Streptococcus suis infections rise in Thailand, 49 cases reported and 3 deaths

Risk factors identified as undercooked pork and contact with pigs

Three people have died from Streptococcus suis infections in Thailand this year, with 49 confirmed cases reported so far, the Department of Disease Control (DDC) announced on Wednesday.

DDC Director-General Dr. Monthien Kanasawad stated that from January 1 to February 10, 2026, the DDC confirmed 49 cases of the disease, affecting individuals ranging from 5 to 90 years old. The majority of the cases involve males, with elderly individuals aged 60 and above being most affected. The second highest group is those aged 50–59, followed by the 40–49 age group.

Provinces with High Case Numbers

The province with the most reported cases is Nakhon Ratchasima, followed by Phrae, Chon Buri, Chaiyaphum, and Surin.

Risk factors linked to the infection include consumption of undercooked pork or pork blood, particularly dishes like laab raw, larb, and koi; drinking alcohol with raw pork; and working in occupations related to pig slaughtering without proper protective equipment. These risk factors are particularly dangerous for individuals with cuts or abrasions on their hands.

At-Risk Groups and Geographic Spread

At-risk groups include the elderly and individuals with underlying conditions such as cirrhosis, diabetes, kidney failure, and cancer, as well as those who have had their spleen removed. These individuals face a higher risk of severe illness and death.

An analysis of the disease's geographical spread shows a significant increase in cases. From January 1 to February 10, 2025, there were 36 cases in 19 provinces, while in 2026, the disease has now spread to 28 provinces, including Bangkok, Nonthaburi, Nakhon Ratchasima, Phrae, Chon Buri, Chaiyaphum, Surin, Buriram, and Roi Et, among others.

Symptoms and Urgent Need for Treatment

DDC deputy director-general Dr Direk Kampaen emphasized that symptoms of Streptococcus suis infection typically appear within 3 days of exposure. Initial symptoms include high fever, body aches, headaches, dizziness, joint pain, skin rashes, lethargy, stiff neck, and seizures. As the infection spreads to the bloodstream and meninges, it can lead to inflammation in the brain, causing hearing loss and unsteady walking. These symptoms may develop within 14 days of fever onset.

Immediate treatment is crucial to prevent severe complications, such as death or permanent disability. Without prompt care, patients may lose their hearing and could face life-threatening consequences.

Prevention and Protective Measures

The Department of Disease Control urges the public to avoid consuming raw or undercooked pork, not to eat pork from sick or dead pigs, and to purchase pork only from certified sources. Individuals working with pigs should wear protective gear, such as boots and gloves, and avoid contact with pigs if they have open wounds. After handling pigs, thorough hand and body hygiene, including washing hands and feet, is essential. Farm owners are also encouraged to follow infection control measures recommended by veterinarians to reduce the risk of further outbreaks.