May 26, 2006
The West Nile Virus surveillance season starts on May 29th with the activation of the Health Unit’s dead bird collection phone line, the “Crow Line.”
The Crow Line will be accepting calls from district residents who wish to report any dead crows, ravens or blue jays found in their area. These birds are highly susceptible to West Nile Virus and are therefore used to signal the prevalence of the disease.
Dead birds called into the Crow Line may be picked up for West Nile Virus testing if it appears the animal did not die from injury or trauma. If a bird of this description is found, the public is urged to call the Thunder Bay District Health Unit at 625-8328 (City) or toll-free 1-866-582-9003 (District of Thunder Bay).
Last year, 159 calls to the Crow Line resulted in 51 birds submitted for testing. Ten (10) birds tested positive for the virus.
The Crow Line helps the Health Unit monitor the presence of West Nile Virus in the bird community. The presence of West Nile Virus in the bird community may lead to the disease being transmitted to mosquitoes and from mosquitoes to humans. The health unit also conducts mosquito trapping and species analysis during the surveillance season.
According to the Health Unit’s 2005 study, the overall risk to human health in the Thunder Bay District was considered minimal since only 52 (0.5%) of 11,370 identifiable mosquitoes were the species (Culex restuans) which can transmit the disease to birds. However, Culex tarsalis, the species which transmits West Nile Virus in western Canada, was found within the District for the first time in 2005. Although they made up a very small proportion of all the mosquitoes trapped (21 of 11,370), the West Nile surveillance program will be monitoring any increase of this species in 2006.
The overall risk to human health in the Thunder Bay District was considered minimal and no remedial actions were recommended. The use of pesticides to control mosquitoes was not considered necessary. Read the Full Study outlining the 2005 status of West Nile in the Thunder Bay District.