Aeromedical Report
SARS and Airline Pilots

By Donald Hudson, M.D., ALPA Aeromedical Advisor
Air Line Pilot, June/July 2003, p.5

Severe Acute Respiratory Syndrome, or SARS, first appeared in southern China about 9 months ago. Since that time, primarily through the international air travel of infected persons, the disease has spread through other areas in south Asia (Vietnam, Taiwan, Indonesia, Hong Kong, Singapore, and the Philippines) but also to locations in North America—primarily Toronto, Canada, and a few isolated cases in the United States as well.

In February, the World Health Organization (WHO) and the U.S. Centers for Disease Control (CDC) began to be very aggressive in combating the dissemination of this disease, primarily by identifying and quarantining ill persons. As of this writing, these efforts are bearing fruit in measurably slowing the spread of this new disease.

By May, available evidence was pointing to a new form of the common coronavirus as the most likely cause of SARS.

Infected persons fall ill 2 to 10 days after close contact with a person who has the disorder and develop a fever higher than 100.4 degrees F (38 degrees C).

Infected persons also show signs of respiratory distress, such as severe cough, shortness of breath, and difficulty in breathing. To date, no reliable test exists for the virus thought to be the cause of SARS, nor is an effective curative treatment available once a person has the disease (care is supportive only). The vast majority of people who become ill recover, but for an unfortunate few, the condition can be fatal. As best as can be determined, approximately 6.5 percent of the people who develop SARS die from the disease.

Even though the number of cases is far below what is seen annually with seasonal respiratory epidemics such as the common flu, this disease is apparently killing otherwise healthy individuals. For that reason, WHO and national health authorities in many countries are making every effort to prevent this disease from gaining a permanent foothold in the global human population. Of course, these efforts and the fear generated by the disease itself have had a significant negative economic effect on the airline industry.

A possible vaccine is likely many months to years away. In all probability, this disease will be with us for the foreseeable future. As of early May, no cases among airline pilots were known.

The ALPA Aeromedical Office is in close, almost daily, contact with both the CDC and the medical departments of the major North American airlines. This collaboration has resulted in the CDC’s establishing on its website a section tailored specifically for airline flight crews: Airline pilots should refer to this site for the latest information and recommendations regarding the outbreak. The Canadian Health Department, which can be reached at 1-800-454-8302, also has a website with information for flight crews, which can be accessed at

As always, ALPA members who have specific questions or concerns may contact the ALPA Aeromedical Office at 303-341-4435 and speak with one of our physicians in complete confidence.

How is SARS spread?

The primary mechanism of spread appears to be breathing in infectious respiratory droplets. This requires close contact with the infected person. Other methods of spread include touching the skin of persons or objects that are contaminated with infectious droplets and then touching one’s own eyes, nose, or mouth. This is why frequent hand washing is the most effective method of preventing spread of the virus.

Can I catch SARS through the ventilation system of an airliner?

To date, no cases of remote transmission of the SARS virus on an airliner have been documented. The ventilation systems of airliners are extremely efficient at filtering moisture droplets, and no evidence has been found that the SARS virus becomes airborne in a desiccated, or dry, form that is infectious to others.

Should I wear a surgical mask while on a layover in a location where SARS has been reported?

As of this writing, the CDC is not recommending routine use of surgical masks by nonmedical personnel, primarily because little evidence exists that the masks are useful in preventing infection during casual exposure. The surgical masks that can be purchased over the counter are best used by an ill person or people/caregivers in close proximity to his or her respiratory secretions. On layovers in a country or area where SARS cases have been reported, a crewmember would be wise to avoid crowds or congested pedestrian locations until the epidemic is brought under better control.