COVID-19 PCR test performance on samples stored at ambient temperature.

The WHO-named Coronavirus Disease 2019 (COVID-19) infection had become a pandemic within a short time period since it was detected in Wuhan. The outbreak required the screening of millions of samples daily and overwhelmed diagnostic laboratories worldwide. During this pandemic, the handling of patient specimens according to the universal guidelines was extremely difficult as the WHO, CDC and ECDC required cold chain compliance during transport and storage of the swab samples. The aim of this study was to compare the effects of two different storage conditions on the COVID-19 real-time PCR assay on 30 positive nasopharyngeal and/or oropharyngeal samples stored at both ambient temperature (22 ± 2 °C) and +4 °C. The results revealed that all the samples stored at ambient temperature remain PCR positive for at least six days without any false-negative result. In conclusion, transporting and storing these types of swab samples at ambient temperature for six days under resource-limited conditions during the COVID-19 pandemics are acceptable.

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) is not detected in the vagina: A prospective study.

OBJECTIVE: To determine whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is present in the vagina of women diagnosed with coronavirus disease-19 (COVID-19) pneumonia. STUDY DESIGN: The study was conducted prospectively in a university affiliated hospital. Forty-one women of reproductive age whose nasopharyngeal PCR test were positive for SARS-CoV-2 and clinically diagnosed with pneumonia were included in the study. Vaginal swabs were obtained for SARS-CoV-2 PCR tests when the patients were admitted to the inpatient service before pneumonia treatment was initiated. RESULTS: Vaginal swab samples of 38 patients were analysed with SARS-CoV-2 PCR tests. None of the vaginal swabs were positive for SARS-CoV-2. CONCLUSIONS: SARS-CoV-2 does not infect the vagina of women diagnosed with SARS-CoV-2 pneumonia.

Seroprevalence of coronavirus disease 2019 (COVID-19) among health care workers from three pandemic hospitals of Turkey.

COVID-19 is a global threat with an increasing number of infections. Research on IgG seroprevalence among health care workers (HCWs) is needed to re-evaluate health policies. This study was performed in three pandemic hospitals in Istanbul and Kocaeli. Different clusters of HCWs were screened for SARS-CoV-2 infection. Seropositivity rate among participants was evaluated by chemiluminescent microparticle immunoassay. We recruited 813 non-infected and 119 PCR-confirmed infected HCWs. Of the previously undiagnosed HCWs, 22 (2.7%) were seropositive. Seropositivity rates were highest for cleaning staff (6%), physicians (4%), nurses (2.2%) and radiology technicians (1%). Non-pandemic clinic (6.4%) and ICU (4.3%) had the highest prevalence. HCWs in "high risk" group had similar seropositivity rate with "no risk" group (2.9 vs 3.5 p = 0.7). These findings might lead to the re-evaluation of infection control and transmission dynamics in hospitals.

Does sampling saliva increase detection of SARS-CoV-2 by RT-PCR? Comparing saliva with oro-nasopharyngeal swabs.

The gold standard method in the diagnosis of SARS-CoV-2 infection is the detection of viral RNA in the nasopharyngeal sample by RT-PCR. Recently, saliva samples have been suggested as an alternative sample. In the present study, we aimed to compare RT-PCR results in nasopharyngeal, oro-nasopharyngeal and saliva samples of COVID-19 patients. 98 of 200 patients were positive in RT-PCR analysis performed before the hospitalization. On day 0, at least one sample was positive in 67 % of 98 patients. The positivity rate was 83 % for both oro-nasopharyngeal and nasopharyngeal samples, while it was 63 % for saliva samples (p < 0.001). On day 5, RT-PCR was performed in 59 patients, 34 % had at least one positive result. The positivity rate was 55 % for both saliva and nasopharyngeal samples, while it was 60 % for oro-nasopharyngeal samples. Our study shows that the sampling saliva does not increase the sensitivity of RT-PCR tests at the early stages of infection. However, on the 5th day, viral RNA detection rates in saliva were similar to nasopharyngeal and oro-nasopharyngeal samples. In conclusion, we suggest that, in patients receiving treatment, RT-PCR in saliva, in addition to the standard samples, is important to determine the isolation period and control transmission.