What is SARS?
Severe acute respiratory syndrome (SARS) is a serious illness, caused by a new virus, SARS-associated coronavirus. The syndrome is characterized by high fever, coughing and respiratory distress (laboured breathing, shortness of breath). It spreads from person to person, primarily through direct close contact. Time from exposure to first symptoms is about five days. The virus can survive outside the body for several hours, for example on the surface of furniture, door knobs, telephone mouthpieces, and much longer in human waste, so transmission may be possible without personal contact. The majority of patients recover, but mortality is about 12 per cent.
On 5 July 2003, WHO declared the last area in the world with local transmission of SARS to have broken the chain of person-to-person transmission. This means that the SARS-virus is no longer circulating in the human population anywhere in the world. This is, however, not a guarantee that SARS has disappeared forever. Seasonal occurrence remains a possibility and transmission may still occur at such a low level as to defy detection. Consequently, it would be unwise to lower the guard, especially since the protective measures now in place in many airports are effective shields not only against SARS but also against other contagious diseases, including new and unknown viral diseases that may occur in the future.
Is it dangerous to travel on board an aircraft which also carries a SARS patient?
Although the global spread had been caused by patients travelling from one part of the world to another by air, the risk of in-flight transmission of SARS is very small, with less than five probable cases reported worldwide, all of which occurred before airport screening procedures were implemented. During the same period, one of the involved airlines transported more than 1.46 million passengers.
For passengers, travelling on board an aircraft which also carries a SARS patient, there may be a risk, especially if they are seated in the immediate vicinity of the SARS patient, i.e. on the same row or up to two rows in front and behind. For the rest of the passengers the risk is insignificant, partly because the cabin air circulates transversally, limiting the spread of droplets to only a few rows of seats, partly because modern passenger aircraft are equipped with high efficiency particulate air filters which clean the air of 99.97 per cent of all particles suspended in the air, including bacteria and virus.
What protective measures does ICAO recommend to manage health risks?
Under the auspices of ICAO, an international working group met in Singapore from 2 to 4 June 2003. Members of the group were medical representatives of ICAO, WHO, IATA, CAAS, MOH of Singapore, and the chief physician of Tan Tock Seng Hospital (designated SARS hospital for Singapore) as well as airport officials from CAAS. The purpose of the meeting was to develop a set of adequate anti-SARS protective measures to be implemented at international airports in SARS-affected areas. Appropriate guidelines for inspectors were also developed.
The eight anti-SARS protective measures, developed by the working group, are now recommended by ICAO, and in July 2003 an inspection team, sent out by ICAO, has conducted evaluations of several international airports in South-East Asia and has in all cases been able to issue a successful report that all ICAO protective measurements had been fully implemented.
An international airport is considered as having adequate protection against SARS if the following protective measures have been adopted:
- An airport public health emergency official has been appointed as responsible for the implementation of all SARS protective measures. This person, who is not necessarily a physician, coordinates the SARS protective measures at the airport.
- Warning is given (e.g. posters, PA announcements) to crew and passengers before or immediately on entering the airport premises that no one with symptoms of SARS will be allowed to board any flight.
Note: Sample text of such warning- "This airport has SARS screening in place. Passengers found to be possible SARS cases will not be allowed to board any flight. The most common symptoms of SARS are fever, cough, and shortness of breath".
- Screening of departing passengers for SARS symptoms is undertaken in accordance with WHO recommendations. This is accomplished by:
- Asking, as a minimum, the three WHO questions, of all departing passengers, preferably before but no later than at check-in
- Objective temperature measurement by a reliable method such as thermal imaging, infrared measurement or the use of thermometers (oral or axillary with disposable sheaths, aural with disposable caps, sublingual strips, forehead fever strips).
Note i: Temperature screening takes place as early as possible and no later than before passengers and crew enter the secure airside area.
Note ii: Temperature screening machines are calibrated and maintained according to the manufacturers recommendations and operators are knowledgeable in their use. Personnel using thermometers are knowledgeable in their proper use and the correct interpretation of readings.
- If any of the WHO questions are answered positively and/or if the temperature reading exceeds 37.5 degrees, the passenger is isolated and evaluated by a designated health care provider.
- A passenger who is coughing is provided with a face mask.
