Pandemic H1N1 Influenza among CSC Inmates 2009 – 2010:
Summary of Vaccination Campaign, Cases, and Outbreaks

June 2011

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III: Results


III Results – Vaccination Campaign

Number and % of Inmates Identified as Meeting Priority Criteria
CSC Region # Priority Inmates Identified Population at Start of Priority Campaign % Inmates Meeting Priority Criteria
Atlantic 596 1366 43.6%
Québec 923 3234 28.5%
Ontario 1324 3821 34.7%
Prairie 1147 3583 32.0%
Pacific 670 1904 35.2%
Total 4660 13,908 33.5%

RESULT: Overall, a third of inmates met the priority sequencing criteria which ranged from 43.6% in the Atlantic Region to 28.5% in the Quebec Region.

Priority and Overall Vaccination Campaign Coverage Rates by Region
Priority Vaccination Campaign
(late Oct. early Dec. 2009)
Overall (Priority + Mass)
Vaccination Campaign
(late Oct. 2009 Jan. 2010)
* Equals the number of inmates at the start of the immunization campaign (13,908) plus new admissions during the campaign (679).
CSC Region # Priority Inmates
Identified
# Inmates Immunized % Priority
Inmates
Immunized
Cumulative Inmate Population Total # Inmates Immunized % Inmate Population Immunized
Atlantic 596 443 74.3% 1433 1101 76.8%
Québec 923 806 87.3% 3388 2080 61.4%
Ontario 1324 1046 79.0% 3964 1612 40.7%
Prairie 1147 1027 89.5% 3787 2268 59.9%
Pacific 670 610 91.0% 2015 1059 52.6%
Total 4660 3932 84.4% 14,587* 8120 55.7%

RESULT: In the priority sequence, 3932 offenders or 84.4% were immunized. In total, 8120 inmates were immunized in CSC (estimated overall coverage 55.7%).

 

Cumulative # of Vaccinations Administered to Inmates (n=8120)*

* Note: graph excludes timeframe outside Oct. 31 – Dec. 18, 2009 when 186 immunizations were given

Cumulative # of Vaccinations Administered to Inmates (n=8120)*
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H1N1 Vaccine Coverage Rates
H1N1 Vaccine Coverage Rates
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RESULT: For all of the regions except Atlantic, the coverage rates were higher in the priority campaign than for the overall campaign.

 

Average Campaign Length in Days (range)
CSC Region Priority Vaccination Campaign Mass Vaccination Campaign
Atlantic 9 (1-29) 3 (1-6)
Québec 11 (2-25) 5 (1-10)
Ontario 12 (2-20) 6 (1-15)
Prairie 8 (1-21) 6 (1-16)
Pacific 10 (1-20) 40 (6-58)
Total 10 (1-29) 12 (1-58)
  • Priority campaign:
    • lasted an average of 10 days (range: 1 day – 29 days)
    • average length was shortest in the Prairie Region (8 days) and longest in the Ontario Region (12 days)
  • Mass campaign:
    • lasted an average of 12 days (range: 1 day – 58 days)
    • average length was shortest in the Atlantic Region (3 days) and longest in the Pacific Region (40 days)

III Results – Influenza Case Definitions

  • Influenza-Like-Illness (ILI)
    • Acute onset of respiratory illness associated with fever and cough; and one or more of the following:
      • sore throat; arthralgia; myalgia; prostration
  • Laboratory-Confirmed (lab-confirmed) Case
    • Laboratory confirmation of pandemic H1N1 influenza virus infection with or without clinical symptoms by one or more of the following tests:
      • RT–PCR (reverse transcriptase-polymerase chain reaction)
      • Viral culture
      • Four-fold rise in influenza A (H1N1) virus specific neutralizing antibodies
  • Epidemiologically-Linked (epi-linked) Case
    • An epi-linked case refers to an individual:
      • whose clinical presentation is consistent with influenza like illness AND
      • confirmed or suspected contact to a laboratory confirmed case AND
      • confirmatory laboratory testing has not been done for this particular individual.
  • Clinical Case
    • A case based on the presentation of clinical signs and symptoms consistent with influenza.
  • Negative for Influenza
    • A patient who is assessed for influenza but subsequently tests negative.

III Results – Influenza Cases and ILI

ILI Case Type distribution by Region
  H1N1 Lab confirmed Epi-linked/ Clinical Negative for Influenza Total
Atlantic 3 14 5 22 (14%)
Quebec 8 2 4 14 (9%)
Ontario 7 11 4 22 (14%)
Prairie 20 7 32 59 (37%)
Pacific 11 11 19 41 (26%)
TOTAL 49 45 64 158 (100%)

All 158 cases are “ILI” by definition; that is, they were “screened-in” based on meeting the symptoms of influenza-like illness.

