[1] Cuba, Puerto Rico, 2004
[2] Trinidad, 2004
[3] Israel: WNV Antibodies in Recently Fledged Arctic Little Stints
(Calidris Minuta). Report and Critique
[4] Russia (Far East), 2003-2004
[5] Detection & Impacts on American crows, owls, raptors, rock pigeons
[recent reports in the scientific literature]
[6] Role of Bird Migration on Spread of WNV in North America
[7] Hawaii USA 2004: Surveillance Protocols & Risk of WNV to Birds in
Hawaii [WNV has not been detected in Hawaii]
[1]
CUBA, PUERTO RICO, 2004
Excerpted from ProMED-mail Feb 8, 2005 (Id: 20050208.0429)
From: Peter Marra <marrap@si.edu>
Date: Feb 8, 2005
[For background, see Smithsonian Institute Press Release, June 14 2004
<http://www.serc.si.edu/for_media/releases_2004/6_14_wnv.jsp> excerpted
below and in ProMED mail posting Feb 7 2005, Id: 20050207.0419.]
...Our research that resulted in finding WNV antibodies in resident
Cuban birds in the spring of 2004 was the result of a joint study with
the Wadsworth Center at the NY State Department of Health, with
collaborators Laura Kramer and Alan Dupuis. Our research was conducted
on the military base located in Guantanamo Bay, Cuba. Our findings
were immediately reported to military officials, and a paper is now in
review at The American Journal of Tropical Medicine and Hygiene. The
paper reports the 1st evidence for circulating WNV in Cuba and Puerto
Rico.
Peter P. Marra Ph.D.
Smithsonian Environmental Research Center
P.O. Box 28. 647 Contees Wharf Rd.
Edgewater, MD 21037 USA
---
Smithsonian Institution Press Release (June 14 2004),
Posted to ProMED-Mail by Joseph Dudley <jdudley@intellibridge.com> (Feb
4 2005)
WNV continues its invasive spread through the Caribbean. Recent
tests confirm that WNV has arrived in Puerto Rico, and Cuba. "This is
the first year we've seen WNV in Puerto Rico," said ecologist Peter
Marra of the Smithsonian Environmental Research Center (SERC). Marra's
team has been sampling birds on that island for three years, and after
sampling 1,205 birds this past winter, they found two individual birds
[a bananaquit and a green heron], both year-round residents with
antibodies to the virus.
"It's the first year we've looked in Cuba," Marra said, "but it's
only 90 miles from Miami, Florida, where birds have tested positive for
at least two years. The researchers expected to find signs of the virus
in Cuba, but the recent test results provide the first confirmed
evidence that the virus is there [two red-legged thrushes and a little
blue heron].
... Marra and his team made a similar discovery in Jamaica when
they found the first proof that the disease had arrived in 2002, after
finding no virus the previous year. Because migratory birds are
believed to spread the virus from one location to another, Marra began
to track the disease in birds in 2001 through a collaboration with the
Wadsworth Center of the New York State Department of Health . While
finding antibodies to the virus in a migratory bird does not prove the
region has active WNV, finding them in a year-round resident bird means
the bird was exposed at one time to live virus, and that the disease is
in fact in the local system...
"One of the most perplexing issues in the West Nile story thus far
has been its behavior in tropical regions," said Marra, "We just aren't
seeing the same sort of bird, horse or human impacts as we did in
temperate areas. This is a huge relief since wildlife and people have
already been seriously impacted from the effects of habitat
destruction. Understanding why West Nile's lethal effects appear to be
reduced in the tropics is something we're preparing to study. Stay
tuned."
-----
[2]
TRINIDAD, SOUTHERNMOST of CARIBBEAN ISLANDS, 2004
Excerpted from ProMED-mail, Jan 6 2005, Id 20050106.0033
From: Kirk Douglas <douglas.o.k@medscape.com>
...The Caribbean Epidemiology Centre (CAREC) has reported detection of
[WNV] seropositivity in horses (2/60, 3 percent) and birds (2/40, 2
percent) of birds. [The following is excerpted from the introduction to
a CAREC report Virus surveillance in the Caribbean - Dec 2004. Full
report can be accessed at
<http://www.carec.org/west-nile-2004/>.]
