IN THIS ISSUE

The purpose of the WNv Bulletins is to provide a summary of the results of the various surveillance activities in Ontario for the current year. This issue will offer an update on findings elsewhere in Canada and in the U.S.. Additionally, this issue of the WNv Bulletin will outline and describe symptoms associated with WNv.

Similar to the activities implemented in 2000, Health Canada has asked that key health care providers, including family and emergency room physicians, infectious disease specialists and neurologists, monitor their patients for symptoms of WNv in 2001. These health care professionals are being asked to promptly report any probable and confirmed cases of viral encephalitis to local/provincial public health authorities.

Most individuals infected with WNv either show mild flu-like symptoms (fever, head/body aches) or no symptoms at all before fully recovering. Symptoms may begin anywhere from 3 to 15 days following the bite from a WNv-infected mosquito.

In the immunocompromised, the elderly and the very young, WNv infection can result in serious illness such as meningitis or encephalitis. Symptoms among these individuals with these conditions may include rapid onset of severe headache, high fever, stiff neck, vomiting, drowsiness, confusion, muscle weakness, loss of consciousness, and in severe instances death may occur. Individuals experiencing onset of these symptoms should seek medical care immediately.

1. Physicians (Hospital, clinic, private practice) :
   
   
   • Send blood samples from suspect WNv patients to the Central Public Health Laboratory (CPHL) in Toronto for serological testing to :
     
     Central Public Health Lab
     81 Resources Road
     Toronto, ON
     M9P 3T1
     
     
   • Report suspect WNv cases immediately to the local Medical Officer of Health and fax "Patient Report Form"
     
     
2. Health Units :
   
   
   • Report suspect WNv cases immediately by telephone to Dr. Margaret Fearon.
     
     Dr. Margaret Fearon
     416-235-5725  (pager : 416-715-4209)
     (After hours duty officer : 416-605-6113)
     
     
   • Report suspect WNv cases immediately by telephone to Dr. Chuck Le Ber or Dr. Dean Middleton at the Ministry of Health and Long-Term Care (MOHLTC), Public Health Branch.
     
     Dr. Chuck Le Ber
     416-327-7421
     
     Dr. Dean Middleton
     416-327-7422
   • Report suspect WNv cases in RDIS under the disease "viral meningitis/encephalitis" as outlined in the April 27, 2001 letter to all MOH's and Communicable Disease Coordinators from Dr. Colin D'Cunha regarding Enhanced Passive Human Surveillance for West Nile Encephalitis.

Mosquito surveillance will be implemented in areas from which a dead bird has tested positive for WNv.

This bulletin summarizes information up to, and including, the 27^th week of the Dead Bird Surveillance season (Week 27 = July 2 to 6, 2001). There have been a total of 1160 reported dead bird sightings and/or submissions. Of these 1160 birds, 666 were submitted to the lab in Guelph for WNv testing ("pickups"), while 409 of those submitted to Guelph were sent to the lab in Winnipeg ("submissions"). Maps stating the number of dead bird submissions to the lab will be provided weekly to health units.

Figure 1.   Ontario Reported Number of WNv Surveillance Program Dead Birds (July 5, 2001) (N=1111**)
** Omitted from graph : 46 reported dead birds = missing, 3 reported dead birds = prior to season**

Data Source : Canadian Cooperative Wildlife Health Centre & Health Canada, July 5, 2001.

Note :

• Week 16 = April 16-20, 2001
• Week 27 = July 2-6, 2001*

* Week 27 data does not include reports from July 6, 2001.

Figure 2.   Types of Ontario Dead Birds Reported in 2001 Season as of July 5, 2001 (N=1160)

Figure 3.   Number of Dead Bird Reports in 2001 by Ontario Health Units as of July 5, 2001 (n=1160)

Note :   "Pickups" are health unit submissions to the lab in Guelph, whereas "Submissions" refer to dead birds sent to the lab in Winnipeg for Federal WNv Testing.

Data Source :   Canadian Cooperative Wildlife Health Centre & Health Canada, July 5, 2001.

WNv has been described worldwide, and is no longer limited to African and Eurasia.

The American media has paid much attention to state health departments and local units with respect to their choices regarding the spraying of chemical pesticides.

Human cases : As of July 6, 2001, there have been no reported positive human cases of WNv in the U.S. in 2001.

Table 1.   Number of dead birds and mosquito pools in 2001 that tested positive for WNv in the U.S., reported as of July 6, 2001.

Maps of the United States WNv Surveillance Programs can be accessed through the United States Geological Survey : Center for Integration of Natural Disaster Information (CINDI) Web site.

• Dead Birds Submitted for WNv Diagnosis by Health Unit in Ontario as of July 9, 2001.
  [PDF version]
• Birds Submitted for WNv Diagnosis by Health Region in Canada as of July 9, 2001.
  [PDF version]

The contribution of the following agencies and individuals in the publication of this year's issues of the WNv Bulletin is greatly appreciated :

Ontario Ministry of Health and Long-Term Care (MOHLTC) : Public Health Branch : Dr. Colin D'Cunha, Dr. Charles Le Ber and Dr. Dean Middleton.

Canadian Cooperative Wildlife Health Centre : Dr. Ian Barker and Ron Templeman.

Health Canada : Dr. Peter Buck and Rob Meyers.

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