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A cold is a mild
viral infectious disease of the nose and
throat, the upper respiratory system. Common
cold is
different from
influenza, a more severe viral
infection of the respiratory tract that shows
the additional symptoms of rapidly rising
fever, chills, and body and muscle aches. For any type of
cold
your immune system is your
best defense
force. Strengthen your immune system
with Transfer
Factor.
Cold Symptoms
Symptoms of a
cold include sneezing, sniffing,
running/blocked nose (often these occur
simultaneously, or one in each nostril),
scratchy, sore, or phlegmy throat, coughing,
headache, and a general feeling of
unwellness; they last between 3 to 10 days,
with residual coughing lasting up to 3
weeks. Cold is the most common of all
diseases, infecting subjects at an average
of slightly over one infection per year with
greater than 3 infections per year not
uncommon in some populations. Children and
their caretakers are at a higher risk,
probably due to the high population density
of schools and the fact that transmission to
family members or caretakers is highly
efficient.
Pathology of Cold
The common
cold is caused by numerous viruses (mainly
rhinoviruses, coronaviruses and also certain
echoviruses, paramyxoviruses and
coxsackieviruses) infecting the upper
respiratory system. Several hundred
cold-causing viruses have been described,
and a virus can mutate to survive, ensuring
that any cure is still a long way off. These
are transmitted from person to person by
droplets resulting from coughs or sneezes.
The droplets or droplet nuclei are either
inhaled directly, or, transmitted from hand
to hand via handshakes or objects such as
door knobs, and then introduced to the nasal
passages when the hand touches the nose, or
eyes.
The cold virus
enters the cells of the lining of the nasopharynx, and rapidly multiplies inside
them. Nasopharynx being the area between the
nose and throat is the central area infected.
The mouth is not a major point of entry and
cold virus transmission does not usually occur
with kissing or swallowing, whereas the nose
and the eye, through its nasolacrymal duct
drainage into the nasopharynx are the major
entrypoints. The specific localization in the
nasopharynx and avoidance of the throat may
be due to the low temperature here as well as
the high concentration of cells with
receptors needed by the cold virus. The cold virus
enters the cell by binding to ICAM-1
receptors in these cells. The presence of
ICAM-1 affects whether a cell will be
infected and its concentration can be
affected by various things including
allergic
rhinitis and some other irritants including
rhinovirus itself and has been a major focal
point in drug research into treatment.
Ninety-five percent of people exposed to a
cold virus become infected, although only 75%
show symptoms. The symptoms start 1-2 days
after infection. They are a result of the
body's defense mechanisms: sneezes, runny
nose and coughs to expel the invader, and
inflammation to attract and activate
immune
cells. The virus takes advantage of sneezes
and coughs to infect the next person before
it is killed by the body's
immune system.
Sneezes expel a significantly larger
concentration of virus "cloud" than coughing.
The "cloud" is partly invisible and falls at
a rate slow enough to last hours - with part
of the water droplets evaporating and leaving
much smaller and invisible "droplet nuclei"
in the air. Droplets by turbulent sneezing or
coughing, or hand contact can also last for
hours on surfaces, although less virus can be
recovered from porous surfaces such as wood
or paper towel than non-porous surfaces such
as a metal bar. A sufferer is most infectious
within the first three days of the illness.
Symptoms however are not necessary for viral
shedding or transmission as a percentage of symptomless subjects exibit virus in nasal
swabs, likely controlling the virus at
concentrations too low for them to have
symptoms.
After a
common
cold, a sufferer develops
immunity to the
particular virus encountered. Because of the
large number of different cold viruses
however, this immunity is of limited use and
a person can easily be infected by another
cold virus to start the process all over
again.
The term
"cold" is misleading, if "cold" refers to
climatic temperature, as the aetiology is
viral. Climate may affect transmission by
some means, such as by causing people to stay
indoors and increasing the proximity to
infected persons, but the cause of the
infection remains primarily viral. Some
allergies, bacterial respiratory infections
and even climate changes can also cause
common-cold-like symptoms that can last for
days). Whether cold, or humid climate can
affect transmission by other means, such as
by affecting the
immune system, or ICAM-1
receptor concentration, or simply increasing
the amount and frequency of nasal secretions
and frequency of hand to face contact has not
yet been thoroughly tested and is not known.
A person can best avoid colds by avoiding
those who are ill and objects they touch, as
well as keeping their immune system in top
form by getting enough sleep, reducing
stress, eating nutritious foods, and avoiding
excess alcohol consumption. It is perhaps the
case that "cold" refers to a "cold
condition," i.e., the hot, cold, dry and wet
"conditions" described by the ancient Roman
physician Galen. Colds are somewhat more
common in winter since during that time of
the year people spend more time indoors in
close proximity of others and ventilation is
less, increasing the infection risk. Some
factors influence the severity of symptoms,
for instance psychological stress and
position in the menstrual cycle. Also, weak
health in general, or other pre-existing
conditions such as
allergies can be
aggravated due to infection.
For any type of
colds
your immune system is your
best defense
force. Strengthen your immune system
with Transfer
Factor.