...The 1st human WN encephalitis case in the Caribbean was
reported at the end of 2001 in Cayman Islands. Subsequently, in January
2002, WNV activity was observed in migratory and resident birds in
Jamaica, Dominican Republic and Puerto Rico. These reports marked the
earliest evidence of WNV introduction into the Caribbean. WNV activity
has also been documented from a serosurvey in which 360 serum samples
were collected in healthy horses in Guadeloupe between June 2002 and
January 2003. The overall prevalence of IgG antibodies to WNV increased
from 2.8 percent in June 2002 to 50 percent in January 2003, which
represents a clear seroconversion in horses within a 6-month period.
In October 2003, WNV was identified in horses in Belize. The 2nd
human WN encephalitis case was reported in the Bahamas in July 2003.
The most recent identification of WNV in the Caribbean was in Trinidad,
where in a serosurvey of 60 horses and 40 birds conducted in October,
2004, WNV
antibodies were identified in 2 horses (3 percent) and 2 birds (5
percent).
----------------
[3]
ISRAEL: WNV ANTIBODIES IN RECENTLY FLEDGED ARTIC LITTLE STINTS
(Calidris minuta)
[3a-Report (edited by WNV-L)]
Forwarded from ProMED-mail, Feb 3 2005, Id: 20050203.0377
Submitted Feb 1 2005 by Reuven Yosef, Mertyn Malkinson, Caroline
Banet-Noach and Roni King of The International Birding and Research
Centre in Eilat (IBRCE), Israel. Address correspondence to
<malkins@agri.huji.ac.il>.
... Mosquitoes have been identified as the major vector for the active
spread of the virus at the local level, and migratory bird populations
as the major vector
transporting the virus between continents in the course of their
natural, annual migrations. Most researchers imply that the major
spread of the virus is from Africa to Europe (e.g., Hannoun et al.
1972).
Israel, the only land bridge between 3 continents, is at a junction for
birds migrating south from Eurasia to Africa in autumn and north to
their
breeding grounds in spring. In spring the Red Sea and the Gulf of
Aqaba/Eilat act as a long deflection barrier diverting many northbound
migrants to Eilat (Shirihai and Christie 1992). Eilat is strategically
located at the northern edge of almost 2000 km of continuous desert
regions of the Sinai, Sahara and the Sahel and many of the avian
migrants land here to rest and refuel after having crossed the
inhospitable deserts to the south (Safriel 1968, Yosef 1998).
Since 1984 a trapping and ringing has been conducted by the IBRCE at
Eilat. Following the recent interest in migratory birds as vectors of
WNV in the
region we sampled birds migrating to Africa in autumn 2001 and upon
their return to Europe in spring 2002. The species that stood out as
having one of the highest levels of antibodies was the Little Stint
(_Calidris minuta_). In spring, of 82 individuals sampled only 2 (2.4
percent) were
positive. In contrast in autumn 2001 we sampled 177 individuals of
which 18 (10.2 percent) were positive. This reversal of results is
further confounded by the fact that 16 of the 18 Little Stint were 1st
year birds, i.e., individuals that had recently fledged and were on
their 1st migration south. Hannoun et al (1972) also found that one
(20 percent) of the 5 Little Stint they sampled in Tunisia was
seropositive.
The Little Stint is a monotypic species in which it is easy to separate
the juveniles from adults based on plumage. The Little Stint breeds on
high-arctic coastal mainland tundra and winters mainly in Africa,
around the Indian Ocean and on coasts of the Indian sub-continent, with
variable numbers also in the Mediterranean basin and the Persian Gulf
(Cramp 1983).
In conclusion, based on our data, and the lack of any other studies on
the species or other tundra breeding avian species, we suggest that the
arctic
region has a greater level of viremia and for the transfer of WNV
between organisms than has previously been realized. We suggest that
future studies not assume blindly that the virus is out of Africa
alone.
