When should you consult a doctor?
How does a doctor diagnose flu?
Influenza is usually recognisable to health care professionals by the symptoms and signs alone.
Symptoms like a high fever, a dry cough, often nasal congestion and aching limbs, make a diagnosis of flu very apparent. If it is known that flu is active in the community, then the diagnosis of flu becomes even more probable.
The when and how of laboratory tests
It is uncommon for laboratory tests to be done. However, in young children, influenza is easily confused with Respiratory Syncitial Virus (RSV) infection, the para-influenza viruses or adenovirus.
Laboratory diagnosis of a viral respiratory illness might be attempted for one of the following reasons:
How is a laboratory test done?
A throat or nose swab would usually be collected for a laboratory test. Influenza viruses have traditionally been cultured in the chick embryo inside a hen's egg. Nowadays, most laboratories use cell cultures to grow the virus. The specific virus strain or bacteria can be identified with these tests.
How can a doctor treat flu?
When should you take antibiotics?
The short answer is: when your doctor prescribes it. Antibiotics are only useful in treating secondary bacterial infections when you have the flu. About 5% of colds develop into secondary bacterial infections.
Remember to complete the course of antibiotics. There is a real concern that people do not complete the full course, or take antibiotics incorrectly (and not according to a doctor's instructions). The incorrect usage of antibiotics is one of the main reasons for the increase in antibiotic resistant "superbugs".
Antiviral drugs
Amantadine (tradename = Symmetrel) and rimantadine (tradename = Flumadine) are two similar drugs that have been available for many years. They are effective against influenza A only, and work by preventing the virus from uncoating inside cells, with the effect that it is unable to multiply.
Amantadine and rimantadine can prevent flu in unvaccinated, at-risk people during outbreaks and are of some benefit as treatment if started early. Due to their severe side-effects on the brain and gastro-intestinal system, and the quick emergence of drug-resistant flu viruses during treatment, these drugs are not often used, and very seldom used in South Africa.
Scientists have developed an exciting new generation of antiviral drugs specifically against the Influenza viruses A and B. These new drugs, already in use in the USA and Europe, are zanamivir (Relenza by GlaxoWellcome) and oseltamivir phosphate (Tamiflu by Roche), which are now both available in South Africa.