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Early Release - Antibody Profiles According to Mild or Severe SARS-CoV-2 Infection, Atlanta, Georgia, USA, 2020 - Volume 26, Number 12—December 2020 - Emerging Infectious Diseases journal - CDC
▻https://wwwnc.cdc.gov/eid/article/26/12/20-3334_article

Among patients with coronavirus disease (#COVID-19), IgM levels increased early after symptom onset for those with mild and severe disease, but IgG levels increased early only in those with severe disease. A similar pattern was observed in a separate serosurveillance cohort. Mild COVID-19 should be investigated separately from severe COVID-19.

#anticorps

Early Release - Clinical Course of Asymptomatic and Mildly Symptomatic Patients with Coronavirus Disease Admitted to Community Treatment Centers, South Korea - Volume 26, Number 10—October 2020 - Emerging Infectious Diseases journal - CDC
▻https://wwwnc.cdc.gov/eid/article/26/10/20-1620_article

Les critères ne sont pas seulement cliniques mais dépendent aussi de l’âge et des facteurs de risque :

We used KCDC guidelines to classify patients. Asymptomatic patients were defined as persons <50 years of age with no underlying conditions who were nonsmokers and had a body temperature of <37.5°C without taking antipyretic drugs. Mildly symptomatic patients were defined as persons <50 years of age with >1 underlying condition and a temperature of <38°C with antipyretic drugs.

Les personnes ainsi concernées sont placés dans des centres d’#isolement médicalisés.

Abstract

We evaluated the clinical course of asymptomatic and mildly symptomatic patients with laboratory-confirmed coronavirus disease (#COVID-19) admitted to community treatment centers (CTCs) for isolation in South Korea.

Of 632 patients, 75 (11.9%) had symptoms at admission, 186 (29.4%) were asymptomatic at admission but developed symptoms during their stay, and 371 (58.7%) remained asymptomatic during their entire clinical course.

Nineteen (3.0%) patients were transferred to hospitals , but 94.3% (573/613) of the remaining patients were discharged from CTCs upon virologic remission.

The mean virologic remission period was 20.1 days (SD + 7.7 days). Nearly 20% of patients remained in the CTCs for 4 weeks after diagnosis.

The virologic remission period was longer in symptomatic patients than in asymptomatic patients. In mildly symptomatic patients, the mean duration from symptom onset to virologic remission was 11.7 days (SD + 8.2 days). These data could help in planning for isolation centers and formulating self-isolation guidelines.

#asymptomatiques

Early Release - Contact Tracing during #Coronavirus Disease Outbreak, South Korea, 2020 - Volume 26, Number 10—October 2020 - Emerging Infectious Diseases journal - CDC
▻https://wwwnc.cdc.gov/eid/article/26/10/20-1315_article?deliveryName=USCDC_333-DM33334

Le #confinement semble bien l’explication du nombre relativement peu élevé de #transmission par les #enfants ; ces derniers seraient même d’importants propagateurs (Cf rectification en-dessous).

We analyzed reports for 59,073 contacts of 5,706 coronavirus disease (#COVID-19) index patients reported in South Korea during January 20–March 27, 2020. Of 10,592 household contacts, 11.8% had COVID-19. Of 48,481 nonhousehold contacts, 1.9% had COVID-19. Use of personal protective measures and social distancing reduces the likelihood of transmission.

[...]

We also found the highest COVID-19 rate (18.6% [95% CI 14.0%–24.0%]) for household contacts of school-aged children and the lowest (5.3% [95% CI 1.3%–13.7%]) for household contacts of children 0–9 years in the middle of school closure.

Early Release - Antibody Responses to #SARS-CoV-2 at 8 Weeks Postinfection in Asymptomatic Patients - Volume 26, Number 10—October 2020 - Emerging Infectious Diseases journal - CDC
▻https://wwwnc.cdc.gov/eid/article/26/10/20-2211_article

We compared levels of severe acute respiratory syndrome coronavirus 2 neutralizing antibodies in recovery plasma from 7 completely asymptomatic coronavirus disease patients with those in symptomatic patients in South Korea. We found that serologic diagnostic testing was positive for 71% (5/7) of completely asymptomatic patients, but neutralizing antibody response occurred in all 7 patients.