Dr. Reuven Yosef, Director
International Birding & Research Centre in Eilat
P. O. Box 774. Eilat 88106, ISRAEL
<malkins@agri.huji.ac.il>
-----
[3b--Responses to Report from Israel]
Forwarded from ProMED-mail, Feb 5 2004, Id 20050205.0391
Submitted by Nick Komar<NCK6@CDC.GOV>, Feb 4 2005, with Comments from
ProMED-mail moderator
In the report published by Dr. Yosef et al. on ProMED-mail [see above],
Dr. Yosef wrote: "We suggest that future studies not assume blindly
that the virus is out of Africa alone."
In reality, studies should not assume anything, but rather build upon
good scientific data. The report, which suggests that Little Stints
(_Calidris
minuta_) are exposed to a high rate of WNV exposure in the arctic is
rife with assumptions. It assumes that: (1) Migrating birds are
important intercontinental "vectors" of WNV; (2) Seropositive migrant
hatch-year sandpipers (stints) were exposed on their breeding grounds
in the Arctic; and (3) Mosquitoes are responsible for local virus
spread.
All 3 of these assumptions can be debated, and none are
well-established scientific facts. For example, Little Stints probably
leave their breeding
sites in July and may be captured in Eilat in August-September. Thus
they migrate several thousand miles over an extended period of time,
resting
frequently in wetlands, many of which could be WNV transmission foci.
It is even possible that the Little Stints captured in Eilat had been
present for
several weeks in Eilat, where WNV has been reported to be endemic.
Before the scientific community starts assuming that WNV is transmitted
in the arctic (where no _Culex_ mosquitoes are present), better
evidence is
needed. The main problem with serological test results from migratory
birds, aside from the difficulties and complexities of flavivirus
serology, is that all such birds have unknown travel histories, and
thus the site of infection is unknown. Also, from the report on
ProMED-mail, I cannot even rule out the possibility that these
hatch-year Little Stints have long-lasting maternal antibody, though
this is unlikely.
Nicholas Komar, ScD <NCK6@CDC.GOV>
Arbovirus Diseases Branch
Centers for Disease Control and Prevention
PO Box 2087. Fort Collins CO 80522
---
Comments from ProMED-mail moderator:
Arctic mosquitoes are notorious pests and can occur in tremendous
numbers. Most are species of Aedes and Ochlerotatus. Culex
mosquitoes are generally absent from such northern areas but Culex
torrentium, an ornithophagic species, is found north of the arctic
circle in Scandanavia. Culex territans, which feeds mainly on
reptiles and amphibia, but also possibly on mammals, is found in Alaska
and the North West Territories of Canada. And, there is at least one
record of Culex. tarsalis being found in the North West Territories of
Canada near the MacKenzie valley. So a few Culex mosquitoes are found
in the far northern areas.
It might be worth remembering that West Nile virus has been
isolated from a very great number of mosquito species -- in about 11
genera. And in Russia the virus has been isolated from both ixodid
ticks (Hyalomma marginatum marginatum) and from argasid ticks
(Orithodoros capensis). - Mod.MS]
---------------
[4]
RUSSIA (FAR EAST), 2003-2004
Forwarded from ProMED-mail, Jan 24 2005 (Id 20050124.0260)
Contributed by V.A. Ternovoi, E.V. Protopopova, and Valery B. Loktev
<loktev@vector.nsc.ru>, The State Research Center of Virology and
Biotechnology Vector, Koltsovo, Novosibirsk Region; S.G. Surmach,
Institute of Biology and Soil Sciences, FEB RAS, Vladivostok; and M.V.
Gazetdinov and G.N. Leonova, Research Institute of Epidemiology and
Microbiology, SB RAMS,Vladivostok, Russia].
