PRO Misqyuitoes, post hurricane

-------- Original Message --------
Subject: PRO Mosquitoes, post hurricane - USA (03)
Date: Wed, 14 Sep 2005 10:11:50 -0400 (EDT)
From: ProMED-mail promed@promed.isid.harvard.edu
Reply-To: promedNOREPLY@promed.isid.harvard.edu
To: promed@promedmail.org

MOSQUITOES, POST HURRICANE - USA (03)
*************************************
A ProMED-mail post
http://www.promedmail.org
ProMED-mail is a program of the
International Society for Infectious Diseases
http://www.isid.org

Sponsored in part by Elsevier, publisher of
Trends in Parasitology
http://www.trends.com

Date: 13 Sep 2005
From: ProMED-mail promed@promedmail.org
Source: The Washington Post, [edited]
http://www.washingtonpost.com/wp-dyn/content/article/2005/09/12/AR2005091201409_pf.ht

Possibility of West Nile virus and St. Louis encephalitis
transmission post hurricane Katrina
-----------------------------------------------
"It's possible you could have a significant outbreak of West Nile," a
virus that can be dangerous or fatal to the elderly and the
immune-compromised, said Anthony S. Fauci, Director of the National
Institute of Allergy and Infectious Diseases. But we won't likely
know for weeks. Robert Edelman, professor of medicine and pediatrics,
University of Maryland School of Medicine, recalled that when
hurricane Camille barreled into the eastern United States in 1969,
heavy rains and the storm surge wiped out mosquitoes for about a
month. Katrina is expected to have a similar effect.

Once the mosquitoes' breeding cycle is restored, and eggs begin to
hatch in standing water, residents in the Gulf area could be at
greater risk for both West Nile and St. Louis encephalitis (SLE),
another mosquito-borne illness. Widespread spraying of the area might
curtail an outbreak. Whether toxic chemicals and oil in the water
might hamper mosquito breeding is not known. Neither West Nile nor
St. Louis encephalitis is passed from person to person.

[Byline: Elizabeth Agnvall]

--
ProMED-mail
promed@promedmail.org

[The above comprises the last 2 paragraphs of a report entitled "Next
Threat: Illness," which discusses several health aspects resulting
from hurricane Katrina.

I agree that flooding has probably flushed out mosquito larval
habitats, and it is only when water recedes that smaller and discrete
water bodies will be formed that are likely to be more attractive to
mosquito breeding. Along the Gulf coast, the primary vectors of SLE
are _Culex pipiens_ and _Culex quinquefasciatus_, mosquitoes that
often breed in waters that are contaminated with feces or other
organic matter, habitats which could become plentiful. Vectors of
West Nile virus comprise several mosquito species, including the _Cx.
pipiens_ complex.

Widespread insecticidal spraying is a possible course of action. This
could involve larviciding aquatic waters suspected, or better still
known, to be larval breeding places, or adulticiding. Both can be
done from ground-based equipment (or boats) or by aerial
applications. Depending on where adult mosquitoes are resting,
thermal fogs or aerosols can be directed at out of door resting
places, such as at vegetation, or indoors (houses and other
buildings) where one might find adult females of the _Cx. pipiens_
complex. To spray or not to spray can be a difficult question. It is
likely to be costly, and the effects of it may be inconclusive.

I wonder what effect the hurricane has had on the local bird
populations, remembering that passeriformes and columbiformes are
reservoir hosts of SLE, while corvids are reservoir hosts for West
Nile virus. - Mod.MS]

[Elsevier Online Reference: Eklund CM. Mosquito-transmitted
encephalitis viruses: A review of their insect and vertebrate hosts
and the mechanisms for survival and dispersion. Experimental
Pathology, 1954.
http://dx.doi.org/10.1016/0014-4894(54)90028-4]

[see also:
Mosquitoes, post hurricane USA (02) 20050912.2696
Mosquitoes, post hurricane USA 20050906.2640
Gastroenteritis, hurricane-related - USA (MS) 20050905.2628
Hurricane Katrina USA (Gulf coast): links 20050904.2618
West Nile virus update 2005 - Western Hemisphere (11) 20050903.2608
2004
----
West Nile virus update 2004 - Western Hemisphere (27) 20041210.3273
2003
----
Eastern equine encephalitis, human - USA (VA) 20030929.2455
1995
----
Dengue and hurricanes (2) 19951006.0927
Dengue and hurricanes 19951006.0922]
..........ms/msp/lm

*##########################################################*
************************************************************
ProMED-mail makes every effort to verify the reports that
are posted, but the accuracy and completeness of the
information, and of any statements or opinions based
thereon, are not guaranteed. The reader assumes all risks in
using information posted or archived by ProMED-mail. ISID
and its associated service providers shall not be held
responsible for errors or omissions or held liable for any
damages incurred as a result of use or reliance upon posted
or archived material.
************************************************************
Visit ProMED-mail's web site at http://www.promedmail.org.
Send all items for posting to: promed@promedmail.org
(NOT to an individual moderator). If you do not give your
full name and affiliation, it may not be posted. Send
commands to subscribe/unsubscribe, get archives, help,
etc. to: majordomo@promedmail.org . For assistance from a
human being send mail to: owner-promed@promedmail.org.
############################################################
############################################################