First detected case of West Nile Virus
Manitoba has reported the first-ever case of a person infected with West Nile virus in the province this year, and three other possible cases are currently under investigation, according to an announcement made by the province on Friday, August 25.
The infected person is in the age range of 40 to 49 and resides in the Winnipeg Health Region. Presenting neurological symptoms, she required hospitalization. It is very likely that she was exposed to the virus between the end of June and the beginning of July, according to details provided in a statement.
The occurrence of West Nile virus infection in Manitoba is not unusual. For example, seven cases had been recorded the previous year, five of which had resulted in hospitalization.
What time of year is West Nile virus most prevalent in Canada?
West Nile virus is generally more prevalent in Canada during the summer and fall months when mosquitoes are most active. The periods from May to September are the most risky due to higher temperatures and increased mosquito activity. However, the presence of the virus can vary from year to year depending on factors such as weather conditions, the density of mosquito and host bird populations, as well as the control measures put in place to limit the spread of the virus. spread of the disease. During these risky times, it is important to take protective measures against mosquito bites, such as using repellents and wearing long clothing.
Case Study: City of Ottawa
The following is a summary of the steps taken by GDG in the City of Ottawa’s West Nile virus surveillance and control program following the identification of a positive mosquito site:
- Installation of CDC light traps: Each week, 35 CDC light traps are strategically installed throughout the city to monitor mosquito populations.
- Mosquito collection and identification: Mosquitoes collected from these traps are carefully identified to the species level.
- Testing for the presence of West Nile virus: Identified mosquitoes are then subjected to PCR tests to determine the presence of West Nile virus.
- Data Analysis and Reporting: Mosquito surveillance and testing data are analyzed to determine if any West Nile virus-positive sites are identified.
- Immediate notification: If a positive mosquito site is identified, the appropriate authorities, such as Ottawa Public Health, are notified promptly. This allows them to prepare a press release to inform the public.
- Increased larval surveillance: Field teams are stepping up their larval surveillance efforts around the location where the positive mosquito cluster was found. This includes :
- Sump treatment: Ensure that sump treatments are carried out in the surrounding area to reduce mosquito breeding sites.
- Verification of the presence of Cx. pipiens: Confirmation of the presence of the mosquito Culex pipiens in surface water sites, as it is a known vector of West Nile virus.
- Public awareness: If necessary, leaflets are distributed in the surrounding neighbourhoods. These flyers remind residents to take action by emptying any standing water on their properties. This helps to reduce mosquito breeding sites and minimize the risk of West Nile virus transmission.
In summary, the City of Ottawa’s West Nile virus surveillance and control program includes proactive mosquito surveillance, immediate notification of positive results, and rapid response to reduce mosquito populations and educate the public about preventative measures. This multi-step approach is critical to protecting public health from threats from West Nile virus.