West Nile Virus Updates


Hello Jeff - Last weekend I found a dead bluejay in my backyard. I would, therfore, like to make a suggestion about downed birds. I suggest that people, especially those living in areas where West Nile Virus is heavily infected should call health departments and find out what to do with dead birds. I know that New York has had enough birds turned into the wildlife pathologist therefore I immediately buried the bird.
If people call their health agencies prior to finding the bird it will enable them to act quickly should they find a dead bird. If your health department does not want to collect dead birds, then prompt burial is needed.
The longer that a bird stays in the open environment, the more likely it will become a source of further infection. If birds are not wanted by wildlife pathologist, then bury any dead birds as quickly and safely as possible...
USA Update
[1] Date: Thu 24 Jul 2003
From: ProMED-mail <>
Source: Office of Animal Health Services, Louisiana
Department of Agriculture and Forestry,
Thu 24 Jul 2003 [edited] <>
Louisiana: WNV Update from the Office of the State Veterinarian ---------------------------------------------------
West Nile virus (WNV) has been found in 3 horses in Caddo and Lafourche Parishes. These are the first 3 that have been confirmed positive by the laboratory.
I would like to remind veterinarians that this is a reportable disease (to our office) when you FIRST suspect WNV or any other encephalitis as a differential. Test the suspect horses, call, email or fax our office to report the suspect case, and submit blood work to the laboratory. We are part of the state and nationwide data base now. I have to forward all known cases to several people within the state and the USA.
Important information that I need is the following: Name of owner, Address of owner, City and Zip code, Name of Horse, Breed, Sex, Age, Address of Horse, location, City, Parish, Zip code, vaccination status, Any other pertinent data or comments. Please help us by collecting as many of these data as possible! Nationwide, from the meetings I attended at AVMA meeting, this data is very much needed.
-- M. A. Littlefield-Chabaud, DVM, MS Assistant State Veterinarian Office of Animal Health Services Louisiana Department of Agriculture and Forestry 5825 Florida Blvd. Baton Rouge, LA 70806 PO Box 1951 Baton Rouge, LA 70821-1951 <>
[2] Date: Fri 25 Jul 2003
From: ProMED-mail <>
Source: Sun-Sentinel, Associated Press report, Fri 25 Jul 2003 [edited]
725virus,0,7750682.story? coll=sfla-news-florida
Florida: First 2 Human Cases of West Nile Virus Infection in 2003 ---------------------------------------------------------
West Nile virus has been detected in 2 Florida residents, marking the state's first human cases of the deadly mosquito-borne virus in 2003. A 76-year-old Marco Island man and an 85-year-old Panhandle woman have been diagnosed with the virus, health officials said Thu 24 Jul 2003.
State health officials placed Collier County under a medical alert, urging people (especially those older than 50 with weakened immune systems) to take extra precautions to avoid getting bitten. The alert also allows the state to spray insecticide if necessary. Officials in Okaloosa County said the woman diagnosed there was recovering at home. The 2 cases come early in the rainy season, when the freshwater mosquito that carries the virus thrives.
The Centers for Disease Control in Atlanta has reported 12 human cases of West Nile so far in 2003 in 8 states, numbers that do not include the 2 Florida cases. In 2002, more than 4000 people in the United States had symptoms of the virus, and 284 died. Hardest hit was Illinois, with 884 cases and 64 deaths. Florida had 28 cases and 2 deaths last year.
-- ProMED-mail <>
[This is the second state (the other was Colorado) reporting confirmed cases of human infection following prior detection of West Nile virus in blood donations. This suggests that surveillance by blood banks can provide early warning of overt disease in the human population. - Mods.MPP/CP]
[3] Date: Tue 29 Jul 2003
From: H.Larry Penning
Source: Florida Today, Associated Press report,
Mon 28 Jul 2003 [edited]
Florida: Another Blood Donor Tests West Nile Virus-Positive
State health officials confirmed the first human case of West Nile virus contracted in Brevard County on Mon 28 Jul 2003. The confirmation came one week after the Central Florida Blood Bank [detected West Nile virus nucleic acid] in the donated blood of a 36-year-old Rockledge man.
