A case of rabies has been confirmed in the UK, the Health Protection Agency (HPA) said.

The potentially fatal disease was confirmed in a patient from London who had been bitten by a dog in South Asia. It was reported that the patient was a grandmother in her 50s.

The patient is receiving hospital treatment and all relevant contacts had been followed up, the HPA said, stressing there was no risk to the public.

Dr Brian McCloskey, director of the HPA for London, said: "It is important to stress that there is no risk to the general public as a result of this case or to patients and visitors at the hospital where the patient is receiving treatment.

"Despite there being tens of thousands of rabies cases each year worldwide, there have been no documented laboratory confirmed cases of human-to-human spread. Therefore the risk to other humans or animals from a patient with rabies is considered negligible.

"However, to take every possible precaution, family members and healthcare staff who had close contact with the patient since they became unwell - which is when they are infectious - have been assessed and offered vaccination if appropriate."

Rabies is usually transferred through saliva from the bite of an infected animal with dogs being the most common transmitter of rabies to humans. More than 55,000 people are estimated to die from rabies every year, with most cases occurring in developing countries, particularly South and South-East Asia.

Professor David Brown, a rabies expert at the HPA, said only four cases of human rabies acquired from dogs have been identified since 2000, all from animals abroad.

The patient is being treated at London's Hospital for Tropical Diseases. A spokeswoman said: "We would like to reassure our patients, visitors and staff there is no risk to them as a result of this case."

The Sun reported that the woman was of Indian origin and was in India with her husband when she was bitten by a puppy. As a matter of routine, if the woman had any pets at home tests would have been carried out on them to check the virus had not been passed on, a spokesman from the Department for Environment, Food and Rural Affairs said.