Objectives In this study, we aimed to study the clinical presentations, and viral clearance of SARS-COV-2 positive quarantined individuals. Design Cross-sectional study. Setting Governmental- designated facility in the eastern province, Saudi Arabia. Participants 128 laboratory-confirmed COVID-19 quarantined individuals who had a history of travel abroad in the last 14 days before the quarantine or were in direct contact with laboratory-confirmed cases. The study was from March 18th-till April 16th. Primary and secondary measures The clinical presentation, prevalence of asymptomatic carriers among SARS-COV-2 positive quarantined subjects, and the difference between virus clearance among symptomatic and asymptomatic individuals. Results Sixty-nine of the 128 residents (54%) were completely asymptomatic until the end of the study. The remaining 59 residents (46%) had only mild symptoms. The most common symptom was a sudden loss of smell and taste, accounting for 47.5%. The median time to virus clearance was significantly different between the two groups. Symptomatic residents cleared the virus at a median of 17 days (95% CI, 12.4–21.6) from the first positive PCR vs. 11days (95% CI, 8.7–13.3) in the asymptomatic group (P = 0.011). False-negative test results occurred in 18.8% of the total residents and false-positive results in 3%. Conclusion The prevalence of asymptomatic carriers among quarantined travelers and those identified by contact tracing is high in our study. Therefore, testing, tracing, and isolating travelers and contacts of laboratory-confirmed cases, regardless of symptoms, were very effective measures for early disease identification and containment. Loss of taste and smell were the most common presentations in our mild symptomatic residents and should be used as a screening tool for COVID-19. The persistent positive PCR beyond 14 days observed in the mild symptomatic residents despite being symptoms free, warrant further studies to determine its implications on disease spread and control.

Background: Assessing the humoral immune response to SARS-CoV-2 is crucial for inferring protective immunity from reinfection and for assessing vaccine efficacy. Data regarding the durability and sustainability of SARS-CoV-2 antibodies are conflicting. In this study, we aimed to determine the seroconversion rate of SARS-CoV-2 infection in a cohort of reverse-transcriptase polymerase chain reaction (RT–PCR)-confirmed SARS-CoV-2 infections and the antibody dynamics, durability, and the correlation of antibody titers with disease severity using the commercially available SARS-CoV-2 anti-spike (S1/S2) protein.Methods: A total of 342 subjects with PCR-confirmed COVID-19 were enrolled. A total of 395 samples were collected at different time points (0–204) after the onset of symptoms or from the day of positive PCR in asymptomatic patients. Demographics, clinical presentation and the date of PCR were collected. All samples were tested using the automated commercial chemiluminescent system (DiaSorin SARS-CoV-2 S1/S2 IgG) on the LIAISONXL® platform (LIAISON).Results: The seroconversion rate for samples collected 14 days after the onset of infection was much higher than that for samples collected before 14 days (79.4% vs. 39.4%). The rate of seroconversion in symptomatic participants (62.1%) was similar to that of asymptomatic participants (56.1%) (p = 0.496). The IgG titer distribution was also similar across both groups (p = 0.142), with a median IgG level of 27.86 AU/ml (3.8–85.5) and 15 AU/ml (3.8–58.85) in symptomatic and asymptomatic participants, respectively. However, IgG titers were significantly higher in ICU patients, with a median of 104 AU/ml (3.8–179) compared to 34 AU/ml (3.8–70) in the non-ICU participants (p < 0.0001). Furthermore, the median time to seroconversion occurred significantly faster in ICU patients than in non-ICU participants (19 versus 47 days) (P < 0.0001). IgG titers were also higher in subjects ≥50 years compared to those <50 years (p < 0.009), male compared to female (p < 0.054) and non-Saudi compared to Saudi (p < 0.003). Approximately 74% of all samples tested beyond 120 days were positive.Conclusion: Antibodies can persist in circulation for longer than 4 months after COVID-19 infection. The majority of patients with COVID-19 mounted humoral immune responses to SARS-CoV-2 infection that strongly correlated with disease severity, older age and male gender. However, the population of individuals who tested negative should be further evaluated.

BACKGROUND The Coronavirus disease 2019 (COVID-19) outbreak in Saudi Arabia was first identified in a traveler from Al Qatif city, on March 2nd, 2020. The disease has quickly spread and reached multiple cities within a few weeks. In an attempt to limit the spread of COVID-19 in Saudi Arabia, the government has implemented strict regulations. Starting March 15th, all travelers coming back to the kingdom were tested for COVID-19 and were quarantined in a government-designated facility. The same rule was applied to all positive cases identified by contact tracing. In this study, we aimed to assess the prevalence of asymptomatic carriers, epidemiological characteristics, clinical presentations, and viral clearance of SARS-COV-2 positive quarantined individuals in a quarantine facility in the eastern province. METHODS We conducted a cross-sectional study on 128 laboratory-confirmed COVID-19 subjects who were quarantined in a government-designated facility. The study period was from March 16th until April 18th, 2020. We collected data on demographics and on clinical symptoms. Also, samples for PCR tests were collected upon admission and were repeated every 72 hours if they were still positive. All negative samples were repeated within 24 hours for confirmation. RESULTS Sixty-nine of the 128 residents (54%) were completely asymptomatic until the end of the study. The remaining 59 residents (46%) had only mild symptoms. The most common symptom was a sudden loss of smell and taste, accounting for 47.5%. The median time to virus clearance was significantly different between the two groups. Symptomatic residents cleared the virus at a median of 17 days (95% CI,12.4-21.6) from the first positive PCR vs. 11days (95% CI, 8.7-13.3) in the asymptomatic group (P=0.011). False-negative test results occurred in 18.8% of the total residents and false-positive results in 3%. CONCLUSION The prevalence of asymptomatic carriers is high in our study. Testing, and isolating travelers and contacts of laboratory-confirmed cases, regardless of symptoms, were very effective measures for early disease identification and containment. Loss of taste and smell was the most common presentation in our mild symptomatic residents, and it might be predictive of mild disease. The persistent positive PCRs observed in the mild asymptomatic residents despite being symptoms free, warrant further studies to determine its implications on disease spread and control.

Infection with COVID-19 is associated with significant morbidity, especially in patients with chronic medical conditions. At least one-fifth of cases require supportive care in intensive care units, which have limited availability in most developing countries. A literature search was conducted on PubMed, Medline, Scopus, Embase, and Google Scholar to find articles published by May 7, 2020 on the role of comorbidities in patients with COVID-19 and the impact of comorbidities on the disease. This review highlighted that patients with comorbidities are more likely to experience severe disease than those with no other conditions; that is, comorbidities correlated with greater disease severity in patients with COVID-19. Proper screening of COVID-19 patients should include careful inquiries into their medical history; this will help healthcare providers identify patients who are more likely to develop serious disease or experience adverse outcomes. Better protection should also be given to patients with COVID-19 and comorbidities upon confirmation of the diagnosis. This literature review showed that the comorbidities most often associated with more severe cases of COVID-19 are hypertension, cardiovascular disease, and diabetes. Individuals with these comorbidities should adopt restrictive measures to prevent exposure to COVID-19, given their higher risk of severe disease.