Summary of Severe Acute Respiratory Syndrome (SARS) Cases: Canada and International

April 25, 2003

Canada

Since yesterday, two additional probable cases of SARS have been reported in Canada. A total of 142 individuals who meet the probable case definition and 200 who meet the suspect case definition of SARS have been reported, including 19 deaths. In addition to suspect and probable cases reported in British Columbia and Ontario, suspect cases have also been reported in Alberta, Saskatchewan, New Brunswick and Prince Edward Island (Table 1).

Table 1: Cumulative Number of SARS Cases Reported in Canada: April 25, 2003

Province/Territory	Individuals Meeting the Criteria for a:		Deaths
	Probable Case1	Suspect Case1
British Columbia	4	60	0
Alberta	0	6	0
Saskatchewan	0	1	0
Manitoba	0	0	0
Ontario	138	127	192
Quebec	0	0	0
Nova Scotia	0	0	0
Newfoundland	0	0	0
New Brunswick	0	2	0
Prince Edward Island	0	4	0
Nunavut	0	0	0
North West Territories	0	0	0
Yukon	0	0	0
TOTAL	142	200	19
1These persons may be excluded the probable or suspect case list if another cause is identified to fully explain their illness 2 18 of 19 deaths were probable cases, while 1 was a suspect case. Another death, not included in this total count was a 46-year-old female who died in the Philippines on April 13, 2003. It is believed she may have contracted SARS while in Toronto.

The current status of all probable and suspect cases in Canada as of April 25, 2003 is presented in Table 2. Of the 342 probable and suspect SARS cases identified to date, 231 (68%), have either recovered, been discharged from hospital, or are currently at home recovering. In addition, of the 92 individuals
currently hospitalised, 70 (76%) are improving or in stable condition. Most of the case fatalities reported have occurred in patients with underlying illness, and nearly all were elderly patients over the age of 70 years.

Table 2: Currently known reported status of probable cases of SARS in Canada: April 25, 2003

Current Status	Number (%) of Probable Cases	Number (%) of Suspect Cases
Hospitalised	49/142 (35%)	43/200 (22%)
Improving	10/49 (20%)	10/43 (23%)
Stable	27/49 (55%)	23/43 (53%)
Critical/Deteriorating	5/49 (11%)	1/43 (2%)
Unknown	7/49 (14%)	9/43 (21%)
Discharged1	75/142 (53%)	85/200 (43%)
At Home2	2/142 (1%)	70/200 (35%)
Deceased	17/142 (12%)	2/200 (1%)
Total Number of Cases for whom Current Status is Known	142 (100%)	200 (100%)
1 Includes cases who have either recovered or are recovering. 2 Refers to indivduals who have never previously been hospitalised, and are at home recovering/recovered.

The current evidence suggests that respiratory droplet transmission, requiring close contact with a case of SARS is the predominant mode of transmission. The mean incubation period is 5 days (median 4 days, range 2 to 10 days). This estimate is based on data available from 42 probable or suspect cases with a single known contact with a SARS case.

In the province of Ontario the majority of cases have been associated with specific transmission settings, such as household, hospital and specific community groups or settings. In the latter community group/setting, a total of 20 probable and 11 suspect cases of SARS were identified in a religious community cluster (BLD cluster). Four members of the index family who are members of this religious group had contact with a SARS case in the emergency room of a Toronto hospital on March 16, 2003. Three of them developed SARS after the exposure and the infection subsequently spread through their extended family. By April 12, 2003, all members of the religious group were quarantined, in an effort to contain any further spread within and outside of this social network. In total, cases among fourteen members of the index family, 3 health care workers and 14 other religious group members have been identified. The religious group has since completed their quarantine with no further cases identified through extensive case finding and contact tracing efforts.

Following the implementation of strict infection control measures in all Ontario hospitals, transmission of SARS to hospital workers has decreased substantially. However, despite these measures there have been recent reports of transmission to hospital workers. In 3 different hospitals transmission has been attributed to exposure during difficult intubations. In two, undiagnosed patients were identified as the source of transmission for 7 hospital workers. Compliance with infection control precautions by staff may not have been complete. In the third, a SARS patient was identified as the source of infection for 7 hospital staff. During the latter intubation, one health care worker accidentally dislodged her face shield. Transmission of SARS to 10-11 hospital staff has also been identified in 4 different low-risk SARS units and one community hospital. Initial investigation suggests that transmission in these settings has occurred while staff were wearing required personal protective equipment and following all recommended infection control precautions. An infection control directive specifically for SARS Units is being developed. A comprehensive investigation is presently underway involving experts from Health Canada, the U.S. Centers for Disease Control and Prevention (CDC), the Province of Ontario, and Toronto Public Health.

