People infected with the viruses Hepatitis B and C may be at an increased risk of Parkinson's disease, according to a study.
The results revealed that people with Hepatitis B were 76 per cent more likely to develop Parkinson's disease, and those with Hepatitis C were 51 per cent more likely to develop Parkinson's disease.
"The development of Parkinson's disease is complex, with both genetic and environmental factors," said Julia Pakpoor from the University of Oxford, Britain.
It is possible that the Hepatitis virus itself or perhaps the treatment for the infection could play a role in triggering Parkinson's or it is possible that people who are susceptible to Hepatitis infections are also more susceptible to the disease, the researchers said.
"We hope that identifying this relationship may help us to better understand how Parkinson's disease develops," Pakpoor added, in the paper detailed in the journal Neurology.
Hepatitis B is spread through contact with blood and body fluids of an infected person, such as unprotected sex, sharing needles, getting a tattoo or piercing with unsterilized tools, or sharing razors or toothbrushes with an infected person.
Hepatitis C is spread through blood-to-blood contact such as sharing needles, razors and toothbrushes and is also passed on at birth by infected mothers.
For the study, the team examined records of people with a first case of Hepatitis B, Hepatitis C, autoimmune Hepatitis, chronic active Hepatitis and HIV from 1999 to 2011, who later developed Parkinson's disease.
A total of 44 people with Hepatitis B developed Parkinson's disease, compared to 25 cases that would be expected in the general population.
For people with Hepatitis C, 73 people developed Parkinson's disease, where about 49 cases would have been expected in the general population.