Short summary:
The loss of smell is an important sign of COVID-19 infection. It is reported in a majority of younger patients and it can be lasting: comments of a prominent French infectious disease specialist Didier Raoult and an article on a study by Austrian virologist Dorothee von Laer.
Didier Raoult: “30% have NOT recovered their sense of smell yet.”
French infectious disease specialist, professor Didier Raoult during his testimony to the French Senate in June 2020:
“In people aged below 50, the loss of smell (anosmia) has a predictive value of 66%” I.e.: if a person had/has anosmia, there is a 66% probability that the person had/has COVID-19.
“30% have NOT recovered their sense of smell yet.”
A recent study from Austria reports similar findings among the seropositive to SARS-CoV-2 inhabitants of an Austrian town.
Taste and smell disorders reported in a majority of seropositive inhabitants of an Austrian town.
The majority of the seropositively tested study participants reported taste and smell disorders.
Medical University of Innsbruck.
The following article is a mostly automatic translation of an article in German that was published on the website of Innsbruck Medical University.
Ischgl study: 42.4 percent are antibody-positive.
Almost 1,500 residents of the Tyrolean community of Ischgl were tested for the new corona virus and SARS-CoV-2 antibodies at the end of April 2020.The first results from the study conducted by the Medical University of Innsbruck and previously unpublished are now available. The focus of the investigation was the determination of the infection of the Ischgl population and the validation of specific antibody test procedures.
79 percent of the people from Ischgl had agreed to take part in the study from April 21 to 27, 2020, so that 1,473 test subjects (1,259 adults, 214 children) from 479 households for the PCR and antibody testing to determine existing or surviving infections, as well as to survey symptoms and course of infection. Since Ischgl is a community that has been affected above average by the current corona pandemic due to so-called superspreading events and was closed to the environment due to the strict quarantine measures, the population-based cross-sectional study can provide important insights into the spread of viruses and the course of infections . However, with regard to the detection of antibodies, the study is not representative of the Austrian population as a whole. “This is a lighthouse study with thankfully very high participation from the Ischgl population.The findings will help to plan future examinations better and make the use of antibody tests even safer, ”said the rector of the Medical University of Innsbruck, W. Wolfgang Fleischhacker.
Key results
The seroprevalence * (antibodies against SARS-CoV-2) of the Ischgl study participants is 42.4 percent (in children under 18 years: 27%). This is the central finding of the antibody study, which was carried out under the direction of the virologist Dorothee von Laer, director of the Institute of Virology at the Medical University of Innsbruck. “In Ischgl we are dealing with the highest seroprevalence ever demonstrated in a study. Even if this does not imply herd immunity, the population of Ischgl should be largely protected, ”says study leader von Laer.
The proportion of people tested seropositive is about six times higher (ten times higher in children) than the number of people who tested positive by a PCR test.
The proportion of people tested seropositive is thus about six times higher (ten times higher in children) than the number of people who previously tested positive by PCR, the rate of officially reported cases is thus only 15 percent of those actually infected. The number of undocumented cases that have not been tested due to an asymptomatic or mild course of infection can only be demonstrated with antibody tests. “We assumed a high rate of undocumented cases before the start of the study and it has now been confirmed, as in other hotspots,” von Laer said.
For Peter Willeit, epidemiologist at the Innsbruck University Clinic of Neurology, the examination is of particular importance: “In no other study did such a high percentage of study participants have antibodies against SARS-CoV-2 in the blood.In Val Gardena, for example, the percentage was 27 percent, in a study in Geneva around 10 percent. It is particularly interesting about the results of the study in Ischgl that a large number of people with antibodies were identified as corona cases only by the study. This underlines the importance of carrying out antibody studies, ”comments Willeit.
Using a questionnaire, the study was also able to draw careful conclusions about the course of the infection. The majority of the seropositively tested study participants reported taste and smell disorders, followed by fever and cough. The infection was mostly asymptomatic among the seropositively tested children. Only nine adults among the study participants had to be treated in the hospital.
Tests on the test bench
The study also focused on the application safety of the test methods for the detection of antibodies. These protein molecules, so-called immunoglobulins, are formed by the immune system to fight pathogens and other foreign substances. “In order to be able to detect the SARS-CoV-2-specific immunoglobulins IgA and IgG in the blood, we have established a three-step procedure with maximum sensitivity and practically 100 percent specificity”, von Laer describes the new test strategy.Two highly sensitive ELISA tests (immunoassay method based on an enzymatic color reaction) were used, the negative results of which were assessed as finally negative. Consistently positive results were assessed as “evidence of past infection with SARS-CoV-2”. If only one ELISA was positive and the other negative, a neutralization test was carried out for further clarification.
The question of immunity and how long carriers of SARS-CoV-2 antibodies are protected from infection has not been resolved by this study either. “It would certainly make sense to continue to support the Ischgl cohort and to re-examine the seroprevalence at a later date,” said Rector Fleischhacker.
(June 25, 2020, text: B. Hoffmann-Ammann, photo: MUI / F. Lechner)
Terminology: use “specialist” instead of “expert”.
We ending this post with a short remark on the appropriate term to use when describing a person expected to have good knowledge of a subject. The absolute “expert” is an inappropriate term. It is used today in propaganda and manipulation.
The appropriate term to use is “specialist”. We, for example, wrote in this article:
“A prominent French infectious disease specialist Didier Raoult.”
From our comment on a social network:
The word “expert” is a propagandist fabrication: the masses should listen to everybody called “expert“.