The importance of surveillance in cases of and mortality from the COVID-19 epidemic in Belo Horizonte, Brazil, 2020

ABSTRACT: Objectives: This study aims to describe the actions carried out by the epidemiological surveillance system in Belo Horizonte to address the COVID-19 epidemic and the timeless of the data for detecting transmission in 2020. Methods: The sources of information used by the epidemiological surveillance of the municipality for COVID-19 were identified and the temporal distribution and interval for detection of confirmed cases of the disease were analyzed. Results: The city's epidemiological surveillance uses outpatient, hospital, public and private laboratory notifications as data sources. For reporting COVID-19 cases in official information systems, there is also an active search of laboratory results linked to suspected deaths investigated. From January to April 2020, 1,449 hospitalized cases of COVID-19 were reported, the first case being detected in late February 2020. Of the total 1,025 laboratory samples of cases hospitalized after the 8th epidemiological week, 87 (8.5%) of COVID-19 cases were confirmed. The median time between the onset of symptoms and the release of laboratory results was 12 days for the analyzed period. Conclusion: Epidemiological surveillance uses several data sources to monitor and analyze the transmission of COVID-19. The timeliness of this system to detect cases of the disease is compromised by the delay in the release of laboratory results, which has been a considerable challenge for adequate surveillance.

摘要：
一、研究目标：本研究旨在阐述贝洛奥里藏特（Belo Horizonte）流行病学监测系统为应对新型冠状病毒肺炎（COVID-19）疫情所开展的防控工作，以及2020年该系统用于病毒传播检测的相关数据的时效性。
二、研究方法：明确该市新型冠状病毒肺炎流行病学监测体系所依托的信息来源，分析确诊病例的时间分布特征与检测间隔情况。
三、研究结果：该市流行病学监测系统以门诊、住院患者及公立、私立实验室的上报数据作为核心信息源。在官方信息系统中填报新型冠状病毒肺炎病例时，还需主动检索与已调查疑似死亡病例相关的实验室检测结果。2020年1月至4月，累计上报1449例新型冠状病毒肺炎住院病例，首例确诊病例于2020年2月末被检出。在第8个流行病学周之后收治的住院病例的1025份实验室样本中，87份（8.5%）确诊为新型冠状病毒肺炎阳性。本分析周期内，从症状发作至实验室检测结果出具的中位时长为12天。
四、研究结论：流行病学监测系统依托多源数据开展新型冠状病毒肺炎的传播监测与分析工作。该系统的病例检测时效性受限于实验室结果出具延迟，这已成为制约防控工作有效性的重大挑战。