2014 Surveillance for West Nile virus in Manitoba
- Positive Surveillance Indicators
- Culex tarsalis Mosquito Trap Catch by Regional Health Authority
- Positive Mosquito Collections (Adult) by RHA
- WNV Patients by Regional Health Authority
- Severity of WNV Disease by Age
- WNV Disease by Gender
- Weekly WNV Surveillance Report
Positive Surveillance Indicators
| Surveillance Indicator | 2014 | 2013 | 2012 |
Corvids 1 |
__ |
__ |
__ |
Mosquito Collections (Adult) |
24 |
19 |
116 |
Horse Cases |
0 |
1 |
7 |
Human Cases (Total) 2 |
5 |
3 |
39 |
| Surveillance Indicator | 2011 | 2010 | 2009 |
Corvids 1 |
__ |
__ |
__ |
Mosquito Collections (Adult) |
0 |
20 |
2 |
Horse Cases |
0 |
0 |
0 |
Human Cases (Total) 2 |
0 |
0 |
2 |
| Surveillance Indicator | 2008 | 2007 | 2006 |
Corvids 1 |
__ |
__ |
__ |
Mosquito Collections (Adult) |
41 |
948 |
171 |
Horse Cases |
0 |
8 |
1 |
Human Cases (Total) 2 |
12 |
587 |
51 |
| Surveillance Indicator | 2005 | 2004 | 2003 |
Corvids 1 |
12 |
16 |
134 |
Mosquito Collections (Adult) |
193 |
57 |
290 |
Horse Cases |
4 |
0 |
47 |
Human Cases (Total) 2 |
58 |
3 |
143 |
| Surveillance Indicator | 2002 | ||
Corvids 1 |
86 |
|
|
Mosquito Collections (Adult) |
15 |
|
|
Horse Cases |
236 |
|
|
Human Cases (Total) 2 |
0 |
|
|
* As of October 22, 2014
1The West Nile virus dead corvid pick up program is not in effect in 2014. Dead corvids are no longer needed as an early indicator of West Nile virus in Manitoba or to determine geographic distribution. Larval sampling, mosquito sampling and testing in addition to other factors (temperature, etc.) will be used to guide the assessment of risk of West Nile virus exposure.
2Additional information on these cases including classification, age, gender, regional health authority of residence and likeliest area of exposure is available here.
Culex tarsalis Mosquito Trap Catch by Regional Health Authority*
| Regional Health Authority | Sept. 14 - Sept. 20 | Sept. 7 - Sept. 13 | August 31 - Sept. 6 |
Interlake- Eastern 1 |
0 |
<1 |
<1 |
Prairie Mountain Health 2 |
0 |
<1 |
3 |
Southern Health-Santé Sud 3 |
0 |
<1 |
5 |
Winnipeg |
0 |
<1 |
1 |
| Manitoba | 0 | <1 | 3 |
| Regional Health Authority | August 24 - August 30 | August 17 - August 23 | August 10 - August 16 |
Interlake- Eastern 1 |
2 |
13 |
269 |
Prairie Mountain Health 2 |
2 |
31 |
35 |
Southern Health-Santé Sud 3 |
34 |
111 |
176 |
Winnipeg |
3 |
25 |
337 |
| Manitoba | 13 | 52 | 185 |
| Regional Health Authority | August 3 - August 9 | July 27 - August 2 | July 20 - July 26 |
Interlake- Eastern 1 |
27 |
15 |
150 |
Prairie Mountain Health 2 |
28 |
11 |
25 |
Southern Health-Santé Sud 3 |
153 |
57 |
49 |
Winnipeg |
27 |
20 |
54 |
| Manitoba | 67 | 28 | 57 |
| Regional Health Authority | July 13 - July 19 | July 6 - July 12 | June 29 - July 5 |
Interlake- Eastern 1 |
55 |
154 |
6 |
Prairie Mountain Health 2 |
4 |
3 |
<1 |
Southern Health-Santé Sud 3 |
22 |
91 |
12 |
Winnipeg |
21 |
74 |
17 |
| Manitoba | 22 | 71 | 9 |
| Regional Health Authority | June 22 - 28 | June 15 - 21 | June 8 - 14 |
Interlake- Eastern 1 |
12 |
<1 |
0 |
Prairie Mountain Health 2 |
1 |
<1 |
0 |
Southern Health-Santé Sud 3 |
2 |
2 |
0 |
Winnipeg |
7 |
<1 |
0 |
| Manitoba | 4 | 1 | 0 |
| Regional Health Authority | June 1 - 7 | May 25 - 31 | May 18 - 24 |
Interlake- Eastern 1 |
<1 |
<1 |
0 |
Prairie Mountain Health 2 |
0 |
0 |
0 |
Southern Health-Santé Sud 3 |
<1 |
<1 |
0 |
Winnipeg |
1 |
<1 |
0 |
| Manitoba | <1 | <1 | 0 |
1 Includes the former Interlake and North Eastman RHAs
2 Includes the former Assiniboine, Brandon and Parkland RHAs.
3 Includes the former Central and South Eastman RHAs
* As of October 22, 2014
Permanent mosquito traps are set up in 29 community areas in southern Manitoba to monitor Culex tarsalis mosquitoes, the mosquitoes that are most likely to transmit West Nile virus to humans in Manitoba. The above table will represent the average number of Culex tarsalis mosquitoes per trap catch for the week by Regional Health Authority (RHA) and provides a relative measure of the activity levels of Culex tarsalis from one RHA to another and over time. This measure is an indicator as to whether Culex tarsalis mosquito populations are rising or falling or staying steady. It should be noted that these RHA averages provide an approximate indication of the number of Culex tarsalis in the RHA, counts in specific locations within the RHA will vary depending on local conditions, temperature, precipitation, etc.
