EPI-AIDs are the provision of assistance by Field Epidemiologists in investigating a public health issue. Field Epidemiologists have investigated close to 250 public health issues since 1975. Here are some recent examples:
In spring 2000, the largest outbreak of E. coli O157:H7 associated
with drinking water in Canada led to 1,346 reported cases of gastroenteritis,
65 hospital admissions, 27 cases of hemolytic uremic syndrome and 6 deaths
in Walkerton, Ontario. A Field Epidemiologist assisted the outbreak investigation
team in conducting a cross-sectional study to determine the impact of the
outbreak and the source of water contamination. It was found that heavy rains
accompanied by flooding led to well water contamination by surface water
polluted by infected cattle. The Walkerton outbreak led to a review of the
safety of ground water sources in Canada.
Waterborne Outbreak of Gastroenteritis Associated with a Contaminated Municipal Water Supply, Walkerton, Ontario, May-June 2000
World Health Organization issued a global alert on March 12, 2003 about Severe
Acute Respiratory Syndrome (SARS). The first severe infectious disease to
emerge in the 21st century, SARS is characterized by a severe and rapidly
progressing respiratory infection leading to acute respiratory distress syndrome.
By mid-May 2003, over 8000 probable cases and over 700 deaths have been reported
throughout the world. In the same period, close to 150 probable cases and
26 deaths had been reported from Canada, most of them from the Greater Toronto
Area. During the first three months of the outbreak, eight of the ten Field
Epidemiologists were involved in the investigation in Vancouver, Ottawa,
Halifax and Toronto conducting cluster investigations and descriptive epidemiology,
designing prevention and control guidelines, responding to public and media
inquiries and planning and implementing studies.
Cluster of Severe Acute Respiratory Syndrome Cases Among Protected Health Care Workers - Toronto, April 2003
Preliminary Clinical Description of Severe Acute Respiratory Syndrome
Epidemiology, Clinical Presentation and Laboratory Investigation of Severe Acute Respiratory Syndrome (SARS) in Canada, March 2003
In the fall of 2000, severe community-acquired pneumonia was reported in
several communities on Baffin Island, Nunavut. A Field Epidemiologist conducted
an epidemiologic investigation to describe the extent of the public health
problem. Ninety-two persons met the case definition. The clinical and radiographical
pattern suggested a bacterial origin, but only three cases had microbiological
confirmation, two of which were Streptococcus pneumoniae. The identification
of etiologic agents is a continuing challenge in Nunavut and other northern
communities where laboratory confirmation is often not available. Data from
this investigation supported the decision to implement a catch-up program
for their publicly-funded 23-valent pneumococcal polysacharride immunization
program and implement a 7-valent conjugate pneumococcal immunization program.
Ongoing surveillance for invasive serotypes of S. pneumoniae will
be crucial to the evaluation of immunization programs and to monitor any
shifts in the major serotypes causing disease in northern communities.
Pneumonia epidemic caused by a virulent strain of Streptococcus pneumoniae serotype 1 in Nunavik, Quebec
Six patients undergoing heart valve replacement surgery in 2001-02 in a New Brunswick hospital had Aspergillus cultured from their excised heart valves. Prosthetic endocarditis and systemic aspergillosis were a real risk in these patients. A Field Epidemiologist assisted in an investigation to determine the extent of the outbreak and the cause of contamination. Environmental investigations revealed fungal and mould contamination of the operating rooms (OR). Contamination of the OR air supply was likely a combination of structural defects in the ventilation system and concurrent external construction. There was also a possibility of hospital laboratory contamination. Around the same time, an aspergillosis outbreak was occurring in a Quebec hospital, resulting in at least five deaths among individuals who underwent open chest surgery. These two outbreaks increased the awareness of the risk and severity of nosocomial aspergillosis and led to the implementation of strict infection control guidelines and monitoring.
In June 2001, Health Canada received a report of excess gastrointestinal illness aboard a cruise ship arriving from Alaska 24 hours prior to its arrival in Vancouver, British Columbia. Fifty-four of 1576 (3.4%) passengers and crew were ill with diarrhea and vomiting. Two Field Epidemiologists participated in the investigation to determine the cause and source of the outbreak. The causal agent was Norwalk-like virus. The exact source was not identified, but the investigation suggested that the disease was transmitted person-to-person. Aggressive cleaning and sanitation measures were implemented and educational messages developed which led to the control of the outbreak.
In 1997, in a region of Ontario, a concerned citizen identified a potential cluster of cases of mesothelioma. Two Field Epidemiologists participated in the investigation to determine whether rates were truly elevated. Case finding through the provincial cancer registry and the worker's compensation registry revealed 35 cases among males. This was four times the expected number, as compared with previous years. Because of asbestos manufacturing in the region, it was thought that most cases were related to occupational exposure. In-depth exposure ascertainment is being planned.
