Transcript Influenza Surveillance In Saskatchewan

Influenza
Surveillance In
Saskatchewan
Ken Brandt
Manager, Virology Section
Provincial Laboratory
Regina, Saskatchewan
Purpose
The early detection of Influenza A and B
in the province
The early detection of novel influenza
strains in the province
Saskatchewan has had an influenza
surveillance program for over thirty
years
Now part of Flu Watch – the
Federal/Provincial influenza surveillance
program
Saskatchewan’s program is unique
- the Flu Watch program is run out of
the Provincial Laboratory instead of
being run by the provincial epidemiologist
- we recruit our own surveillance
physicians not NARES
Currently have 13 sentinel physicians
that geographically cover all areas of
the province
They report influenza-like illness (ILI) on
a weekly basis
Requested to send 2 NPS specimens
each week on patients they see with ILI
ILI definition for 2004 – 2005
Acute onset of respiratory illness with
fever and cough and with one or more
of the following – sore throat, arthralgia,
myalgia, or prostration which could be due
to influenza virus. In children under 5,
gastrointestinal symptoms may also be
present. In patients under 5 or 65 and
older, fever may not be prominent.
Problems with ILI
- sentinel physicians may not see any patients
with ILI on their recording day
- symptoms seen may not match ILI definition
or the symptoms shown may be due to other
viruses
For example:
- 68 year old male presents with cough and
nasal congestion
- 15 year old male with fever, cough, sore
throat and flu-like symptoms
- 10 year old male with fever, cough, sore
throat and nausea/vomiting
Which one has influenza?
- 68 year old male presents with cough
and nasal congestion = Influenza A
- 15 year old male with fever, cough, sore
throat and flu-like symptoms =
Parainfluenza 2
- 10 year old male with fever, cough, sore
throat and nausea/vomiting =
Adenovirus
Laboratory confirmed cases of influenza from
the clinical specimens submitted to us are
the main source of data that we use in
Saskatchewan for Flu Watch
- advantage over ILI is that you know exactly
what you are dealing with
The number of clinical specimens
received on a daily basis from all areas
of the province provide a more accurate
picture of respiratory virus activity in the
province than weekly ILI data
Direct correlation with the number of
incoming specimens and influenza
positives
500
400
300
200
100
0
specimens
positives
Se
pt.
2
Oc 6
t. 1
7
No
v.
No 7
v.
De 28
c.
19
Ja
n.
9
Totals
Influenza 2003-2004
Date received
Therefore, in reality, we do not just have
13 surveillance physicians but every
physician submitting a specimen
becomes a surveillance physician
Because we routinely screen for
influenza on all respiratory specimens
no matter what month we are providing
year round surveillance
Respiratory specimen protocol:
- Direct DFA using Chemicon’s Simulfluor
Respiratory screen – detects the
presence of 7 respiratory viruses
including Influenza A, Influenza B,
Parainfluenza 1,2 and 3, RSV and
Adenovirus
- Tissue culture isolation (PMK, MDCK,
HP2)
- Molecular testing
HAI is done on all tissue culture positive
Influenza A isolates to determine strain –
i.e. H1N1 or H3N2
• Critical - if the isolate is not H1N1 or
H3N2 it is sent to our molecular lab for
further testing as it may be a novel or
pandemic strain
Additional data used to determine
influenza activity in the province:
- reports of school and work site
absenteeism
- confirmed outbreaks in hospitals, LTC
facilities
In conclusion:
- In Saskatchewan, influenza surveillance
or Flu Watch is laboratory based
- The main source of data for influenza
activity is lab confirmed positive
influenza tests
- other sources of data include number of
incoming respiratory specimens, ILI data from
surveillance physicians, reports of school and
work site absenteeism and outbreaks
- strain identification is critical in providing timely
information for pandemic planning