The role of saliva PCR assay in the diagnosis of COVID-19.

INTRODUCTION: The introduction of a self-collection sampling method with less discomfort would be of great benefit in reducing the risk of medical provider's contamination and patient's acceptance. The aim of the present study was to investigate saliva samples' diagnostic performance for the COVID-19 RT-PCR test compared to pharyngeal swabs. METHODOLOGY: From individuals referred to a medical center with presentations compatible with COVID-19 who were eligible for molecular diagnostic tests, 80 cases were selected. Nasopharyngeal and oropharyngeal swabs (placed into the same transport tube) along with self-collected saliva sample were taken from each participant for COVID-19 RT-PCR assay. The results of pharyngeal swabs and saliva sample were compared. RESULTS: Sixty-two (78%) infected cases were detected, of whom 31 (39%) cases tested positive for both pharyngeal swab and saliva samples. 24 (30%) and 7 (9%) cases tested positive only for pharyngeal or saliva samples, respectively. The overall percentage of agreement between pharyngeal swab and saliva sample was 61%, with a kappa value of 0.24 (p-value = 0.019, 95% CI: 0.04-0.44), showing a fair level of agreement. The diagnostic sensitivity of pharyngeal swabs was 88.71% (95% CI: 78.11-95.34), and the diagnostic sensitivity of saliva samples was 61.29% (95% CI: 48.07-73.40). Compared to pharyngeal swabs (oropharyngeal and nasopharyngeal swabs in the same collection tube), an important observation was that seven more positive cases were detected among saliva samples. CONCLUSIONS: The findings of the present study indicated that self-collected saliva samples cannot replace pharyngeal swabs. Still, saliva samples significantly increased the case detection rate and can be used along with pharyngeal swabs.

The Performance of SARS-CoV-2 Serology Testing in the Diagnosis of COVID-19.

BACKGROUND & OBJECTIVE: COVID-19 reverse transcription-polymerase chain reaction (RT-PCR) has been a reference test for diagnosing a disease since the very beginning of the pandemic. COVID-19 serology tests have also been developed and used to estimate the prevalence of individuals who have already been infected. We aimed to evaluate the performance of serology tests for the diagnosis of patients who had been referred to medical centers with acute symptoms. METHODS: In this cross-sectional study, 80 individuals suspected of COVID-19 who had been referred to Imam Khomeini Hospital Complex, Tehran, Iran, were examined. Upper respiratory tract specimens for RT-PCR and blood samples for COVID-19 IgM and IgG antibody level tests were collected and the results were compared. RESULTS: The overall proportion in agreement, the agreement between positive results, and the agreement between negative results when comparing RT-PCR and IgM serology test were 40% (kappa = -0.006, P = 0.9), 32%, and 66.6%, respectively, and when comparing RT-PCR and IgG serology test were 46% (kappa = -0.006, P = 0.94), 43.5%, and 55.5%, respectively. CONCLUSION: The absence of a gold standard method for the diagnosis of COVID-19 makes it very challenging to determine the true sensitivity and specificity of different methods. The study results revealed no agreement between the two methods; so the RT-PCR test for upper respiratory tract specimen cannot be replaced with COVID-19 serology test for the diagnosis of patients with acute symptoms.

Is There A Correlation Between COVID-19 and Hepatitis A and Hepatitis E Serum Antibody Level?

BACKGROUND & OBJECTIVE: The prevalence of COVID-19 and its severity have been observed to be on a lower level in underdeveloped countries with poorer standards of hygiene. This disparity may be attributed to the higher seroprevalence of other viral diseases, which can result in the presence of antibodies protective against COVID-19. Two of the widespread diseases in such countries are infection to hepatitis A and E viruses (HAV and HEV). In the present study, we explored the relationship between the level of antibodies against these viruses and the susceptibility to COVID-19. METHODS: Ninety patients were studied in two groups of controls and cases, each consisting 45 individuals. The cases were patients with the clinical symptoms of COVID-19 and positive RT-PCR test results. The controls were individuals referred to the respiratory triage of Imam Khomeini Hospital Complex and were not demonstrating relevant clinical symptoms of COVID-19 and their RT-PCR test results were negative. Levels of HAV and HEV antibodies were measured and compared in these two groups. RESULTS: The median of HAV antibody level was 13.6 (IQR=11.5-16.9) and 13.2 (IQR =10.7-14.7) in cases and controls, respectively, showing no statistically significant difference (P=0.1). Likewise, the median of HEV antibody level was 6.7 (IQR=5.3-7.1) and 7.1 (IQR=6.3-7.5) in cases and controls, respectively, which again showed no statistically significant difference (P=0.41). CONCLUSION: The present study was carried out in a region with a relatively high prevalence of HAV and HEV infections. Contrary to our expectations, no statistically significant relationship was observed between the levels of antibodies against these viruses and the susceptibility to COVID-19. Further studies with larger sample sizes and in other countries are needed to come to a definite conclusion.

Case Report: Encephalitis Caused by Balamuthia mandrillaris in a 3-Year-Old Iranian Girl.

