Risk factors for prolonged nucleic acid conversion time in patients with COVID-19

Objectives: The time for PCR positivity to negativity is defined as nucleic acid conversion time (NCT) and is very important in terminating the isolation of patients and determining infectiousness in patients with COVID-19. The aim of this study is to determine the median NCT and to evaluate the clinical and laboratory parameters affecting it in patients with COVID-19. Methods: This study included 318 patients with mild to moderate COVID-19 diagnosed with PCR positivity retrospectively. Results: The median NCT was 11 days. Patients were divided into 2 groups as early (<11 days) and late conversion (≥11 days). Older age, sore throat, onset fever, fever 72 h after hospitalization, history of exposure to SARS-CoV-2 virus without a mask, and moderated disease were significantly more common in the late conversion group. In addition, favipiravir use was higher in early conversion group and hydroxychloroquine use was higher in late conversion group. In multivariate analysis, sore throat (OR = 2.570;95% CI: 1.051–6.284, P = 0.039) and hydroxychloroquine use (OR = 3.518, 95% CI: 1.163–10.635, P = 0,026) were independent risk factors for late conversion. Favipiravir use (OR = 0.062, 95% CI: 0.021–0.184, P = 0.0001) negatively affected the late conversion. Conclusion: NCT was longer in patients with COVID-19 who had sore throat at admission and were treated with hydroxychloroquine instead of favipiravir. [ FROM AUTHOR] Copyright of Journal of Health Sciences (Qassim University) is the property of Journal of Health Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Prolonged SARS-CoV-2 nucleic acid conversion time in military personnel outbreaks with presence of specific IgG antibodies.

Coronavirus disease 2019 (COVID-19) is transmitted person-to-person mainly by close contact or droplets from respiratory tract. However, the actual time of viral shedding is still uncertain as well as the different routes of transmission. We aimed to characterize RNA shedding from nasopharyngeal and rectal samples in prolonged cases of mild COVID-19 in young male soldiers. Seventy patients from three different military locations were monitored after recommending to follow more strict isolation measures to prevent the spread of the virus. Then, nasopharyngeal, rectal, and blood samples were taken. SARS-CoV-2 RNA was detected by RT-PCR and specific antibodies by chemiluminescent immunoassays. The median nucleic acid conversion time (NACT) was 60 days (IQR: 7-85 days). Rectal swabs were taken in 60 % of patients. Seven patients (10 %) were positive in nasopharyngeal and rectal swabs, and five (7.14 %) remained positive in rectal swabs, but negative in nasopharyngeal samples. Four patients (5.71 %) that had been discharged, were positive again after 15 days. No significant difference was found in nucleic acid conversion time between age groups nor clinical classification. Maintaining distancing among different positive patients is essential as a possible re-exposure to the virus could cause a longer nucleic acid conversion time in SARS-COV-2 infections.

Immune responses and pathogenesis in persistently PCR-positive patients with SARS-CoV-2 infection.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 emerged in China in December 2019 and then rapidly spread worldwide. Why COVID-19 patients with the same clinical condition have different outcomes remains unclear. This study aimed to examine the differences in the phenotype and functions of major populations of immune cells between COVID-19 patients with same severity but different outcomes. Four common type adult inpatients with laboratory confirmed COVID-19 from Beijing YouAn Hospital, Capital Medical University were included in this study. The patients were divided into two groups based on whether or not COVID-19 polymerase chain reaction (PCR)-negative conversion occurred within 3 weeks. Peripheral blood samples were collected to compare the differences in the phenotype and functions of major populations of immune cells between the two groups of patients. The result shows that the proportions of CD3+ CD8+ CD38+ HLA-DR+ CD27- effector T killer cells generally declined, whereas that of CD3+ CD4+ CD8+ double-positive T cells (DPTs) increased in the persistently PCR-positive patients. In summary, considering the imbalance between effector T killer cells/CD3+CD4+CD8+ DPTs was a possible key factor for PCR-negative conversion in patients with COVID-19.

Prolonged nucleic acid conversion and false-negative RT-PCR results in patients with COVID-19: A case series.

BACKGROUND: Prolonged nucleic acid conversion and false-negative real-time polymerase chain reaction (RT-PCR) results might occur in COVID-19 patients rather than infection recurrence. PRESENTATION OF CASES: We reported four cases who had negative RT-PCR results, in addition to the last two consecutive negative results. Patient-1 had negative RT-PCR results twice (the 6th and 8th) from a total of 11 swabs. Patient-2 had negative RT-PCR results once (the 5th) from a total of 8 swabs. Patient-3 showed negative results of RT-PCR twice (the 4th and 6th) from a total of 11 swabs. Patient-4 had negative RT-PCR results twice (the 2nd and 10th) from a total of 14 swabs. DISCUSSION: The fluctuating trend of our RT-PCR results in our cases might be due to insufficient viral material in the specimen, laboratory errors during sampling, restrictions on sample transportation, or mutations in the primary and probe target regions in the SARS-CoV-2 genome. Several factors might affect the occurrence of prolonged nucleic acid conversion, including older age, comorbidities, such as diabetes and hypertension, and impaired immune function. CONCLUSION: Here, we confirmed the occurrence of prolonged nucleic acid conversion and the possibility of false negative RT-PCR results in COVID-19 patients.