scholarly journals Saliva, a relevant alternative sample for SARS-CoV2 detection

Author(s):  
Monique Melo Costa ◽  
Nicolas Benoit ◽  
Jerome Dormoi ◽  
Remy Amalvict ◽  
Nicolas Gomez ◽  
...  

AbstractBackgroundCurrently, COVID-19 diagnosis relies on quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR) from nasopharyngeal swab (NPS) specimens, but NPSs present several limitations. The simplicity, low invasive and possibility of self-collection of saliva imposed this specimen as a relevant alternative for SARS-CoV-2 detection. However, the discrepancy of saliva test results compared to NPSs made of its use controversial. Here, we proposed to assess Salivettes®, as a standardized saliva collection device, and to compare SARS-CoV-2 positivity on paired NPS and saliva specimens.MethodsA total of 303 individuals randomly selected among those investigated for SARS-CoV-2 were enrolled, including 30 (9.9%) patients previously positively tested using NPS (follow-up group), 90 (29.7%) mildly symptomatic and 183 (60.4%) asymptomatic.ResultsThe RT-qPCR revealed a positive rate of 11.6% (n=35) and 17.2% (n=52) for NPSs and saliva samples, respectively. The sensitivity and specificity of saliva samples were 82.9% and 91.4%, respectively, using NPS as reference. The highest proportion of discordant results concerned the follow-up group (33.3%). Although in the symptomatic and asymptomatic groups the agreement exceeded 90.0%, 17 individuals were detected positive only in saliva samples, with consistent medical arguments.ConclusionSaliva collected with Salivette® demonstrated more sensitive for detecting symptomatic and pre-symptomatic infections.

2020 ◽  
Author(s):  
George M. Bwire ◽  
Mtebe V. Majigo ◽  
Belinda J. Njiro ◽  
Akili Mawazo

AbstractBackgroundTesting is one of the commendable preventive measures against coronavirus disease (COVID-19), and needs to be done using both most appropriate specimen and an accurate diagnostic test like real time reverse transcription polymerase chain reaction (qRT-PCR). However, the detection rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA from different clinical specimens after onset of symptoms is not yet well established. For guiding the selection of specimens for clinical diagnosis of COVID-19, a systematic review aiming at profiling the positive detection rate from different clinical specimens using PCR was conducted.MethodsThe systematic search was done using PubMed/MEDLINE, Science direct, Google Scholar, among others. The search included studies on laboratory diagnosis of SARS-CoV-2 from different clinical specimens using PCR. Data extraction was done using Microsoft Excel spread sheet 2010 and reported according to PRISMA-P guidelines. Using Open Meta Analyst software, DerSimonian–Laird random effects analysis was performed to determine a summary estimate (positive rate [PR]/proportions) and their 95% confidence interval (95%CI).ResultsA total of 8136 different clinical specimens were analyzed to detect SARS-CoV-2, with majority being nasopharyngeal swabs (69.6%). Lower respiratory tract (LRT) specimens had a PR of 71.3% (95%CI:60.3%-82.3%) while no virus was detected from the urinogenital specimens. Bronchoalveolar lavage fluid (BLF) specimen had the PR of 91.8% (95%CI:79.9-103.7%), followed by rectal swabs, 87.8 % (95%CI:78.6%-96.9%) then sputum, 68.1% (95%CI:56.9%-79.4%). Low PR was observed in oropharyngeal swabs, 7.6% (95%CI:5.7%-9.6%) and blood samples, 1.0% (95%CI: -0.1%-2.1%), whilst no SARS-CoV-2 was detected in urine samples. Nasopharyngeal swab, a widely used specimen had a PR of 45.5% (95%CI:31.2%-59.7%).ConclusionIn this study, SARS-CoV-2 was highly detected in lower respiratory tract specimens while there was no detected virus in urinogenital specimens. Regarding the type of clinical specimens, bronchoalveolar lavage fluid had the highest positive rate followed by rectal swab then sputum. Nasopharyngeal swab which is widely used had a moderate detection rate. Low positive rate was recorded in oropharyngeal swab and blood sample while no virus was found in urine samples. More importantly, the virus was detected in feces, suggesting SARS-CoV-2 transmission by the fecal route.


