A dog imported into Britain from Sri Lanka has died of rabies but not before it had bitten three people.
According to the the Health Protection Agency (HPA) the three have to date shown no ill effects but they could be in for a worrying time.
All three were already vaccinated because of their work and have also been given a booster.
Though symptoms usually appear two to eight weeks after infection, it can take two years or more before they occur.
The dog was one of a batch of 11 rescued by the charity Animal SOS and part of a litter of five; they were being held at quarantine kennels in Chingford, northeast London.
The head of the charity who brought the dogs into Britain, Kim Cooling was bitten along with kennel manager Sarah Page and kennel worker Matthew Brett.
Veterinary experts are now investigating after the puppy died from the deadly disease; the four other puppies have been put down as a precaution.
The eight-week-old puppy arrived at the kennels ten days ago and staff soon noticed strange behaviours and were forced to isolate her.
After the biting incidents the dog had a seizure and died and kennel officials contacted the Department for Environment, Food and Rural Affairs (DEFRA); vets carried out a post mortem on the dog and discovered it had rabies.
In order to guarantee full protection against the killer disease the three victims now face a programme of five booster vaccinations.
Mrs Cooling established the charity to rescue stray dogs 16 years ago after holidaying in Sri Lanka and says all the animals are fully screened before they leave and they have never experienced such a problem before.
The manager of the Chingford Mount kennels, says dogs coming from Sri Lanka are vaccinated against rabies before they leave the country for Great Britain, but in this case, the puppies were too young to vaccinate.
At no time were other pets on the premises in any danger and the kennel says, that the infected dog was identified and isolated immediately, shows the quarantine procedures work.
The disease was eradicated from Britain in 1922 and there has not been a death from rabies since 1902; most dogs entering the country spend six months in quarantine.
Experts say for someone to contract rabies, saliva containing the virus has to penetrate the skin, usually through an animal bite.
It is possible to contract rabies if infected saliva gets in through broken skin, if for example a person has an open cut on their hand.