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WSWS : News
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America
West Nile Fever spreading throughout US
By Walter Gilberti
23 August 2002
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The outbreak of illnesses associated with the West Nile virus
has reached epidemic proportions, with new cases reported in Ohio,
Illinois, Maryland, New York City, Michigan and Georgia. In Georgia
two men, a 51-year-old and a 76-year-old died, on Thursday.
Across the country the number of cases is over 250 and rising.
Last week, the director for the Centers for Disease Control (CDC),
Dr. Julie Gerberding, characterized this summers record
number of cases as an emerging infectious disease epidemic.
The virus has crossed the Mississippi River, with cases reported
in Missouri and infected livestock and birds in Colorado and Wyoming,
making it only a matter of time before it reaches the West Coast.
Infected birds have also been found in southern Ontario, but as
of yet there have been no reported cases of the fever among humans
in Canada.
Already at least 13 deaths have been attributed to the virus:
eight in Louisiana, two each in Mississippi and Georgia and one
in Illinois. This number surpasses the total number of deaths
for last year, and the peak period for the disease is still two
weeks away.
According to Lyle Petersen, an expert on the West Nile virus
at the CDC, the number of seriously ill people could exceed 1,000,
with 100 dying from the disease. Its safe to assume
we can expect more cases, and potentially a lot more cases,
he said. It is likely that only the end of summer will halt the
spread of the disease in most states.
At the end of last week, Petersen reported that at least 160
people in nine states and Washington DC had been hospitalized
with serious and even life-threatening symptoms, including brain
infections, meningitis and encephalitis. Scientists have yet to
determine why 147 of these more serious cases62 new cases
the previous weekare clustered in the state of Louisiana.
The seriousness of the outbreak in that state prompted Louisiana
state epidemiologist Raoult Ratard to comment, An epidemic
this size is like a hurricane. If you dont take shelter,
you may be swept away.
What has alarmed some researchers who have followed the history
and etiology of the virus since it first appeared in New York
City in the summer of 1999 is that the age range for serious illness
has dropped considerably, an indication that the virus is becoming
more virulent. The median age for contracting West Nile encephalitis
is currently 55, which is 10 years younger than the median age
at the time of the 1999 outbreak. Two new cases in the Chicago
area last week involved women in their forties.
Where the disease has established itself over a longer period
of timeNorth Africa, the Middle East and parts of Eastern
Europethe frequency of its more severe manifestations has
increased. Because the disease in its milder form may show no
symptoms, or be confused with other ailments, it is very difficult
to ascertain what percentage of the populations of these regions
is actually infected.
While infants and the elderly continue to have the greatest
risk of mortality from the virus, any person with a compromised
immune system is threatened. The vast majority of individuals
who contract the virus develop immunity to the disease, although
it is not clear whether this immunity is life-long.
The disease is often called West Nile Fever, which is a generic
term for a non-contagious illness exhibiting a variety of symptoms
that range from mild flu-like aches and fever, sometimes accompanied
by a rash, muscle weakness and malaise, to life-threatening infections
of the brain (encephalitis) and its outer covering (meningitis).
The effects of the illness can be long-term, with some survivors
of the original outbreak still suffering from muscle weakness,
memory loss, sleep impairment and depression.
The West Nile virus is a mosquito-borne pathogen belonging
to a family of viruses called flaviviridae (Genus Flavivirus).
While foreign in origin, the West Nile strain is related to US-based
viruses that cause Eastern Equine Encephalitis (EEE) and St Louis
encephalitis. Last year there were four deaths in Louisiana from
the latter disease. Another term associated with the West Nile
virus and its relatives is Arbovirus, because of its penchant
for attacking the brain and central nervous system.
Scientists are not certain how the virus reached North America,
since it appears to use mosquitoes of the Genus Culex as its vector.
While the cycle for the transmission of the virus involves its
being passed from an infected bird to a mosquito, and then to
a human, it is as yet unclear how the bird becomes infected. What
makes the current outbreak unusual, when compared to transmission
cycles of the disease in other parts of the world, is that only
in Israel has West Nile been associated with infected birds.
The West Nile virus was first isolated in 1937 by doctors testing
a woman for African sleeping sickness in the West Nile district
of Uganda. Since then it has made its way throughout much of Africa,
Asia and Europe, and is one of several viruses that make up the
Japanese Encephalitis Serocomplex.
There is no vaccine or cure for West Nile disease. However,
the US Food and Drug Administration has begun tests in New York
City with the drug interferon. Interferon has shown some promising
results in combating the virus that causes Hepatitis C, and in
the treatment of Kaposis sarcoma in AIDS patients.
Viruses, unlike bacteria, lack cellular structure, and are
for this reason not considered to be living organisms, which is
probably why they are generally unresponsive to antibiotics. A
West Nile fact sheet produced by the CDC explains that treatment
for West Nile encephalitis would include hospitalization,
intravenous fluids, airway management, respiratory support (ventilator),
prevention of secondary infection (pneumonia, urinary tract, etc.),
and good nursing care. The last factor may become critically
important in the event of West Niles spread, since there
is an acute nursing shortage in many US hospitals.
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