Claims from airline passengers who have suffered deep vein thrombosis (DVT) could bankrupt aviation insurers, MAP Syndicate underwriter David Shipley told delegates at the Association of Lloyd's Members' (ALM) annual conference last week.

Although few claims have been filed at present, Shipley said a potential flood of claims could have a similar effect to the raft of asbestosis claims that are currently crippling the insurance market.

DVT has been hitting the headlines since last year, when a number of high-profile cases were brought to light.

Blood clot is the simple term for DVT, otherwise known as Economy Class Syndrome. This condition is caused by blood clotting due to sluggish circulation and, in the case of airline passengers, is caused by people sitting in cramped conditions with reduced air pressure.

The blood clot can cause stiffness and pain, and if it moves around the body, can cause a massive blockage in the heart or lungs, cutting off the oxygen supply to the body. The condition requires prompt medical treatment and is made more likely by lack of movement and dehydration on long flights.

Medical research has indicated that some people are predisposed to DVT. Those at risk include the elderly, people with a history of blood clots, women on the pill, people who have had recent surgery and those suffering from cancer or heart failure.

The missing link
The link between DVT and flights lasting more than eight hours was first noted in the Lancet Journal in 1968.

Recently, it was revealed that airlines had known about the risk of DVT for years, after British Airways medical officer Dr David Flower told Panorama that his airline had been aware of about DVT since 1991, but refused to warn passengers about the risk of blood clots forming in the legs.

British Airways issued advice to passengers about exercising during flights but the in-flight advice only mentioned “circulatory problems”.

Airlines have also been accused of refusing access to scientists studying DVT. Five scientists said their requests for information had been ignored.

Now it is feared that up to one in ten long-haul passengers may suffer the condition, and 1,000 British travellers a year could be killed by it.

Going to court
Some DVT cases have already been filed against airlines. Watford legal firm Collins is currently preparing to launch a representative test case that could make airlines and aviation insurers liable for the condition in the UK courts. Collins has acted for claimants in a number of transport-related cases, including the Hatfield crash.

The firm is currently building cases against several airlines and aviation insurers after serving legal documents forcing them to reveal all the relevant documents they hold on DVT. Lawyers for the firm have written to British Airways, JMC and Thomas Cook. Both the airlines have confirmed that they are “investigating the allegations”.

Senior partner Des Collins said the firm planned to bring its test case before the courts by early next year. It involves a woman prone to DVT who claims an airline failed to prevent her condition from deteriorating, despite her warning the airline before she embarked on one of its flights.

At present, airlines are basing their defence on an international treaty, the Warsaw Convention, which compensates passengers only for airborne accidents and not injuries resulting from in-flight incidents.

The Geneva summit was organised by the World Health Organisation and was the latest in a series of meetings in Europe and Australia on the subject. The airlines involved in the meeting included British Airways, Virgin, Air France, Cathay Pacific and Qantas.

At the meeting, medical specialists and representatives took the decision to institute a two-year worldwide project into the risks of developing DVT on long-haul flights. This is the first time major international research has been conducted on the subject.

The Aviation Health Institute has campaigned for years for airlines to take action on DVT and welcomed the move.

Airlines have been receiving claims for DVT-related injuries for years, but few have led to litigation, as airlines have preferred to settle claims out of court with relatively small payouts.

Aviation lawyers have cast doubt upon the validity of claims, saying that airlines have to carry people with all kinds of ailments and complaints, and if the airline does not know about a passenger's conditions in advance, there is no claim.

Many aviation underwriters are remaining tight-lipped on how hard the raft of claims is likely to hit balance sheets.

But if the comments of Andrew Shipley at the ALM meeting are anything to go by, DVT claims are a problem that could be dogging the insurance industry for years to come.