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Subject: [WNV-L] Update Range & Cases, 2003 US & Can (3)
Date:
July 25, 2003
Posted by:
Environmental Risk Analysis Program <envrisk@cornell.edu>
[1] Background re: WNV Range & Impact, US & Canada. Lois Levitan
[2] Update from Canada:
(a) Range Expanded into Alberta. Calgary Herald
(b) Health Canada Surveillance Report
[3] Update from US
(a) Excerpts from comments by ProMED Moderator
(b) 1st Detection in NYC in 2003: Mosquitoes, Staten Island)
(c) Human Case, Fort Worth, Texas
(d) Human Case, Colorado: 1st Case 2003
(e) Human Case, South Dakota: 1st Case 2003
(f) US Surveillance Update through July 23, 2003
[1] BACKGROUND re: WEST NILE VIRUS RANGE & IMPACT in US and CANADA
The 2002 WNV epidemic in the US was the largest arboviral
meningoencephalitis epidemic documented in the western hemisphere and
the largest reported WNME epidemic. In 2002 WNV was detected in 44
states (2,289 counties) across the US and 5 provinces in Canada, from
Saskatchewan to Nova Scotia. In the US the only states where it has
not been detected are Alaska, Arizona (several cases imported from
elsewhere), Hawaii (case in infected tourist from Minn), Nevada,
Oregon (it has been found in a human case contracted elsewhere and in
a horse in a border county in Idaho) and Utah. In many states WNV was
detected in all, or nearly all, counties, including several on the
Mexican border.
In 2001, WNV was detected 359 counties in 27 states and Washington
DC. Despite this large reported increase, CDC believes that the
ArboNET data reported in their Dec 20 MMWR likely underestimate the
actual geographic range and intensity of WNV transmission in the US
because (a) only 27% of birds reported in 2002 were tested as
compared with 50% in 2001; (b) some data were not yet reported; and
(c) there is not a nationwide surveillance case definition for WNME
and WNF.
Prior to the 2003 season, WNV had been detected in 5 Canadian
provinces (Manitoba, Nova Scotia, Ontario, Quebec, Saskatchewan), as
well as in an "imported" human case in Alberta likely acquired while
travelling in the US. In 2003 it has been detected for the first
time in New Brunswick (see WNV-L posting Tues July 22) and Alberta.
For additional background see the Environmental Risk Analysis
Program's West Nile Virus Introduction
http://environmentalrisk.cornell.edu/WNV/ and "Historical Summary,
by State and Country"
http://environmentalrisk.cornell.edu/WNV/Update/ for background re:
1999-2002 WNV range and impact.
Lois Levitan, WNV-L moderator
[2] UPDATE from CANADA. Excerpted from ProMED-mail (Id: 20030725.1811)
(a) Range Expanded into Alberta, Canada. WNV Detected in
mosquitoes and birds.
(b) Health Canada Surveillance Report (as of Thu 24 Jul 2003)
[2a]
RANGE EXPANDED INTO ALBERTA, CANADA. WNV DETECTED in MOSQUITOES & BIRDS
Date: Wed 23 Jul 2003
Source: Calgary Herald, Wed 23 Jul 2003, byline Kerry Williamson [edited]
http://www.canada.com/calgary/story.asp?id=80484F92-8FA3-400C-A4AB-D9D8B9A64525
Alberta Environment announced on the afternoon of Tue 22 Jul 2003
that a sample of mosquitoes trapped in Brooks tested WNV-positive.
The mosquitoes were collected on 15 Jul 2003, just 6 days after the
virus
first turned up in the province. On 9 Jul 2003, the province
confirmed a dead magpie found near Camrose, southeast of Edmonton,
had tested WNV-positive. A bird found near Medicine Hat has also
tested positive.
The mosquitoes trapped in Brooks were _Culex tarsalis_, the species
experts expected to surface in Alberta with WNV. With the disease
spreading westward, health officials believed it was only a matter of
time. "We knew it was in the mosquito population, and now we've just
happened to catch some with the disease," said Robert Moyles, a
spokesman for Alberta Environment. "These mosquitoes may have shown
up in Brooks, but we already have magpies in Camrose and Medicine
Hat, so chances are pretty good there are mosquitoes with it there,
too."
"The species more likely to carry it is more likely to show up in
southern Alberta ... they like the warmer temperatures. When it gets
a bit warmer, we see their numbers increase from the bottom of the
province on up" he said. Last week's tests did show that the
proportion of _Culex tarsalis_ in the Calgary area in the past
week-and-a-half had more than doubled from one to 2 percent,
something that was expected as temperatures rise. "The finding (in
Brooks) doesn't change or alter the overall risk to people," said Dr.
Brent Friesen, medical officer of health for the Calgary Health
Region. "There's certainly no need for people to stop or discontinue
activities or enjoying the outdoors."
More than 200 pools of mosquitoes have been tested in the past few
weeks. Alberta's mosquito surveillance program collects adult female
mosquitoes from traps across the province each week. The insects are
frozen, sorted, identified, and shipped to the provincial laboratory
in Calgary for testing.
