On January 16, 2018, the Taiwan Centers for Disease Control (Taiwan CDC) announced one new confirmed case of listeriosis, which is also the first case confirmed in Taiwan since listeriosis was recently listed as a notifiable disease. The case is an 80-something year-old man who resides in central Taiwan. In late December 2017, he sought medical attention after developing symptoms, including fever and vomiting. Subsequently, he lost consciousness and entered into a coma. Listeriosis was confirmed in the case after the hospital reported the case to the competent authority for laboratory testing. As of now, the case has gradually been recovering and is still being treated in the hospital.

According to the epidemiological investigation, the case has a history of stroke but has not traveled recently. He cooked mostly his own meals. Prior to disease onset, he had consumed self-made canned fish by curing raw fish. However, the source of infection is still being investigated. Currently, none of the contacts has developed any suspected symptoms. The local health authority has provided the case’s family member health education about hand and food hygiene and will continue to follow up on the health of the case’s contacts.

According to the past surveillance data compiled by Taiwan CDC, the majority of the listeriosis cases confirmed in Taiwan are elderly aged above 65, followed by people aged between 45 and 64 and a few cases of mother-to-child transmission. At the moment, there is no vaccine to prevent listeriosis and the severity of the disease depends on the case’s immunity. People with a healthy immune system are less likely to acquire listeriosis or merely experience gastrointestinal symptoms such as diarrhea, nausea and vomiting. However, the elderly people, the immunocompromised patients, pregnant women, fetuses and newborns are more likely to develop invasive infection. To reinforce the surveillance and prevention efforts of listeriosis in Taiwan, Taiwan CDC has listed listeriosis as a Category IV Notifibale Infectious Disease beginning January 1, 2018.

Listerosis is primarily transmitted through ingesting contaminated food. In Taiwan, packaged ready-to-eat meat products have been tested positive for the bacteria. On the other hand, sashimi is also another at-risk food item. Listeria can continue to grow at 4℃ and can only be killed through heating at a temperature over 72℃. Therefore, the most effective way to ward off listerosis is to practice good dietary and hand hygiene; avoid consuming raw food, consume only thoroughly cooked beef, pork, poultry, fish and vegetables; use separate chopping boards, knives, utensils and plates for handling raw and cooked foods to avoid cross contamination; thoroughly wash hands, utensils and plates after handling raw food; avoid consuming unpasteurized milk and milk products; consume cut fruits as soon as possible; and avoid consuming refrigerated foods after the expiration date.

Taiwan CDC reminds the public to seek immediate medical attention and voluntarily inform the physician of relevant food consumption and travel history when symptoms such as influenza-like illness, including fever and headache, or gastrointestinal symptoms, including nausea and vomiting, develop in order to ensure prompt treatment. Healthcare providers are also urged to report suspected cases to the competent authority within 72 hours of diagnosis in order to facilitate the implementation of subsequent prevention measures. For more information, please visit the Taiwan CDC website at http://www.cdc.gov.tw or call the toll-free Communicable Disease Reporting and Consultation Hotline, 1922 (or 0800-001922).