New Delhi (CNN)The death toll from an outbreak of Nipah virus has risen to 10 in India's southern state of Kerala.
10 confirmed dead from Nipah virus outbreak in India, including nurse treating patients
Nine patients that tested positive for the virus have been quarantined and are being treated, Rajeev Sadanandan, additional chief secretary for the state's Department of Health and Family Welfare, told CNN on Tuesday.
The outbreak began in the northern district of Kozhikode and has spread to neighboring Malappuram district, Sadanandan said.
Symptoms of Nipah virus can begin with headache and drowsiness but quickly transform into a coma within a matter of days, according to the US Centers for Disease Control and Prevention.
Other symptoms include acute respiratory syndrome -- where the lungs cannot get enough oxygen to the body -- and fatal encephalitis, an inflammation of the brain.
There is no vaccine, and treatment is limited to supportive care.