Anal swab as a potentially optimal specimen for SARS-CoV-2 detection to evaluate hospital discharge of COVID-19 patients

Molecular Diagnosis of COVID-19; Biosafety and Pre-analytical Recommendations

From the beginning of the COVID-19 epidemic, clinical laboratories around the world have been involved with tests for detection of SARS-CoV-2. At present, RT-PCR (real-time reverse transcription polymerase chain reaction assay) is seen as the gold standard for identifying the virus. Many factors are involved in achieving the highest accuracy in this test, including parameters related to the pre-analysis stage. Having instructions on the type of sample, how to take the sample, and its storage and transportation help control the interfering factors at this stage. Studies have shown that pre-analytical factors might be the cause of the high SARS-CoV-2 test false-negative rates. Also, the safety of personnel in molecular laboratories is of utmost importance, and it requires strict guidelines to ensure the safety of exposed individuals and prevent the virus from spreading. Since the onset of the outbreak, various instructions and guidelines have been developed in this field by the institutions and the Ministry of Health of each country; these guidelines are seriously in need of integration and operation. In this study, we try to collect all the information and research done from the beginning of this pandemic in December 2019 - August 2022 concerning biosafety and protective measures, sample types, sampling methods, container, and storage solutions, sampling equipment, and sample storage and transportation for molecular testing of SARS-CoV-2.

Biased, wrong and counterfeited evidences published during the COVID-19 pandemic, a systematic review of retracted COVID-19 papers

In 2020 COVID-19 led to an unprecedented stream of papers being submitted to journals. Scientists and physicians all around the globe were in need for information about this new disease. In this climate, many articles were accepted after extremely fast peer-reviews to provide the scientific community with the latest discoveries and knowledge. Unfortunately, this also led to articles retraction due to authors' misconduct or errors in methodology and/or conclusions. The aim of this study is to investigate the number and characteristics of retracted papers, and to explore the main causes that led to retraction. We conducted a systematic review on retracted articles, using PubMed as data source. Our inclusion criteria were the following: English-language retracted articles that reported original data, results, opinions or hypotheses on COVID-19 and Sars-CoV-2. Twenty-seven retracted articles were identified, mainly reporting observational studies and opinion pieces. Many articles published during the first year of the pandemic have been retracted, mainly due to the authors' scientific misconduct. Duplications, plagiarism, frauds and absence of consent, were the main reasons for retractions. In modern medicine, researchers are required to publish frequently, and, especially during situations like the COVID-19 pandemic, when articles were rapidly published, gaps in peer-reviews system and in the path to scientific publication arose.

The COVID-19 pandemic - what have urologists learned?

On 11 March 2020, the WHO declared the coronavirus disease 2019 (COVID-19) outbreak a pandemic and COVID-19 emerged as one of the biggest challenges in public health and economy in the twenty-first century. The respiratory tract has been the centre of attention, but COVID-19-associated complications affecting the genitourinary tract are reported frequently, raising concerns about possible long-term damage in these organs. The angiotensin-converting enzyme 2 (ACE2) receptor, which has a central role in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) invasion, is highly expressed in the genitourinary tract, indicating that these organs could be at a high risk of cell damage. The detection of SARS-CoV-2 in urine and semen is very rare; however, COVID-19 can manifest through urological symptoms and complications, including acute kidney injury (AKI), which is associated with poor survival, severe structural changes in testes and impairment of spermatogenesis, and hormonal imbalances (mostly secondary hypogonadism). The effect of altered total testosterone levels or androgen deprivation therapy on survival of patients with COVID-19 was intensively debated at the beginning of the pandemic; however, androgen inhibition did not show any effect in preventing or treating COVID-19 in a clinical study. Thus, urologists have a crucial role in detecting and managing damage of the genitourinary tract caused by COVID-19.

Longitudinal, virological, and serological assessment of hospitalized COVID-19 patients

Here we described the virological and serological assessment of 23 COVID-19 patients hospitalized and followed up in Milan, Italy, during the first wave of COVID-19 pandemic. Nasopharyngeal (NPS), anal swabs, and blood samples were collected from 23 COVID-19 patients, at hospital admission, and periodically up to discharge, for a median time of 20 days (3-83 days). RNA was isolated and tested for SARS-CoV-2 by qRT-PCR; anti-SARS-CoV-2 IgM and IgG antibody titers were evaluated in serum samples by ELISA. SARS-CoV-2 genome was detected in the NPS swabs of the 23 patients, at the admission, and 8/19 (42.1%) were still positive at the discharge. Anal swabs were positive to SARS-CoV-2 RNA detection in 20/23 (86.9%) patients; 6/19 (31.6%) were still positive at discharge. The mean time of RNA negative conversion was 17 days (4-36 days) and 33 days (4-77 days), for NPS and anal swabs, respectively. SARS-CoV-2-RNA was detected in the blood of 6/23 (26.1%) patients. Thirteen/23 (56.5%) and 17/23 (73.9%) patients were seropositive for IgM and IgG, respectively, at the admission, and the median IgM and IgG levels significantly (p < 0.05) increased after 13 days. Although the limited cohort size, our report provides evidence that SARS-CoV-2 is shed through multiple routes, with important implications in healthcare settings.