Frozen samples from dead birds collected in the Far Eastern Region
of Russia during 2003-2004 were analyzed by an anti-West Nile virus
MAb-modified immunoenzyme assay for antigen detection and by RT-PCR. 4
positive samples from cinereous vultures (_Aegypius monachus_) and 2
positive samples from the cattle egret (_Bubulcus ibis_) were found.
The samples were positive in ELISA and RT-PCR.
Sequencing of 400 bp fragments of the E protein gene showed high
homology with the WNV/LEIV-Vlg99-27889 strain of West Nile virus
(isolated in
Volgograd, Russia, in 1999). Additionally, 4 positive samples from
other species of birds (Ixobrychus eurhytmus, Pica pica, Corvus
macrorhynchos, Falco tunnuncules) collected during the autumn of 2004
were found during screening with anti-West Nile virus MAb-modified
ELISA.
These results confirm that WNV is circulating in the Far Eastern
region of Russia at present.
Valery B. Loktev, Professor, Dr. Sci, M.D., PhD. <loktev@vector.nsc.ru>
Head of The Department of Molecular Virology,
Deputy Director, Institute of Molecular Biology,
State Research Center of Virology & Biotechnology, VECTOR
Koltsovo, Novosibirsk region, 630559 Russia
---------------
[5]
DETECTION & IMPACTS ON AMERICAN CROWS, OWLS, RAPTORS, ROCK PIGEONS
[RECENT REPORTS IN THE SCIENTIFIC LITERATURE]
[5a]
WEST NILE VIRUS DEVASTATES AN AMERICAN CROW POPULATION
Caffrey, C, S.C.R. Smith, and T.J. Weston. 2005. Condor 107(1): 128-132.
Abstract: In its spread west across North America in 2002, West
Nile virus (WNV) reached a population of marked American Crows (Corvus
brachyrhynchos) in Stillwater, Oklahoma, in late summer. Within two
months, 46 of 120 individuals were missing or known to be dead, 39 of
which (33% of the population) are estimated to have died for
WNV-related reasons. In 2003, 56 of 78 marked crows disappeared or were
found dead between June and November. Five of the 28 juvenile losses
were possibly unrelated to WNV, thus we estimate that 65% of our
population died because of this pathogen in 2003. The total loss of 72%
of population members, including 82% of juveniles, in a single year of
WNV exposure raises concern for precipitous declines in American Crow
populations in coming years.
[The lead author can be contacted at <clcaffrey@audubon.org>. Full text
<http://environmentalrisk.cornell.edu/WNV/WNVEducDocs/Caffrey-
Condor05.pdf>]
[5b]
The following references to recent articles from American Birds, sent
by Carolee Caffrey, as well as references/full text for other articles
about WNV impact on birds can be found at:
<http://environmentalrisk.cornell.edu/WNV/SciRefs/SciRefs.php>
DETERMINING IMPACTS OF WEST NILE VIRUS ON CROWS AND OTHER BIRDS.
Carolee Caffrey.
CHRISTMAS BIRD COUNT DATA SUGGEST WEST NILE VIRUS MAY NOT BE A
CONSERVATION ISSUE IN THE NORTHEASTERN UNITED STATES.
Carolee Caffrey and Charles C Peterson.
COMBINED DATA FROM PROJECT FEEDERWATCH AND THE CHRISTMAS BIRD COUNT
INDICATE DECLINES OF CHICKADEES AND CORVIDS: POSSIBLE IMPACTS OF WEST
NILE VIRUS. David N Bonter and Wesley M Hochachka.
[5c]
DIFFERENTIAL VIRULENCE OF WEST NILE STRAINS FOR AMERICAN CROWS
Aaron C. Brault, Stanley A. Langevin, Richard A. Bowen, Nicholas A.