Health officials plan to take another blood sample from the Rockledge man in a few weeks to make sure he has fully recovered from the viral infection. He was thought to have been infected by the virus, which is spread by mosquitoes, while outside on the 4th of July. The man recovered from a brief illness by the time he gave blood on 15 Jul 2003 at the blood bank's Rockledge branch. The health department is also testing another positive [test result] for West Nile virus that the blood bank reported late last week in a 40-year-old Stuart donor. The blood bank found the 2 men's infected samples among 15 000 donations it has tested since 30 Jun 2003, using a new machine that identifies [viral nucleic acid]. The Stuart man, who suffered no significant illness, was working outside in the Rockledge area between late May and early July; he gave blood on 6 Jul 2003.
There have been no medical alerts in Brevard in 2003 for mosquito-borne illnesses. But state health officials issued alerts for West Nile virus infection for 2 counties earlier in July after an 85-year-old female in Okaloosa County and a 75-year-old male in Collier County contracted the disease. Both are recovering.
In 2002, West Nile virus killed 284 of 4156 people infected in America. 2 of 28 people infected in Florida died.
-- H.Larry Penning <>
[4] Date: Fri 25 Jul 2003
From: ProMED-mail
Source: Lincoln Journal Star, Fri 25 Jul 2003 [edited]
Nebraska: 2 suspected Cases of West Nile Virus Infection (One Imported) -------------------------------------------------
x 2 suspected [human] cases of West Nile virus infection have been reported by local health officials in Nebraska. A 63-year-old Fremont man has been confirmed to have contracted the virus by the Three Rivers Public Health Department. And preliminary tests show that a 19-year-old Lincoln woman could have West Nile virus infection, said Tim Timmons of the Lincoln-Lancaster County Health Department. Neither case has been confirmed by the state Health and Human Services System. Spokesman Bill Wiley said the system is awaiting confirmation from the Centers for Disease Control and Prevention in Atlanta.
The Lincoln woman, a Nebraska Wesleyan University student, became ill last week. She reported that she had been bitten by mosquitos while on a July 4th boating trip in northern Kansas and is recovering.
In 2002, there were 174 known cases in people in 48 of Nebraska's 93 counties. Most of those cases were in July, August, and September. 8 people have died from the virus in Nebraska so far in 2003 [sic: should read 2002. There have been zero human cases reported so far from Nebraska in 2003, see:
&controlCaseCount03.htm. CDC human totals for Nebraska for 2002, updated as of 7 Jul this year, 2003, are 152 cases & 7 deaths, see:
surv&controlCaseCount02.htm> - Mod.JW].
****** [5] Date: Thu 31 Jul 2003 From: ProMED-mail <> Source: Colorado Department of Health, Associated Press report, 31 Jul 2003 [edited]
Colorado: 13 More Cases of West Nile Virus Infection Confirmed ---------------------------------------------------
13 more cases of West Nile virus infection have been confirmed in humans in Colorado, and many more are expected as the exotic disease takes hold, state health officials said on Wed 30 Jul 2003. The latest human cases bring the total to 18, with 10 more suspected cases. The disease has been found in humans in 12 counties on the Eastern Plains and along the Front Range. West Nile first appeared in in the state in 2002, infecting 13 people. None of the Colorado cases has been fatal.
Dr. Ned Calonge, the state's chief medical officer, said the number of West Nile cases will rise but other diseases, such as [influenza], affect more people, he said. Influenza kills about 800 Coloradans each year. Calonge said that the number of West Nile virus cases is expected to decline after the disease has been in the state a few years.
