Strengthening early testing and surveillance of COVID-19 to enhance identification of asymptomatic patients.

To the Editor:

Clinicians are often uncertain if a patient presents with respiratory symptoms may have coronavirus disease 2019 (COVID-19). We read with great interest a study performed by Huang and colleagues [1], which described the epidemiological and clinical characteristics of 22 close contacts of a 22-year-old man with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). They found that SARS-CoV-2 shown stronger infectivity in the incubation-period with more rapid transmission in the younger population. COVID-19 identified in this population had faster onset and different non-specific and not typical manifestations and were much milder than those in the older population. This makes early detection, surveillance and diagnosis of these asymptomatic patients particularly difficult among this population, especially if they have no travel or contact history. In other words, they pose a particular challenge to various control measures which are crucial to mitigate the COVID-19 pandemic [2,3]. Some of the major limitations of the study include the small sample size and the convenience sampling of patients in a single institution with no control group. Nevertheless, the authors should be commended for their meticulous analysis of the various sociodemographic, clinical and laboratory parameters that enable important though preliminary

observations to be reported. In another study on the clinical characteristics of 24 asymptomatic COVID-19 patients in Nanjing, China, it was shown that the communicable could be up to three weeks, and their cohabiting family members can be infected which could potentially be complicated by severe COVID-19 pneumonia [4].

This challenge of absence of symptomatology has also been echoed by Luo and colleagues, who investigated the case of a physician with symptomatic COVID-19 in Wuhan, China. All five of the physician's immediate family members living in the same household were asymptomatic, and subsequently found to have laboratory evidence of SARS-CoV-2 infection [5]. Identifying patients with COVID-19 is extremely important to facilitate isolation of COVID-19 cases and quarantine of close contacts. Hence, physicians should consider COVID-19 tests for patients with mild influenza like illnesses (ILI) in settings offering first-contact care to reduce the risk of community transmission.

There is yet another significant implication from the study [1], where provision of COVID-19 tests and its regular surveillance should be regularly reviewed at a country level. Here, the authors reviewed the latest literature and offered practical recommendations. Table 1 presents a series of healthcare policy suggestions that could prepare a country for early detection, surveillance and reporting for infectious pandemics of international concern. These were mainly based on the Global Health Security (GHS) index, which has been a comprehensive evaluation of the GHS capabilities worldwide and jointly composed by the Nuclear Threat Initiative (NTI), the Johns Hopkins centre for Health Security (JHU) and The Economist Intelligence Unit (EIU) [6]. In addition, we also retrieved standards from the International Health Regulations [7] and the Joint External Evaluation tool [8] that have been used to examine the capacity of countries in their prevention, detection, assessment, notification and response to population risks of global concern. We believe these constructs (Table 1) will be essential to be revisited by policy-makers to enable early identification of the COVID-19 – where we are still uncertain about its future transmission to the global communities.

Table 1

Recommendations for strengthening COVID-19 tests and its surveillance at country level.

Proposed recommendations	Source code
1). National procurement protocol should be in place which can be used by policy-makers for the acquisition of laboratory needs	(GHS 2.1.1b)
2). Participation of countries in regional or international laboratory network	(GHS 2.1.2a; JEE D.1.3)
3). Nationwide specimen transport system	(GHS 2.1.2b; JEE D.1.2)
4). National laboratory that serves as an accredited reference facility (e.g. ISO 15189:2003, US Clinical Laboratory Improvement Amendments (CLIA)	(GHS 2.1.3a; JEE D.1.4)
5). Establishment and evaluation of ongoing event-based surveillance and analysis for COVID-19 at least weekly	(GHS 2.2.1a; IHR 3.1.1.3; JEE D.2.1)
6). Presence of an electronic reporting surveillance system that continuously collect real-time laboratory data	(GHS 2.2.2b)
7). Regular feedback and reporting of surveillance results are disseminated to all levels and relevant stakeholders	(IHR 3.1.1.7; JEE D.2.3)
8). Early warning function of the indicator based surveillance and its evaluation	(IHR 3.1.1.8a)
7). Governmental commitment to share surveillance data during a public health emergency with other nations	(GHS 2.2.2c)
8). The national public health system has access to electronic health records of individuals; the surveillance system being equipped with a fully secure interoperable electronic tool that is connected to other relevant electronic tools	(GHS 2.2.5b)(JEE D.2.2)
9). Preparing country for trained field epidemiologists	(GHS 2.3.2a)
10). Synthesis of a list of priority diseases (COVID-19) for surveillance	(IHR 3.1.1.1; JEE D1.1)
11). Building specific units designated for surveillance of public health risk	(IHR 3.1.1.2)

References refer to: 1). GHS, Global Health Security Index. Available at: https://www.ghsindex.org/about/. Accessed on 04 May, 2020; 2). IHR, International Health Regulation, WE-SPAR State Party annual report. WHO. Available at: https://extranet.who.int/e-spar/. Accessed on 04 May, 2020; 3). JEE, Joint External Evaluation tool (JEE tool) WHO - second edition. IHR (2005) Monitoring and Evaluation framework. Available at: https://www.who.int/ihr/publications/WHO_HSE_GCR_2018_2/en/. Accessed on 04 May, 2020

Funding

None

Declaration of Competing Interest

We declared no conflict of interests.