EASTERN EQUINE ENCEPHALITIS - USA (22): (VIRGINIA, MASSACHUSETTS)

***********************************************
A ProMED-mail post

ProMED-mail is a program of the
International Society for Infectious Diseases


[1] Virginia
Date: 19 Aug 2010
Source: WPCVA.com [edited]



The Virginia Department of Agriculture and Consumer Services (VDACS)
has confirmed the 1st case of eastern equine encephalitis (EEE) in a
horse this year [2010].

The horse, an 18-month-old mustang female from Suffolk, was
euthanized 26 Jul 2010 because of the severity of her signs: extreme
weakness and ataxia, the inability to coordinate voluntary muscle
movements, unsteady movements and staggering gait. The horse received
an initial vaccination and a booster in the fall of 2009, as well as
a booster in May of 2010. [This is a little unusual in a vaccinated
animal. One can only wonder if the vaccine was given in a location
such as the nuchal ligament where the horse would not be able to
develop an antibody response].

Many states are experiencing an unusually high level of EEE infection
this year [2010], but this is the 1st reported case in Virginia. Last
year [2009], the state had 8 cases, most of them in the Tidewater area.

The disease has a mortality rate of around 80 percent, so prevention
is a key part of equine health. Generally, EEE is transmitted by
mosquitoes. Prevention methods include vaccination, destroying
standing water breeding sites for mosquitoes, using insect repellents
and removing animals from mosquito-infested areas during peak biting
times, usually dusk to dawn.

In an April 2010 press release, Dr. Richard Wilkes, VDACS' State
Veterinarian, encouraged horse owners to work with their
veterinarians to plan a vaccination schedule that would protect their
horses from EEE and West Nile Virus. Available vaccines are generally
effective in drastically reducing the incidence of both EEE and WNV
in horses. For the vaccine to be effective, it must be handled and
administered properly and be given at least 2 weeks before the horse
is exposed to the virus. Additionally, to stimulate full immunity,
horses must be vaccinated twice, about 30 days apart, in the 1st year
of vaccination. The vaccines are effective for 6 to 12 months, so
horses should be re-vaccinated at least annually. In an area where
the disease occurs frequently, such as southeast and Tidewater
Virginia, most veterinarians recommend vaccination every 6 months.

For more information, please contact the Office of the State
Veterinarian at 804.692.0601 or consult your local veterinarian.

--
Communicated by:
HealthMap Alerts via
ProMED-mail

******
[2] Massachusetts
Date: 19 Aug 2010
Source: South Coast Today [edited]



Another horse has been infected with eastern equine encephalitis,
according to Wayne Andrews, superintendent for the Bristol County
Mosquito Control Project. This brings the state's reported total of
EEE cases in horses to 4.

Andrews said he learned of the horse, which is from Lancaster and
experienced an onset of signs on 12 Aug 2010, in an e-mail from state
officials.

Further details, including the animal's current medical status, were
unavailable Wednesday [18 Aug 2010] evening.

A horse case in Worcester County "is a fairly rare event, but it
happens out there," Andrews said. This marks the county's 2nd case
this year [2010], after a Warren horse contracted the virus last
month [July 2010]. EEE cases have also been reported this year in the
Plymouth County towns of Middleboro and Plympton.

Also Wednesday [18 Aug 2010], Andrews reported that 2 additional
mosquito pools, consisting of the primarily bird-biting _Culiseta
melanura_, have tested positive for EEE.

One human case of EEE has been reported this year. Officials say a
Rhode Island man likely contracted the disease while visiting
southeastern Massachusetts several weeks ago.

[Byline: Anika Clark]

--
Communicated by:
HealthMap Alerts via
ProMED-mail

[Vaccinate, vaccinate, vaccinate seems to be the mantra of all
veterinarians to horse owners.

The 1st article here is unusual, in that the horse appeared, from the
article, to be vaccinated, yet it still succumbed to the disease. We
are left to wonder whether the vaccine was handled properly, kept
refrigerated and mixed properly, or if a full dose was given. Or was
the vaccine administered inappropriately, such as into the nuchal
ligament so that antibody response would not develop? We may never
know. - Mod.TG]

[see also:
Eastern equine encephalitis - USA (21): (GA) equine 20100819.2893
Eastern equine encephalitis - USA (20): (FL), fatal 20100818.2871
Eastern equine encephalitis - USA (19): (MI) equine, human susp. 20100817.2850
Eastern equine encephalitis - USA (18): (MA) equine, human 20100816.2836
Eastern equine encephalitis - USA (17): (FL) equine 20100815.2813
Eastern equine encephalitis - USA (16): (MI) 20100814.2790
Eastern equine encephalitis - USA (15): (FL) sentinel avian 20100810.2728
Eastern equine encephalitis - USA (14): (FL), equine, sentinel avian
20100807.2691
Eastern equine encephalitis, equine - USA (13) (FL, MA) 20100806.2675
Eastern equine encephalitis - USA (12): (MA) 20100803.2620
Eastern equine encephalitis - USA (11): (FL) fatal, human, equine 20100731.2569
Eastern equine encephalitis - USA (10): (MA, MI) 20100728.2529
Eastern equine encephalitis - USA (09): (FL) fatal 20100723.2469
Eastern equine encephalitis - USA (08): (LA) 20100716.2374
Eastern equine encephalitis - USA (07): (FL) 20100715.2363
Eastern equine encephalitis - USA (06): (FL, GA) 20100710.2312
Eastern equine encephalitis - USA (05): (FL) 20100708.2274
Eastern equine encephalitis - USA (04): (FL) 20100630.2178
Eastern equine encephalitis - USA (03): (FL) 20100627.2146
Eastern equine encephalitis - USA (02): (FL) sentinel avian 20100623.2101
Eastern equine encephalitis - USA: (FL) 20100527.1755]
...................................................sb/tg/msp/dk

*##########################################################*
************************************************************
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.
************************************************************
Donate to ProMED-mail. Details available at:

************************************************************
Visit ProMED-mail's web site at .
Send all items for posting to: promed@promedmail.org (NOT to
an individual moderator). If you do not give your full name
name and affiliation, it may not be posted. You may unsub-
scribe at .
For assistance from a human being, send mail to:
.
############################################################