RESUMEN
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.
Asunto(s)
COVID-19/fisiopatología , Olfato/fisiología , Gusto/fisiología , Adulto , Enfermedades Asintomáticas/epidemiología , COVID-19/epidemiología , COVID-19/metabolismo , Trazado de Contacto/métodos , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Cuarentena , SARS-CoV-2/aislamiento & purificación , Arabia Saudita/epidemiologíaRESUMEN
BACKGROUND: Lynch Syndrome (LS) is a familial cancer condition caused by germline mutations in DNA mismatch repair genes. Individuals with LS have a greatly increased risk of developing colorectal cancer (CRC) and it is therefore important to identify mutation carriers so they can undergo regular surveillance. Tumor DNA from LS patients characteristically shows microsatellite instability (MSI). Our aim here was to screen young CRC patients for MSI as a first step in the identification of unrecognized cases of LS in the Saudi population. MATERIALS AND METHODS: Archival tumor tissue was obtained from 284 CRC patients treated at 4 institutes in Dammam and Riyadh between 2006 and 2015 and aged less than 60 years at diagnosis. MSI screening was performed using the BAT-26 microsatellite marker and positive cases confirmed using the pentaplex MSI analysis system. Positive cases were screened for BRAF mutations to exclude sporadic CRC and were evaluated for loss of expression of 4 DNA mismatch repair proteins using immunohistochemistry. RESULTS: MSI was found in 33/284 (11.6%) cases, of which only one showed a BRAF mutation. Saudi MSI cases showed similar instability in the BAT-26 and BAT-25 markers to Australian MSI cases, but significantly lower frequencies of instability in 3 other microsatellite markers. CONCLUSIONS: MSI screening of young Saudi CRC patients reveals that approximately 1 in 9 are candidates for LS. Patients with MSI are strongly recommended to undergo genetic counselling and germline mutation testing for LS. Other affected family members can then be identified and offered regular surveillance for early detection of LS-associated cancers.