SARS-CoV-2 shedding, infectivity, and evolution in an immunocompromised adult patient.

This study aimed to provide further insight into the evolutionary dynamics of SARS-CoV-2 by analyzing the case of a 40-year-old man who had previously undergone autologous hematopoietic stem cell transplantation due to a diffuse large B-cell lymphoma. He developed a persistent SARS-CoV-2 infection lasting at least 218 days and did not manifest a humoral immune response to the virus during this follow-up period. Whole-genome sequencing and viral cultures confirmed a persistent infection with a replication-positive virus that had undergone genetic variation for at least 196 days after symptom onset.

Absence of neutralizing antibodies against the Omicron SARS-CoV-2 variant in convalescent sera from individuals infected with the ancestral SARS-CoV-2 virus or its Gamma variant.

OBJECTIVES: The aim of the present study was to evaluate if neutralizing antibody responses induced by infection with the SARS-CoV-2 strain that was dominant at the beginning of the pandemic or by the Gamma variant was effective against the Omicron variant. METHODS: Convalescent sera from 109 individuals, never exposed to a SARS-CoV-2 vaccine, who had mild or moderate symptoms not requiring hospitalization following either a documented SARS-CoV-2 ancestral strain infection or a Gamma variant infection, were assayed for in vitro neutralizing antibody activity against their original strains and the Omicron variant. RESULTS: Following an infection with the ancestral strain, 56 (93.3%), 45 (77.6%) and 1 (1.7%) serum sample were positive for neutralizing antibodies against the ancestral, Gamma variant, and Omicron variant, respectively. After infection with the Gamma variant, 43 (87.8%) and 2 (4.1%) sera were positive for neutralizing antibodies against the Gamma and Omicron variants, respectively. CONCLUSIONS: Neutralizing antibodies generated following mild or moderate infection with the SARS-CoV-2 ancestral strain or the Gamma variant are not protective against the Omicron variant.

Absence of neutralizing antibodies against the Omicron SARS-CoV-2 variant in convalescent sera from individuals infected with the ancestral SARS-CoV-2 virus or its Gamma variant

Abstract Objectives: The aim of the present study was to evaluate if neutralizing antibody responses induced by infection with the SARS-CoV-2 strain that was dominant at the beginning of the pandemic or by the Gamma variant was effective against the Omicron variant. Methods: Convalescent sera from 109 individuals, never exposed to a SARS-CoV-2 vaccine, who had mild or moderate symptoms not requiring hospitalization following either a documented SARS-CoV-2 ancestral strain infection or a Gamma variant infection, were assayed for in vitro neutralizing antibody activity against their original strains and the Omicron variant. Results: Following an infection with the ancestral strain, 56 (93.3%), 45 (77.6%) and 1 (1.7%) serum sample were positive for neutralizing antibodies against the ancestral, Gamma variant, and Omicron variant, respectively. After infection with the Gamma variant, 43 (87.8%) and 2 (4.1%) sera were positive for neutralizing antibodies against the Gamma and Omicron variants, respectively. Conclusions: Neutralizing antibodies generated following mild or moderate infection with the SARS-CoV-2 ancestral strain or the Gamma variant are not protective against the Omicron variant. HIGHLIGHTS Individuals previously infected with SARS-CoV-2 ancestral strain do not develop neutralizing antibodies against the Omicron variant. Omicron variant escapes immune response after SARS CoV-2 previous infection with the SARS CoV-2 Gamma variant. Individuals previously infected with SARS-CoV-2 ancestral strain or with SARS-CoV-2 Gamma variant will likely have little protection if subsequently exposed to the Omicron variant.

Are mobile phones part of the chain of transmission of SARS-CoV-2 in hospital settings?

Mobile phones (MPs) have become an important work tool around the world including in hospitals. We evaluated whether SARS-CoV-2 can remain on the surface of MPs of first-line healthcare workers (HCW) and also the knowledge of HCWs about SARS-CoV-2 cross-transmission and conceptions on the virus survival on the MPs of HCWs. A cross-sectional study was conducted in the COVID-19 Intensive Care Unit of a teaching hospital. An educational campaign was carried out on cross-transmission of SARS-CoV-2, and its permanence in fomites, in addition to the proper use and disinfection of MPs. Herewith an electronic questionnaire was applied including queried conceptions about hand hygiene and care with MP before and after the pandemic. The MPs were swabbed with a nylon FLOQ Swab™, in an attempt to increase the recovery of SARS-CoV-2. All MP swab samples were subjected to SARS-CoV-2 RT-PCR; RT-PCR positive samples were subjected to viral culture in Vero cells (ATCC® CCL-81™). Fifty-one MPs were swabbed and a questionnaire on hand hygiene and the use and disinfection of MP was applied after an educational campaign. Most HCWs increased adherence to hand hygiene and MP disinfection during the pandemic. Fifty-one MP swabs were collected and two were positive by RT-PCR (4%), with Cycle threshold (Ct ) values of 34-36, however, the cultures of these samples were negative. Although most HCWs believed in the importance of cross-transmission and increased adherence to hand hygiene and disinfection of MP during the pandemic, SARS-CoV-2 RNA was detected in MPs. Our results suggest the need for a universal policy in infection control guidelines on how to care for electronic devices in hospital settings.

SARS-CoV-2 reinfection caused by the P.1 lineage in Araraquara city, Sao Paulo State, Brazil.

Reinfection by the severe acute respiratory syndrome coronavirus type 2 (SARS-COV-2) has been reported in many countries, suggesting that the virus may continue to circulate among humans despite the possibility of local herd immunity due to massive previous infections. The emergence of variants of concern (VOC) that are more transmissible than the previous circulating ones has raised particular concerns on the vaccines effectiveness and reinfection rates. The P.1 lineage was first identified in December 2020 in Manaus city and is now globally spread. We report the first case of reinfection of SARS-CoV-2 caused by the P.1 variant outside of Manaus. The potential of these new variants to escape naturally and vaccine- induced immunity highlights the need for a global vigilance.

Zika virus infection among symptomatic patients from two healthcare centers in Sao Paulo State, Brazil: prevalence, clinical characteristics, viral detection in body fluids and serodynamics.

Zika virus (ZIKV) clinical presentation and frequency/duration of shedding need further clarification. Symptomatic ZIKV-infected individuals identified in two hospitals in Sao Paulo State, Brazil, were investigated regarding clinical characteristics, shedding in body fluids, and serodynamics. Ninety-four of 235 symptomatic patients (Site A: 58%; Site B: 16%) had Real-Time PCR-confirmed ZIKV infection; fever, headache and gastrointestinal symptoms were less frequent, and rash was more frequent compared to ZIKV-negative patients. Real-Time PCR in serum had worse performance compared to plasma, while urine had the highest sensitivity. Shedding in genital fluids and saliva was rare. IgM positivity was the highest <14 days after the symptoms onset (86%), decreasing >28 days (24%); IgG positivity increased >14 days (96%) remaining positive in 94% of patients >28 days. ZIKV prevalence varied importantly in two neighboring cities during the same transmission season. Urine Real-Time PCR can improve diagnostic sensitivity; serum testing is less useful. Accurate serological tests are needed to improve diagnosis and surveillance.