Saliva specimen complements anal swab in assessing patients with COVID-19 for discharge from hospital

Since December 2019, coronavirus disease 2019 (COVID-19) caused by SARS coronavirus 2 (SARS-CoV-2) has spread and threatens public health worldwide. The recurrence of SARS-CoV-2 RNA detection in patients after discharge from hospital signals a risk of transmission from such patients to the community and challenges the current discharge criteria of COVID-19 patients. A wide range of clinical specimens has been used to detect SARS-CoV-2. However, to date, a consensus has not been reached regarding the most appropriate specimens to use for viral RNA detection in assessing COVID-19 patients for discharge. An anal swab sample was proposed as the standard because of prolonged viral detection. In this retrospective longitudinal study of viral RNA detection in 60 confirmed COVID-19 patients, we used saliva, oropharyngeal/nasopharyngeal swab (O/N swab) and anal swab procedures from admission to discharge. The conversion times of saliva and anal swab were longer than that of O/N swab. The conversion time of hyper sensitive-CRP was the shortest and correlated with that of CT scanning and viral detection. Some patients were found to be RNA-positive in saliva while RNA-negative in anal swab while the reverse was true in some other patients, which indicated that false negatives were inevitable if only the anal swab is used for evaluating suitability for discharge. These results indicated that double-checking for viral RNA using multiple and diverse specimens was essential, and saliva could be a candidate to supplement anal swabs to reduce false-negative results and facilitate pandemic control.

Transmission of severe acute respiratory syndrome coronavirus 2 via fecal-oral: Current knowledge

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in more than 93 million cases and 2 million deaths in the world. SARS-CoV-2 respiratory tract infection and its main clinical manifestations such as cough and shortness of breath are well known to the scientific community. However, a growing number of studies have reported SARS-CoV-2-related gastrointestinal involvement based on clinical manifestations, such as diarrhea, nausea, vomiting, and abdominal pain as well as on the pathophysiological mechanisms associated with coronavirus disease 2019. Furthermore, current evidence suggests SARS-CoV-2 transmission via the fecal-oral route and aerosol dissemination. Moreover, studies have shown a high risk of contamination through hospital surfaces and personal fomites. Indeed, viable SARS-CoV-2 specimens can be obtained from aerosols, which raises the possibility of transmission through aerosolized viral particles from feces. Therefore, the infection by SARS-CoV-2 via fecal-oral route or aerosolized particles should be considered. In addition, a possible viral spread to sources of drinking water, sewage, and rivers as well as the possible risk of viral transmission in shared toilets become a major public health concern, especially in the least developed countries. Since authors have emphasized the presence of viral RNA and even viable SARS-CoV-2 in human feces, studies on the possible fecal-oral coronavirus disease 2019 transmission become essential to understand better the dynamics of its transmission and, then, to reinforce preventive measures against this infection, leading to a more satisfactory control of the incidence of the infection.

SARS-CoV-2 Tests: Bridging the Gap between Laboratory Sensors and Clinical Applications

This review covers emerging biosensors for SARS-CoV-2 detection together with a review of the biochemical and clinical assays that are in use in hospitals and clinical laboratories. We discuss the gap in bridging the current practice of testing laboratories with nucleic acid amplification methods, and the robustness of assays the laboratories seek, and what emerging SARS-CoV-2 sensors have currently addressed in the literature. Together with the established nucleic acid and biochemical tests, we review emerging technology and antibody tests to determine the effectiveness of vaccines on individuals.

Abdominal imaging in COVID-19

Initially thought of as a respiratory infection, coronavirus disease-2019 (COVID-19) is now recognized as a complex disease with a wide clinical spectrum, including digestive involvement. While several studies have evaluated chest imaging findings in COVID-19, few papers have looked at the abdominal imaging features of these patients. Liver, biliary, pancreas and bowel involvement have been reported in COVID-19 infected patients. In this review, we aim to summarize currently available data related to abdominal imaging techniques in COVID-19, in accordance with relevant clinical and laboratory workup of these patients. Underlying mechanisms, indications and imaging findings related to COVID-19 are discussed based on published data. Also, practice points for clinicians are highlighted in order to adequately recognize digestive-related injuries of severe acute respiratory syndrome coronavirus 2 infection. While there’s been a steady accumulation of data with respect to abdominal imaging findings in COVID-19, currently available recommendations are based on limited research. There is a wide spectrum of abdominal imaging findings in COVID-19, which includes hepato-biliary, pancreatic and luminal pathology.

A systematic review and meta-analysis of discharged COVID-19 patients retesting positive for RT-PCR

BACKGROUND

With the increased number of patients discharged after having COVID-19, more and more studies have reported cases whose retesting was positive (RP) during the convalescent period, which brings a new public health challenge to the world.

METHODS

We searched PubMed, Web of Science, The Cochrane Library, CNKI, WanFang and VIP from December 1, 2019 to December 31, 2020. The included studies were assessed using JBI critical appraisal tools and Newcastle-Ottawa Scale. The RP rate of discharge patients was analyzed by a meta-analysis. We adhered to PRISMA reporting guideline.

FINDINGS

We have included 117 studies with 2669 RP participants after discharge. The methodological quality of 66 case reports were low to high, 42 case series and 3 cohort study were moderate to high, 3 case-control studies were moderate and 3 cross-sectional studies were low to moderate. The clinical manifestations of most RP patients were mild or asymptomatic, and CT imaging and laboratory examinations were usually normal. The existing risk factors suggest that more attention should be paid to sever patients, elderly patients, and patients with co-morbidities. The summary RP rate was 12·2% (95% CI 10·6-13·7) with high heterogeneity (I²  = 85%).

INTERPRETATION

To date, the causes and risk factors of RP result in discharged patients are not fully understood. High-quality etiological and clinical studies are needed to investigate these issues to further help us to make strategies to control and prevent its occurrence.