SARS-CoV-2 Seroprevalence in Healthcare Workers before the Vaccination in Poland: Evolution from the First to the Second Pandemic Outbreak.

Healthcare workers (HCWs) are on the frontline, struggling with the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To describe recent or past infections, the serological assays enabled the assessment of the immune response developed in coronavirus disease (COVID-19) in the period when testing was hardly available. In this study, we investigated SARS-CoV-2 seroprevalence in HCWs in a Polish teaching hospital and the Regional Occupational Medicine Center after both the first and the second waves. ELISA-based tests for anti-SARS-CoV-2 IgA and IgG were used to determine immune response to SARS-CoV-2 in volunteer HCWs who worked in those institutions in May 2020 (208 participants aged 47.1 ± 12.5, 88% women) and in December 2020 (179 participants aged 45.2 ± 12.4, 86% woman). Risk factors for seropositivity were also assessed using a questionnaire filled out by all participants. We reported a significant increase in seroprevalence after the second wave (22.9%) compared with the first outbreak (2.4%) (OR 12.1; 95%CI 4.6-31.3; p < 0.0001). An association between IgG seroprevalence and severity of infections was noted. Furthermore, we demonstrated that amongst medical personnel, nurses exhibited a proportionally higher SARS-CoV-2 seroprevalence. Moreover, given the high seroprevalence in non-clinical group of HCWs, we suggest that community transmission can play a superior role to workplace exposure.

Analysis of the concentration of selected serological parameters in patients undergoing antibiotic treatment of Lyme disease and assessment of their potential application in the control of the therapy effectiveness - pilot study.

OBJECTIVE: The aim of the study was to analyze the concentrations of some serological parameters in patients undergoing antibiotic therapy for LD, and to assess the potential use of IgG anti-C6VlsE in the assessment of treatment effectiveness. MATERIAL AND METHODS: The study involved 21 patients diagnosed with LD. To determine the levels of anti-C6VlsE IgG, metalloproteinases and cytokines, blood was collected three times: before treatment, immediately after treatment, and 3-4 months after treatment. RESULTS: Immediately after the antibiotic therapy, all the patients in the study group declared improvement in their health. At 3-4 months post-treatment, 50% of patients reported recurrence of the disease symptoms. The anti-C6VlsE IgG concentrations at the analyzed time points exhibited varied dynamics: in 15% of patients, a decrease in the concentration of anti-C6VlsE was observed in the three consecutive serum samples; an increase of anti-C6VlsE IgG was detected in 35% of cases; in 15% of the subjects, the concentration of anti-C6VlsE IgG increased immediately after the antibiotic therapy and declined after 3-4 months, whereas a reverse situation was noted in 10% of the patients. CONCLUSIONS: The presence of high concentrations of anti-C6VlsE IgG is associated with appearance of response to Borreliella spp. infection, which suggests that the parameter can be used in the diagnosis of the active form of borreliosis. However, from a practical point of view, a marker of successful elimination of infection should indicate the effectiveness or failure of antibiotic therapy within a relatively short post-treatment period. The anti-C6VlsE IgG antibodies do not seem to satisfy this provision.

Analysis of selected serological parameters in patients with diagnosed Lyme borreliosis and in seropositive patients with no clinical symptoms.

OBJECTIVES: The aim of the study was to analyze some metalloproteinases, cytokines, and chemokines in LB patients and healthy seropositive subjects. The presence of IgM/IgG antibodies against specific Borreliella antigens was analyzed in the presence or absence of clinical manifestations of LB. MATERIAL AND METHODS: The study involved 38 patients diagnosed with LB and arthralgia and/or arthritis symptoms, and 57 foresters presenting no clinical symptoms of LB. The ELISA test was applied for general screening of anti-Borreliella IgM/IgG. Western blot was used for confirmatory diagnosis of LB for the positive and borderline results. Serum IL-2, IL-4, IL-6, IL-10, IL-17A, IFN-γ, TNF, IL-8, CCL5, CXCL9/MIG, CCL2/MCP-1, CXCL10/IP-10 concentrations were measured with the use of the Human Cytometric CBA test. The concentration of MMP-2 and MMP-9 in the serum was determined with the use of ELISA tests. RESULTS: Analysis of the cytokines and chemokines revealed that only the concentration of IL-2 was significantly higher (2.4 pg/m; p=0.00641) in patients with LB symptoms than in the seropositive individuals (0.4 pg/ml). The MMP2 concentration was significantly higher (233.3 ng/ml; p=0.00294) in patients with clinical manifestations of LB than in those occupationally exposed to tick bites, but did not have anti-Borreliella antibodies (192.0 ng/ml). CONCLUSIONS: The presence of IgG antibodies against a number of Borreliella antigens and the differences in the IL-2 and MMP2 levels in seropositive or seronegative individuals and symptomatic LB patients, may indicate differences in the intensity of the immune response to the infection and, consequently, may induce development of clinical manifestations of the disease in seropositive and seronegative individuals.

Seroprevalence of Antibodies against SARS-CoV-2 in Children with Juvenile Idiopathic Arthritis a Case-Control Study.

There is limited data on the effect of the novel coronavirus disease (COVID-19) caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) on pediatric rheumatology. We examined the prevalence of antibodies against SARS-CoV-2 in children with juvenile idiopathic arthritis (JIA) and a negative history of COVID-19 and the correlation of the presence of these antibodies with disease activity measured by juvenile arthritis disease activity score (JADAS). In total, 62 patients diagnosed with JIA, under treatment with various antirheumatic drugs, and 32 healthy children (control group) were included. Serum samples were analyzed for inflammatory markers and antibodies and their state evaluated with the juvenile arthritis disease activity score (JADAS). JIA patients do not have a higher seroprevalence of anti-SARS-CoV-2 antibodies than healthy subjects. We found anti-SARS-CoV-2 antibodies in JIA patients who did not have a history of COVID-19. The study showed no unequivocal correlation between the presence of SARS-CoV-2 antibodies and JIA activity; therefore, this relationship requires further observation. We also identified a possible link between patients' humoral immune response and disease-modifying antirheumatic treatment, which will be confirmed in follow-up studies.

[Lactobacillus speciesas opportunistic pathogens in children]. / Paleczki z rodzaju Lactobacillus--czynnik zakazen oportunistycznych u dzieci.

The purpose of this research was the analysis of the Lactobacillus spp. strain occurrence in diagnostic materials obtained in the clinical pediatric hospital as well as to evaluate the phenotypic features of isolated strains and bile salts hydrolase (BSH) activity. Isolated strains were grown booth on media routinely used in clinical microbiology (TSA, Columbia + 5% sheep blood, D-coccosel) and on selective media (MRS) to isolated Lactobacillus bacteria. Strains were identified on the basis of biochemical profile in API 50CH test. Strains morphology and appearance of bile salts hydrolase activity were determined. During the research 107 Lactobacillus strains were isolated in oncology ward (37%), pulmonology (24%), home marrow transplantation (10%), intensive care unit (11%), and others. The strains were isolated from blood (9%), cerebrospinal fluid (1%), peritoneal fluid (1%), intestinal fistula (1%), respiratory tract (81%) and others. L. rhamnosus species dominated. The isolates grew poorly on routine media white on selective (MRS) media they grew well. Bile salts hydrolase (BSH) activity was detected in 20% of the strains. The results of the research show that Lactobacillus rods colonise patients with lowered immunity and may be the source of serious opportunistic infections in children. Phenotypic features, including many similar to Enterococcus species, make the diagnosis of these bacteria difficult. The use of MRS media can make it easier to isolate Lactobacillus rods from clinical materials.