-- ProMED-mail <>
[6] Date: Fri 1 Aug 2003
From: Ami Logan
Source: New Mexico, Fri 1 Aug 2003 [edited]
New Mexico: First Human Case of West Nile Virus Infection
A Valencia County woman is the first human case of West Nile virus infection in New Mexico. Until now, only horses and birds had been infected with the virus there. The woman had not traveled outside of New Mexico, so that means she was bitten by infected mosquitoes in this state. She was seen by her physician with symptoms of fever, headache, and a rash. She did not develop meningitis, which can be fatal.
The state health department says residents of Valencia County, as well as all New Mexicans, are encouraged to take precautionary steps to avoid mosquito bites. In the meantime, the state has set up surveillance sites around the state to check for West Nile virus.
So far in 2003, West Nile virus has been found in a horse in Sierra County, a horse in Chavez County and a golden eagle in Santa Fe County.
-- Ami Logan <>
[7] Date: Sat 2 Aug 2003
From: ProMED-mail
Source: Morbidity and Mortality Weekly Report,
Fri 1 Aug 2003 / 52(30);713-714 [edited]
United States: West Nile Virus Activity; Thu 24 Jul to Wed 30 Jul 2003 ----------------------------------------------------------------------
This report summarizes West Nile virus (WNV) surveillance data reported to CDC through ArboNET as of 3 a.m., Mountain Daylight Time, 30 Jul 2003.
During the reporting week of 24 to 30 Jul 2003, a total of 32 human cases of WNV infection were reported from 7 states (Alabama, Colorado, Florida, Louisiana, Mississippi, South Dakota, and Texas). During the same period, WNV infections were reported in 277 dead corvids (crows and related species), 70 other dead birds, 36 horses, one dog, one unidentified animal species, and 352 mosquito pools.
During 2003, a total of 44 human cases of WNV infection have been reported from Texas (n = 11), Louisiana (n = 10), Alabama (n = 6), Colorado (n = 4), Florida (n = 4), South Dakota (n = 4), Iowa (n = one), Minnesota (n = one), Mississippi (n = one), Ohio (n = one), and South Carolina (n = one). Among 43 (98 percent) cases for which demographic data were available, 27 (63 percent) occurred among men; the median age was 55 years (range: 5 to 87 years), and the dates of illness onset ranged from 29 May to 19 Jul 2003. In addition, 828 dead corvids and 220 other dead birds with WNV infection were reported from 36 states; 90 WNV infections in horses have been reported from 19 states (Alabama, Arkansas, Colorado, Florida, Georgia, Kansas, Kentucky, Minnesota, Missouri, Montana, Nebraska, New Mexico, North Carolina, North Dakota, Oklahoma, South Dakota, Texas, Wisconsin, and Wyoming), one infection was reported in an unidentified species (Florida), and 2 WNV infections were reported in dogs (Florida and South Dakota).
During 2003, WNV seroconversions have been reported in 86 sentinel chicken flocks from 6 states (Colorado, Florida, Iowa, Louisiana, North Carolina, and Nebraska). South Dakota and Louisiana each reported 3 seropositive sentinel horses; 679 WNV-positive mosquito pools have been reported from 18 states (Colorado, Connecticut, Georgia, Illinois, Indiana, Kansas, Louisiana, Maryland, Massachusetts, Michigan, Mississippi, Nebraska, New Jersey, South Dakota, Tennessee, Texas, Virginia, and Wisconsin).
Additional information about WNV activity is available from CDC at: and
-- ProMED-mail <>
[The reports above of the first human case in New Mexico and the suspected case in Nebraska are additional to the data included in the CDC-ArboNET report for the period 24 to 30 Jul 2003. - Mod.CP]
Date Sun 3 Aug 2003
From: ProMED-mail
Source: Health Canada, West Nile Virus Surveillance,
Thu 31 Jul 2003 [edited]
West Nile Virus Surveillance Data as of Thu 31 Aug 2003
Human ---- One confirmed case in Saskatchewan; WNV detected in blood donation [see: West Nile virus, blood donor - Canada (Saskatchewan) 20030726.1842].