2020 ◽  
Author(s):  
Sebastian Marschner ◽  
Stefanie Corradini ◽  
Josefine Rauch ◽  
Richard Zacharias ◽  
Ana Sujic ◽  
...  

Abstract Background Starting in December 2019, the current pandemic caused by the severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) confronts the world with an unprecedented challenge. With no vaccine or drug being currently available to control the pandemic spread, prevention and PCR (Polymerase chain reaction) testing becomes a crucial pillar of medical systems. Aim of the present study was to report on the first results of the measures taken in a large German Department of Radiation Oncology, including PCR testing of asymptomatic cancer patients. Methods Pandemic-adapted hygiene regulations and prevention measures for patients and staff were implemented. A visiting ban on both wards was implemented from the beginning and medical staff and patients were required to wear face masks at all times. The waiting rooms were rearranged to ensure distance between patients of at least 1.5 meters. Clinical follow up was mainly done by telephone and all patients had to complete a questionnaire regarding symptoms and contacts with COVID-19 patients before entering our department. Educational documents were created for patients to raise awareness of symptoms and avoidance strategies for interactions with other people. Indications for therapy and fractionation schemes were adapted when possible. In a subsequent step, all new asymptomatic patients were tested via nasopharyngeal swab at our screening station shortly before their simulation CT. Results All these measures and implementations have been well accepted. Regarding the PCR testing, only 1 out of 139 asymptomatic patients of our cohort so far tested positive for SARS-CoV-2, reflecting a prevalence of 0.72% in this cancer patient population. Up to this point no staff members was tested positive. The start of the treatment for the PCR-positive patient was deferred for two weeks. Conclusion Due to the pandemic-adapted implementations, our department seems well prepared during this crisis. The initial screening helps to identify asymptomatic COVID-19 patients in order to protect other patients and our staff from infection and the observed PCR prevalence is in line with comparable studies. A regular PCR testing (e.g. twice a week) of all patients and staff would in principle be desirable but is limited due to testing capacities at present.


2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110261
Author(s):  
Sungwoo Choi ◽  
Hyo Jeong Choi ◽  
Ho Jung Kim

The most common method for SARS-CoV-2 testing is throat or nasal swabbing by real-time reverse transcription polymerase chain reaction (RT-PCR) assay. In South Korea, drive-through swab test is used for screening system and community treatment centers (CTCs), which admit and treat confirmed COVID-19 patients with mild symptoms, are being used. This retrospective study was conducted on patients admitted to a CTC on March 6, 2020. A total of 313 patients were admitted. The nasal and throat swabs were collected from the upper respiratory tract, and a sputum test was performed to obtain lower respiratory samples. The positive rate of the first set of test, sputum test was higher than that of the swab test ( p = 0.011). In the second set of test, 1 week after the first ones, the rate of positive swab tests was relatively high ( p = 0.026). In the first set of test, 66 of 152 (43.4%) patients showed 24-h consecutive negative swab test results, when the sputum test results were considered together, that number fell to 29 patients (19.1%) ( p < 0.001). Also, in the second set of test, 63 of 164 (38.4%) patients met the discharge criteria only when the swab test was considered; that number fell to 30 (18.3%) when the sputum test results were also considered ( p < 0.001). Using the swab test alone is insufficient for screening test and discharge decision. Patients who may have positive result in the sputum test can be missed.


2021 ◽  
pp. 101053952110110
Author(s):  
Salma Abbas ◽  
Aun Raza ◽  
Ayesha Iftikhar ◽  
Aamir Khan ◽  
Shahzaib Khan ◽  
...  