[Submitted to ProMED by Akira Goto <dolphin@mail.ne.jp>]
[2b]
HEALTH CANADA SURVEILLANCE REPORT (as of July 24, 2003)
Date Thu 24 Jul 2003
Source: Health Canada, West Nile Virus Surveillance, Thu 24 Jul 2003 [edited]
http://www.hc-sc.gc.ca/pphb-dgspsp/wnv-vwn/pdf_sr-rs/2003/situation_report_071703_db.pdf
Human: No confirmed reports
Equines: No confirmed reports
Mosquitoes: FALSE POSITIVE-ONTARIO: The Ministry of Health and
Long-Term Care (MOHLTC) has been advised that as of Tue 15 Jul 2003
the report of one West Nile virus-positive mosquito pool (in
Ontario), which was posted on 24 Jun 2003 is incorrect. The sample
taken 18 Jun 2003 which was tested by a private laboratory, upon
further confirmatory testing, has proven negative for West Nile
virus.
As of 24 Jul 2003, 1 pool of mosquitoes has tested positive in
Ontario (Haldimand Region), and 1 pool of mosquitoes has tested
positive in Alberta (Palliser Region)
Wild Birds: Test Results by Province:
Province/No. submitted for testing/No.tested/No. confirmed positive/
Newfoundland and Labrador/ 30/ 29/ 0/
Prince Edward Island/ 192/ 180/ 0/
Nova Scotia/ 392/ 380/ 0/
New Brunswick/ 375/ 364 1/
Quebec/ 929/ 858/ 7/
Ontario/ 1042/ 923/ 39/
Manitoba/ 790/ 713/ 69/
Saskatchewan/ 706/ 558/ 15/
Alberta/ 483/ 469/ 2/
British Columbia/ 1316/ 1290/ 0/
Yukon/ 7/ 6/ 0/
Northwest Territories/ 10/ 10/ 0/
Nunavut/ 1/ 1/ 0/
The totals for Canada for 2003 so far are 6273 birds submitted for
testing, 5781 birds tested, and 133 confirmed West Nile
virus-positive. In addition there were 1864 sightings of dead birds
recorded.
[This represents an increase of 995 birds tested and 71 more birds
confirmed positive since the last update on Thu 17 2003. The only
other confirmed reports are 2 pools of mosquitoes. - ProMED Mod.CP]
--------
[3]
UPDATE from US. Excerpted from ProMED-mail (Id: 20030724.1807)
[3a] Excerpts from comment by ProMED Moderator:
Now that WNV surveillance data reported to CDC through ArboNET are
appearing weekly in MMWR (see part 7 below), ProMED-mail will no
longer provide abstracted information from the USGS West Nile virus
maps. A summary map of the current situation is reproduced in MMWR,
and the more detailed USGS maps, down to county level in some
categories, can be accessed at http://westnilemaps.usgs.gov
The following update includes additional reports of the presence of
WNV in blood donations detected prior to the appearance of
symptomatic cases of WNV infection. If validated by further
experience, the screening test now under trial in blood transfusion
facilities may provide a sensitive early indicator of WNV infection
in the human population.
Now that the 2003 WNV season is in full swing, only extensions of WNV
geographic range or host species and exceptional items will be posted
separately from these weekly updates. - Mod.CP.
[Additional note from WNV-L moderator: Searchable archives of ProMED
postings are on the web]
[3b]
FIRST DETECTION IN NEW YORK CITY IN 2003: MOSQUITOES, STATEN ISLAND
Date: Fri 18 Jul 2003
Source: Daily News, Fri 18 Jul 2003 [edited] Submitted by Pablo Nart,
byline: Paul Shin
http://www.nydailynews.com/boroughs/story/101654p-92010c.html
Mosquitoes collected in the Willowbrook Park area in Staten Island
tested WNV-positive, the first time the potentially fatal virus has
been detected in the city this year. The Health Department does not
plan to start spraying pesticides yet, but officials said they have
stepped up surveillance for infected mosquitoes and their larvae in
Staten Island.
In 2002, 29 cases of WNV were reported in NYC, resulting in 3 deaths.
[3c]
HUMAN CASE, FORT WORTH, TEXAS
Source: Fort Worth Star-Telegram, Sun 20 Jul 2003, byline Peyton D.
Woodson [edited]
http://story.news.yahoo.com/news?tmpl=story&cid=427&ncid=427&e=3&u=/kr/20030720/lo_krfortworth/testsconfirmwnilecase
County health officials have confirmed Fort Worth's first human case
of WNV in 2003. The patient, described as an elderly man who lives in
the 76104 ZIP code area near the hospital district, is expected to
make a full recover. Vanassa Joseph, a spokeswoman for the Tarrant
County Health Department, said the county's lab returned the positive
test results on Fri 18 Jul 2003. They will be sent to the Texas
Department of Health for further confirmation. Fort Worth had one
human case of WNV in 2002.No one in Fort Worth has died of the
disease.
