Avian Flu Symptoms
Author: Frank Vanderlugt

Avian influenza viruses are usually type A viruses found mainly
in birds, but infections can occur in humans. Not all bird flu
strains produce serious illness, but the current H5N1 strain is
unusually pathogenic and has been shown to be transmissible to
humans.

Unlike most bird flu viruses, the H5N1 virus can be passed
easily from birds to humans without first incubating in other
animals such as pigs. Most cases have been traced directly to
contact with sick poultry, and human-to-human transmission
appears to have occurred in at least one instance. According to
the World Health Organization, as of July 26, 2006 there have
been 232 cases of flu worldwide, mostly in Southeast Asia. More
than half the cases have been fatal. These statistics include
only cases in which diagnosis has been confirmed by lab tests.
However, the true incidence may be higher, and the true death
rate lower, since cases of severe illness or death are most
likely to be diagnosed and reported, while milder cases go
unnoticed and unreported.

Infected birds shed influenza virus in their saliva, nasal
secretions, and feces. Domesticated birds may become infected
through direct contact with other birds or through contact with
contaminated surfaces, water or feed. There are two main forms
of avian flu that are distinguished by low and high extremes of
virulence. The "low pathogenic" form can go undetected and
usually causes only mild symptoms in birds, such as ruffled
feathers and decreased egg laying. However, the highly
pathogenic form spreads rapidly through poultry flocks, affects
multiple internal organs and has a mortality rate of up to
90-100% within 48 hours. The virus can persist for more than a
month in infected materials such as bird feces.

Symptoms of avian influenza in humans have ranged from typical
human influenza-like symptoms such as cough, fever, sore
throat, and muscle aches to eye infections, pneumonia, severe
respiratory distress, and other severe and life-threatening
complications. The symptoms of avian influenza may depend on
which virus caused the infection. In many patients, the disease
caused by the H5N1 virus follows an unusually aggressive
clinical course, with rapid deterioration and a high risk of
death.

The incubation period of avian flu in humans is longer than the
usual seasonal flu, perhaps up to 18 days, though usually less
than a week. Initial symptoms include a fever higher than 38
degrees C, and the systemic malaise typical of influenza.
Unlike typical flue, symptoms can also include watery diarrhea,
vomiting, abdominal and chest pain, and bleeding from the nose
and gums. In two Vietnamese patients, the clinical diagnosis
was acute encephalitis, as neither patient had respiratory
symptoms when first evaluated by medical staff. In a case from
Thailand, the patient had fever and diarrhea, but no
respiratory symptoms.

However, most commonly patients have symptoms in the lower
respiratory tract when they first seek treatment, and almost
all develop viral pneumonia unresponsive to antibiotics.

Evidence suggests that some antiviral drugs, such as
oseltamivir (Tamiflu), can reduce the duration of viral
replication and improve survival, provided they are
administered within 48 hours following onset of symptoms.
However, given the high mortality rate of H5N1, and evidence of
long-lasting viral infection in this disease, administration of
the drug should also be considered later in the course of the
illness.


About The Author: Frank Vanderlugt is interested in flu.
http://www.avian-flu-symptons-now.com