Health care personnel (HCP) are at high risk for coronavirus disease-2019 acquisition. Serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) indicate past infection. Our institution offered SARS-CoV-2 antibody testing to HCP. We surveyed HCP with positive test results to explore past exposure to SARS-CoV-2, details of symptoms during the preceding 6 months, and a history of SARS-CoV-2 polymerase chain reaction testing. A total of 2162 HCP underwent antibody testing. Eight hundred fifty-seven (39.6%) employees tested positive and, of these, 820 (95.7%) participated in the survey. When adjusted for age, males had higher odds of testing positive for SARS-CoV-2 antibodies compared with females (OR = 1.68; 95% CI = 1.37-2.05; P = .00) and clinical staff had higher odds of SARS-CoV-2 seropositivity compared with nonclinical staff (OR = 1.273; 95% CI = 1.06-1.53; P = .01). Implementation of effective infection control measures is essential to protect HCP from coronavirus disease-2019.


Open Medicine ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 749-753
Author(s):  
Wenyuan Li ◽  
Beibei Huang ◽  
Qiang Shen ◽  
Shouwei Jiang ◽  
Kun Jin ◽  
...  

Abstract In recent months, the novel coronavirus disease 2019 (COVID-19) pandemic has become a major public health crisis with takeover more than 1 million lives worldwide. The long-lasting existence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has not yet been reported. Herein, we report a case of SARS-CoV-2 infection with intermittent viral polymerase chain reaction (PCR)-positive for >4 months after clinical rehabilitation. A 35-year-old male was diagnosed with COVID-19 pneumonia with fever but without other specific symptoms. The treatment with lopinavir-ritonavir, oxygen inhalation, and other symptomatic supportive treatment facilitated recovery, and the patient was discharged. However, his viral PCR test was continually positive in oropharyngeal swabs for >4 months after that. At the end of June 2020, he was still under quarantine and observation. The contribution of current antivirus therapy might be limited. The prognosis of COVID-19 patients might be irrelevant to the virus status. Thus, further investigation to evaluate the contagiousness of convalescent patients and the mechanism underlying the persistent existence of SARS-CoV-2 after recovery is essential. A new strategy of disease control, especially extending the follow-up period for recovered COVID-19 patients, is necessary to adapt to the current situation of pandemic.


Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 949
Author(s):  
Asta Raskiliene ◽  
Alina Smalinskiene ◽  
Vilma Kriaucioniene ◽  
Vaiva Lesauskaite ◽  
Janina Petkeviciene

MC4R, LEP, and LEPR genes are involved in the hypothalamic leptin-melanocortin regulation pathway, which is important for energy homeostasis. Our study aimed to evaluate the associations between the MC4R rs17782313, LEP rs7799039, and LEPR rs1137101 polymorphisms with obesity-related parameters in childhood and adulthood. The data were obtained from the Kaunas Cardiovascular Risk Cohort study, which started in 1977 with 1082 participants aged 12–13 years. In 2012–2014, the follow-up survey was carried out. Genotype analysis of all respondents (n = 509) aged 48–49 years was performed for the gene polymorphisms using Real-Time Polymerase Chain Reaction. Anthropometric measurements were performed in childhood and adulthood. In childhood, only skinfold thicknesses were associated with gene variants being the lowest in children with MC4R TT genotype and LEP AG genotype. In adulthood, odds of obesity and metabolic syndrome was higher in MC4R CT/CC genotype than TT genotype carriers (OR 1.8; 95% CI 1.2–2.8 and OR 1.6; 95% CI 1.1–2.4, respectively). In men, physical activity attenuated the effect of the MC4R rs17782313 on obesity. The LEP GG genotype was associated with higher BMI, waist circumference, and visceral fat level only in men. No associations of the LEPR rs1137101 polymorphisms with anthropometric measurements and leptin level were found. In conclusion, the associations of the MC4R and LEP gene polymorphisms with obesity-related parameters strengthened with age.


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