The Department of Disease Control (DDC) has alerted the public to be wary of uncooked pork following 12 deaths linked to Streptococcus suis in four provinces in the lower northeastern region.
Dr Taweechai Wisanuyothin, chief of DDC Office 9, said on Saturday that 149 cases of hearing loss caused by the bacterium in four surveillance areas -- Nakhon Ratchasima, Buri Ram, Surin and Chaiyaphum -- were reported between Jan 7 and Sep 3.
The highest number of cases was found in Nakhon Ratchaisima with 89 cases including six deaths, followed by Chaiyaphum with 31 cases and four fatalities, Surin with 16 cases and one death, and Buri Ram with 13 cases and one death.
The majority of the reported cases involved elderly individuals aged 65 and older, said Dr Taweechai.
Streptococcus suis is a peanut-shaped bacterium that is normally found in the upper respiratory tract, particularly the tonsils and nasal cavity, and the alimentary and genital tracts of swine.
Dr Taweechai said humans can contract the bacterium through the consumption or exposure to raw pork, pigs' blood and internal organs. It can also enter through an open wound, scratch or eye conjunctiva, he said.
Normally, infection by the bacteria manifests as a fever with hearing loss following 14 days later. Patients suffer a high fever, severe headache, dizziness, vomiting and neck stiffness.
It can lead to permanent hearing loss, and even death in some groups of immuno-suppresed people.
The DDC is recommending people only buy pork from a reliable source and consume meat, internal organs and blood that has been cooked at 60–70 degrees Celsius for more than 10 minutes.
He added that separate utensils should be used to pick up cooked pork and raw pork.
"Do not buy pork with a strong smell or dark colour. Also, do not touch raw pork and blood with bare hands.
"If there is a wound, it must be covered tightly and wash your hands after touching the pig every time," he said.
"If there are any signs of the reported symptoms, see a doctor immediately," said Dr Taweechai.