Panella, Brad J. Biggerstaff, Barry R. Miller and Nicholas Komar
Emerging Infectious Diseases 10 (12):
<http://www.cdc.gov/ncidod/EID/vol10no12/04-0486.htm>
Crow deaths were observed after West Nile virus (WNV) was
introduced into North America, and this phenomenon has subsequently
been used to monitor the spread of the virus. To investigate potential
differences in the crow virulence of different WNV strains, American
Crows were inoculated with Old World strains of WNV from Kenya and
Australia (Kunjin) and a North American (NY99) WNV genotype. Infection
of crows with NY99 genotype resulted in high serum viremia levels and
death; the Kenyan and Kunjin genotypes elicited low viremia levels and
minimal deaths but resulted in the generation of neutralizing
antibodies capable of providing 100% protection from infection with the
NY99 strain. These results suggest that genetic alterations in NY99 WNV
are responsible for the crow-virulent phenotype and that increased
replication of this strain in crows could spread WNV in North America.
[The authors are with the Centers for Disease Control and Prevention,
Fort Collins, Colorado, the University of California, Davis,
California, and Colorado State University, Fort Collins, Colorado, all
in USA]
[5c]
DETECTING WEST NILE VIRUS IN OWLS AND RAPTORS BY AN ANTIGEN-CAPTURE
ASSAY [Dispatch]
Ady Y. Gancz, Douglas G. Campbell, Ian K. Barker, Robbin Lindsay and
Bruce Hunter
Emerging Infectious Diseases. Dec 2004. 10(12):
<http://www.cdc.gov/ncidod/EID/vol10no12/04-0168.htm>
We evaluated a rapid antigen-capture assay (VecTest) for
detection of West Nile virus in oropharyngeal and cloacal swabs,
collected at necropsy from owls (N = 93) and raptors (N = 27).
Sensitivity was 93.5%–95.2% for northern owl species but <42.9% for all
other species. Specificity was 100% for owls and 85.7% for raptors.
[The authors are with the University of Guelph, Ontario, CA and the
Canadian Science Center for Human and Animal Health, Winnipeg,
Manitoba, CA]
[5d]
WEST NILE VIRUS OUTBREAK IN NORTH AMERICAN OWLS, ONTARIO, 2002
[Research]
Ady Y. Gancz, Ian K. Barke, Robbin Lindsay, Antonia Dibernardo,
Katherine McKeever and Bruce Hunter
Emerging Infectious Diseases. Dec 2004. 10(12):
<http://www.cdc.gov/ncidod/EID/vol10no12/04-0167.htm>
From July to September 2002, an outbreak of West Nile virus
(WNV) caused a high number of deaths in captive owls at the Owl
Foundation, Vineland, Ontario, Canada. Peak death rates occurred in
mid-August, and the epidemiologic curve resembled that of corvids in
the surrounding Niagara region. The outbreak occurred in the midst of a
louse fly (Icosta americana, family Hippoboscidae) infestation. Of the
flies tested, 16 (88.9 %) of 18 contained WNV RNA. Species with
northern native breeding range and birds >1 year of age were at
significantly higher risk for WNV-related deaths. Species with northern
native breeding range and of medium-to-large body size were at
significantly higher risk for exposure to WNV. Taxonomic relations (at
the subfamily level) did not significantly affect exposure to WNV or
WNV-related deaths. Northern native breeding range and medium-to-large
body size were associated with earlier death within the outbreak
period. Of the survivors, 69 (75.8 %) of 91 were seropositive for WNV.
[The authors are with the University of Guelph, Ontario, CA; Health
Canada, Winnipeg, Manitoba, CA; and the Owl Foundation, Vineland,
Ontario, CA]
[5e]
WEST NILE VIRUS VIREMIA IN WILD ROCK PIGEONS [Dispatch]
Andrew B. Allison, Daniel G. Mead, Samantha E.J. Gibbs, Douglas M.
Hoffman and David E. Stallknecht
Emerging Infectious Diseases. Dec 2004. 10(12):
<http://www.cdc.gov/ncidod/EID/vol10no12/04-0511.htm>
Feral rock pigeons were screened for neutralizing antibodies to
West Nile virus (WNV) during late winter/spring and summer of 2002 and
2003. Additionally, virus isolation from serum was attempted from 269
birds collected during peak transmission periods. The observed viremia
levels and seroprevalence indicate that this species could be involved
in amplifying WNV in urban settings.
