In 1979, 72 per cent of passengers on one aircraft contracted influenza. The attack rate was associated with the ventilation system not being in operation during a three hour ground delay. Since 1979, there have been several other reported cases of on-board transmission of diseases. For example, in 1996 six of the 249 passengers on board a flight from Chicago to Hawaii were found to have caught the pathogenic bacterium which causes tuberculosis when they travelled on the same flight as a woman suffering from the disease.

Regulations

Airlines are expected to comply with international health regulations, which are designed to prevent the international spread of disease while interfering as little as possible with travel and trade. It is their responsibility to be familiar with the specific laws and regulations concerning infectious diseases applying to passengers and shipments at points of entry for each destination country, as well as the laws on safety procedures and on release of passenger information (data privacy) where they carry infectious agents or people.

The WHO’s International Health Regulations 2005, which do not come into effect until 2007, will establish basic rules for international coordination in the detection, investigation and response to diseases, including treatment, and will establish special measures to be adopted during a public health emergency of international concern.

In some countries, proposals are afoot to hold carriers directly responsible for disease outbreaks if they fail to comply with regulations. A good example is the proposed amendments to the US Code of Federal Regulations Parts 70 and 71 which imposes fines of US$250,000 and US$500,000 for any violation of the regulations by an individual and organization respectively.

Air carrier liability

Airlines have a potential liability exposure to passengers (a) where the airline or its ground handlers know or have reasonable cause to suspect at check-in or at the gate that a passenger has an illness but fails to take any precautionary steps to check that the passenger is medically fit to fly or deny boarding the passenger; (b) where the airline discovers in flight that a passenger on board has an illness but fails either to take steps to isolate the passenger or honour requests by other passengers for alternative seating; (c) where the airline fails to call and await the assistance of medical authorities at destination before permitting disembarkation; (d) where the airline is notified that a passenger on one of its flights had an illness but fails to take reasonable steps to trace all the passengers on that flight; (e) where passengers are infected because defective equipment or systems have resulted in the contamination of the air supply; (f) where the airline fails to prevent sick crews from continuing in the workplace; and, possibly, (g) failing to warn passengers of the risk of disease transmission during air travel and the steps that can be taken to help prevent infection.

If a passenger contracts a disease prior to his flight then the carrier will not be liable to that passenger under the Warsaw/Montreal liability regime if the illness then develops during the flight since the passenger would have embarked with a pre-existing medical condition.

If, however, it is established that a passenger on board was in a contagious stage of disease and other passengers bring claims for illnesses they contracted on board, then the claimants will need to prove they contracted the disease on board the aircraft or during the period of embarkation and/or disembarkation and that the fact that they were exposed to the disease constituted an "accident" for the purposes of Article 17 of the Warsaw or Montreal Conventions. The former issue may well present significant evidential difficulties. Without very clear evidence, it is always arguable that disease transmission could have occurred prior to embarkation, e.g. on public transport to airport, check-in queues, security checkpoints, customs, shops and restaurants.

In relation to whether there has been an article 17 accident, the carrier does face a liability risk provided the contraction arose as a result of an unexpected and unusual event that was external to the passenger. Poor air quality in an aircraft cabin leading to a passenger contracting pneumonia has already been held to amount to an accident (Dias v Transbrazil Airline (1998).

Following the Olympic Airways v Hussain (2004) case - in which an asthma sufferer died following exposure to cigarette smoke after his request to be moved further away from the smoking section had been refused - and the English Court of Appeal’s analysis of this judgment in the UK DVT litigation, it is also open to a court to hold that an airline’s failure to isolate a passenger or move another passenger against a known risk that a disease may be contracted on board is an "accident".

Refusal of carriage

Many airlines reserve in their tickets and general conditions of carriage a right to refuse carriage to a passenger if necessary to comply with government regulations or if carriage endangers safety or health or comfort of other passengers and the crew. In reality, unless the passenger discloses their medical condition or is exhibiting clear symptoms, these provisions will be of little benefit to the carrier. The carrier must also keep in mind that there are specific air carriage regulations - like the US Air Carrier Access Act or broader anti-discrimination regulations elsewhere - which may prevent refusal of carriage unless there is something more than just a "reasonable belief" that someone has an infectious disease. The carrier may need to weigh the legal consequences of refusing carriage to one passenger against the risk of allowing them to fly with an infectious condition.

Flight cancellations

Flight cancellations may arise as a result a dramatic turndown in demand as we saw in Asia during the SARS epidemic. An airline’s liability for cancellation is governed by its contract with passengers and by domestic or EU law rather than international air law conventions.

Many carriers exclude or limit their liability in respect of flight cancellations in their ticket conditions of contract or general conditions of carriage. However, these are not watertight. It is always open to passengers to argue that these conditions (a) were not incorporated into the contract (an argument which often succeeds in Thailand, for example); or (b) that they amount to unfair contract terms and, therefore, are void; or (c) that they do not apply to non-performance of the contract.

If a flight is cancelled due to government action then the airline may be able to rely upon force majeure provisions in its conditions of carriage allowing it to walk away from its obligation to carry the passengers. Alternatively, it may be able to rely upon the doctrine of frustration provided that the action of the government was not foreseeable.

If flights to which EU Regulation 261/2004 applies are cancelled, the carrier will have certain obligations including offering passengers a choice between re-routing and reimbursement of the full ticket price; plus assistance (phone calls, refreshments and accommodation); plus compensation. If flight cancellations occur as a result of government action or for other reasons outside the carrier’s control, the carrier may avoid having to pay compensation but will remain obliged to provide a refund or re-routing and care and assistance to the passenger.

Conclusions

Absent actual evidence of disease transmission during a stage of transportation for which airlines are responsible, airlines have minimal exposure to awards of damages although claims will have to be defended. On the other hand, if there is evidence to demonstrate that passengers are being or have been exposed to an infectious disease then the potential exposure to private law damages and government imposed penalties is significant.

BLG Aerospace has conducted an extensive investigation into the above issues after handling a number of SARS and influenza related claims in Hong Kong.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.