CDC warns of ongoing diarrhea risks ahead of Mid-Autumn Festival

Taipei, Sept. 10 (CNA) The Centers for Disease Control (CDC) on Tuesday warned the public about the risks of diarrhea ahead of next week's Mid-Autumn Festival, noting that a significant number of clusters in Taiwan had been caused by a previously less common strain of norovirus.

A total of 130,472 individuals with diarrhea visited emergency and outpatient departments from Sept. 1-7, a 1.5 percent decrease compared to the previous week but the highest for the same period since 2019, CDC Epidemic Intelligence Center Director Kuo Hung-wei (郭宏偉) said at a news conference.

Kuo continued that 101 diarrhea clusters were also reported in the past four weeks, marking a five-year high for the same period. Most of the clusters occurred in the food and hospitality industries, while 26 tested positive for norovirus across various sectors, he said.

Nearly 60 percent of this year's norovirus-positive diarrhea clusters were detected with the GII.17 strain, a shift from the previously common GII.4 strain. Additionally, 47 norovirus-related diarrhea clusters recorded from January to June were linked to the consumption of grilled oysters, according to the CDC.

CDC Deputy Director-General Lo Yi-chun (羅一鈞) said that the GII.17 strain was responsible for two major outbreaks in 2015 and 2016 and tends to circulate only once every few years and primarily affect adults.

He added that the recent diarrhea cases in Taiwan mainly involved adults aged 15 to 64 who prefer eating raw food, while children have been relatively less affected.

With the Mid-Autumn Festival -- a holiday popular among Taiwanese for gathering and barbecuing -- approaching on Sept. 17, Lo predicted that the number of diarrhea cases will increase after the festival with the possibility of reaching 150,000.

"Norovirus can only be killed when the internal temperature [of the food] reaches above 66 degrees Celsius," Lo said, reminding the public to exercise caution when grilling seafood during the holiday, such as continuing to grill for at least an additional three to five minutes after the shells of seafood like oysters and shellfish have opened.

Meanwhile, there were 14,241 outpatient and emergency visits due to enterovirus last week, similar to the previous week's number but still above the epidemic threshold of 11,000 visits, the CDC said.

Lo said that the number of enterovirus cases had peaked but is expected to remain high around the Mid-Autumn Festival.

The CDC also said that five new domestic cases of mpox were recorded in Taiwan from Sept. 3-9 with all cases involving a strain called clade IIb, different from clade Ib -- the strain reported in Africa that made the World Health Organization to declare the mpox outbreak in the continent a public health emergency of international concern on Aug. 14.

The five cases, all Taiwanese men aged 30 to 60, included four from northern Taiwan and one from central Taiwan, with symptoms beginning to appear between Aug. 26 and Aug. 31, according to the CDC.