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Blood donations suggest COVID-19 was in the US last December
A study in Clinical infectious diseases yesterday found that 1% of American blood donations in late last year and early 2020 contained antibodies to SARS-CoV-2, suggesting that the virus was present in the United States earlier than previously thought.
SARS-CoV-2, the virus that causes COVID-19, was first recognized in Wuhan, China, in December 2019, and the initial case in the US was identified on January 19.
Researchers performed serological tests on 7,389 blood samples collected through routine American Red Cross blood donations from December 13, 2019 to January 17, 2020 in nine states: California, Connecticut, Iowa, Massachusetts, Michigan, Oregon, Rhode Island, Washington, and Wisconsin.
Blood samples were tested for anti-SARS-CoV-2 antibodies against whole viral peak protein by enzyme-linked immunosorbent assay (ELISA), microneutralization tests, and receptor-binding domain (RBD) blocking activity assays. ).
Of the 7,389 samples, 1.1% – 84 samples from residents of the nine states – showed virus-neutralizing activity, binding activity, or RBD-blocking activity, suggesting the presence of reactive antibodies against SARS-CoV-2 . The mean age of reactive donors was 52 years, with a higher percentage of reactive donations in men (2.6% vs 1.4% from December 13 to December 16, 2019; 1.1% vs 0.7 % from December 30, 2019 to January 17, 2020).
The first reactive samples came from donations collected December 13-16, 2019, from residents of California, Oregon, and Washington.
“The presence of these serum antibodies indicates that isolated SARS-CoV-2 infections may have occurred in the western part of the United States earlier than previously recognized or that a small portion of the population may have pre-existing antibodies that are bind SARS-CoV -2, “the authors concluded.
November 30 Clin Infect Dis study
Study finds irreversible damage in COVID-19 lung transplant patients
A report in Translational Medicine Science yesterday detailed irreversible lung damage in three patients with severe COVID-19 infection who received lung transplants, with lung damage similar to end-stage pulmonary fibrosis. The study suggests that some COVID-19 patients develop fibrotic lung disease and that lung transplants may be a viable option for survival.
The researchers examined the lungs removed from three bilateral lung transplant patients with COVID-19 associated respiratory failure that did not resolve and two patients who had died of COVID-19 associated pneumonia.
All patients had SARS-CoV-2 associated pneumonia and required prolonged mechanical ventilation and extracorporeal membrane oxygenation (ECMO) support.
The researchers found no evidence of SARS-CoV-2 RNA in the transplant patient’s lung samples using single-molecule fluorescent in situ hybridization, but they did find extensive lesions and fibrosis (thickening or scarring of air-exchange tissues. lung) that resembled extreme stage pulmonary fibrosis.
Lung samples from transplant patients showed cavities with dead tissue that contained bacterial pathogens, suggesting acute secondary infections. All lung samples showed regions of diffuse hemorrhage, or bleeding, in the air sacs where gas exchange occurs.
The researchers compared RNA sequences from lung tissue from COVID-19 patients with samples from pulmonary fibrosis patients, finding similarities suggesting common pathways of tissue damage and fibrosis.
Transplant patients were treated with anti-rejection drugs and antibiotics for secondary bacterial infections and showed improvement 3 months after transplantation, with oxygen saturations greater than 95% in room air and better cognitive status and muscle strength. No transplant patients showed evidence of COVID-19 reinfection.
Although they do not support the routine use of lung transplantation, the authors recommend bilateral transplantation for severe COVID-19 patients with prolonged mechanical ventilation and unlikely lung recovery. “Our findings suggest that some severe COVID-19 patients develop fibrotic lung disease for which lung transplantation is their only survival option,” the authors noted.
November 30 Science Transl Med study
Two Korean studies suggest children are unlikely to transmit COVID-19
Two studies from South Korea in Emerging infectious diseases Yesterday they add to mounting evidence that children are less likely than adults to transmit COVID-19.
The first study examined the transmission of SARS-CoV-2 between February 18 and June 7 among 12 children (under 19 years of age) and their uninfected guardians isolated together in seven Korean hospitals.
Infected children were encouraged to wear face masks, but compliance was low – only four children were reported to have worn personal protective equipment (PPE) most of the time. The guardians — 10 mothers, one father, and one uncle — complied with PPE recommendations, wearing a variety of protective masks and gloves, but most reported frequent close contact with the isolated child. The isolation was lifted after two consecutive negative respiratory samples were obtained from the infected child at least 24 hours apart.
None of the guardians tested positive for SARS-CoV-2 during the study, and transmission from children to guardians was not observed during the period of isolation or within 2 weeks after the end of isolation.
“The proper use of PPE, especially face masks, could have protected the uninfected guardians in our study,” the authors suggested. “The study adds to growing evidence that young children are less likely to contribute to the spread of COVID-19 among their adult guardians.”
The second study evaluated the exposure and transmission of SARS-CoV-2 in a child care center attended by a presymptomatic 4-year-old boy. The facility had adhered to local health protocols, including wearing masks for all adult personnel, frequent hand hygiene, and disinfecting surfaces, but children were inconsistently wearing masks.
The infected child attended the 17-classroom center from February 19-21, developed a fever on February 22, and was diagnosed with SARS-CoV-2 infection on February 27. The child care center was closed after the identification of a positive case, and an investigation identified 190 contacts – 154 children and 36 adults – in the center, including 13 classmates aged 4 or 5 and two teachers in the classroom of the boy.
All 190 people tested negative for SARS-CoV-2 when tested 8 or 9 days after exposure, and although two close contacts showed symptoms on the last day of quarantine, subsequent test results were negative.
“This research adds indirect evidence of a low infectious potential in a child care setting with exposure to a presymptomatic child,” the study authors wrote.
November 30 Emerg Infect Dis hospital isolation study and child care study