In British Columbia, the fourth probable case (onset April 4, 2003) was a health care worker who was exposed to the second travel-related probable case in that province. There are currently 4 suspect cases associated with this health care worker, including two health care workers, and two patients. Although quarantine has been completed for many of the patients who had contact with the health care workers, this situation is being carefully monitored by public health officials in BC.

Travellers who have returned from an affected area in Asia and their close contacts account for the remaining cases in Ontario and the other provinces.

The total number of probable cases reported to date in Canada, by reported symptom onset date and type of exposure (where known) is provided below (Figure 1).

 

Figure 1: Number of probable cases of SARS in Canada by symptom onset date and
exposure type: February 23 to April 24, 2003
(N=140, excludes 2 for whom onset date is unknown*)

* For April 25, 2003, data from the province of Ontario was not received at the time this report was prepared.

Source: Provincial-Territorial Ministries of Health

 

The following list of exposure sites was provided by the Ontario Ministry of Health and Long-Term Care as of April 25, 2003. It is important to note that transmission did not occur at most of these sites. However, quarantine measures were frequently implemented as a precautionary public health measure.

Site	Potential Dates of Exposure	Evidence of Transmission	Current/ Historical3
Ward Damiani Funeral Home 4671 Highway #7 W Woodbridge	April 18 (after 7:30 pm) April 19 (9 to 11 am)	No	Current
Sunnybrook Hospital CCU and CVICU	April 16 - 18	No	Current
GO Train Appleby to Union (middle car upper deck)	April 15 7:32 am departure	No	Current
GO Train, Union to Appleby (middle car upper deck)	April 14 4:30 pm departure	No	Current
St. David's Church Maple (2601 Major MacKenzie/Graveside Glendale Memorial Gardens)	April 19 (11:30 am)	No	Current
Sunnybrook Hospital SARS Unit	April 12 - 13	Yes	Historical
Highland Funeral Home	April 3	Yes	Historical
Hewlett Packard, Markam	March 29-April 1	one close contact	Historical
Metro Hall2	March 31-April 4	No	Historical
BLD Mass	March 28	Yes	Historical
BLD Life in the Spirit Seminar	March 29	Yes	Historical
York Central Hospital	March 16 - 28	Yes	Historical
Scarborough Grace Hospital1	March 16 - 25	Yes	Historical
1 The Scarborough Grace has recently passed an external audit, and will be reopening shortly. 2 Employees on the 19th floor were placed under quarantine from April 14-17. 3 Current refers to exposure risks within two incubation periods (20 days) of the potential exposure period. For historical exposures, two incubation periods have elapsed since the potential period of exposure.

---

International

Since November 1, 2002, 4,442 cases of SARS (4,299 outside of Canada) have been reported to the World Health Organization (Table 3). Outside of mainland China, the vast majority of reported cases have originated from Hong Kong, Special Administrative Region of China. As of April 25, 2003, 248 deaths have been reported outside of Canada, the majority (219) of which were reported in mainland China and Hong Kong, SAR.

The WHO is reporting that the severity of illness in cases linked to the previously identified cluster of cases in the Amoy Gardens housing complex is greater, relative to cases derived from other exposure settings. The report indicates that while 20% of Amoy-related cases require intensive care, this is true for only 10% of non-Amoy-related cases. In addition, 66% of Amoy Gardens patients present with diarrhea as a symptom, compared to only 2% to 7% of cases in other related-outbreaks.

Table 3: Cumulative Number of SARS Cases* and Deaths Reported to the World Health Organisation: November 1, 2002 to April 25, 2003

Country	Number of Cases	Number of Deaths
Australia	4	0
Brazil	2	0
Bulgaria	1	0
Canada	140	19**
China, mainland***	2422	110
China, Hong Kong SAR	1488	109****
China, Taiwan	37	0
France	5	0
Germany	7	0
India	1	0
Indonesia	1	0
Italy	4	0
Japan	2	0
Kuwait	1	0
Malaysia	5	2
Mongolia	3	0
Philippines	2	1
Republic of Ireland	1	0
Romania	1	0
Singapore	192	19
South Africa	1	0
Spain	1	0
Sweden	3	0
Switzerland	1	0
Thailand	8	2
United Kingdom	6	0
United States	37*	0
Vietnam	63	5
TOTAL	4439	267
*Cumulative number of cases includes deaths. Case definitions vary from one country to another. Only probable cases are being reported by all countries. The US will no longer be reporting suspect cases under investigation as of April 21, 2003. **18 of 19 deaths were in probable cases, while 1 was in a suspect case. ***The start of the period of surveillance was changed to November 1 2002 to capture cases of atypical pneumonia in China that are now recognised as being cases of SARS. ****One death attributed to Hong Kong SAR occurred in a case medically transferred from Vietnam. Source: http://www.who.int/csr/sarscountry/2003_04_25/en/, with updates from Canada.