A British woman's life is at risk after she contracted rabies from a puppy overseas and was misdiagnosed by doctors at home three times.

Rabies was eradicated from the UK over a century ago—but the patient is fighting for life in hospital isolation, almost two months after being bitten in India.

Understood to be in her 50s, the woman is said to have visited her doctor once and a hospital's accident and emergency department twice over four days feeling ill, but was sent home each time, The Sun reported.

Sources said she returned to her doctor once more, when she was forwarded to the hospital with a suspected case of rabies and then properly diagnosed.

The Hospital for Tropical Diseases based at University College Hospital in London confirmed the case, affirming patients, staff and visitors were not at risk, although it is understood that relatives and hospital staff have been offered precautionary vaccines, The (London) Daily Telegraph reported.

Possibly life-threatening, rabies is an acute virus disease of the nervous system. Symptoms include abnormal behavior plus increased salivation, then paralysis and death if it goes untreated. It is prevalent in south and south-east Asian countries and is transmitted by saliva, usually through the bite of an animal.

The British Health Protection Authority (HPA) says only four people in the UK have contracted the disease since 2009, compared to the 55,000 who die from it globally each year.

The HPA has attempted to quell panic by pointing out that there have been no documented laboratory confirmed cases of rabies spreading from human-to-human, "Therefore the risk to other humans or animals from a patient with rabies is considered negligible," Brian McCloskey, director of the HPA for London, said.