Equines ------
5 confirmed equine cases; Ontario (1), Manitoba (2), Saskatchewan (1), Alberta (1).
Mosquitoes -- correction ---------
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 31 Jul 2003, 4 pools of mosquitoes have tested positive; Quebec (1), Ontario (1), Manitoba (1), Alberta (1).
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/ 207/ 192/ 0/ Nova Scotia/ 478/ 461/ 0/ New Brunswick/ 491/ 467 1/ Quebec/ 1079/ 998/ 14/ Ontario/ 1242/ 1086/ 74/ Manitoba/ 833/ 750/ 82/ Saskatchewan/ 819/ 644/ 27/ Alberta/ 707/ 691/ 8/ British Columbia/ 1422/ 1395/ 0/ Yukon/ 7/ 6/ 0/ Northwest Territories/ 10/ 10/ 0/ Nunavut/ 1/ 1/ 0/
-- ProMED-mail <>
[The totals for Canada for 2003 so far are 7329 birds submitted for testing, 6733 birds tested, and 206 confirmed West Nile virus-positive. In addition there were 1989 sightings of dead birds recorded. This represents an increase of 952 birds tested and 73 more birds confirmed positive since the last update on Thu 24 Jul 2003.
Equine cases (5) and a human case are reported fro the first time, and the number of positive mosquito pools has increased by 2.
No positive West Nile virus results have been reported yet from the peripheral provinces of Newfoundland and Labrador, Prince Edward Island, Nova Scotia, British Columbia, Yukon, Northwest Territories and Nunavut -- not surprising for the last 3 areas since it is still pretty cold up there around the Arctic Circle, & mosquitoes aren´t flying there yet. - Mod.CP/JW]
Now, for a very interesting article and one that leaves many questions unanswered. I am wondering how and why UK birds would have immunity to NY99 West Nile LIKE virus. I understand that birds in the UK would probably build up immunity to the central African strain and even Israeli strain, (i.e as birds migrate from Africa to the UK) but wonder why UK birds would build up immunity to NY 99 WNV when birds in the Americas have not built up immunity that that strain of WNV.
Patricia Doyle
WEST NILE VIRUS, BIRDS: ANTIBODY - UK (02) ******************************************
A ProMED-mail post <> ProMED-mail is a program of the International Society for Infectious Diseases <>
Date: Wed 30 Jul 2003 From: Graeme Kirk <> Source: Cage and Aviary Birds, Sat 2 Aug 2003 [edited]
Research Suggests West Nile Virus is Endemic in the UK
[The following are edited extracts from an article written by Graeme Kirk for the 2 Aug 2003 edition of the weekly "Cage and Aviary Birds" - Mod.CP]
The UK bird population would appear to be safe from attack by West Nile virus (WNV), according to new research, because the vast majority of birds have already been exposed. A new study [see: West Nile virus, birds: antibody - UK 20030719.1772], carried out by researchers from the Centre for Ecology and Hydrology (CEH), examined more than 350 wild-caught and farm birds of 30 different species, from blackbirds and carrion crows to song thrushes and robins. Most of the birds had blood samples taken before being released, while brain tissue samples were also taken from crows and magpies caught and destroyed as part of pest control programmes.
The samples were tested for antibodies against up to 3 WNV types: NY, isolated in New York State, USA, in 1999; DAK, isolated in Central African Republic in 1967; and Is, isolated in Israel in the early 1980s. The results were startling, showing that 84 (59.6 percent) of the 141 samples tested for WNV-Is, 233 (66 percent) of the 353 samples tested for WNV-NY and a staggering 157 (91.3 percent) of the 172 samples tested for WNV-DAK had antibodies against the virus and had, therefore, been exposed to WNV at some time. Tests were also carried out to try and find active WNV in the samples taken -- without success -- although researchers were confident that it would be found if enough birds were tested.
