Clinical outcomes after tracheostomy in patients with coronavirus disease 2019: a single-center experience in Japan.

PURPOSE: Many patients with coronavirus disease 2019 require mechanical ventilation and tracheostomy. However, the timing and indications for tracheostomy are controversial. This study assessed 11 patients with coronavirus disease 2019 who underwent tracheostomy with clinical information and retrospective analyses. METHODS: A single-center retrospective observational study was performed on patients with coronavirus disease 2019 who underwent tracheostomy between 2020 and 2021. RESULTS: Failure to wean was the most common indication for tracheostomy, followed by extracorporeal membrane oxygenation decannulation and the need for secretion management. After tracheostomy, six patients (54.5%) were liberated from the ventilator. The time from intubation to tracheostomy (21.1 ± 9.14 days) was correlated with the duration of ventilator dependency (36.83 ± 20.45 days, r2 = 0.792, p = 0.018). The mean Acute Physiological and Chronic Health Evaluation II score was significantly lower in the ventilator-liberated group (23 ± 2.77) than in the non-ventilator-liberated group (31 ± 6.13, p = 0.0292). Furthermore, patients with Acute Physiological and Chronic Health Evaluation II scores of < 27 points achieved ventilator liberation and a long-term survival (p = 0.0006). CONCLUSIONS: This study describes the outcomes of a cohort of patients who underwent tracheostomy after intubation for coronavirus disease 2019. The Acute Physiological and Chronic Health Evaluation II score predicted whether or not the patient could achieve ventilator liberation.

Antibody titers against SARS-CoV-2 decline, but do not disappear for several months.

BACKGROUND: To develop an effective vaccine against a novel viral pathogen, it is important to understand the longitudinal antibody responses against its first infection. Here we performed a longitudinal study of antibody responses against SARS-CoV-2 in symptomatic patients. METHODS: Sequential blood samples were collected from 39 individuals at various timepoints between 0 and 154 days after onset. IgG or IgM titers to the receptor binding domain (RBD) of the S protein, the ectodomain of the S protein, and the N protein were determined by using an ELISA. Neutralizing antibody titers were measured by using a plaque reduction assay. FINDINGS: The IgG titers to the RBD of the S protein, the ectodomain of the S protein, and the N protein peaked at about 20 days after onset, gradually decreased thereafter, and were maintained for several months after onset. Extrapolation modeling analysis suggested that the IgG antibodies were maintained for this amount of time because the rate of reduction slowed after 30 days post-onset. IgM titers to the RBD decreased rapidly and disappeared in some individuals after 90 days post-onset. All patients, except one, possessed neutralizing antibodies against authentic SARS-CoV-2, which they retained at 90 days after onset. The highest antibody titers in patients with severe infections were higher than those in patients with mild or moderate infections, but the decrease in antibody titer in the severe infection cohort was more remarkable than that in the mild or moderate infection cohort. INTERPRETATION: Although the number of patients is limited, our results show that the antibody response against the first SARS-CoV-2 infection in symptomatic patients is typical of that observed in an acute viral infection. FUNDING: The Japan Agency for Medical Research and Development and the National Institutes of Allergy and Infectious Diseases.

Comparison of Rapid Antigen Tests for COVID-19.

Reverse transcription-quantitative PCR (RT-qPCR)-based tests are widely used to diagnose coronavirus disease 2019 (COVID-19). As a result that these tests cannot be done in local clinics where RT-qPCR testing capability is lacking, rapid antigen tests (RATs) for COVID-19 based on lateral flow immunoassays are used for rapid diagnosis. However, their sensitivity compared with each other and with RT-qPCR and infectious virus isolation has not been examined. Here, we compared the sensitivity among four RATs by using severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolates and several types of COVID-19 patient specimens and compared their sensitivity with that of RT-qPCR and infectious virus isolation. Although the RATs read the samples containing large amounts of virus as positive, even the most sensitive RAT read the samples containing small amounts of virus as negative. Moreover, all RATs tested failed to detect viral antigens in several specimens from which the virus was isolated. The current RATs will likely miss some COVID-19 patients who are shedding infectious SARS-CoV-2.