Neutralizing antibodies play an essential role in virus clearance and have been considered a critical immune player for protection against viral diseases. Knowledge of the neutralizing antibody response in asymptomatic patients is critical for diagnosing the disease, understanding pathogenesis, and interpreting seroepidemiologic data to define prevalence and risk factors for infection. Production of neutralizing antibodies in asymptomatic COVID-19 patients was reported recently. Wu et al. reported that ≈30% of recovered mild COVID-19 patients generated a deficient level of neutralizing antibody titers; in 10 of the 175 patients, the level was below the limit of detection (F. Wu et al., unpub. data, ▻https://doi.org/10.1101/2020.03.30.20047365External Link). The difference in results from our study compared with the previous study might be caused by differences in the timing of the test. In the previous study, antibody tests were performed 2–3 weeks after symptom onset, whereas we tested 2 months after symptom onset or laboratory diagnosis. #Seroconversion in asymptomatic patients might take longer .

#asymptomatique #asymptomatiques #anticorps #sérologie #immunité

COVID-19 : #Asymptomatique, une personne en contamine 71 autres en prenant un ascenseur - Marie Claire
▻https://www.marieclaire.fr/covid-19-asymptomatique-elle-contamine-71-personnes-en-prenant-un-ascens

https://cache.marieclaire.fr/data/photo/w600_h315_ci/5r/ascenseur-news-corona.jpg

C’est après avoir séjourné aux États-Unis qu’une habitante de la province de Heilongjiang en Chine, qui avait pourtant respecté les mesures de quatorzaine imposées et avait été testée négative au COVID-19, a contaminé 71 personnes.

Asymptomatique, elle aurait transmis le virus en empruntant l’ascenseur de sa résidence, donc sans avoir de contact direct avec quiconque. Les chercheurs chinois alertent de la situation dans une publication de la revue américaine Emerging Infectious Diseases.

#coronavirus

Early Release - COVID-19 in Patient with Sarcoidosis Receiving Long-Term #Hydroxychloroquine Treatment, France, 2020 - Volume 26, Number 10—October 2020 - Emerging Infectious Diseases journal - CDC
▻https://wwwnc.cdc.gov/eid/article/26/10/20-1816_article

https://wwwnc.cdc.gov/eid/images/og-eid-logo-2.jpg

Un cas de personne qui a développé une #COVID-19 malgré la prise régulière (et efficace) d’HCQ (et seulement d’HCQ) pour une maladie chronique (Sarcoidose).

Des publications antérieures allaient dans le même sens (pas d’effet préventif de l’#HCQ) mais celle-ci est la seule où le patient ne prenait QUE de l’HCQ (des immunosuppresseurs y étaient associés dans les précédentes).

This observation of COVID-19 with diffuse interstitial pneumonia requiring hospital admission in a patient on long-term hydroxychloroquine treatment suggests that hydroxychloroquine may not be as effective as suggested by in vitro data. This patient had always been considered highly adherent to his medications, which was confirmed by therapeutic drug monitoring. Because plasma concentration was within therapeutic range by the time the patient was admitted, the failure of hydroxychloroquine to prevent COVID-19 cannot be attributed to underdosage or suboptimal adherence. Two recent studies suggested that hydroxychloroquine provides no protection against COVID-19 in patients with a broad range of autoimmune diseases from New York, USA (3), and in patients with systemic lupus erythematosus from France (4). The case we present is unique in that the patient was not receiving any immunomodulatory agent other than hydroxychloroquine.

Early Release - Culture-Competent #SARS-CoV-2 in Nasopharynx of Symptomatic Neonates, Children, and Adolescents - Volume 26, Number 10—October 2020 - Emerging Infectious Diseases journal - CDC
▻https://wwwnc.cdc.gov/eid/article/26/10/20-2403_article?deliveryName=USCDC_333-DM32083

Étude suisse PCR/culture chez des #enfants symptomatiques.

[Children] should be considered as transmitters unless proven otherwise. To address this point, the laboratory of the Geneva University Hospitals and Faculty of Medicine, University of Geneva (Geneva, Switzerland), used cell culture to systematically assess cultivable SARS-CoV-2 in the upper respiratory tract (URT) of 23 children with #COVID-19.

[...]

Of 638 patients <16 years of age, 23 (3.6%) tested positive for SARS-CoV-2. Median age was 12.0 years (interquartile range [IQR] 3.8–14.5 years, range 7 days–15.9 years).

[...]

We isolated SARS-CoV-2 from 12 (52%) children.

[....]

Our data show that viral load at diagnosis is comparable to that of adults (6,7) and that symptomatic children of all ages shed infectious virus in early acute illness, a prerequisite for further #transmission. Isolation of infectious virus was largely comparable with that of adults , [...]

