Wintertime Unwelcome Guest Norovirus... When Did 'Gul Phobia' Start? [News Seolcham]

(51) Oyster Farm Sewage Recall Triggers Oyster Phobia
Japan Also Sees Sharp Annual Increase in Infection Cases

As the winter season arrives, more consumers are seeking oyster dishes, but the recent spread of norovirus has put oyster farms on high alert. The Ministry of Oceans and Fisheries announced in this month's 'Oyster Aquaculture Industry Development Plan' that it will expand facilities to prevent the inflow of contaminants to block concerns about norovirus caused by land and marine pollution sources. Even outside designated areas set for hygiene management compliance, similar levels of management will be implemented. The goal is to increase oyster production by 100,000 tons to 400,000 tons by 2030 and to double export revenue to 160 million dollars.

The spread of 'Oyster Phobia' in Korea is estimated to have started in June 2012 when the U.S. Food and Drug Administration (FDA) banned the distribution and sale of Korean oysters in the United States. At that time, the FDA stated that "Korean shellfish farms were highly likely contaminated with norovirus due to exposure to human feces," recommending not only the ban on distribution and sale of Korean oysters in the U.S. but also voluntary recalls of existing products. Although the export restrictions were lifted in February the following year, this incident severely damaged the image of Korea's oyster aquaculture industry. Additionally, major oyster export countries such as Japan and Taiwan subsequently suspended imports of Korean oyster products, dealing a heavy blow to the domestic oyster farming industry.

The recent resurgence of oyster phobia is due to the increasing number of norovirus infections during the winter season. According to infectious disease statistics from the Korea Disease Control and Prevention Agency, the number of norovirus-infected patients reached 6,762 last year, a 14% increase compared to the previous year (5,926). The number of norovirus infection cases has been rising annually: 3,219 in 2020, 4,082 in 2021, and 4,673 in 2022.

In fact, the increase in norovirus infections is not limited to Korea. Japan, which is geographically close to Korea, is also experiencing a rise in infections. According to food poisoning statistics from Japan's Ministry of Health, Labour and Welfare, 7,026 people were infected with norovirus last year. This is a sharp increase compared to 2,175 in 2022 and 5,502 in 2023.

The United States also sees 19 to 21 million norovirus infection cases annually. The U.S. Centers for Disease Control and Prevention (CDC) reports about 2,500 norovirus outbreaks each year, resulting in an average of 900 deaths annually.

The main infection routes of norovirus are consumption of water or shellfish such as oysters and clams contaminated with norovirus, or undercooked seafood. Occasionally, person-to-person transmission or droplet infection can occur through contact with infected individuals. Symptoms such as vomiting and diarrhea appear within 12 to 48 hours after infection, and some people may experience abdominal pain, chills, and fever.

The Korea Disease Control and Prevention Agency recommends preventive measures against norovirus infection, including washing hands for at least 30 seconds, washing food ingredients thoroughly, and cooking food sufficiently at temperatures above 85 degrees Celsius. Infected individuals should avoid contact with others for 48 hours after symptoms disappear, and when using the restroom, they should close the toilet lid before flushing to prevent the spread of norovirus through droplets.

According to the Korea Disease Control and Prevention Agency's sentinel surveillance of gastrointestinal infections conducted at 210 hospital-level medical institutions with more than 200 beds nationwide, the number of norovirus patients reached 291 in the 52nd week of last year (December 22?28), increasing approximately 3.6 times over the past five weeks.

The number of patients rose from 80 in the 48th week (November 24?30) to 114 in the 49th week (December 1?7), 142 in the 50th week (December 8?14), and 247 in the 51st week (December 15?21), indicating the start of a full-scale outbreak. Notably, in the 52nd week of last year, infants aged 0 to 6 accounted for 58.8% of the total patients, requiring special attention from caregivers.