Adaptive immune system in severe COVID-19 patients in the first week of illness: A pilot study.

Introduction: The presentation of the course of COVID-19-related T-cell responses in the first week of the disease may be a more specific period for adaptive immune response assessment. This study aimed to clarify the relationship between changes in peripheral blood lymphocyte counts and death in patients with COVID-19 pneumonia. Methods: Thirty-three patients (14 females and 19 males) admitted for severe and desaturated COVID-19 pneumonia confirmed by polymerase chain reaction were included. Lymphocyte subsets and CD4+/CD8+ and CD16+/CD56+ rates were measured using flow cytometry from peripheral blood at admission and on the day of death or hospital discharge. Results: Twenty-eight patients survived and five died. On the day of admission, the CD4+ cell count was significantly higher and the saturation of O2 was significantly lower in the deceased patients compared to the survivors (P < 0.05). The CD16+/CD56+ rate was significantly lower on the day of death in the deceased patients than in discharge day for the survivors (P = 0.013). Conclusion: CD4+ lymphocyte percentages and O2 saturation in samples taken on the day of admission to the hospital and CD16+/CD56+ ratios taken at the time of discharge from the hospital were found to be associated with the mortality in patients with severe COVID-19.

Comparison of the healthcare-associated infections in intensive care units in Turkey before and during COVID-19.

Background: Secondary bacterial infections are an important cause of mortality in patients with coronavirus disease 2019 (COVID-19). All healthcare providers acted with utmost care with the reflex of protecting themselves during the COVID-19 period. We aimed to compare the rates of ventilator-associated pneumonia (VAP) and bloodstream infections (BSIs) in our intensive care units (ICUs) before and during the COVID-19 outbreak surges. Methods: This multicenter, retrospective, cross-sectional study was performed in six centers in Turkey. We collected the patient demographic characteristics, comorbidities, reasons for ICU admission, mortality and morbidity scores at ICU admission, and laboratory test data. Results: A total of 558 patients who required intensive care from six centers were included in the study. Four hundred twenty-two of these patients (males (62%), whose mean age was 70 [IQR, 58-79] years) were followed up in the COVID period, and 136 (males (57%), whose mean age was 73 [IQR, 61-82] years) were followed up in the pre-COVID period. BSI and VAP rates were 20.7 (19 events in 916 patient days) and 17 (74 events in 4361 patient days) with a -3.8 difference (P = 0.463), and 33.7 (31 events in 919 patient days) and 34.6 (93 events in 2685 patient days) with a 0.9 difference (P = 0.897), respectively. The mortality rates were 71 (52%) in pre-COVID and 291 (69%) in COVID periods. Conclusion: Protective measures that prioritize healthcare workers rather than patients and exceed standard measures made no difference in terms of reducing mortality.

Carbapenem-resistant Klebsiella pneumoniae outbreak in a COVID-19 intensive care unit; a case-control study.

We analysed a carbapenem-resistant Klebsiella pneumoniae (CRKP) outbreak in the coronavirus disease (COVID) ICU. We retrospectively collected data from ICU records. We identified 25 cases between 12 November 2020 and 19 December 2020, and compared them to 42 controls present in the ICU during the same period. The presence of a femoral haemodialysis catheter was strongly associated with invasive CRKP infections (cases, 9 [36%]; controls, 0 [0%]; odds ratio [OR] 95% confidence intervals [CIs], 21 (5; 89)). We found a significant association between old age and CRKP infection with adverse outcomes. Sequence analysis revealed three distinct carbapenemase genes: blaNDM-1, blaOXA-48 and blaKPC-2. We launched rectal swab sampling upon admission to the ICU, cohorted colonized patients and cases and conducted an intensive training programme for newly employed staff. This study revealed that the emergence and dissemination of CRKP in COVID ICUs were associated with increased adverse outcomes. The presence of a femoral haemodialysis catheter was a significant risk factor for CRKP infections.

Investigation and long-term monitoring of the presence of neutralizing antibody in patients with COVID-19 disease of different clinical severity.