[...]

A limitation of our study was the small number of children assessed. However, although the Canton of Geneva was a region severely affected by SARS-CoV-2 (8), only 23 cases were diagnosed in children at our hospital during the study period. These findings confirm that children are not a major risk group for COVID-19. Another limitation is our reliance solely on leftover material initially received for routine diagnostic purposes that we retrospectively analyzed.

[...]

Therefore, our findings probably underestimate the true rate of infectious virus presence in symptomatic children, and we cannot comment whether our data reflect the rates of infectious virus shedding in the community.

[...]

SARS-CoV-2 viral load and shedding patterns of culture-competent virus in 12 symptomatic children resemble those in adults. Therefore, transmission of SARS-CoV-2 from children is plausible . Considering the relatively low frequency of infected children, even in severely affected areas, biological or other unknown factors could lead to the lower transmission in this population. Large serologic investigations and systematic surveillance for acute respiratory diseases and asymptomatic presentations are needed to assess the role of children in this pandemic.

#contagiosité

Early Release - Clusters of #Coronavirus Disease in Communities, Japan, January–April 2020 - Volume 26, Number 9—September 2020 - Emerging Infectious Diseases journal - CDC
▻https://wwwnc.cdc.gov/eid/article/26/9/20-2272_article

https://wwwnc.cdc.gov/eid/images/og-eid-logo-2.jpg

The most frequently observed age groups among probable primary cases were 20–29 years (n = 6; u%) and 30–39 years (n = 5, 23%) (Figure 2, panel A). For 16 clusters, we determined the date of transmission from probable primary case-patients to other case-patients in a cluster and found 41% (9/22) of probable primary case-patients were presymptomatic or asymptomatic at the time of #transmission ; only 1 had a cough at the time of transmission (Figure 2, panel B).

#asymptomatique #pré-symptomatique

Early Release - Effect of Environmental Conditions on #SARS-CoV-2 Stability in Human Nasal Mucus and Sputum - Volume 26, Number 9—September 2020 - Emerging Infectious Diseases journal - CDC
▻https://wwwnc.cdc.gov/eid/article/26/9/20-2267_article?deliveryName=USCDC_333-DM30183

Abstract

We found that environmental conditions affect the stability of severe acute respiratory syndrome coronavirus 2 in nasal mucus and sputum. The virus is more stable at low-temperature and low-humidity conditions, whereas warmer temperature and higher humidity shortened half-life. Although infectious virus was undetectable after 48 hours, viral RNA remained detectable for 7 days.

#température #humidité

COVID-19 Outbreak Associated with Air Conditioning in Restaurant, Guangzhou, China, 2020

During January 26–February 10, 2020, an outbreak of 2019 novel coronavirus disease in an air-conditioned restaurant in #Guangzhou, China, involved 3 family clusters. The airflow direction was consistent with droplet transmission. To prevent the spread of the virus in restaurants, we recommend increasing the distance between tables and improving ventilation.

https://wwwnc.cdc.gov/eid/images/20-0764-F1.jpg

ping @simplicissimus @reka

Early Release - Aerosol and Surface Distribution of Severe Acute Respiratory Syndrome Coronavirus 2 in Hospital Wards, Wuhan, China, 2020 - Volume 26, Number 7—July 2020 - Emerging Infectious Diseases journal - CDC
▻https://wwwnc.cdc.gov/eid/article/26/7/20-0885_article

Guo Z-D, Wang Z-Y, Zhang S-F, Li X, Li L, Li C, et al. Aerosol and surface distribution of severe acute respiratory syndrome coronavirus 2 in hospital wards, Wuhan, China, 2020. Emerg Infect Dis. 2020 Jul

https://wwwnc.cdc.gov/eid/images/og-eid-logo-2.jpg

This study led to 3 conclusions. First, #SARS-CoV-2 was widely distributed in the #air and on object surfaces in both the ICU and GW, implying a potentially high infection risk for medical staff and other close contacts. Second, the environmental contamination was greater in the ICU than in the GW; thus, stricter protective measures should be taken by medical staff working in the ICU. Third, the SARS-CoV-2 aerosol distribution characteristics in the GW indicate that the transmission distance of SARS-CoV-2 might be 4 m.

[...]

Our study has 2 limitations. First, the results of the nucleic acid test do not indicate the amount of viable virus. Second, for the unknown minimal infectious dose, the #aerosol transmission distance cannot be strictly determined.

#aérosol