While it will take some time for the full repercussions of the work to be explored, one initial conclusion is that the UK bird population is not at risk from WNV by virtue of its herd immunity, built up over many years. While no work has been done to verify this, it is also likely that all captive bird populations with access to open-air flights will have been challenged by WNV at some stage by virtue of the virus's transmission methods. Whether or not imported birds from the Americas could prove vulnerable if exposed to WNV from the UK population is yet to be seen, but the current high numbers of bird deaths in the USA and Canada show that there is no in-built immunity to WNV on that continent, leaving American stock open to challenge from the virus.
The apparent herd immunity against WNV found in UK birds is hardly surprising, considering the annual migration patterns of the many species that overwinter in Africa. This is backed up by the fact that antibodies to the Central African WNV-DAK strain proved the most prevalent in the tests carried out by CEH. With migratory birds arriving back in the UK each spring, the transfer of the disease to the native wild -- and captive -- bird population was just a matter of the presence of the appropriate methods of transmission, in this case mosquitoes and, to a lesser extent, ticks and mites.
It is impossible to tell when this process began, but it is clear that migration has been going on for many thousands of years, and it's therefore possible that WNV was in the UK bird population well before any of the virus strains were isolated in the laboratory. Dr Ernie Gould of CEH also suggests it's likely that some antibodies to WNV are passed from mother to chick: "The egg is a rich source of antibodies, but the levels of antibody we have recorded in adult birds mean this is not likely to be the only source of antibodies in the chicks. I would go as far as to say that the initial antibodies received from the egg are sufficient to allow the young birds to fight off the virus when they are exposed to it. This could be the reason why bird deaths from WNV have never been seen as a problem in the UK."
While Dr Gould and his team were unable to isolate any active virus in any of the samples tested, he is positive it is there. Tests on 69 juvenile spring-born birds caught and sampled during the summer of 2002 showed that 35 of these had been exposed to the virus and had developed antibodies. In each of these cases the source of infection had to be in the UK.
"We have to presume that the virus is circulating harmlessly in the bird population at a sub-clinical (showing no symptoms) level and is building herd immunity," Dr Gould said, "while we have not physically isolated the live virus, we have found RNA from the virus which suggests it is present. To draw another analogy with the human population, measles virus is known to persist in the jejunum (part of the small intestine) of people who have immunity to the virus. If you know where to look you will find it. Purists say that until the virus has actually been isolated, it cannot be considered to be in a population, but I am convinced that if we do enough sampling, it will be found."
One of the most worrying points about WNV is that it can prove fatal to humans. Indeed it was deemed responsible for the deaths of about 270 people in the USA during 2002. To date there have been no human cases of WNV found in the UK. The Public Health Laboratories recently studied brain samples from 150 unexplained brain encephalopathies and found no evidence of the virus. Dr Gould said, however, that would be surprised if there has been no cross-infection of WNV to humans in the UK. "Research in the Volgograd region of Russia has shown that ticks can be important in the transmission of WNV. While it's likely that this is one method of infection at work in the UK, the spread rate is too high for ticks to be responsible for the level of antibodies we have seen. The primary route of infection has to be the mosquito."
So, if UK mosquitoes are carrying the virus (something Dr Gould hopes to start studying shortly), why haven't we seen cases in the human and animal population? "Possibly because we've not looked hard enough," Dr Gould says. In July, the Chief Medical Officer -- who had seen an early draft of the paper produced by Dr Gould and his team -- suggested that medical professionals should step up their efforts to test for WNV in the human population.
-- Graeme Kirk Acting Deputy Editor Cage and Aviary Birds <>
[see also: West Nile virus, birds: antibody - UK 20030719.1772 2002 ---- Usutu virus, emergence in Europe (02) 20020918.5339 Usutu virus, emergence in Europe 20020722.4838] ...
Patricia A. Doyle, PhD Please visit my "Emerging Diseases" message board at:
Zhan le Devlesa tai sastimasa
Go with God and in Good Health



This Site Served by TheHostPros