WNV: Notes & News re: Aedes japonicus

<x-rich>This memo was first circulated yesterday to the WESTNILEVIRUS-L
listserv which we've set up to keep the Cornell community
informed.--Lois

~~~~~~~

Two versions of an Associated Press story appeared today about a
species of mosquito that is new to the US and may be a vector of West
Nile Virus -- a short piece in the New York Times (B6- Connecticut) and
a longer one in Newsday (see below).

The mosquito, Aedes japonicus, was first found in the US a year or so
ago by Scott Campbell, Suffolk County Department of Health Services
entomologist. Aedes japonicus has since been found in several NJ and
downstate NY locations, as well as in Connecticut--indicating that
perhaps it is moving northward. Mosquito entomologists don't know for
sure how long Aedes japonicus may have been in the NE, nor how
prevalent they are, because everyone is looking so much more carefully
since the West Nile Virus outbreak last year. The reason for the
coverage now is that the first generations of Aedes japonicus are
emerging this spring.

The same mosquito control strategy that has been developed to eliminate
Culex pipiens breeding sites will also be effective in reducing numbers
of Aedes japonicus. Like Culex pipiens (the known vector of West Nile
Virus), Aedes japonicus breeds in artificial containers, but also in
rock and tree holes. Unlike Culex pipiens, it is primarily a mammal
feeder (C.p. prefers to bite birds).

Mosquito entomologists have been aware for some months at least that
Aedes japonicus is what is called a "competent laboratory vector" of
West Nile Virus. Research is now being conducted to understand the
potential role of Aedes japonicus in actual, field-based WNV
transmission. (For an example of the difference between lab and field
tests: most of the tests done to uncover basic information about
"transmission competency" in the laboratory injected virus into the
mosquitoes, whereas this would never happen in the real world.)

Lois Levitan

~~~~~~~~~~~~~~~~~~~~~

Newsday 5/9/2000

<bold><bigger>Mosquito From Asia Could Carry West Nile

</bigger></bold>THE ASSOCIATED PRESS

Bridgeport, Conn. - A new mosquito from Asia has been found in 35
locations

in Connecticut, causing concern that it could spread the potentially
deadly

West Nile strain of the encephalitis virus.

At least in the laboratory, Aedes japonicus-native to Japan and
Korea-is even

better at spreading the West Nile strain than the current carrier,
Culex

pipiens, commonly known as the house mosquito.

In Army tests at Fort Detrick in Frederick, Md., japonicus was found to
be

the "most competent vector" for West Nile virus in a laboratory
setting, when

compared with other mosquitoes.

But whether or not it will spread the virus in the wild is not yet
known.

"There's a difference between a laboratory vector and a real-world
vector,"

said Michael Turell, the Army research entomologist who conducted the

japonicus test.

For example, he said, "If it only feeds on frogs in the real world,
it's not

going to be important." Turell said there were indications that
japonicus

feeds on birds, humans and other mammals but said a real-world feeding
study

was necessary.

Last April, scientists from Connecticut announced a search across the
state

for japonicus after it was found on Long Island and in New Jersey.
Scientists

suspect the mosquito came to the Northeast in shipments of used tires
from

Asia. Water collects in tires, providing a good breeding site.

Japonicus was found in Connecticut tire dumps last summer. It has since

established itself in seven of the state's eight counties, said
Theodore

Andreadis, chief medical entomologist for the Connecticut Agricultural

Experiment Station in New Haven.

Barbara Reynolds of the federal Centers for Disease Control and
Prevention

said gathering and testing of many mosquito species were ongoing and
that

only Culex pipiens has shown evidence of West Nile so far.

The West Nile strain was detected in New York State last year, the
first

documented occurrence in the Western Hemisphere. It killed seven people
in

New York State and made at least 62 others seriously ill.

Dead birds infected with the virus were found in New York, New Jersey
and

Connecticut. Most people infected with the virus suffer flulike
symptoms. But

the most susceptible, the very young and elderly, can suffer deadly
brain

swelling.

~~~~~~~~~~~~~~~~~~~~~

Bridgeport--

        A new mosquito from Asia has been found in 35 places in Connecticut,

causing concern that it could spread the potentially deadly West Nile

strain of the encephalitis virus.

        In Unites States Army tests at fort Detrick in Frederick, Md., aedes

japonicus, native to Japan and Korea, was found to be more effective
than

other mosquitoes at spreading the West Nile virus in a laboratory. But

whether the insect will spread the virus in the wild is not known.

        In April 1999, scientists announced a search across Connecticut for

japonicus after it was found on Long Island and New Jersey. Scientists

suspect the mosquito came to the Northeast in shipments of used tires
from

Asia.

        Japonicus was found in Connecticut tire dumps last summer. The insect
has

since established itself in seven of the state's eight counties, said

Theodore Andreadis of the Connecticut Agricultural Experiment Station.

</x-rich>
Received on Wed May 10 14:39:34 2000