West Nile Cases Triple in One Week
Virus Quickly Spreading Westward, Worst May Be Yet to Come
WebMD News Archive
Aug. 7, 2003 -- This year's West
Nile virus outbreak is already outpacing last year's and showing some
disturbing new trends that have health officials reaching for the mosquito
According to the CDC, the number of people
infected with the West Nile virus has more than tripled in the last week alone
to at least 164 people in 16 states compared to only 112 cases in four states
that were reported at this time in 2002. So far this year, the CDC attributes
four deaths to the virus.
"The bottom line is that it's here, it's happening in a lot
of jurisdictions, every sign indicates that it's on the increase, and now is
the time to for people to step up their efforts to fight the bite," says
CDC Director Julie Gerberding in a telebriefing today.
Gerberding says that so far all 164 West Nile cases have been
attributed to mosquito bites, and the disease does not appear to be spreading
through other means. The CDC recently began screening the blood supply for the
West Nile virus to prevent transmission of the virus through infected
Disturbing New Trends
Aside from outpacing last year's outbreak, officials say the
West Nile virus also appears to be acting in some other troubling new ways.
In previous years, the virus primarily affected older people
and caused the most serious illness in senior citizens. So far this year, the
average age of Americans infected with the West Nile virus is 45 compared to 55
in last year's outbreak.
Gerberding says it's too early to draw conclusions about the
age of West Nile victims, and that change might be due to better reporting of
milder cases of West Nile illness among younger people.
The West Nile virus causes two types of illnesses in humans:
brain swelling disorders known as encephalitis or meningitis that are
responsible for most of the deaths attributed to the virus, and a less serious
flu-like West Nile fever that may not require hospitalization.
Virus Spreading Westward
The first U.S. cases of West Nile virus in humans were
discovered in the Northeast in 1999 but since then the virus has quickly spread
across the country. Last year, several states in the Midwest and South were
among those hardest hit by the virus, and now the virus appears to be spreading
For example, last year at this time Colorado had yet to report
a single case of West Nile virus infection in humans. But this year, Colorado
has reported nearly four times as many cases of West Nile virus infection in
humans than any other state with at least 72 reported cases, including at least
one death. Texas has had the second highest number of cases with 29 cases so
far and at least two deaths. Alabama makes up the last of the states to have a
West Nile virus death reported so far this year.