fever refers to a broad spectrum of conditions where viral
infections are associated with elevations of body temperature.
The term encompasses a wide variety of viral infections,
some of which can be clearly identified by their symptoms
and signs. These viral infections may show generalised symptoms
but may target specific organs.
body aches and a skin rash characterise most of these viral
fevers. They may affect any age group and are seen world-wide.
They require only symptomatic treatment. Some are highly
contagious. Most of them are not dangerous and self-limited,
but some can progress rapidly leading to death.
Most viral infections are spread by inhalation of aerosolised
particles, by intake of contaminated water or food, or by
direct contact. Infection then spreads locally and thereafter
into the blood stream or lymph channels. Some of the viral
infections can be transmitted sexually or by direct inoculation
into the blood stream.
duration of the primary infection may vary from days to
several weeks. Manifestation of the disease clinically is
usually a consequence of the virus multiplying at a specific
site. Even though the fever comes down, in some infections
the virus continues to multiply and cause persistent infection.
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, malaise
and body and muscle aches that may lead to the onset of
fever. The fever may be low grade or high grade and remittent.
Inflammation of the pharynx, 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 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, can cause a bleeding tendency, which
results in bleeding from the skin and several other internal
organs and can be fatal.
The diagnosis and management of viral fevers is based more
on the clinical presentation than by laboratory investigations.
Since these infections are commonly self-limited, investigations
are unnecessary. 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.
Treatment of viral fever is purely symptomatic with antipyretic
and analgesic drugs. Bed rest and adequate fluid intake
is advised. Nasal decongestants may be beneficial. Specific
antiviral therapy is not routinely recommended. Steroids
are not advised as it may lead to bacterial super-infection.
Only in cases of super-infection do antibiotics need to
be prescribed. It is important that antibiotics are NOT
routinely used for prophylaxis. Complications of viral infections
like pneumonia (viral or super-infection by bacteria) need
to be addressed specifically by clearance of respiratory
secretions and utilising ventilator assistance if hypoxia
is severe. Most viral fevers recover completely in a week
although fatigue may persist for a few weeks.
Viral fevers are difficult to prevent. They occur as epidemics
of infection depending on their mode of spread. Vaccines
have been tried targeting the respiratory and gastrointestinal
viruses with little success due to several sub-groups of
viruses with different forms of antigenicity, all of which
cannot be covered with a single vaccine. Fortunately since
most infections are mild and self-limited, we can be assured
of a full recovery.
(R) thedailystar.net 2004