Cold Complications
Bacteria that
are normally present in the respiratory
tract can take advantage of the weakened
immune system during a
common
cold and
produce a co-infection. Middle ear infection
(in children) and bacterial sinusitis are
common coinfections. A possible explanation
for these coinfections is that strong
blowing of the nose drives nasal fluids into
those areas. The best way to blow the nose
is keeping both nasal openings open when
blowing and wiping rather than fully
covering them, permitting pressure to
dissipate partly here. This will reduce the
pressure which could drive fluid into the
ears or sinuses where it can cause
infection.

Cold Prevention
The best way
to avoid a cold is to avoid close contact
with existing sufferers, to thoroughly wash
hands regularly, and to avoid touching the
face. Anti-bacterial soaps have no effect on
the cold virus - it is the mechanical action
of hand washing that removes the virus
particles. In 2002, the Centers for Disease
Control and Prevention recommended alcohol
based hand gels as an effective method for
reducing infectious viruses on the hands.
However, as with standard handwashing,
alcohol gels provide no residual protection
from re-infection. In some countries, such
as China and Japan, people with the
common cold wear surgical masks out of courtesy to
protect others.
Because of the
large variety of viruses causing the common
cold, vaccination is impractical.
There is no cure for the
common
cold,
i.e. there is no treatment that directly
fights the cold virus. Only the body's
immune
system can effectively destroy the invader.
A cold may be composed of several million
viral particles, and typically within a few
days the body begins mass producing a better
tailored antibody that can prevent the virus
from infecting cells, as well as white blood
cells which destroy the virus through phagocytosis and destroy infected cells to
prevent further viral replication.
Furthermore the duration of infection is on
the order of a few days to one week so at
most a "cure" could hope to reduce the
duration by only a few days.
For any type of
colds
your immune system is your
best defense
force. Strengthen your immune system
with Transfer
Factor.
Available treatments for
cold therefore
focus on relieving the symptoms.
For some people, even without these
remedies, colds are relatively minor
inconveniences and they can go on with their
daily activities with tolerable discomfort.
This discomfort has to be weighed against the
price and possible side effects of the
remedies, and the possibility, not yet
scientifically proven, that by suppressing
responses evolved to fight the cold, the
symptom supressants may prolong the illness.
Common
cold treatments include: analgesics
such as NSAIDs such as aspirin or
acetaminophen as well as localised versions
targeting the throat (often delivered in
lozenge form), nasal decongestants which
reduce the inflammation in the nasal passages
by constricting local blood vessels, cough
suppressants (which work to suppress the
cough reflex of the brain or by diluting the
mucus in the lungs), and first-generation
anti-histamines such as brompheniramine,
chlorpheniramine, and clemastine (which
reduce mucus gland secretion and thus combat
blocked/runny noses but also may make the
user drowsy). Second generation
anti-histamines do not have a useful effect
on colds.
A warm and humid environment and drinking
lots of fluids, especially hot liquids,
alleviate symptoms somewhat. Common home
remedies include camomile tea, chicken soup,
nebulized medicinal mixtures, hot compresses,
mustard plasters, hot toddies, Licorice,
vitamin C, and Echinacea. Although there have
been scientific studies done on echinacea its
effectiveness has not been demonstrated,
whilst there is some evidence that
Vitamin C
will reduce the length of the infection
(although it will not, as commonly believed,
prevent contracting a cold in the first
place). Coffee, or its active component,
caffeine, has also been shown to improve mood
and mental performance during rhinovirus
infection. Hot beer is also recommended, and
though it probably does little to fight the
infection directly, at least it can help to a
good night of relaxed sleep.
Zinc-containing preparates have been
claimed to be effective in the treatment of
cold infections. Some studies have attributed
this to a placebo effect related to the
strong and unpleasant taste of zinc preparates (Reference: Farr et al. (1987),
while other studies claim that zinc lozenges
are effective in reducing the duration and
severity of common colds.
Zinc nasal sprays, however, claim clinical
proof that they work. The trick seems to be
threefold. One, the treatment has to be a
nasal spray. Two, treatment should be started
at the first sign of a cold before it has the
chance to get established. Three, the type of
zinc must be zinc gluconate usually labelled
as zincum gluconicum. There have been several
hundred lawsuits filed alleging that zinc
nasal sprays may cause permanent damage to
the sense of smell. References:
- Belongia EA, Berg R, Liu K. A
randomized trial of zinc nasal spray for
the treatment of upper respiratory illness
in adults.
- American Journal of Medicine 2001,
p.111, 103–108. Hirt M, Nobel S, Barron E.
Zinc nasal gel for the treatment of common
cold symptoms: a double-blind,
placebo-controlled trial.
- Ear Nose Throat Journal 2000,
p.79,778–781. Mossad SB. Effect of zincum
gluconicum nasal gel on the duration and
symptom severity of the common cold in
otherwise healthy adults.
- QJM. 2003;96:35–43. Zicam, an over the
counter (OTC) product of GumTech
International, has developed a
patent-pending solution in which zincum
gluconicum nasal gel has been utilized to
decrease symptoms and shorten the duration
of the common cold up to 85%.
For any type of
influenza
your immune system is your best defense
force. Strengthen your immune system
with Transfer
Factor.
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