[The authors are with the University of Georgia and the United States
Department of Agriculture–Wildlife Services, both in Athens, Georgia,
USA]
----------------------
[6]
ROLE OF BIRD MIGRATION IN SPREAD OF WNV IN NORTH AMERICA
[6a]
Excerpted from ProMED-Mail, Oct 7 2003 (Id 20031007.2512)
From: Richard W. Wilsnack, Ph.D. <rwilsnac@medicine.nodak.edu>
Department of Neuroscience, University of North Dakota
School of Medicine & Health Sciences, Grand Forks, ND 58202-9037
The human cases of WNV infection reported [as of Oct] 2003 for the USA
& Canada show a conspicuous pattern: most of the reported
cases in Canada have occurred east of the Rocky Mountains, but in the
USA they have occurred west of the Mississippi River.
More than 85 percent of reported U.S. cases (from data summarized
on ProMED-mail) have occurred in a vertical column of 8 states: Texas,
New Mexico, Colorado, Nebraska, South Dakota, Wyoming, North Dakota,
and Montana. In Canada more than 90 percent of reported cases have been
in the 3 prairie provinces: Alberta, Saskatchewan, & Manitoba. The
Rocky Mountains seem to be an important boundary for this year's human
infections, if one contrasts the case reports in New Mexico with those
in Arizona, Colorado versus Utah, and Montana and Wyoming versus Idaho.
The states and provinces with the most WNV cases are on major
migratory routes for birds traveling north as far as Canada. Compared
with human WNV infections in earlier years, it appears that in 2003 the
disease moved not merely west, but to a different set of migration
routes. The role of migratory birds in WNV transmission has been
discussed in the past on ProMED-mail, but 2 general questions have not
yet been addressed adequately in scholarly publications, online
reports, announcements, or discussion group e-mail (such as ProMED-mail
and
westnilevirus-l).
(1) To what extent has the U.S. distribution of human WNV cases been
predictable or constrained by major bird migration "routes" and the
timing of migrations in each year of cases? For example, in 2003, after
taking into account effects of population distributions, have the Texas
cases been particularly prevalent in western Texas, and have the
Colorado cases been particularly prevalent east of the Rockies? There
have been excellent discussions of how migratory "species" are likely
to be involved in long-range transmission of WNV (1, 2), but these
should be supplemented by quantified analysis of route effects, for
example relating cases (or case probabilities), after appropriate time
lags, to concentrations of migratory bird species in the same locales.
Routes and the timing of their use may be essential to study in
addition to bird species because (a) any list of identified
transmission species may long
remain seriously incomplete, and (b) transmission may depend on the
populations of certain mosquito species along migration routes at the
"right" times.
(2) What explanations have been proposed (and possibly tested) thus
far for the 2003 shift of WNV cases from the eastern USA & Ontario to
the states and provinces of the central plains? For example, if there
is a link with bird migration routes and timetables (perhaps in
conjunction with the size of local mosquito populations), can the shift
to more western routes be related to climate patterns in 2003, such as
daily temperature ranges and averages, rainfall patterns, and the
timing of changes in these seasonally? There has been debate on
ProMED-mail about whether droughts may concentrate mosquitoes and
(migratory) birds at the same water sources, but how the timing of
weather conditions can bring birds and mosquitoes together may need a
closer look.
Information relevant to these questions might be very helpful for
states and provinces trying to prepare for next year's West Nile virus
outbreak.
References:
1. JH Rappole, SR Derrickson, & Z Hubalek, Migratory birds and spread
of West Nile Virus in the Western hemisphere. Emerging Infectious
Diseases 6 (4) July-August 2000.
2. AT Peterson, DA Vieglais, & JK Andreasen, "Migratory birds modeled
as critical transport agents for West Nile Virus in North America.
Vector Borne Zoonotic Diseases 3 (1) Spring 2003. 27-37.
