tetano
Editor, Senior Moderator
Clin Microbiol Infect
. 2021 Jan 6;S1198-743X(20)30789-8.
doi: 10.1016/j.cmi.2020.12.029. Online ahead of print.
The importance of anosmia, ageusia and age in community presentation of symptomatic and asymptomatic SARS-CoV-2 infection in Louisiana, USA; a cross-sectional prevalence study
Amy K Feehan[SUP] 1 [/SUP], Daniel Fort[SUP] 2 [/SUP], Cruz Velasco[SUP] 2 [/SUP], Jeffrey H Burton[SUP] 2 [/SUP], Julia Garcia-Diaz[SUP] 3 [/SUP], Eboni G Price-Haywood[SUP] 3 [/SUP], Eric Sapp[SUP] 4 [/SUP], Dawn Pevey[SUP] 2 [/SUP], Leonardo Seoane[SUP] 5 [/SUP]
Affiliations
Abstract
Objective: While many seroprevalence studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been performed, few are demographically representative. This investigation focused on defining the nature and frequency of symptomatic and asymptomatic SARS-CoV-2 infection in a representative, cross-sectional sample of communities in Louisiana, USA.
Methods: A sample of 4,778 adults from New Orleans and Baton Rouge, Louisiana were given a survey of symptoms and comorbidities, nasopharyngeal swab to test for an active infection (PCR), and blood draw to test for a past infection (immunoglobulin G). Odds ratios, cluster analysis, quantification of virus and antibody, and linear modeling were used to understand whether certain symptoms were associated with a positive test, how symptoms grouped together, whether virus or antibody varied by symptom status, and whether being symptomatic was different across the age span.
Results: Reported anosmia/ageusia was strongly associated with a positive test; 40.6% (93/229) tested positive versus 4.8% (218/4,549) positivity in those who did not report anosmia/ageusia (Common OR: 13.6; CI 10.1, 18.3). Of the people who tested positive, 47.3% (147/311) were completely asymptomatic. Symptom presentation clustered into three groups; low/no symptoms (0.4?0.9 average ?SD), highly symptomatic (7.5?1.9) or moderately symptomatic (4.0?1.5). Quantity of virus was lower in the asymptomatic versus symptomatic group (cycle number 23.3?8.3 versus 17.3?9.0, average ?SD; p<0.001). Modeling the probability of symptoms showed changes with age; the highest probability of reporting symptoms was 64.6% (CI 50.4-76.5) at age 29 which decreased to a probability of 49.3% (CI 36.6-62.0) at age 60 and only 25.1% (CI 5.0-68.1) at age 80.
Conclusion: Anosmia/ageusia can be used to differentiate SARS-CoV-2 infection from other illnesses, and, given the high ratio of asymptomatic individuals, contact tracing should include those without symptoms. Regular testing in congregant settings of those over age 60 may help mitigate asymptomatic spread.
Keywords: Ageusia; Asymptomatic infection; SARS-CoV-2 prevalence; anosmia; symptom incidence.
. 2021 Jan 6;S1198-743X(20)30789-8.
doi: 10.1016/j.cmi.2020.12.029. Online ahead of print.
The importance of anosmia, ageusia and age in community presentation of symptomatic and asymptomatic SARS-CoV-2 infection in Louisiana, USA; a cross-sectional prevalence study
Amy K Feehan[SUP] 1 [/SUP], Daniel Fort[SUP] 2 [/SUP], Cruz Velasco[SUP] 2 [/SUP], Jeffrey H Burton[SUP] 2 [/SUP], Julia Garcia-Diaz[SUP] 3 [/SUP], Eboni G Price-Haywood[SUP] 3 [/SUP], Eric Sapp[SUP] 4 [/SUP], Dawn Pevey[SUP] 2 [/SUP], Leonardo Seoane[SUP] 5 [/SUP]
Affiliations
- PMID: 33421576
- DOI: 10.1016/j.cmi.2020.12.029
Abstract
Objective: While many seroprevalence studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been performed, few are demographically representative. This investigation focused on defining the nature and frequency of symptomatic and asymptomatic SARS-CoV-2 infection in a representative, cross-sectional sample of communities in Louisiana, USA.
Methods: A sample of 4,778 adults from New Orleans and Baton Rouge, Louisiana were given a survey of symptoms and comorbidities, nasopharyngeal swab to test for an active infection (PCR), and blood draw to test for a past infection (immunoglobulin G). Odds ratios, cluster analysis, quantification of virus and antibody, and linear modeling were used to understand whether certain symptoms were associated with a positive test, how symptoms grouped together, whether virus or antibody varied by symptom status, and whether being symptomatic was different across the age span.
Results: Reported anosmia/ageusia was strongly associated with a positive test; 40.6% (93/229) tested positive versus 4.8% (218/4,549) positivity in those who did not report anosmia/ageusia (Common OR: 13.6; CI 10.1, 18.3). Of the people who tested positive, 47.3% (147/311) were completely asymptomatic. Symptom presentation clustered into three groups; low/no symptoms (0.4?0.9 average ?SD), highly symptomatic (7.5?1.9) or moderately symptomatic (4.0?1.5). Quantity of virus was lower in the asymptomatic versus symptomatic group (cycle number 23.3?8.3 versus 17.3?9.0, average ?SD; p<0.001). Modeling the probability of symptoms showed changes with age; the highest probability of reporting symptoms was 64.6% (CI 50.4-76.5) at age 29 which decreased to a probability of 49.3% (CI 36.6-62.0) at age 60 and only 25.1% (CI 5.0-68.1) at age 80.
Conclusion: Anosmia/ageusia can be used to differentiate SARS-CoV-2 infection from other illnesses, and, given the high ratio of asymptomatic individuals, contact tracing should include those without symptoms. Regular testing in congregant settings of those over age 60 may help mitigate asymptomatic spread.
Keywords: Ageusia; Asymptomatic infection; SARS-CoV-2 prevalence; anosmia; symptom incidence.