Note: normally, two Centers for Disease Control (CDC) mosquito traps baited with carbon dioxide are run for two nights each week in each Manitoba community except Winnipeg and Brandon (where proportionately more traps are used because of larger community size).
The average number of Culex tarsalis per trap catch (a trap catch – may also be called a “collection”- represents the mosquitoes collected by one trap during one night from approximately one hour before sunset until approximately one hour after sunrise) is calculated by dividing the total number of Culex tarsalis collected for the whole week in a given RHA by the number of collections.
Positive Mosquito Collections (Adult) by RHA*
| Positive Mosquito Collections (Adult) by RHA | |
| Interlake- Eastern 1 | 7 |
| Prairie Mountain Health 2 | 1 |
| Southern Health-Santé Sud 3 | 11 |
| Winnipeg | 5 |
| Total | 24 |
Mosquito samples from the following communities have tested positive for WNV in 2014: Altona, Beausejour, Gimli, Headingley, Morden, Niverville, Oakbank, Portage la Prairie, Selkirk, West St. Paul, Winkler, Virden and Winnipeg.
1 Includes the former Interlake and North Eastman RHAs
2 Includes the former Assiniboine, Brandon and Parkland RHAs.
3 Includes the former Central and South Eastman RHAs
* As of October 22, 2014
WNV Human Cases by Regional Health Authority*
Represents the Regional Health Authority of residence of the patient.
| Regional Health Authority |
Asymptomatic | West Nile Virus Non-Neurological Syndrome | West
Nile Virus Neurological Syndrome |
Unclassified Positive Test Results |
TOTAL |
Interlake- Eastern 1 |
0 |
1 |
0 |
0 |
1 |
Northern 2 |
0 |
0 |
0 |
0 |
0 |
Prairie Mountain Health 3 |
0 |
2 |
0 |
0 |
2 |
Southern Health-Santé Sud 4 |
0 |
1 |
0 |
0 |
1 |
Winnipeg |
0 |
0 |
1 |
0 |
1 |
| Total | 0 |
4 |
1 |
0 |
5 |
| Out of Province | 0 |
0 |
0 |
0 |
0 |
1 Includes the former Interlake and North Eastman RHAs
2 Includes the former Burntwood and NorMan RHAs
3 Includes the former Assiniboine, Brandon and Parkland RHAs.
4 Includes the former Central and South Eastman RHAs
* As of October 22, 2014
Note: 2014 human case classifications include both preliminary and final classifications and may be subject to change as further information becomes available. One of these cases was not likely exposed during the 2014 WNV season.
Severity of WNV Disease By Age*
| Age in Years | Asymptomatic | West Nile Virus Non-Neurological Syndrome | West
Nile Virus Neurological Syndrome |
Unclassified Positive Test Results |
Total |
| 0 - 9 | 0 |
0 |
0 |
0 |
0 |
| 10 - 19 | 0 |
0 |
0 |
0 |
0 |
| 20 - 29 | 0 |
0 |
0 |
0 |
0 |
| 30 - 39 | 0 |
0 |
1 |
0 |
1 |
| 40 - 49 | 0 |
0 |
0 |
0 |
0 |
| 50 - 59 | 0 |
1 |
0 |
0 |
1 |
| 60 - 69 | 0 |
2 |
0 |
0 |
2 |
| Over 70 | 0 |
1 |
0 |
0 |
1 |
| Total | 0 |
4 |
1 |
0 |
5 |
* As of October 22, 2014
Note: 2014 human case classifications include both preliminary and final classifications and may be subject to change as further information becomes available. One of these cases was not likely exposed during the 2014 WNV season.
WNV Disease by Gender*
| Gender | Asymptomatic | West Nile Virus Non-Neurological Syndrome | West Nile Virus Neurological Syndrome |
Unclassified Positive Test Results |
Total |
| Male | 0 |
3 |
1 |
0 |
4 |
| Female | 0 |
1 |
0 |
0 |
1 |
| Total | 0 |
4 |
1 |
0 |
5 |
* As of October 22, 2014
Note: 2014 human case classifications include both preliminary and final classifications and may be subject to change as further information becomes available. One of these cases was not likely exposed during the 2014 WNV season.
Weekly WNV Surveillance Report
- Week 37
- Week 36
- Week 35
- Week 34
- Week 33
- Week 32
- Week 31
- Week 30
- Week 29
- Week 28
- Week 27
- Week 26
- Week 25
- Week 24
- Week 23
- Week 22
Additional information and maps are available at the Public Health Agency of Canada website.
For WNV health concerns, contact your doctor or call:
Health Links - Info Santé
204-788-8200 (Winnipeg) or toll-free 1-888-315-9257