[Comments from ProMED-mail moderator: Richard Wilsnack is extending a
thread from last fall -- see refs below. Charles Calisher, a former
moderator, comments: One problem I have with use of the term
'migratory' is that it is often confused with 'movement.' Birds born
in non-West Nile virus areas obviously fly in and become targets for
the virus, but that problem will soon disappear, as WNV spreads further
south in this hemisphere. The big question here is timing, as Richard
points out. If WNV-infected birds are migrating northward in the
spring, wouldn't that virus become diluted in all the other WNV that is
already there?"
Perhaps equally important factors in the spread of WNV in
North America are the range and behavior of the mosquito vectors. In
WNV update 2003 - USA (27) 20031002.2477, Dr Lyle Petersen of the CDC
characterized the 2003 outbreak as different from previous U.S.
onslaughts because the virus has sharply affected rural areas. Previous
outbreaks were spread by mosquitoes that tended to live near homes and
buildings. The reason is the type of mosquito responsible for passing
the virus in Western states, Culex tarsalis, lives among farmland,
travels far, and is 'the most efficient vector of WNV ever discovered.
- Mod.CP]
[6b]
Excerpted from ProMED-mail, Oct 9, 2003 (Id 20031009.2545)
From: Joseph P. Dudley, Ph.D. <jdudley@intellibridge.com>
Senior Analyst, BioSecurity & Agriculture, Intellibridge,
1101 30th Street, NW Suite 100B, Washington DC 20007
It is very interesting and enlightening to compare the animated map of
Common Grackle migrations and concentrations at
<http://www.birdsource.org/GIS/images/cgrack_as96moani.gif> with the
animated map of the spread and distribution of WNV in North America
from 1999-2002 posted on the Cornell
Laboratory of Ornithology's [sic] website
<http://environmentalrisk.cornell.edu/WNV/>.
--------------------
[7]
HAWAII, USA: SURVEILLANCE PROTOCOLS & RISK OF WNV TO BIRDS IN HAWAII
Excerpted from series of comments on ProMED-mail
[7a]
Date: Oct 12 2004 (Id 20041012.2787)
From: Thierry M. Work <thierry_work@usgs.gov>
USGS National Wildlife Health Center, Hawaii Field Station,
PO Box 50167. 300 Ala Moana Blvd., Room 5231, Honolulu, HI 96850
[Response to question raised in earlier ProMED-mail posting (ID
20041001.2705) about why a bird in Hawaii was suspected to have WNV,
and was subsequently tested and found not to be infected with WNV]
Since the entry of WNV into the US in 1999 and its impact on wild
birds, the conservation community in Hawaii has been very concerned
that if WNV gets into the state, the impacts to native avifauna such as
endangered crows and raptors could be catastrophic (not to mention the
probable negative effects on tourism). To reduce the chances of the
virus getting here, several strategies have been adopted.
1) The US Fish and Wildlife Service heads an interagency
working group that has been working on ways to prevent WNV from
reaching Hawaii. These measures include convincing the US Postal
Service to stop mailing birds into Hawaii without agricultural
inspections, beefing up state quarantine procedures for avian imports,
and working with the Hawaii Department of Health (DOH) to enhance
mosquito and dead bird surveillance. Current efforts are focused on
developing a coherent incident command structure so that a swift
response can be implemented should the virus get here.
2) Since 2002, the US Geological Survey has been taking weekly
blood samples from wild finches, sparrows, and doves around Honolulu
International Airport, Barber's Point, and Dillingham airfields. The
USDA Wildlife Services captures these birds around airports to mitigate
aircraft bird strike hazards. The USGS is bleeding these birds in
efforts to detect WNV activity in areas considered high risk for entry
of the virus into the state. The samples were being tested with the
blocking ELISA at Orange County Vector Control District; however,
because resources in California are being redirected to WNV problems
there, the Hawaii DOH began testing bird sera using the IgM ELISA.
