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Covering West Nile Virus (Again)

The Centers for Disease Control and Prevention (CDC) issued an
advisory again this summer warning of the increased risks of mosquito-
borne West Nile Virus, now a familiar enough, though unwelcome,
summer visitor to warrant its own acronym - WNV.

West Nile Virus often has no symptoms or only mild symptoms,
but one in about 150 infected persons develops a serious illness characterized
by high fever, headache, a stiff neck, stupor, disorientation
and other effects that can last for several weeks. Neurological damage
can be permanent.

Casual contact with an infected person does not spread WNV,
and there is no specific treatment. People who spend a lot of time
outdoors in the summer are more likely to be bitten by an infected
mosquito. People more than 50 years old generally develop more
serious symptoms.

The best way to avoid being infected? Prevent mosquito bites,
use repellents containing DEET (N, N-diethyl-meta-toluamide) particularly
at dusk and dawn when mosquitoes are most active. Lightcolored
clothes and good window screening also help, and eliminating
or replacing sitting water, found in places such as bird baths and
children’s wading pools.

Reprinted here is an edited version of a WNV "backgrounder"
initially published in Environment Writer’s May 2000 issue.

Introduction

As the weather warms and mosquito season moves into high gear,
West Nile Virus is making headlines again. This year, the "neverheard-
of-it" syndrome is no excuse for uninformed reporting. Media
have an opportunity for more deliberate coverage and analysis of
this emerging environmental disease

For now, neither panic in the streets nor blasé inattention or inaction
will be the antidote. Journalists instead can report the wealth of
information that is known, in hopes of encouraging timely and effective
public understanding and response.

Why Cover It?

West Nile Virus can make people sick or kill them. Seven people died in
the 1999 Northeast outbreak that severely sickened 62 people. Some 3–
15 percent of all cases are fatal, although fatalities are most likely among
the elderly and those with weak immune systems.

But if the media approach WNV solely as a human health story,
they may repeat the errors of the past in which environmental risks
were viewed primarily from the perspective of potential cancer-causing
impacts, but not a broader ecological standpoint. The public should
understand that the impacts of the virus on wildlife can have systemic
effects on entire ecosystems.

The virus is of news value, in part, because it is fairly new to the
western hemisphere. It is passed along to humans from mosquitoes
that have fed on infected birds, such as crows found throughout the
United States. (Note: Crows do not pass the virus directly to humans.)
http://www.cdc.gov/ncidod/dvbid/westnile/index.htm and
http://www.cdc.gov/ncidod/dvbid/westnile/surv&control 03Maps.htm

Story Ideas

1. What surveillance programs are being conducted in your area to
detect West Nile Virus in humans? (Or for that matter, St. Louis
encephalitis and other "notifiable" diseases.) What are the findings
to date? What is the significance of the findings? Check with state
and local health agencies and the CDC.

2. Take a look at the role birds will play in detecting the disease,
alerting public health officials to hot spots and helping direct mosquito
control operations. What types of birds can be infected by the
virus and what effect could it have on migratory bird populations?
Will migratory birds spread the disease to other parts of the hemisphere
and other species of wildlife?

3. How should people handle dead birds? Who should they call?
Can they touch them? What signs/symptoms should the public be
on the lookout for?

4. What populations of birds or domestic animals and mosquitoes in
your area could take part in the transmission cycle of West Nile Virus?
Who is monitoring those animal populations and how effectively? Will it
spread to warmer climates where it could become established as a yearround
threat to wildlife, domestic animals, and humans?

5. Does your area have mosquito control and abatement programs,
districts, or agencies? How effective are they? What other mosquitoborne
diseases affect people or animals in your area? What mosquito-
control methods are used, and are they preventive or reactive?

6. Is there a truck or aerial insecticide-spraying program in your
area? What insecticides are used? What are the benefits and potential
adverse effects? How, where, and when are the pesticides applied?
What precautions should people take to avoid unnecessary or
harmful exposure to pesticides being sprayed? Have government
agencies and the media been effective in informing people about
those precautions?

7. How can residents protect themselves from mosquitoes and best
suppress mosquito breeding near their homes?

The Virus: Its Effects and How It is Transmitted

West Nile Virus is primarily a disease of birds. It is commonly found
in Africa, West Asia, and the Middle East but has also caused outbreaks
in Europe. In humans, it can cause encephalitis, an infection
of the brain. West Nile Virus is similar to the virus that causes St.
Louis encephalitis, which for years has been found in the United
States. West Nile had not been found in the United States before the
late summer of 1999.

Most people infected by the West Nile Virus have no symptoms
or experience something similar to flu. Symptoms of West Nile Virus
may include fever, headache, achy muscles, and extreme fatigue,
perhaps accompanied by a skin rash and swollen lymph glands. In a
fraction of cases, fever leads to encephalitis, which is fatal in some
cases or may cause neurological damage.