The worst ice storm in recent memory struck Ontario, Quebec and New Brunswick in January 1998. Nearly double the annual total of freezing rain fell in the week of the storm and resulted in loss of electrical power and extremely icy conditions. Many were put at risk of injury and illness. A Field Epidemiologist was asked to describe the adverse health events related to the storm in one health unit in Eastern Ontario. As compared to a similar period during the previous year, an increase was noted in emergency room visits for carbon monoxide poisoning and injuries due to falls. There was also an increase in admissions for myocardial infarctions, gastrointestinal illness and fractures. In general, increases were less than expected. Recommendations focused on means to prevent the risk of carbon monoxide poisoning associated with alternate sources of home heating.
Over 200,000 Catholic youth from around the world gathered in Canada from July 13 to 22 and in Toronto from July 23 to 28, 2002 for World Youth Days and a visit to Toronto by Pope John Paul the Second. Syndromic surveillance was used for the first time in Canada to systematically monitor communicable diseases, environment-related illness (e.g. heat stroke) and A-list bioterrorism agents. Fourteen current and former Field Epidemiologists were involved in national and Toronto-based surveillance activities for this mass gathering event. Many heat-related illnesses occurred and a cluster of S. aureus food poisoning was identified among 18 pilgrims. Syndromic surveillance identified the outbreak and permitted rapid investigation and control.
Following an outbreak of E. coli O157:H7 in New Brunswick, the provincial government asked the CFEP and the Waterborne, Foodborne and Zoonotic Infections Division to help them design and implement a two-day workshop on enteric outbreak investigation for frontline public health workers in 2002. A second-year Field Epidemiologist and the CFEP Director participated in the development of the curriculum and the training of close to 100 public health inspectors and nurses in both official languages. A similar training was conducted in Alberta in 2003.
Field Epidemiologists are occasionally invited to participate in international missions through the World Health Organization (WHO) or other international partners. Recently, Field Epidemiologists have participated in:
During the war in Kosovo in 1999, under the direction of the United Nations High Commission for Refugees (UNHCR), the CFEP sent a Field Epidemiologist and the Program Director to Skopje, Macedonia. They participated in the planning of a health needs assessment survey among refugees hosted by Macedonian families.
As part of the Canadian Public Health Association's (CPHA) health information mission in Kosovo, two Field Epidemiologists traveled to the Prizreni Region in April and May 2001 to teach basic computer skills, including MS Windows and EpiInfo, to Kosovar health professionals.
Three second-year Field Epidemiologists and the CFEP Director joined an international
team of experts in Uganda in December 2000 to assist the Ugandan government
in the control of an Ebola Hemorragic Fever outbreak. They participated in
surveillance activities including setting up a surveillance database, active
case finding and descriptive epidemiology.
Outbreak of Ebola Hemorrhagic Fever, Uganda, August 2000 - January 2001
From December 2001 to January 2002, a second-year Field Epidemiologist joined
an international team of experts in Gabon to assist the Gabonese government
in the control of an Ebola Hemorragic Fever outbreak. She participated in
surveillance activities, case finding, follow-up of contacts and educational
Outbreak(s) of Ebola haemorrhagic fever, Congo and Gabon, October 2001–July 2002 (PDF Document)
STOP is an international initiative assisting the WHO in the Global Polio Eradication Initiative. Field Epidemiologists have participated in STOP missions through the Canadian Public Health Association (CPHA), the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO). Their role has been to assist local governments in their polio eradication and measles elimination efforts through surveillance for acute flaccid paralysis, polio and measles and immunization activities. Since 1999, Field Epidemiologists have participated in STOP missions in seven different countries.
The CFEP offers epidemiological assistance by deploying Field Epidemiologists to the field upon request. Field Epidemiologists can assist with the following:
Any Canadian region, province, territory or federal group investigating a public health issue may request Field Epidemiology assistance (EPI-AID) by consulting the CFEP Procedures for Requesting and Undertaking Field Investigations.
Requests from health care facilities, local and regional health departments should be directed to the Chief Medical Officer of Health of the province or territory. Provinces, territories, federal divisions, departments and agencies should contact the CFEP staff directly.
The request for field epidemiology assistance (EPI-AID) is assessed by the CFEP directors. If the EPI-AID is approved, terms of reference for the Field Epidemiologist are negotiated with the organization requesting assistance. Negotiation usually includes co-authorship on any publication arising from the investigation. All data collected during the EPI-AID are the property of the organization requesting assistance.
A Field Epidemiologist can usually be deployed to the field within 24 and 48 hours.
All costs associated with the Field Epidemiologist's work on an EPI-AID are covered by the CFEP, including travel, accommodation and per diem.