Seasonal Misinformation : The Recurrent Misinformation about the Next Pandemic

By Wei-Ping Li, Ph.D.

One of the most common and recurring misinformation spreads in Taiwan is that some viruses or bacteria have begun to spread in China, resulting in severe pneumonia and high mortality rates, and are about to be prevalent in Taiwan. As the end of 2024 approached, the Taiwanese again were scared by a rumor like this, with news media outlets and online influencers propelling the information and causing a frenzy in social media. It turned out to be an exaggeration. However, these rumors have revealed intriguing aspects, such as how the false information spread and evolved. The cases also demonstrate how the Taiwanese were troubled by their experiences of the COVID-19 pandemic. 

The information about an outbreak of pneumonia in China caused by a virus known as "Human Metapneumovirus" (HMPV, 人類間質肺炎病毒) first caught the attention of the Taiwanese around December 19, when a Taiwanese toxicologist shared on his Facebook page a news clip from the New Tang Dynasty Television (NTDTV), a media outlet affiliated with the Epoch Times, warning followers that the HMPV was spreading rapidly in China and the death rate was high. In the NTDTV news footage, a Chinese doctor explained that the HMPV mortality rate could be as high as 43% for certain individuals.     

The toxicologist's Facebook post about the HMPV outbreak was soon reported as "news" by Taiwanese media. Several media outlets covered the information with shocking headlines, ignoring the fact that the mortality rate of 43% applied to only "certain groups" instead of the overall population. For example, a headline from the online media outlet Newtalk read, "The mortality rate may reach 43%! Chinese media confirmed that the new virus is raging, and the China CDC issued an emergency statement..."(Note 1). Some outlets, however, emphasized that HMPV was a "new" virus with no vaccine to prevent it. Furthermore, the majority of news reports highlighted that the disease outbreak occurred in China. 

Screenshots of news headlines about the outbreak of HMPV in China and the 43% mortality rate.

In addition to the extensive coverage by media outlets, rumors spread swiftly on social media. As the chart below illustrates, since December 24, Taiwan FactCheck Center and Cofacts, an open-source fact-checking platform in Taiwan, have received increasing requests to verify the information, and the number of requests peaked on December 26. The number of inquiries and their pattern suggest that Taiwanese people were worried about the virus and its potential consequences.

The number of requests to verify the HMPV-related rumor that the Taiwan FactCheck Center and Cofacts received from 12/15/2025 to 12/31/2024. The vertical axis is the number of requests. 

According to the Taiwan FactCheck Center, the number of HMPV cases in China was, in fact, rising. However, instead of being a "new virus," HMPV has been around worldwide for a long time. The virus has not resulted in a high death rate among healthy people, either. Actually, the "43% mortality rate" was from research published in 2013 in a medical journal that studied the impact of HMPV on Hematopoietic Cell Transplantation recipients. The study found that this specific group had a 43% mortality rate within 100 days after infection.

Interestingly, this was not the first time that a rumor exaggerated the 43% death rate caused by the HMPV virus. As early as late May and early June of 2023, false information pieces about "an unknown virus" going rampant and “causing a 43% death rate” were propagated among Chinese online users. Unlike the disinformation circulated in 2024, the 2023 rumor claimed that the outbreak caused by the HMPV virus occurred in "the United States" rather than China. According to the fact-checking by AFP, this false information about the HMPV epidemic in the U.S., which generated four million views on Weibo with the hashtag "new U.S. virus has 43% mortality rate after 100 days of infection," misrepresented the previously mentioned  Hematopoietic Cell Transplantation recipients research. 

Another intriguing aspect is that although this “unknown virus is rampant in the U.S.” misinformation garnered much attention in China, it did not spread in Taiwan. It is quite interesting to note how the false information pieces identified the origin of the virus differently and incited concerns among audiences in China and Taiwan. The memory of COVID-19 remains fresh in people’s minds as the debate over the virus's origin continues. In China, people were worried about “the virus from the U.S.” since, throughout the COVID-19 pandemic, the Chinese government and media had repeatedly suggested that the virus could be from Fort Detrick in the U.S. On the contrary, in Taiwan, the suspicion that the virus came from China still lingers. As a result, while the Chinese are concerned about the virus from the U.S., Taiwanese people are alarmed by news about the diseases spread in China, and misinformation in Taiwan mostly pinpointed China as the source of the outbreak.

 
A post on Chinese social media during May and June 2023 stated an HMPV outbreak in the United States. This post misrepresented a study by saying that the death rate of the HMPV virus was as high as 43%.

As previously mentioned, several false claims about virus outbreaks have been circulated among Taiwanese social media users in the past three years, including the winters of 2022, 2023, and June 2024. For example, Taiwanese social media users disseminated false information asserting that many Beijing residents became ill with the mutant virus after China's relaxation of its overseas travel restrictions in December 2022. In November 2023, a series of posts alleged that "lung inflation caused by bacteria (Mycoplasma pneumoniae) from China have invaded Taiwan," "WHO announced that pneumonia currently spread in China was caused by a new virus," and "Several virus outbreaks in Shanghai!400,000 people and 100 medical staff were infected in one day." These articles sparked a new wave of concern. The piece that claimed the Mycoplasma pneumoniae bacterium had "invaded Taiwan" also reemerged in June 2024, with identical messages circulating on social media. 

These incorrect information pieces share several common features: Like seasonal flu, false information about airborne diseases often surges at specific times. They are most prevalent during the winter, when the number of flu cases increases. Furthermore, they all mentioned China as the country where the outbreak occurred. Apparently, the rumors seemed to come whenever there was a pickup in the airborne disease cases in China. 

Several factors drive the rumors about the disease outbreaks. First of all, many people have anticipated that airborne disease will proliferate throughout the winter. News of the virus or bacteria could attract even more attention on social media, accelerating its spread. Second, Taiwanese people have also been concerned about the possibility of another COVID-19-style outbreak. They still remember how the Chinese government handled the pandemic information with little transparency. The worry about similar incidents happening again has thus kept the Taiwanese on the lookout for any suspicious signs of a pandemic. As a result, anxiety and distrust fuel the proliferation of misinformation. Even though media outlets and online influencers may have the best intentions to inform people, they have also taken advantage of people's concerns to disseminate information that still needs to be verified. Meanwhile, algorithms that prioritize audiences' interest and engagement accelerate the spread. 

The Google Trend graphic shows the trend of search interest in the word "pneumonia[肺炎]" in Taiwan. As the graphic illustrates, the search interest in "pneumonia[肺炎]" peaked during the winter of 2022, 2023, June 2024, and December 2024. The trend has matched the surge of misinformation about the outbreaks of airborne diseases caused by viruses or bacteria.  

It should be noted that one of the media's essential responsibilities in public health is to increase awareness and safeguard the public. It is critical that the media issue early warnings when there is a sign of an outbreak. However, the media and online influencers still need to make sure to deliver correct facts and avoid amplifying unfounded claims, especially in this post-pandemic era. 

Note 1: The original headline in Chinese is "死亡率恐達43%? 中媒認了新病毒肆虐 中國疾管緊急說話了......" See Chi-Cheng Chang, "死亡率恐達43%? 中媒認了新病毒肆虐 中國疾管緊急說話了......," Newtalk, December 27, 2024, https://newtalk.tw/news/view/2024-12-26/950459. 

Wei-Ping Li is a research fellow at the Taiwan FactCheck Center. 
Claire Chen (Managing Editor at the Taiwan FactCheck Center) contributed to this analysis.