[3d]
HUMAN CASE, COLORADO: 1st CASE 2003
Source: Casper Star-Tribune, Associated Press report, Wed 23 Jul 2003 [edited]
http://www.trib.com/AP/wire_detail.php?wire_num=82288
State officials announced Tue 22 Jul 2003 that a 28-year-old man from
northern Colorado is the first person in the state known to have
contracted WNV infection in 2003.
The man became ill on 6 Jul 2003 and saw his physician 5 days later,
said Lori Maldonado, spokeswoman for the state Department of Public
Health and Environment. Tests at state labs confirmed the presence of
WNV Mon 21 Jul 2003. Officials have sent the results to the federal
Centers for Disease Control and Prevention, but they were sure the
test was positive.
"It is not surprising that Colorado's first human case of West Nile
virus infection for 2003 would come from Weld County, because there
already has been a great deal of virus activity in the area," said
state epidemiologist
Dr. Ned Calonge. Weld County is on Colorado's northern border, south
of Cheyenne, Wyoming.
The virus first showed up in Colorado in August 2002, but none ofthe
13 human cases detected in 2002 was fatal. (see: Colorado virus home
page at http://www.cdphe.state.co.us/dc/Zoonosis/wnv/wnvhom.html).
[3e]
HUMAN CASE, SOUTH DAKOTA, 1st CASE 2003
Source: Argus Leader http://www.argusleader.com/news/Wednesdayarticle2.shtml
It was announced Tues July 22 that a Lyman Co, South Dakota, resident
became sick Sunday, and that tests confirmed WNV as cause of
encephalitis. The patient is hospitalized in Sioux Falls. The first
confirmed bird death in Lyman County was 11 Jul 2003, 2 days before
the human patient fell ill.
South Dakota is the eighth state with a confirmed [human] case of
WNV. The CDC had confirmed 8 cases in 5 states as of Monday, and
Colorado and Iowa recently reported new cases.
[3f]
US SURVEILLANCE UPDATE, THROUGH JULY 23, 2003
Source: Morbidity and Mortality Weekly Report, Fri 25 Jul 2003 / 52(29);686
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5229a4.htm
This report summarizes West Nile virus (WNV) surveillance data reported to
CDC through ArboNET as of 8 a.m., Mountain Daylight Time, Wed 23 Jul 2003.
During the reporting week of Thu 17 Jul to Wed 23 Jul 2003, 6 human cases
of WNV infection were reported from 5 states (Iowa, Minnesota, Ohio, South
Dakota, and Texas). During the same period, WNV infections were reported in
309 dead corvids (crows and related species), 69 other dead birds, 12
horses, and 144 mosquito pools.
During 2003, a total of 11 human cases of WNV infection have been reported
from Texas (n = 5), Alabama (n = one), Iowa (n = one), Minnesota (n = one),
Ohio (n = one), South Carolina (n = one), and South Dakota (n = one). Among
these cases, 7 (64 percent) occurred among men; the median age was 70 years
(range: 42 to 80 years), and the dates of illness onset ranged from 29 May
to 13 Jul 2003. In addition, 551 dead corvids and 150 other dead birds with
WNV infection were reported from 34 states; 55 WNV infections in horses
have been reported from 16 states (Alabama, Arkansas, Colorado, Georgia,
Kansas, Kentucky, Minnesota, Missouri, Nebraska, New Mexico, North
Carolina, North Dakota, Oklahoma, Texas, Wisconsin, and Wyoming), and one
WNV infection was reported in a dog (South Dakota). During 2003, WNV
seroconversions have been reported in 56 sentinel chicken flocks from
Florida, Iowa, and North Carolina. South Dakota reported 3 seropositive
sentinel horses; 327 WNV-positive mosquito pools have been reported from 15
states (Colorado, Georgia, Illinois, Indiana, Kansas, Maryland,
Massachusetts, Michigan, Mississippi, Nebraska, New Jersey, South Dakota,
Texas, Virginia, and Wisconsin).
Additional information about WNV activity is available from CDC at
http://www.cdc.gov/ncidod/dvbid/westnile/index.htm and
http://westnilemaps.usgs.gov/
[The positive mosquito pool in Staten Island and the suspected human case
in Colorado are additional to the figures listed in the MMWR update.
- Pro-MED Mod.CP]
----------------------------------------------------------------------------------------------------------------- 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 moderated by Dr. Lois Levitan at Cornell University's Center for the Environment. Archives are posted at: http://environmentalrisk.cornell.edu/WNV/WNV-L_ArchiveIndex.html. To subscribe (or unsubscribe), send an email request with your name and contact information to <envrisk@cornell.edu>. To receive messages once a day in digest format, subscribers can send an email to <listproc@cornell.edu> with message: "set WESTNILEVIRUS-L mail digest-nomime". Subscribers are encouraged to post to the group by sending messages to <envrisk@cornell.edu>. Please put "WNV Listserv" in the subject line and send only unformatted text, without attachments. -----------------------------------------------------------------------------------------------------------------