What is viral fever ?
In medical terms, any fever caused as a result of viral infection is a viral fever. However, colloquially, the term 'viral fever' has come to mean a special type of fever that develops and then gets treated without the offending virus being specifically identified. The course and duration of the fever too does not seem to follow any set pattern and is frequently accompanied by, though not always by all of them, generalised bodyache, running nose, cough, shivering, feeling miserable, irritable and depressed.

How long do they last ?
Normally between 3 to 7 days with the former being termed as the 'three day fever' and the latter as the 'seven day fever'.

What are the symptoms?
Once the virus enters the body, there is an incubation period when the virus multiplies to a level high enough to cause infection. This is followed by a phase of fatigue and body and muscle aches that may lead to the onset of fever. The fever may be low grade or high grade. Inflammation of the throat, a running nose, nasal congestion, headache, redness of the eyes, cough, muscle and joint pains and a skin rash could be present. Fatigue and body pain could be disproportionate to the level of fever, and lymph glands in the neck may swell up. The illness is usually self-limited but the fatigue and cough may persist for a few weeks. Sometimes pneumonia, vomiting and diarrhoea, jaundice or arthritis (joint swelling) may complicate the initial viral fever. Some viral fevers are spread by insects, for example, arbovirus, and can cause a bleeding tendency, which results in bleeding from the skin and several other internal organs and can be fatal.

>>How is it diagnosed?
The diagnosis and management of viral fevers is based on the clinical presentation rather than on laboratory investigations. The diagnosis is made by the typical history of fever with severe muscle and joint pains. Skin rash and lymph gland swellings have to be specifically looked for. Laboratory investigations are undertaken to rule out other bacterial infections rather than to confirm viral fever. Blood tests will not show any increase in the white blood cells, which typically occurs with bacterial infections. The numbers of lymphocytes may be increased. The erythrocyte sedimentation rate (ESR) may be elevated. Confirmation of the fever is done by a culture of virus from the relevant specimens such as nasal swabs, and skin rash or by increase in antibody levels in serial blood samples.

>>What medicines should one take ?
This must be decided by your medical doctor. Therefore, the doctor should be consulted without delay and his advice followed diligently. However, it is noteworthy at this point the famous saying 'a viral fever usually gets treated in 7 days with medications and in a week without any'. But without prejudice, please consult your doctor as a matter of routine! Normally, treatment is given for specific complaints like fever, headache, running nose, cough, etc.

>>What are the precautions that one must take ?
Remember that any viral fever causes the body immune system to be severely tested. Therefore, the more danger arises as a consequence of having the viral infection than from the specific infection itself. Cough is usually not a good sign and chest infections caused by bacteria (like pneumonia) are quite common - especially in the young and old. Therefore, your doctor would normally prescribe some antibiotics which strictly are not indicated in viral fevers and they are known to cause more harm than good unless absolutely indicated.

>>How can one avoid getting these infections ?
Frankly, there is very little chance of avoiding these. Though several vaccines have been developed and successfully tested, particularly in the USA where these infections, when they have occurred have lead to severe epidemics and fatalities, largely the causative viral strains are unknown and having them once does not guarantee any immunity from further infections, especially in the sub-continent. The best methods to be followed are staying away from persons who are sneezing and coughing, particularly during season-change and having a sound body constitution helps. Try not to use tissue papers and handkerchiefs of the suffers and dispose or wash them as hygienically as possible.

>>Are any preventive measures available ?
As has been entailed above, some shots are indeed available, especially for influenza. Unfortunately, since many a times one really does not know what causes the fever in the first place and the disease is cured before any confirmed diagnosis as to the cause can first be made, and also since the offending virus more often than not mutates into a new variety against which there are no effective vaccines are available. Therefore, it is not always easy to take immunisation shots beforehand and be free from getting a viral fever.
Do consult your doctor for further guidance and advice in this matter.