 

ILI Case Type distribution by Origin and Gender
  H1N1 Lab confirmed Epi-linked/ Clinical Negative for Influenza Total
Origin
Canadian-born non-Aboriginal 28 30 30 88 (56%)
Canadian-born Aboriginal 17 10 32 59 (37%)
Foreign-born 4 5 2 11 (7%)
Gender
Male 48 43 63 154 (97%)
Female 1 2 1 4 (3%)

All 158 cases are “ILI” by definition; that is, they were “screened-in” based on meeting the symptoms of influenza-like illness.

 

Epidemic Curve of H1N1 Influenza Cases* (n=91)
Epidemic Curve of H1N1 Influenza Cases* (n=91)
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* 3 epi-linked / clinical cases which occurred in 2010 are not shown
** If date of symptom onset not reported, use the earliest of the following: date tested, treatment start date, date case reported.

 

Symptoms (n-158)
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Cases include lab-confirmed , clinical, and epi-linked categories
* Missing symptom information was excluded from the analysis

 

Risk Factors (n=158)
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Cases include lab-confirmed , clinical, and epi-linked categories
* Missing risk factor information was excluded from the analysis

 

Symptoms

  • Cases reported symptoms more frequently than those negative for influenza
  • Fever was not a prominent symptom (only reported by 39% of cases and 29% of those who tested negative for influenza)

Risk Factors

  • Most common risk factors for cases: hepatitis / cirrhosis (17%), bronchopulmonary disorders (15%) and age 65+ years (7%).
  • Most risk factors were more common among those who tested negative
    • inmates with underlying conditions were more likely to be assessed due to increased risk of poor outcomes
Testing
Nasopharyngeal Swab Nasal Swab* Throat Swab* Serum Bronchoalveolar Lavage Chest X-ray Sputum

* Note: Nasopharyngeal swab is the best way to test for influenza infection (nasal and throat swabs are not recommended). One offender tested positive with a nasal swab while the rest of the nasal/ throat swabs were negative and could represent false negative results.

67% (105) 2.6% (4) 0.6% (1) 0.6% (1) 0.6% (1) 3.2% (5) 1.9% (3)
  • Overall % positive for all tested = 44.1%
Severity
Hospitalization** Isolation Oxygen Therapy Pneumonia
** Includes CSC Regional Hospital
3.2% (5) 53% (82) 1.3% (2) 0.6% (1)
  • No inmates were ventilated, admitted to the ICU (intensive care unit) or experienced ARDS (acute respiratory distress syndrome)

Treatment

  • 53% (n=83) of inmates with ILI were treated with Oseltamivir (Tamiflu).
  • Oseltamivir was the only antiviral medication used for treatment.
  • No serious adverse events to treatment were reported.

Case Status

  • At the time of reporting, 81% (n=113) of offenders were stable and 19% (n=26) were recovering.
  • There were no inmates deaths due to H1N1.

 

Symptoms by Treatment Status (n=158)
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Inmates who reported symptoms were more likely to be treated with antivirals (Oseltamivir)

 

Risk Factors by Treatment Status (n=158)
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Inmates who reported risk factors for severity were more likely to be treated with antivirals (Oseltamivir)


III Results – Outbreaks

OUTBREAK DEFINITION: Two or more cases of ILI within a seven-day period including at least one lab-confirmed case.

Institution Region # cases during outbreak
period
Date* outbreak started Date** of last case in outbreak Date outbreak ended***
*This is the first reported date of symptom onset
** This is the latest date of symptom onset for the last case in the outbreak
*** Outbreaks end 14 days (2 incubation periods) after latest symptom onset of last case
Springhill ATL 8 Nov. 25 Dec. 20 Jan. 3
Archambault QUE 6 Nov. 24 Dec. 1 Dec. 15
Centre Régional de Réception QUE 2 Nov. 12 Nov. 19 Dec. 3
Joyceville ONT 5 Nov. 7 Nov. 16 Nov. 30
Pittsburgh ONT 12 Nov. 3 Nov. 18 Dec. 2
Riverbend PRA 3 Nov. 6 Nov. 16 Nov. 30
Saskatchewan Penitentiary PRA 15 Nov. 9 Dec. 9 Dec. 23
Matsqui PAC 7 Nov. 8 Nov. 12 Nov. 26
Pacific/Regional Treatment Centre PAC 11 Nov. 3 Nov. 12 Nov. 26

Outbreak summary

  • There were a total of 9 outbreaks in CSC institutions during the 2009/2010 influenza season
    • All due to the pandemic H1N1 strain
    • 2 outbreaks in each region, except only 1 in Atlantic
  • The outbreaks varied in size
    • Smallest was 2 cases at Centre Régional de Réception (QUE)
    • Largest was 15 cases at Saskatchewan Penitentiary (PRA)
  • The outbreaks occurred between October 2009 and January 2010
    • Pittsburgh (ONT) and Pacific/Regional Treatment Centre (PAC) outbreaks began first on November 3, 2009
    • Springhill (ATL) outbreak ended last on January 3, 2010
    • The timing of the outbreaks corresponds with the national data from PHAC

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