Note i: A positive response to any of the three questions is normally a trigger for the check-in staff or the immigration staff to make the decision that a secondary screening is required. However, the answer to the query as to whether the passenger comes from a SARS affected area is of little importance when the two other questions are answered in the negative. Consequently, these passengers need not be sent for secondary screening if there are no other indications for them to be so screened.
Note ii: The current WHO recommended level (38 degrees Celsius) is based on core body temperature and since the temperature measuring devices may vary, a lower screening temperature is specified to avoid false negatives.
- If the secondary screening determines that the person in question is a possible case of SARS, then the person has to undergo a medical examination and assessment by a qualified medical practitioner.
- If the medical practitioner determines that the said person is well and does not meet the WHO SARS suspect case definition, the person is allowed to continue the voyage.
- If the medical practitioner determines that the said person meets the suspect SARS case definition, the person is taken to the designated SARS hospital.
- If the person does not meet the SARS case definition but the medical practitioner determines that the person is ill, continuation of the voyage may only be allowed after the usual IATA procedures for such cases have been followed (submission of the MEDIF form to the airline's medical service).
- Disembarking passengers arriving from affected areas are normally screened by responding to questionnaires, completed during the flight or at the latest, immediately upon disembarkation. These questionnaires are reviewed at the time of disembarkation. Passengers offering positive responses are referred for secondary screening.
Note i : A positive response to any of the three WHO questions is normally a trigger for the check-in staff or the immigration staff to make the decision that a secondary screening is required. However, the answer to the query as to whether the passenger comes from a SARS affected area is of less importance when the two other questions are answered in the negative. Consequently, these passengers need not be sent for secondary screening if there are no other indications for them to be so screened.
Note ii: Temperature screening of disembarking passengers is accomplished as early as possible after disembarkation and before passengers are divided into transit and arriving passengers and always before immigration clearance. Steps are taken to prevent passengers arriving from affected areas to enter any common arrival or transit areas before screening has taken place.
Passengers arriving from non-affected areas but who may have been routed through/from an affected area are normally screened as well.
Note iii: The initial, secondary and tertiary screening procedures are in the same format as for departing passengers.
- All passengers are provided with information about SARS symptoms and the appropriate public health contact numbers if available.
- Procedures are in place to respond to the arrival of an aircraft with a possible SARS case on board. These procedures are:
- Formal questions to be asked of the pilot-in-command (PIC) of the arriving aircraft (number of passengers involved, their symptoms, and time of onset of symptoms)
- Information to be provided to the PIC: where to park (usually away from the jet-bridge), no disembarkation of ill passenger/s until medical clearance, which doors to open
- In the eventuality that a sick passenger has to be removed from the aircraft before being medically assessed, removal to a designated isolation area should await the arrival of the medical practitioner. In this situation all infection control measures are to be employed including personal protective equipment for persons in close contact with the passenger. Persons using the equipment are to be trained in its proper use.
- A sick passenger (meeting the WHO SARS suspect case definition) should be removed directly from the aircraft, without passing through arrival areas used by other passengers. Only if direct removal is impossible should other procedures be employed. In all cases, contact with other passengers and airport staff must be minimized.
- Airport management and designated public health authorities are immediately alerted.
- Passengers and crew from this flight are segregated until contact information is obtained and passengers and crew have been advised of the precautionary measures necessary
- Procedures are in place for Immigration and Customs clearance of ill passengers taken directly from the arriving aircraft.
- The necessary infection control measures are implemented by the airport authorities.
Note i: Personal protective equipment is worn by all persons in close contact with the suspect case. This equipment includes disposable surgical gloves, eye protection (close fitting goggles or face shield), facemask or respirator, disposable outer garment. In all cases a facemask is provided to the ill person.
Note ii: Receiving hospital and ambulance service are designated.
Note iii: All disposable materials possibly in contact with the suspect case including protective equipment worn by caregivers to be disposed of as biohazardous waste.
Note iv: All surfaces in contact with or possibly contaminated by the suspect case are to be properly disinfected.
- All airport workers are subject to daily temperature screening at the beginning of their work shift.
- Workers are reminded by posted information or other means of their obligation not to report to work if they are unwell.
Where can I find further information on SARS?
For further more detailed and up-to-date information, please consult the web sites of the World Health Organization (WHO) and the Center for Disease Control (CDC).