It is about half a century since free-living amoebae were recognized as pathogenic organisms, but there is still much we should learn about these rare fatal human infectious agents. A recently introduced causative agent of granulomatous amoebic encephalitis, Balamuthia mandrillaris, has been reported in a limited number of countries around the world. A 3-year-old girl was referred to our tertiary hospital because of inability to establish a proper diagnosis. She had been experiencing neurologic complaints including ataxia, altered level of consciousness, dizziness, seizure, and left-sided hemiparesis. The patient's history, physical examination results, and laboratory investigations had led to a wide differential diagnosis. Computed tomography (CT) scan and magnetic resonance imaging analyses revealed multiple mass lesions. As a result, the patient underwent an intraoperative frozen section biopsy of the brain lesion. The frozen section study showed numerous cells with amoeba-like appearances in the background of mixed inflammatory cells. Medications for free-living amoebic meningoencephalitis were administered. PCR assay demonstrated B. mandrillaris as the pathogenic amoeba. Unfortunately, the patient died 14 days after her admission. To our knowledge, this is the first report of B. mandrillaris meningoencephalitis in the Middle East and the first time we have captured the organism during a frozen-section study.

The association between the level of serum 25(OH) vitamin D, obesity, and underlying diseases with the risk of developing COVID-19 infection: A case-control study of hospitalized patients in Tehran, Iran.

BACKGROUND AND OBJECTIVES: The outbreak of COVID-19 has created a global public health crisis. Little is known about the predisposing factors of this infection. The aim of this study was to explore an association between the serum vitamin D level, obesity, and underlying health conditions, as well as the vulnerability to COVID-19 in the Iranian population. METHODS: We conducted a case-control study of 201 patients with coronavirus infection and 201 controls. Cases and controls were matched for age and gender. The study was carried out for 2 months (February 2020-April 2020) at Imam Khomeini Hospital Complex, Tehran, Iran. Serum 25(OH) vitamin D was measured using the enzyme-linked immunosorbent assay method. Information containing age, gender, clinical symptoms, body mass index, computed tomography scan findings, and underlying health conditions related to each participant were elicited from health records. RESULTS: A significant negative correlation (p = .02) was observed between the serum vitamin D level and developing coronavirus infection. Also, the results showed that the COVID-19 cases were more likely to be overweight than the controls (p = .023). Diabetes mellitus, hypertension, and respiratory infections were found in 20.89%, 9.65%, and 6.96% of cases, respectively. These underlying health conditions were not significantly different between cases and controls (p = .81). CONCLUSIONS: Vitamin D deficiency and obesity are two main predisposing factors associated with the vulnerability to coronavirus infection in the Iranian population.

Pathological Findings of Postmortem Biopsies From Lung, Heart, and Liver of 7 Deceased COVID-19 Patients.

Background. A novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been affecting almost all nations around the world. Most infected patients who have been admitted to intensive care units show SARS signs. In this study, we aimed to achieve a better understanding of pathological alterations that take place during the novel coronavirus infection in most presumed affected organs. Methods. We performed postmortem core needle biopsies from lung, heart, and liver on 7 deceased patients who had died of coronavirus disease 2019. Prepared tissue sections were observed by 2 expert pathologists. Results. Diffuse alveolar damage was the main pathologic finding in the lung tissue samples. Patients with hospitalization durations of more than 10 days showed evidence of organization. Multinucleated cells in alveolar spaces and alveolar walls, atypical enlarged cells, accumulation of macrophages in alveolar spaces, and congestion of vascular channels were the other histopathologic alteration of the lung. None of our heart biopsy samples met the criteria for myocarditis. Liver biopsies showed congestion, micro- and macro-vesicular changes, and minimal to mild portal inflammation, in the majority of cases. Conclusions. Similar to the previous coronavirus infection in 2003, the main pathologic finding in the lung was diffuse alveolar damage with a pattern of organization in prolonged cases. The SARS-CoV-2 infection does not cause myocarditis, and the ischemia of myocardium is the most probable justification of the observed pathologic changes in the heart. Liver tissue sections mostly showed nonspecific findings; however, ischemia of the liver can be identified in some cases.

The Novel Coronavirus SARS-CoV-2 Vulnerability Association with ABO/Rh Blood Types.

BACKGROUND & OBJECTIVE: Coronavirus disease 2019 (COVID-19) is the most recent emerging viral disease. Defining the epidemiological aspects and factors influencing the susceptibility of the patients to COVID-19 has been an ongoing struggle. In the present study, we have investigated the connection between ABO histo-blood group phenotypes and the COVID-19. METHODS: This study was conducted on 397 patients with confirmed diagnoses of COVID-19 admitted to our center. Also, 500 individuals were selected to form the controls, all of whom had been disclosed to the same medical center in June 2019, before the onset of the outbreak. RESULTS: Our results demonstrated ABO histo-blood phenotypes are correlated with patients' susceptibility to the infection. A higher rate of infection was observed among patients with the AB histo-blood group, while patients with the O histo-blood group have shown a lower rate of infection. The Rh blood group phenotype was not statistically significant in determining a patient's vulnerability. CONCLUSION: Similar to several previous studies about other viral diseases' association with ABO histo-blood groups, we have concluded that an individual's ABO histo-blood group phenotype and his/her susceptibility to COVID-19 are indeed connected. So far, only one research has been conducted about this association. Interestingly, while we observed a decreased vulnerability to the disease among patients with an O histo-blood group, we have reached discordant results regarding the increased susceptibility among individuals with an AB histo-blood group, unlike A histo-blood group in the previous study.