(Bloomberg) -- Up to three in every 10 Chinese adults experienced long Covid symptoms in a survey of more than 70,000 residents, offering rare insight into the scale of lingering issues plaguing the country’s 1.4 billion people well after the dismantling of pandemic curbs triggered a case surge.
The large-scale study from the Chinese Academy of Science, published in The Lancet Regional Health this month, is the largest on long Covid in China yet conducted. Researchers used an online questionnaire to look at long Covid symptoms and SARS-CoV-2 infection status among the people, nearly all of whom were aged 18 to 60, over the course of a year.
More than 30% of those surveyed reported fatigue, 28% had memory decline, 18% saw their ability to exercise decrease and almost 17% reported brain fog. Vaccination — especially with multiple boosters — reduced these symptoms by 30% to 70%, according to the research, though reinfection led to a higher incidence and severity of long Covid.
Women were more likely to suffer from symptoms, which varied by age group with the exception of sleep disorders and muscle and joint pain that proved more common in older people, the study said. Scientists also found that people in northern China, a chillier part of the country, have a higher prevalence of long Covid. Risk factors for symptoms include underlying diseases, drinking alcohol smoking and the severity of acute infection.
“This underscores the consistency of Long Covid features across national borders, cultures and healthcare settings,” epidemiologist Ziyad Al-Aly, who studies long Covid, wrote in a piece commenting on the research. “Long Covid is clearly a serious public health challenge in China, as it is globally.”
While Chinese researchers were among the first in the world to begin reporting on symptoms of long Covid in their patients, earlier studies mainly focused on people in Wuhan, the central mainland city where the pandemic first emerged in 2019. More than four years later, scientists are recognizing the longer-term impacts of Covid, including on brain health, and now worry that symptoms like brain fog may be early indicators of a coming surge in mental health conditions including dementia.
A large study of US veterans published earlier in 2024 showed Covid’s effects can last for more than three years, causing lingering pulmonary and gastrointestinal symptoms. Reports from America’s Centers for Disease Control and Prevention found that in 2022 some 18 million adults said they’d ever had long Covid.
©2024 Bloomberg L.P.