W E S T N I L E V I R U S :Alberta’s Response Plan (2003)

HEALTH AND WELLNESS

AGRICULTURE, FOOD AND RURAL DEVELOPMENT

ENVIRONMENT

SUSTAINABLE RESOURCE DEVELOPMENT

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An interdepartmental planUnder the leadership of the Provincial Health Office, four government departments have expandedand updated a coordinated provincial plan for responding to West Nile virus (WNv) in Alberta.

The four government departments are:

• Alberta Health and Wellness

• Alberta Agriculture, Food and Rural Development

• Alberta Environment

• Alberta Sustainable Resource Development

Purpose of the planTo minimize the risk of WNv infection

Basis of the planAlberta’s WNv plan has been modified for 2003 within the context of:

• Health Canada’s National Guidelines for Response to West Nile virus (2003draft)

• What has been learned about WNv in the USA and Canada since it was firstidentified in North America in 1999

• U.S. Centers for Disease Control and Prevention Epidemic/Epizootic WestNile Virus in the United States: Revised Guidelines for Surveillance,Prevention and Control (2001)

• Alberta’s geography and ecology, including its migratory bird and mosquitospecies

Key componentsA number of coordinated activities will provide a comprehensive program for:

• Surveillance or monitoring for WNv in Alberta

• Communicating with the public and with professionals

New in 2003Humans • Laboratory testing in Alberta for faster results

• Blood supply protected

• Enhanced WNv education program for physicians

Birds • Crows tested locally in Alberta

Horses • Licensed vaccine available

• Information for veterinarians and horse owners

Mosquitoes • Monitoring larvae and adult mosquitoes in selected areas of the province

Communication • Public awareness campaign including Government of Alberta Web site

Alberta’s West Nile Virus Response Plan (2003)

Alber ta’s West Nile virus Response Plan (2003)

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WEST NILE VIRUS MONITORING AND RESPONSE

H U M A N S

All cases reported Under the authority of the Public Health Act, human cases of WNv infectionare reported to public health officials in Alberta.

The milder form of the infection (WNv fever) and the more serious form of thedisease known as WNv neurological syndrome are both reported to AlbertaHealth and Wellness, regional Medical Officers of Health, Health Canada and ifnecessary, to the Canadian Blood Services.

Blood supply protected The Canadian Blood Services will be notified when a person with a suspectedor confirmed case of WNv has donated or received blood or blood products, anorgan or other human tissue. Measures will then be taken by Canadian BloodServices to prevent the possibility of WNv transmission.

Physicians alerted Once WNv is confirmed in Alberta in a bird, horse, and mosquito pool or in aperson who does not have a history of travel to an area with WNv, theProvincial Health Office will contact all physicians to ask them to considerWNv when someone presents with specific symptoms.

Medical officers of health will also contact key medical personnel such asemergency room physicians, neurologists and infectious disease specialists todiscuss enhanced WNv monitoring within the regional health authority.

WNv education for MDs In early spring, the Provincial Health Office will distribute information aboutWNv and reporting requirements to physicians.

Opportunities for physicians to learn more about WNv will be made availablethrough accredited Continuing Medical Education programming at theUniversity of Calgary and the University of Alberta in May 2003.

Faster lab results In 2003, the Provincial Laboratory for Public Health (microbiology) will bedoing the initial blood tests for people who go to their physicians or toemergency rooms with symptoms that may indicate WNv infection. Withtesting being done in Alberta in 2003, waiting time for results will besignificantly reduced.

Public informed On an ongoing basis, the Provincial Health Office will monitor and report onthe number of suspect or confirmed cases of WNv human infections in Alberta.

The numbers of confirmed cases of WNv will be posted on the Alberta Healthand Wellness West Nile virus Web site.

Prevention stressed A public awareness campaign will inform Albertans of WNv, how it is spreadand the measures they can take to protect themselves and their children.

