The group of morbilliviruses form part of the family of paramyxoviruses, members of which infect humans and many species of animals, including terrestrial and aquatic mammals, birds and reptiles. There are seven different species of morbillivirus, including the phocine distemper virus (PDV) currently causing seal deaths in European waters, particularly in Denmark. Other animals, which can be infected with similar (but different) viruses, include dolphins and dogs, where the virus causes canine distemper against which most pet dogs are vaccinated.
Since June 2002, PDV has accounted for over 2000 seal deaths around the Danish and Swedish coasts. A widespread outbreak in the UK cannot be ruled out. Seal deaths have been reported and the virus has now been isolated.
The virus was first identified in 1988, when an epizootic occurred resulting in more than 18,000 deaths in seals. PDV is extremely contagious and is transmitted via close contact or the air-borne (droplet or aerosol) route. It affects the immune system of the seal, leaving it susceptible to other infections. Signs of infection include respiratory problems, coughing, nasal discharge, a reluctance to move, subcutaneous emphysema (air under the skin) around the head and neck and possibly problems of the nervous system.
Human health risk
PDV has never been recorded as a cause of human illness, either during this current outbreak or during previous epizootics in seals.
However sick, dying or dead seals may be more accessible to the general public and consequently there may be increased contact between people and seals. This increases the opportunity for other infectious organisms associated with seals to cause human infections, particularly through infected bites and wounds.
Principles of good practice
Occupational groups at Risk
Occupational groups that come into contact with sick and dying seals are at greater risk than the general public. This includes those working for or on a voluntary basis for animal welfare organisations involved in the collection, treatment and management of seals. Those with responsibility for disposing of the carcases of dead seals are also at increased risk.
Where there is any possibility of exposure, workers should be made aware of possible risks and protective measures that can be taken to reduce these risks.
Protective measures include:
- Good personal hygiene should be observed at all times with particular attention to hand washing
- Personal protective clothing i.e. heavy-duty gloves, boots and ideally goggles should be made available for workers.
After use all protective clothing should be washed with soap and warm water and disinfected. Rinse in clean water and dry items thoroughly.
- Following any injury, such as a bite, medical advice should be obtained as soon as possible.
- Any unusual illness should be reported to the medical adviser.
Members of the Public
Members of the public are advised to avoid contact with live or dead seals. To protect the health of dogs they should be not be allowed to come in contact with seals or seal carcases. Anyone coming into contact with a sick or dead seal should be aware of the possible risks and take appropriate measures to reduce these risks:
Preventative measures include:
- Members of the public should not handle injured or sick seals or seal carcases, but should contact the specialist services of animal welfare groups such as the SSPCA.
- If against this advice there is contact with seals personal hygiene should be of paramount importance with attention to hand washing using soap and running water
- Following any injury, such as a bite from a seal, medical advice should be sought immediately.
In the first instance, all calls concerning stranded seals, whether alive or dead, should be made to the UK National Seals Helpline at 08712 447999. Callers reporting sick or dead seals should note the exact location of the animal and any signs of illness that have been observed. Details will be passed to the appropriate bodies, including the SSPCA and the Scottish Agricultural College.