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Although no H7N9 or MERS cases have been detected in North America, and currently the PHAC (Public Health Agency of Canada) considers the risks to Canadians to be low at this time, Canada – like the United State’s CDC – is gearing up surveillance procedures in order to be able to detect introduction of the virus at the earliest opportunity.
Yesterday, PHAC released two new Interim guidelines for National Surveillance on these emerging viruses.
You’ll find that both documents follow the same format, but are customized for each virus. A few brief excerpts from the MERS-CoV Guidance follow, but you’ll probably want to examine both documents in their entirety.
Surveillance Goals and Objectives
Given the evidence to date, the main goal of public health response is early detection and containment.
To accomplish this goal, following national surveillance objectives have been developed:
- Detect human cases of MERS-CoV infection in Canada
- Monitor the incidence and the geographical distribution of new cases over time
- Describe and monitor changes in the epidemiological and virological features of the disease(e.g. clinical features and progression, morbidity, mortality, incubation period, mode of transmission, at risk populations)
- Notify and disseminate information to stakeholders in order to facilitate timely and appropriate public health activities
Case Definition
The Public Health Agency of Canada has developed case definitions for classification and reporting of human cases of MERS-CoV. They are located on the Public Health Agency of Canada website.
Case Identification and Interview
Laboratory-confirmation of a MERS-CoV case is an immediate trigger to launch a thorough investigation. However, because collection, shipment, and testing of specimens often require several days or longer, the investigation may need to begin before laboratory test results are available for suspected cases. Even if laboratory-confirmation is not possible, an investigation should still be launched if a patient is strongly suspected to have MERS-CoV infection.
The patient and/or family members (if the patient is too ill to be interviewed or has died) should be interviewed within the first 24–48 hours of the investigation to collect basic demographic, clinical, and epidemiological information. A sample case investigation/reporting form for the interview can be found on the Public Health Agency’s website. Provinces and territories may choose to use this form, or a similar form developed for use within their jurisdiction.
Essential Basic Information
Within 24 hours of notification, the following priority data elements (Box 1) should be submitted on the initial case report form or through electronic methods for confirmed and probable cases (within 24 hours of PT notification)Footnote 1.
Contact Monitoring
Close contacts of confirmed or probable cases should be identified and monitored for the appearance of respiratory symptoms for 14 days after last exposure to the confirmed or probable case, while the case was symptomatic. Any contact that becomes ill with symptoms compatible with MERS-CoV in that period of time should be tested for MERS-CoV. Ring testing (testing those with closest and most prolonged contact) should be considered, and a subset of those with progressively less contact should be identified to evaluate transmissibility and evidence of asymptomatic infection.
A line-listing of all contacts and exposed persons that records demographic information, date of first and last common exposure or date of contact with the confirmed or probable case, and date of onset if fever or respiratory symptoms develop should be maintained. The common exposures and type of contact with the confirmed or probable case should be thoroughly documented for any contacts that become infected with MERS-CoV.
Additional information can be found in the Interim Guidance for Public Health Management of Human Illness Associated with MERS-CoV.
Surveillance in the setting under investigation should be enhanced to detect cases that might arise subsequent to the discovery of the index case. The geographical area targeted will need to be assessed and defined by the suspected exposures of the confirmed case under investigation. The duration of the enhanced surveillance will depend on the findings of the investigation and whether there is evidence indicating that sustained transmission may be occurring in the area. A minimum of one month of enhanced surveillance is a reasonable starting point.
Enhancements include:
- Establish mechanisms for rapid transfer of specimens to the National Microbiology Laboratory (NML)
- Inform clinicians in the community of the need for increased vigilance and triggers for identification and notification
- Increase testing for MERS-CoV of SARI cases at) local health care facilities in the area under investigation.
- If resources allow, consider some testing of milder cases of influenza-like illness presenting to surveillance sites.
PHAC also updated their Public Health Advisory on MERS-CoV for Canadians earlier today:
Public Health Notice: Middle East Respiratory Syndrome Coronavirus (MERS-CoV)
24 Oct 2013
Information is reviewed on a regular basis and updated as required.Why you should take note
Since April 2012, cases of the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) have been identified in eight countries: the United Kingdom (UK), Jordan, Qatar, Saudi Arabia, the United Arab Emirates, France, Tunisia and Italy. The initial cases in the UK, France, Tunisia and Italy were linked to travel to the Middle East.
Coronaviruses are the cause of the common cold, but can also be the cause of more severe illnesses with flu-like symptoms, including Severe Acute Respiratory Syndrome (SARS), with some cases resulting in death. This new virus is not the SARS virus. Additional cases of this new strain of coronavirus are expected. Official numbers are available here
.
Risk to Canadians
The risk to Canadians is low. This virus does not appear to spread easily from person to person.
At the same time, we do not yet fully understand exactly how people become infected with MERS-CoV. Experts are still investigating its source and how it spreads.
In the cases where it has appeared to have spread between people, those cases involved close contacts: family members, co-workers, fellow patients and healthcare workers.
Federal and provincial laboratories have been testing specimens and there are currently no cases in Canada.
Canadians can help protect themselves against these types of viruses by following some general measures:
- Avoid close contact with anyone showing signs of illness (such as coughing and sneezing);
- Cough and sneeze in your arm rather than your hand;
- Wash your hands often and thoroughly;
- Stay at home when sick.
Note: The United States issued similar interim guidance for MERS-CoV in August (see CDC HAN Update On MERS-CoV) and for H7N9 in June (see CDC: Updated H7N9 Guidance Docs).