Ongoing coordination The PHO will participate in the regular F/P/T (Federal/ Provincial/ Territorial)teleconferences that address WNv in Canada. Alberta’s InterdepartmentalCommittee will continue to evaluate Alberta’s WNv plan within the context ofwhat is happening in this province, nationally and internationally.

Alber ta’s West Nile virus Response Plan (2003)

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B I R D S

Role in surveillance Birds are the natural hosts for WNv. Since 1999, WNv has been identified inover 160 species of wild, captive and domestic birds in North America. Whilethe majority of these species appear to be unaffected, members of the crowfamily (Corvids) seem to be highly susceptible to the WNv and die soon afterinfection. Crows, therefore, are widely used as sentinels or early warningindicators of the presence of WNv in a geographic area.

The main purpose of WNv surveillance in birds is to identify the presence ofthe virus so that steps can be taken to reduce the risk of disease in humans.

WNv expected in 2003 It is highly likely that migratory birds returning to Alberta in the spring of 2003will bring WNv into some areas of the province. As a result, there is thepossibility of limited bird mortality over a wide geographical range in thespring and early summer. Mosquitoes that bite infected birds will potentiallypick up the virus and spread it within an area and then, to other parts of theprovince throughout the summer.

Monitoring dead crows The wild bird surveillance program in Alberta in 2003 will focus on dead crowsbecause they are widespread throughout the province, they have a high WNvmortality rate and there is a rapid, reliable diagnostic test that can be used todetect the presence of the virus.

The surveillance program will monitor evidence of WNv in crows in the sixnatural regions in the province - Grassland, Parkland, Foothills, RockyMountains, Boreal Forest and Canadian Shield. When there is confirmation of anumber of WNv positive birds in each natural region, ongoing surveillance willnot be necessary, as the strategies to reduce human health risks will notchange.

Laboratory testing Because WNv in a dead crow can be identified in an Alberta Agriculture, Foodand Rural Development laboratory, results can be quickly available to healthpractitioners, the public, veterinarians and horse owners.

WNv and other species The Fish and Wildlife Division will continue to monitor clusters of mortality,regardless of where, or in what species of wild bird or mammal they occur.

Messages to the public Information regarding Alberta’s WNv surveillance program in birds, frequentlyasked questions, information on how to handle dead birds, Fish and WildlifeOffices, and numbers of WNv positive birds will be available on theGovernment of Alberta’s Fish and Wildlife Web site.

Alber ta’s West Nile virus Response Plan (2003)

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H O R S E S

Role in surveillance The objective of WNv horse surveillance in Alberta is to identify the presenceof the virus so that steps can be taken to reduce the risk of infection in humansand horses.

Because clinical disease in horses can be quite dramatic, horses may be the firstspecies in Alberta to be recognized with WNv. Horses, with crows, willtherefore act as sentinels for WNv in the province.

Low risk/serious illness Although the risk of an individual horse becoming infected with WNv is verylow, a small proportion of horses infected with WNv will develop varyingdegrees of clinical disease. Up to 35% of these sick horses will die or have tobe euthanized because of complications resulting from the illness.

Reporting The Canadian Food Inspection Agency (CFIA) expects to have legislationpassed before the start of the mosquito season making WNv infections in allbirds and animals an Immediately Notifiable Disease under the Canada Healthof Animals Act. This will require the testing laboratory to notify the CFIAwithin 48 hours if they suspect a specimen from an animal is infected withWNv.

Alberta Agriculture, Food and Rural Development (AAFRD) will make WNv inhorses a Reportable Disease in the Designated Communicable DiseaseRegulation. This will require anyone knowing or suspecting WNv infection in ahorse to report the occurrence to the Chief Provincial Veterinarian (CPV).

When the first case of equine WNv is confirmed in Alberta, the CPV will notifythe Provincial Health Office, other government departments and the public.

Information for owners AAFRD and the Alberta Veterinary Medical Association have developed acomprehensive communication plan that informs veterinarians of thesurveillance and reporting protocols, and horse owners of the precautions theycan take to minimize the risk of WNv to their animals.