3) In efforts to expand testing to other areas of considered
high risk for WNV entry into Hawaii, the USGS trained Hawaii DOH
personnel to bleed birds at Kahului Airport on Maui. The bird that
turned up suspect positive was bled on 20 Sep 2004 during that training
session. Weekly serosurveillance and testing of birds continues in Maui
and Honolulu.
4) Orange County Vector Control District is working with
Hawaii DOH to develop their capacity to use the blocking ELISA in
Hawaii. Efforts are also afoot to try and develop confirmatory
capabilities for WNV in Hawaii thereby reducing response times.
---
RESPONSES TO QUESTIONS ABOUT AVIAN FAUNA OF HAWAII
[7b]
Date: Oct 19 2004 (Id 20041019.2833)
From: Richard I. Frankel, M.D., M.P.H., Associate Chief of Staff for
Education, VA Pacific Islands Health Care System
<Richard.Frankel@med.va.gov>
Replying as an amateur ornithologist, of the 284 species reported to
CDC's WNV avian mortality database from 1999 to the present, Hawaii
does have populations of Barn Owls, Black Crowned Night Herons, Chukar,
House Finch, House Sparrow, Mallard, Northern Cardinal, Rock Dove,
Western Meadowlark, and of course Chickens and Nene. This is off the
top of my head, so I may have missed some.
(<http://www.cdc.gov/ncidod/dvbid/westnile/birdspecies.htm>)
There are a dozen or fewer Hawaiian crows in existence, at a breeding
facility that is trying to save the species from the extinction -- the
fate of so many Hawaiian bird species.
--
[7c]
[ProMED moderator CP's comment to 7b: The high lethality of WNV for
corvids and some other birds in mainland USA contrasts with the lesser
avian mortality observed elsewhere (e.g. Mexico and Europe). Whether
this is due to subspecies differences or pre-exposure to other
flaviviruses remains an open question.]
---
[7d]
Date of posting: Nov 1, 2004 (Id: 20041101.2958) (Submitted Oct 25
2004)
From: Thierry M. Work <thierry_work@usgs.gov>
... Hawaii has the highest per capita number of endangered birds in any
of the 50 United States, including one species of endemic corvid (the
Hawaiian crow, of which there are less than 50 individuals, all
captive), 2 species of endangered raptors (the Hawaiian hawk and owl),
and several species of endangered honeycreepers (passerines) and
waterfowl (coots, ducks, stilts, and gallinules). Most of these animals
are presumably vulnerable to WNV, and we do have the vector here (Cx.
quiquefasciatus) along with other potential vectors (Ae. albopictus).
Other diseases introduced into Hawaii, such as avian malaria,
avian pox, and toxoplasmosis, have had significant demographic impacts
on native
passerines. In contrast, similar diseases in the lower 48 states do not
have nearly the impact they have here, because native avifauna in
Hawaii have evolved in relative isolation and free from pathogens,
until these were introduced by humans approximately 200-300 years ago.
Although SLEV (St. Louis encephalitis virus) has a very similar
ecology to WNV, and has been in the western US for a few decades, it
has not made it
to Hawaii. Thus, it would seem that a similar scenario would play out
with WNV. Unfortunately, WNV in the US has managed to rewrite the
textbooks and
confound expectations at every turn. It was initially thought only to
affect crows but now has been found to kill raptors, alligators, seals,
and squirrels. It is behaving like a typical pathogen introduced into a
naive ecosystem. Given this record, and its ability to spread rapidly
across borders, the outlook is not good if it gets to Hawaii. Hawaii is
unique among the other US states in that it has approximately 5000 km
of ocean separating it from the mainland. Thus, unlike other states, we
don't just have to sit here and wait for it to arrive. We can take
aggressive measures to ensure early detection, and, if it gets here,
eradicate it. But, this will necessitate political will.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
WESTNILEVIRUS-L is an email discussion group for communication
and discussion about West Nile Virus, particularly regarding policy,
risk reduction and public education issues. It is hosted at Cornell
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Received on Fri Feb 11 16:04:33 2005
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