Understanding the immune responses elicited by severe acute respiratory syndrome virus (SARS-CoV-2) infection is critical to public health policy and vaccine development and prevention of reinfections for COVID-19. It is important to know the neutralizing capacity of antibodies and to monitor their persistence. Patients with COVID-19 were divided into four groups (severe-critical, moderate, mild, and asymptomatic) according to their clinical severity. Antibodies against SARS-CoV-2 spike viral surface protein were investigated by ELISA method 3 and 9 months after the onset of the disease. Neutralizing antibody (NAb) response was evaluated by microneutralization test. Patients who received at least two doses of COVID-19 vaccine after illness were enrolled. SARS-CoV-2 immunoglobulin G (IgG) and NAb titers were shown to be strongly correlated with disease severity. Anti-SARS-CoV-2 IgG and NAb levels were found to be compatible with each other. After 9 months of follow-up, both IgG and NAb levels continued unabated in individuals who had the disease. In individuals who received at least two doses of the vaccine, these levels increased, except for severe-critical patients. High levels of anti-SARS-CoV-2 IgG are indicative, as it is difficult to investigate NAb in routine laboratories. At the same time, it can be predicted that this period may be much longer if it continues for at least 9 months and is reinforced with vaccination.

Is vaccination necessary for COVID-19 patients? A retrospective cohort study investigating reinfection rates and symptomatology in a tertiary hospital.

BACKGROUND: Durability of immune response by the COVID-19 natural infection and the necessity of vaccines in recovered patients are important inquiries for the healthcare provider. RESEARCH DESIGN AND METHODS: Here, we investigated the characteristics and the rate of cases with reinfection that have been admitted to our tertiary hospital. RESULTS: A total of 119985 patients were applied between March 2020 and May 2021. Of these patients, 32607 (27%, 32,607/119985) tested positive. A total of 27 (0.08%, 27/32607) patients were found to be reinfected beyond 90 days. Only one of these reinfected patients (0.003, 1/32607) had novel COVID-19 pneumonia and was hospitalized for the second time. Other 26 reinfected patients were followed up as outpatients. CONCLUSIONS: COVID-19 reinfection is extremely rare. However, the reinfection may be severe in patients with immune deficiency. Healthcare providers may prioritize uninfected and immune-compromised patients for vaccination.

Tocilizumab treatment in severe COVID-19: a multicenter retrospective study with matched controls.

Coronavirus disease-2019 (COVID-19) associated pneumonia may progress into acute respiratory distress syndrome (ARDS). Some patients develop features of macrophage activation syndrome (MAS). Elevated levels of IL-6 were reported to be associated with severe disease, and anti-IL-6R tocilizumab has been shown to be effective in some patients. This retrospective multicenter case-control study aimed to evaluate the efficacy of tocilizumab in hospitalized COVID-19 patients, who received standard of care with or without tocilizumab. Primary outcome was the progression to intubation or death. PSMATCH (SAS) procedure was used to achieve exact propensity score (PS) matching. Data from 1289 patients were collected, and study population was reduced to 1073 based on inclusion-exclusion criteria. The composite outcome was observed more frequently in tocilizumab-users, but there was a significant imbalance between arms in all critical parameters. Primary analyses were carried out in 348 patients (174 in each arm) after exact PS matching according to gender, ferritin, and procalcitonin. Logistic regression models revealed that tocilizumab significantly reduced the intubation or death (OR 0.40, p = 0.0017). When intubation is considered alone, tocilizumab-users had > 60% reduction in odds of intubation. Multiple imputation approach, which increased the size of the matched patients up to 506, provided no significant difference between arms despite a similar trend for intubation alone group. Analysis of this retrospective cohort showed more frequent intubation or death in tocilizumab-users, but PS-matched analyses revealed significant results for supporting tocilizumab use overall in a subset of patients matched according to gender, ferritin and procalcitonin levels.

Sars-Cov-2 virus and vaccination; biological and statistical framework.