Information will be provided to horse owners on steps that can be taken toreduce exposure to mosquitoes that may carry WNv (e.g. reducing mosquitobreeding sites, ensuring the barn has screening in good repair, applyingrepellents containing DEET, regularly changing water in water tanks, etc).

Horse owners will also be advised to consult their veterinarian regarding theuse of the newly licensed WNv vaccine for horses.

Messages to the public AAFRD will also provide a fact sheet, articles in Agri-News, public informationspots on Call of the Land and materials for various stakeholder publications.

Information will be posted on the AAFRD Web site and every Friday, the CPVwill update the site with respect to the status of WNv in horses in Alberta.

Alber ta’s West Nile virus Response Plan (2003)

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M O S Q U I T O E S

Role in surveillance A mosquito surveillance program will be introduced in Alberta in 2003. Thisprogram will augment the existing surveillance system for birds and horses.

The purpose of the mosquito surveillance program will be to understandmosquito behaviour in Alberta and to detect the virus so that steps can betaken to reduce risk of disease in humans.

Specific objectives To identify and map larval habitats by season.

To study how climate and environmental factors in Alberta influence mosquitosurvival.

To perform WNv testing of selected mosquito pools in different geographicalareas of the province.

This information will be used for a better understanding of the role of themosquito in WNv transmission in Alberta.

Larvicide programs In 2003, as in previous years, some municipalities in Alberta will use chemicallarvicides within the context of their nuisance control programs.

The collection of surveillance data by these municipalities in 2003 will add tocurrent knowledge and will guide planning for 2004.

Adulticide programs Other jurisdictions in the U.S. and Canada have used ground and aerialspraying against adult mosquitoes when WNv was or was thought to be in ornear large urban centers.

Chemical control of adult mosquitoes is not a component of Alberta’s WNvplan because:

• there is no evidence of WNv in Alberta

• very few mosquitoes (2 or 3 of the 43 known species in the province) carrythe virus and it is unknown what proportion must be controlled to reducethe transmission of WNv

• spraying mosquitoes is the least efficient method of mosquito control

• spraying adult mosquitoes is only effective for a short duration of time asthe pesticide affects only those mosquitoes airborne at the time of thespraying

• buildings and other physical barriers limit the success of spraying

• spraying adult mosquitoes may have toxic effects on some humans andecosystems (e.g. honey bees, butterflies and other beneficial insectpopulations)

• at this time, it is unclear whether spraying adult mosquitoes reduces therisk of WNv infection in humans or horses.

Messages to the public Surveillance results will be reported to all four departments, localmunicipalities and they will be posted on the Alberta Health and WellnessWeb site.

Alber ta’s West Nile virus Response Plan (2003)

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COMMUNICATION PLAN

Specific objectives To inform Albertans when evidence of West Nile virus is identified in Albertaso that they can take steps to reduce their risk of infection.

To provide up-to-date information to Albertans about personal measures toprotect against being bitten by mosquitoes, the most effective means ofreducing the risk of infection.

Albertans notified As early as possible, the Government of Alberta will inform Albertans of thefirst evidence of West Nile virus in the province, whether in birds, horses,mosquitoes or humans. At that time, Albertans will be encouraged to take stepsto protect themselves from mosquito bites.

News releases will also inform Albertans of other developments, such as casesin other animals and humans.

Regular updates of West Nile virus in birds, horses, humans and mosquitoeswill be posted on the Alberta Health and Wellness Web site.

Public awareness Information about West Nile virus and the steps people can take to protectthemselves from the disease will be made available to Albertans in a number ofways:

• Beginning in May, a public awareness campaign will direct Albertans toreliable information through the government’s Web site, Albertans will beable to find reliable information and remind them of simple steps they cantake to protect themselves from the disease.

• More detailed information and links to other reliable sources will beavailable through the Government of Alberta’s Web site: www.gov.ab.ca

• Albertans can also call the Alberta Connects line at 310-4455 for moreinformation.