■新冠肺炎可能會對認知能力產生長遠影響。 資料圖片【原文】下文摘錄自香港《文匯報》10月28日︰
英美多家大學聯合進行的研究顯示，新冠肺炎（coronavirus）可能會在患者腦部產生「腦霧」（brain fog）現象，會對認知能力（cognitive ability）產生長遠影響，重症患者的智商（IQ）甚至可能因此減少8.5點，相當於腦部老化10年。
研究由倫敦帝國學院（Imperial College London）、劍橋大學（University of Cambridge）、芝加哥大學（University of Chicago）及倫敦國王學院（King's College London）的團隊聯合進行，分析了84,285名新冠肺炎患者康復後的情況，他們當中60人曾經需要使用呼吸機（ventilator）、147人曾經住院、176人曾因呼吸困難在家接受治療，3,466人曾出現呼吸困難但沒有接受治療，9,201人則沒有出現呼吸系統症狀。
研究發現，大多數確診患者在邏輯（logic）、字義（word definitions）、空間定向（spatial orientation）、專注力（attention）及情緒（emotion）控制測試中，得分均低過沒有感染人士。曾經進入深切治療部或使用呼吸機的患者，智商可以下降多達8.5點，或相當於腦部老化10年；但即使是沒有出現呼吸道症狀的輕症人士，智商也會減少4點，相當於腦部老化5年。
研究人員指出，新冠肺炎對患者腦部的影響，已經大得可以讓患者本人在日常生活中感覺到差異，認為醫學界應該更深入研究新冠肺炎對患者腦部的影響。
另一項由倫敦帝國學院進行的研究則發現，感染新冠病毒後人體內的抗體（antibody）水平會「迅速減少」，可能導致重複感染。研究分析了6月至9月間，36萬名英格蘭（England）人的兩輪抗體測試結果，在6月底至7月初的首輪測試中，每1,000人中約有60人有抗體，但在9月的最新一輪測試中，每1,000人中只有44人的抗體呈陽性，顯示從夏季到秋季，有抗體的人數減少了26%。
研究人員沃德（Helen Ward）說，志願者的免疫力在3個月內迅速下降，而且65歲以上年齡組別跌幅更大；無症狀（asymptomatic）感染者比症狀嚴重患者的跌幅更大。有抗體的醫護人員數量仍相對較高，研究人員認為這可能是由於醫護定期暴露於病毒環境。
人類會在生活中多次感染另外四種冠狀病毒，例如普通感冒（common cold），一般人每6個月到12個月就會重新感染（re-infect）一次。
全球範圍內二次感染新冠病毒的案例很少，但研究人員警告說，這可能是由於人體免疫力在3月和4月這段高感染率時期後才開始減弱。
Coronavirus causes IQ to fall or ages the brain by a decade
【譯文】A joint study conducted by a number of universities in the United Kingdom and the United States showed that coronavirus would cause a phenomenon called "brain fog" that brought about long-term impact on the cognitive ability. Survivors of the worst cases of the virus even recorded the equivalent of an 8.5-point drop in their IQ, similar to a decade of brain ageing.
Jointly conducted by a team with scientists from Imperial College London, University of Cambridge, University of Chicago, and King's College London, the study analyzed 84,285 patients who had recovered from confirmed or suspected Covid-19. Among them, 60 Covid-sufferers were put on a ventilator, 147 were hospitalized, 176 had received treatment at home due to respiratory problems, 3,466 struggled with their breathing but were not medically cared for and 9,201 had no respiratory symptoms at all.
The study indicated that recovered Covid-19 patients scored more poorly than people who had not had the virus on tests for logic, word definitions, spatial orientation, maintaining attention and processing their emotions.
Those who were in intensive care or needed ventilation recorded the equivalent of an 8.5-point drop in their IQ or 10 years of brain ageing; but even those with mild or no respiratory symptoms would still have their IQ reduced by 4 points, comparable to 5 years of brain ageing.
Researchers pointed out that the impact of coronavirus on the brain was great enough for an individual to notice a difference on his/her day-to-day life, suggesting medical professionals to carry out more in-depth studies on the impact of the virus on patients.
Another study conducted by Imperial College London found that the level of protective antibodies in the human body would reduce "quite rapidly" after coronavirus infection, giving rise to a risk of catching the virus multiple times. The study analyzed the results of two rounds of antibody testing on 360,000 people in England between June and September. In the first round of testing, at the end of June and early July, about 60 in 1,000 people had detectable antibodies. But in the latest set of tests in September, only 44 per 1,000 people were positive. It suggested the number of people testing positive for antibodies had fallen by 26% between summer and autumn.
The researcher Helen Ward said that the antibodies of volunteers declined rapidly over an approximate three-month period, and a greater decline was seen in the age group over 65; while asymptomatic coronavirus sufferers would have their antibodies dropped more dramatically when compared to patients with severe symptoms. The number of healthcare workers having antibodies was still relatively high, which might be caused by their regular exposure to the virus.
Most people catch four other seasonal human coronaviruses multiple times in their lives, which cause common cold symptoms and people can be re-infected every 6 to 12 months. Although there had been very few confirmed cases of people getting Covid-19 twice, researchers warned that this might be due to immunity only just starting to fade since the peak infection rates of March and April.■龐嘉儀
Q&A
1. 全球至今有多少個國家/地區出現新冠病毒確診病例？
2. 全球至今有超過多少宗確診病例？
3. 全球至今有超過多少宗死亡個案？
4. 世界衞生組織（WHO）於2020年3月11日將新冠疫情定義為什麼？
Answer
1. 190個
2. 逾4,700萬
3. 逾120萬
4. 大流行（pandemic）