ABSTRACT
Objective: To analyze and compare the effects of different clinical characteristics on the negative conversion time of nucleic acid detection after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infection, and to provide a scientific basis for the isolation and treatment of coronavirus disease 2019 (COVID-19). Methods: The epidemiological and clinical data of 228 mild SARS-CoV-2 Omicron variant infected patients diagnosed in Shanghai were retrospectively collected from April 27, 2022 to June 8, 2022 in Wujiaochang designated Hospital, Yangpu District, Shanghai. The negative conversion time of nucleic acid detection was used as the outcome variable, and the patients were divided into A (18 days) and B (>18 days). Univariate and multivariate logistic regression analysis were used to analyze the influencing factors of the negative conversion time of nucleic acid detection. Results: The mean nucleic acid conversion time of 228 patients was (18.7+or-12.1) d, with the median time of 18 (2-46) d. Among them, 120 patients in group A had an average nucleic acid conversion time of (13.2+or-2.0) d, and 108 cases in group B had an average nucleic acid conversion time of (20.8+or-1.3) d. Univariate analysis showed that there were no statistically significant differences in the effects of hypertension, coronary heart disease, diabetes, hypokalemia, malignant tumors, neuropsychiatric diseases, chronic digestive diseases on the negative nucleic acid conversion time (P > 0.05);however, there were significant differences in the effects of combined cerebrovascular disease, leukopenia, chronic respiratory system diseases and vaccination on the negative nucleic acid conversion time (P < 0.05). Further multivariate logistic regression analysis revealed that the combination of chronic respiratory diseases and non-vaccination were significant risk factors for prolongation of negative nucleic acid conversion time (P < 0.05). Conclusions: The results of this study show that gender, age and whether hypertension, coronary heart disease, diabetes mellitus, hypokalemia, malignant tumor, neuropsychiatric disease and chronic digestive disease have no significant effect on the nucleic acid conversion time, whereas chronic respiratory disease and no vaccination are significantly correlated with the prolongation of nucleic acid conversion time in SARS-CoV-2 Omicron-infected patients.
ABSTRACT
Introduction : Acute gastroenteritis is a typical disorder that accounts for 8-12% of pediatric outpatient visits. Campylobacter and Salmonella infections account for about 8.4% and 11% of global diarrhea cases. Due to the importance of these bacteria in pediatric diseases, the aim of this study was to determine the infectious rate of Salmonella and Campylobacter species and also the frequency of the gene encoding Cytholethal distending toxin in children with community-acquired diarrhea. Materials and Methods: Stool samples of children under 5 years of age with diarrhea were collected. The samples were related to children referred to hospitals in Hamadan, Ardabil, Bandar Abbas and two hospitals in Tehran. DNA was extracted from the samples using a DNA extraction kit from stool. The presence of Campylobacter in the studied samples was detected by polymerase chain reaction using specific primers. A control stool sample was spiked with 10-fold dilution of C. jejuni suspension for LOD (detection limit determination) measurement. Results: In this study, PCR results showed a LOD of 100 CFU per gram in the spiked feces sample. Accordingly, out of 144 fecal samples of children with acute diarrhea, one case was positive for Campylobacter jejuni;this sample was also positive for the presence of cdtB gene. Presence of Salmonella was confirmed in two samples of the patients (1.4%). Conclusion: Low prevalence of Campylobacter and Salmonella was detected in symptomatic children under 5 years of age during the Covid-19 pandemic. Examination of these samples for viruses and other microbial agents can clarify the etiology of diarrhea in children referred to the hospitals.
ABSTRACT
Corona virus disease 2019 (COVID-19) is an emerging pandemic of highly contagious caused by severe acute respiratory syndrome coronavirus -2 (SARS-CoV-2). Understanding the infectivity of various clinical samples and its transmission routes have been the main focus of current researches since the causative pathogens was identified. In this comprehensive review, we discuss the viral shedding from different clinical samples and reveal that infectious virus may be mainly discharged through respiratory and digestive systems. Also, SARS-CoV-2 showed a potential tropism for eyes, kidney, testis, placenta and other extrapulmonary tissues and high viral loads correlated with severe conditions. A better understanding of viral shedding may help the studies on pathogenesis and transmission of SARS-CoV-2 and provide suggestions for the disease control.