Social impact of brain fog and analysis of risk factors: Long COVID in Japanese population.

OBJECTIVE: To reveal the clinical features and assess risk factors linked to brain fog and its societal implications, including labor productivity, providing valuable insights for the future care of individuals who have experienced coronavirus disease 2019 (COVID-19). METHODS: We analyzed a comprehensive cohort dataset comprising 1,009 patients with COVID-19 admitted to Japanese hospitals. To assess brain fog, we analyzed patients who responded to a questionnaire indicating symptoms such as memory impairment and poor concentration. RESULTS: The prevalence of brain fog symptoms decreased 3 months posthospitalization but remained stable up to 12 months. Neurological symptoms such as taste and smell disorders and numbness at hospitalization correlated with a higher frequency of identifying brain fog as a long COVID manifestation. Our findings indicated that advanced age, female sex, a high body mass index, oxygen required during hospitalization, chronic obstructive pulmonary disease, asthma, and elevated C-reactive protein and elevated D-dimer levels were risk factors in patients exhibiting brain fog. Additionally, we demonstrated the negative impact of brain fog on labor productivity by presenteeism scores. INTERPRETATIONS: This study clarified the clinical characteristics of patients experiencing brain fog as a long COVID manifestation, specifically emphasizing neurological symptoms during hospitalization and their correlation with brain fog. Additionally, the study identified associated risk factors for its onset and revealed that the emergence of brain fog was linked to a decline in labor productivity.

Identification of B.1.346 lineage of SARS-CoV-2 in Japan: Genomic evidence of re-entry of Clade 20C

ObjectivesWhole SARS-CoV-2 genome sequencing from COVID-19 patients is useful for infection control and regional trends evaluation. We report a lineage data collected from hospitals in the Kanto region of Japan. MethodsWe performed whole genome sequencing in specimens of 198 COVID-19 patients at 13 collaborating hospitals in the Kanto region. Phylogenetic analysis and fingerprinting of the nucleotide substitutions underwent to differentiate and classify the viral lineages. ResultsMore than 90% of the strains belonged to Clade 20B and two lineages (B.1.1.284 and B.1.1.214) have been detected predominantly in the Kanto region. However, one sample from a COVID-19 patient in November 2020, belonged to the B.1.346 lineage of Clade 20C, which has been prevalent in western United States. The patient had no history of overseas travel and no contact with anyone who had travelled abroad, suggesting that this strain appeared likely to have been imported from western United States, across the strict quarantine barrier. ConclusionB.1.1.284 and B.1.1.214 have been identified predominantly in the Kanto region and B.1.346 of clade 20C in one patient was probably imported from western United States. These results illustrate that a decentralized network of hospitals can be significantly advantageous for monitoring regional molecular epidemiologic trends. Highlights{middle dot} Whole SARS-CoV-2 genome sequencing is useful for infection control {middle dot} B.1.1.284 and B.1.1.214 have been identified predominantly in the Kanto region {middle dot} B.1.346 of Clade 20C was detected in one COVID-19 patient in November {middle dot} Molecular genomic data sharing provides benefits to public health against COVID-19