Lancet: Loss of taste and smell is the strongest predictor of new crown infection

, fever and cough were considered the most common symptoms of neo-coronavirus infection. However, the latest study found that taste loss is more specific to new coronary infection symptoms, and the symptoms last longer, as the strongest predictive indicator of whether or not they have been infected.
the results were published june 4 in the June 4 issue of The Lancet, an international authoritative medical journal, entitled Quantifying additional COVID-19 symptoms will save lives. The team was from King's College London, UK.
researchers say public health authorities around the world are trying to control the spread of the new coronavirus by raising public awareness and tracking contacts, specifically by identifying and isolating high-risk groups infected with the virus. In many countries, conventional large-scale swab nucleic acid detection capabilities are still inadequate. Therefore, in order to reduce the number of people infected in the community, it is important to use a combination of symptoms that are quickly identified by the patient.
the study used self-reporting symptom data from users of the COVID Symptom Study application. Of these, 18,401 user data were critical to the study because they were also tested for sars-CoV-2. Results: 7104 positive and 11297 negative.
previous reports, in addition to the most definitive high fever and new persistent cough symptoms, loss of smell and taste is a potential predictive factor for COVID-19. Users who reported loss of smell and taste in the sample had a positive rate of 65.03 percent, three times the negative rate of 21.71 percent, suggesting that people with loss of smell and taste should isolate themselves.
April 2020, WHO and many EU countries, the United States and Australia listed loss of smell and taste as one of the main symptoms of neo-crown pneumonia, and the UK government added it to its list of symptoms on 18 May 2020.
19 May 2020, 76,260 of the more than 3.2 million UK users using the COVID Symptoms Study app had been tested for SARS-CoV-2 nucleic acid and reported symptoms. Of the 13,863 people who tested positive, 71.5 per cent reported fever or cough, indicating that only those who reported a fever or cough were isolated and screened and nearly 30 per cent of positive cases could be missed. Of the 13,863 patients who tested positive for the new crown, 64.5 percent reported losing their sense of smell and taste, and 15.9 percent reported no fever or cough symptoms.
loss of sense of smell and taste is a symptom of the new crown, especially in young people and working people, who may be able to get around and spread disease, and are therefore critical to disease control. These 15.9% of new crown patients without typical symptoms may be able to significantly reduce the spread of the virus if they can be quickly identified and isolated.
researchers also quantified 76260 users who used the COVID Symptoms Study app because they were also tested for SARS-CoV-2. Quantitative indicators include sensitivity, specificity, positive predictive values, negative predictive values, fever, cough, loss of smell and taste. Of the 76,260 people, 13,863 tested positive and 62,397 tested negative. The researchers found that "loss of smell and taste" was more predictive than "fever or cough." "Smell and taste loss" is the strongest predictor of new coronavirus infections. In addition, the researchers found that the medium duration of symptoms of loss of smell was 5 days, while the medium duration of fever was only 2 days.
as countries around the world are lifting the blockade to return to normal, accurate tracking of infected people will be particularly important. The inclusion of olfactory and taste loss on the COVID-19 symptom list is significant because it will help track nearly 16 per cent of cases that may be missed. Locking in loss of smell and taste, combined with fever or cough, can determine 8
% of new corona cases with symptoms, although symptoms may be relatively low in patients in the early stages of infection.
results provide theoretical support for the addition of more identifying features to COVID-19, which has been adopted by WHO and other countries such as Public Health England. However, there are still risk factors that cannot be ignored: unlike loss of smell and taste, many of the symptoms of the new crown may be nonse specific, which may require algorithms like called COVID Symptoms Research to improve predictive power.
, like all observational studies, the findings have limitations, such as self-reporting that relies on symptoms, a problem found in most non-large-scale population tests. Direct self-testing of newly developed olfactory and taste loss can improve the detection of symptoms and provide a basis for further confirmation testing. However, loss of smell and taste may not be so discernable symptoms for the elderly and those who are less likely to report symptoms, such as those living in nursing homes.
researchers believe that loss of smell and taste is a common symptom of COVID-19, and since the non-flu-like symptoms are recognized, infections can be reduced and life-saving. Data suggest that low-cost "olfactory differential screening tests" in workplaces and entrances around the world may capture more new corona-positive cases than temperature sensors.
previously, people with less obvious symptoms may inadvertently become silent transmitters of the new coronavirus, adding new symptoms is critical for disease control.