There is no vaccine for West Nile and no known cure. As with
other viral diseases, treatment consists of support until it has run its
course. The incubation period - the time between an infectious bite
and the onset of symptoms - is usually 5 to 15 days.

Humans contract West Nile Virus largely from mosquito bites.
Although some 150 species of mosquitoes are found in the United
States, the primary transmitter of West Nile is Culex pipiens. The
female mosquito catches the virus when she bites an infected bird
and can then pass it along if she later bites a human. Humans do not
get it from other humans or animals.

The virus can infect many different species of birds and other
animals, but crows seem particularly vulnerable¡ªmonitoring programs
focus on them. In fact, birds were key to solving the 1999
outbreak. CDC epidemiologists identified the West Nile Virus and
linked it to the human illness after pathologists found the disease in
flamingos, herons, and bald eagles that had been dying at the Bronx
Zoo. The virus has been found also in horses and a cat.

Background and Context

The West Nile Virus and the encephalitis it can cause pose serious
public health concerns, but journalists can best serve their audiences
by keeping the risks in perspective.

Possibly the most newsworthy thing about West Nile Virus is
merely that it is somewhat new - not that it is an unusually large
"big picture" threat to public health. Other mosquito-borne or insect-
borne viral encephalitis diseases are found regularly in the United
States.

It may be worth portraying deaths from West Nile in the context
of other infectious diseases. CDC reported 66 human cases of severe
disease and nine deaths in 2001 from West Nile Virus. By comparison,
some 3,000 cases of bacterial meningitis occur annually in
the U.S., despite the availability of vaccines. Some 10-13 percent of
those patients die despite getting antibiotics, and another 10 percent
have severe after-effects, including mental retardation.

Incidence of the virus in wildlife may be as important an issue as
incidence among humans. This is not only because wildlife may be a
reservoir that can potentially threaten humans, but because diseases
introduced in wildlife have the potential to impact wildlife populations,
in this case bird populations, which, in turn, could affect local
or regional ecosystems.

The U.S. Geological Survey's (USGS) National Wildlife Health
Center and other surveillance agencies have found West Nile in at
least 18 species of wild birds ranging from pigeons and bluejays to a
mallard duck. Continued monitoring will be essential to detecting
risks to both humans and wildlife.

USGS's National Mapping Division works with state and federal
agencies to incorporate the epidemiology information on the outbreak
with a geographic information system (GIS) for display and
analysis.

Issues

Some important public policy issues may warrant media scrutiny
and analysis:
- How are local mosquito-control programs funded, and how well-funded
are they? Is this funding a federal, state, or local responsibility?
- Is the cure sometimes worse than the disease and is prevention an
alternative to remedy an after-the-fact situation through aerial spraying?
Authorities said aerial spraying of the pesticide Malathion in
New York during 1999 was not only safe but was also justified because
of the risk of disease. But some environmentalists question
the risks of such broad public exposures.
- How many other ¡°emerging diseases¡± are popping up on the radar
screens of health surveillance authorities (or sneaking under the radar,
as West Nile almost did)?
- What work is being done on vaccines for insect-borne viral encephalitis
diseases? How well funded is the research, and what priority
is it being given?
- What other exotic species are threatening our landscapes, our waters,
and our native plants and wildlife?
- What sort of cooperation exists among state and federal agencies
working on human, domestic animal, and wildlife health and disease
problems?

Key Players
Here are some of the major news sources on West Nile Virus:
- U.S. Centers for Disease Control and Prevention. Federal agency
responsible for disease surveillance and epidemiological detective
work.
- U.S. Geological Survey (USGS) and the USGS National Wildlife
Health Center. Federal agency responsible for monitoring the viral
infection in wildlife and mapping the infection in humans and wildlife.
- U.S. Environmental Protection Agency. Responsible for pesticide
safety.
- City, county, and state health departments. Agencies responsible
for collecting reports of diseases and passing them along to CDC,
and also for preventing and responding to local disease outbreaks.
- Local and state mosquito control and abatement districts or agencies.
Responsible for keeping mosquito populations down.
- State wildlife agencies. May help monitor health of bird populations.
- Local medical research centers or hospitals. May treat actual cases
and have experts to interview.

Sources on the Web

U.S. Geological Survey, West Nile Virus Resource

CDC
http://www.cdc.gov/ncidod/dvbid/westnile/index.htm

EPA
http://www.epa.gov/pesticides/citizens/mosquitocontrol.htm

West Nile Virus Response Manual
http://www.bioterry.com/west-nile-virus/

West Nile Center
Awareness/Education/Prevention