INTRODUCTION: The Development of the SARS-CoV-2 virus vaccine and its update on an ongoing pandemic is the first subject of the world health agenda. AREAS COVERED: First, we will scrutinize the biological features of the measles virus (MV), variola virus (smallpox virus), influenza virus, and their vaccines to compare them with the SARS-CoV-2 virus and vaccine. Next, we will discuss the statistical details of measuring the effectiveness of an improved vaccine. EXPERT OPINION: Amidst the pandemic, we ought to acknowledge our prior experiences with respiratory viruses and vaccines. In the planning stage of observational Phase-III vaccine effectiveness studies, the sample size, sampling method, statistical model, and selection of variables are crucial in obtaining high-quality and valid results.

Predictive performance of CT for adverse outcomes among COVID-19 suspected patients: a two-center retrospective study.

The aim of the study was to compare the performance of various computed tomography (CT) reporting tools, including zonal CT visual score (ZCVS), the number of involved lobes, and Radiological Society of North America (RSNA) categorization in predicting adverse outcomes among patients hospitalized due to the lower respiratory symptoms during the coronavirus disease 2019 (COVID-19) pandemic. A total of 405 patients admitted with severe respiratory symptoms who underwent a chest CT were enrolled. The primary adverse outcome was intensive care unit (ICU) admission of patients. Predictive performances of reporting tools were compared using the area under the receiver operating characteristic curves (AUC ROC). Among the 405 patients, 39 (9.63%) required ICU support during their hospital stay. At least two or more observers reported a typical and indeterminate COVID-19 pneumonia CT pattern according to RSNA categorization in 70% (285/405) of patients. Among these, 63% (179/285) had a positive polymerase chain reaction (PCR test for the SARS-CoV-2 virus. The median number of lobes involved according to CT was higher in patients who required ICU support (median interquartile range [IQR], 5[3; 5] vs. 3[0; 5]). The median ZCVS score was higher among the patients that subsequently required ICU support (median [IQR], 4[0; 12] vs. 13[5.75; 24]). The bootstrap comparisons of AUC ROC showed significant differences between reporting tools, and the ZCVS was found to be superior (AUC ROC, 71-75%). The ZCVS score at the first admission showed a linear and significant association with adverse outcomes among patients with the lower respiratory tract symptoms during the COVID-19 pandemic.

A novel approach to managing COVID-19 patients; results of lopinavir plus doxycycline cohort.

This manuscript aims to present a treatment algorithm we applied to manage COVID-19 patients admitted to our hospital. During the study period, 2043 patients with suspected COVID-19 were admitted to the emergency department. Molecular tests indicated that 475 of these patients tested positive for COVID-19. We administered hydroxychloroquine plus doxycycline to mild cases (isolated at home) for 3 days and lopinavir plus doxycycline to moderate and severe cases (hospitalized) for 5 days. The overall case fatality rate was 4.2% (20/475).

A Statistical Modeling of the Course of COVID-19 (SARS-CoV-2) Outbreak: A Comparative Analysis.

This study aims to provide both a model by using cumulative cases and cumulative death toll for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) outbreak in four countries, China, Italy, South Korea, and Turkey, starting from the first diagnosis and to compare associated indicators. The most successful estimation was obtained from the cubic model with natural logarithm for China, Italy, South Korea, and Turkey. The success of the models was around 99%. However, differences began to emerge in China, Italy, and South Korea after the second week. Although the highest number of new cases per 1 million people in China was 9.8 on February 28, 2020; it was 108.4 on March 21, 2020, in Italy; and this was 16.6 on March 5, 2020, in South Korea. On the other hand, the number of new cases was 24.6 per 1 million people on March 27, 2020, in Turkey. The log-cubic model proposed in this study has been set forth to obtain successful results for aforementioned countries, as well as to estimate the course of the COVID-19 outbreak. Other factors such as climacteric factors and genetic differences, which may have an impact on viral spreading and transmission, would also have strengthened the model prediction capacity.