Emerging microbes & infections
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Coronavirus disease 2019 (COVID-19) has become a pandemic with increasing numbers of cases worldwide. SARS-CoV-2, the causative virus of COVID-19, is mainly transmitted through respiratory droplets or through direct and indirect contact with an infected person. The possibility of potential faecal-oral transmission was investigated in this study. ⋯ A small number of patients had strong faecal detoxification ability. The live virus in faeces could be an important source of contamination, which may lead to infection and further spread in areas with poor sanitary conditions. The findings of this study have public health significance and they should be considered when formulating disease control strategies.
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Emerg Microbes Infect · Dec 2020
Viral loads in throat and anal swabs in children infected with SARS-CoV-2.
Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) assay on anal swabs was recently reported to be persistently positive even after throat testing was negative during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, data about the consistent performance of RT-PCR assay on throat and anal swabs remain limited in paediatric patients. Here, we retrospectively reviewed RT-PCR-testing results of 212 paediatric patients with suspected SARS-CoV-2 infection at Wuhan Children's Hospital. ⋯ Furthermore, viral loads detected on both throat and anal swabs also showed no significant difference (P = 0.9511) and correlation (Pearson r = 0.0434, P = 0.8406), and exhibited an inconsistent kinetic change through the course of SARS-CoV-2 infection. Besides, viral loads in the throat and anal swabs were correlated with different types of immune states, immune-reactive phase, and the resolution phase/immunologic tolerance, respectively. These findings revealed that RT-PCR-testing on throat and anal swabs showed significant difference for monitoring SARS-CoV-2 infection and correlated with different immune state in paediatric patients.
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Emerg Microbes Infect · Dec 2020
LetterA multi-family cluster of COVID-19 associated with asymptomatic and pre-symptomatic transmission in Jixi City, Heilongjiang, China, 2020.
We investigated a multi-family cluster of 22 cases in Jixi, where pre-symptomatic and asymptomatic transmission resulted in at least 41% of household infections of SARS-CoV-2. Our study illustrates the challenge of controlling COVID-19 due to the presence of asymptomatic and pre-symptomatic transmission even when extensive testing and contact tracing are conducted.
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Emerg Microbes Infect · Dec 2020
Delayed specific IgM antibody responses observed among COVID-19 patients with severe progression.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly worldwide since it was confirmed as the causative agent of COVID-19. Molecular diagnosis of the disease is typically performed via nucleic acid-based detection of the virus from swabs, sputum or bronchoalveolar lavage fluid (BALF). However, the positive rate from the commonly used specimens (swabs or sputum) was less than 75%. ⋯ The GICA was found to be positive with the detected 82.2% (37/45) of RT-qPCR confirmed COVID-19 cases, as well as 32.0% (8/25) of clinically confirmed, RT-qPCR negative patients (4-14 days after symptom onset). Investigation of IgM-negative, RT-qPCR-positive COVID-19 patients showed that half of them developed severe disease. The GICA was found to be a useful test to complement existing PCR-based assays for confirmation of COVID-19, and a delayed specific IgM antibody response was observed among COVID-19 patients with severe progression.
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Emerg Microbes Infect · Dec 2020
Dynamic changes of throat swabs RNA and serum antibodies for SARS-CoV-2 and their diagnostic performances in patients with COVID-19.
Dynamic changes of RNA and antibodies in SARS-CoV-2 infected patients remain largely unknown, and influence factors for antibody production have not been fully clarified. In this study, consecutive throat swabs specimens (n = 1875) from 187 patients were collected to analyse the dynamic changes of RNA. Moreover, 162 serial serum samples from 31 patients were tested for seroconversion of IgM and IgG. ⋯ The sensitivity and specificity for IgM (or IgG) was 87.04% and 96.92%, respectively. Multivariate logistic regression indicated that reduced lymphocytes and short positive conversion time for SARS-CoV-2 RNA were independent factors for negative results of IgM and IgG. In conclusion, RNA and antibodies should be combined for COVID-19 diagnosis, and delayed seroconversion was influenced by the decreased lymphocytes and short positive conversion time for RNA.