by:

• Washing your hands or clean them with alcohol-based hand rubs frequently, especially after you cough or sneeze and before you eat.
• Covering your nose and mouth with a clean tissue when you cough or sneeze, and throw the tissue in a rubbish bin immediately after you have used it.
• Alternatively, cough and sneeze into your sleeve.
• Avoid touching your eyes, nose or mouth, as you could infect yourself that way.
• Limit close (one- to two-metre) contact with people who are sick with flu.
• If you get sick, stay at home and limit contact with others to keep from infecting them.

Symptoms of an influenza like illness:

These are the same for pandemic and seasonal influenza.

Typical symptoms include a sudden onset of high fever, cough, runny or stuffy nose, sore throat, headache, body aches, chills, tiredness, and lack of appetite. Some of those affected have reported nausea, vomiting, and diarrhea.

Who is at risk of complications

• Persons (adults or children) with underlying medical conditions and who are receiving regular medical care for chronic pulmonary disease (including asthma) and cardiac disease (excluding hypertension), chronic renal and hepatic diseases, diabetes mellitus and similar metabolic disorders.
• Individuals who are immunosuppressed (HIV-infected, on immunosuppressive therapy, etc.)
• Adults and children who have any condition (e.g. difficulty in understanding, spinal cord injuries, seizure or other neuromuscular disorders) which make it difficult to cough and are at risk of inhaling respiratory secretions.
• Children and adolescents on aspirin therapy and at risk of Reye's syndrome if contracting any kind of flu.
• Residents of nursing homes, and other chronic-care facilities.
• Pregnant women.