As the COVID-19 pandemic forces countries around the world into a state of emergency, healthcare systems are scrambling for the resources necessary to diagnose and treat patients. Lab diagnostics have become a central focus in efforts to fight the disease.

While COVID-19 has so far had a lower case fatality rate than SARS and MERS, it has shown to be highly contagious [1] in comparison to the common influenza virus, as indicated by its high basic reproductive number. Clinical data and anecdotal evidence from frontline healthcare workers also suggest that some people infected with COVID-19 remain asymptomatic [2] but can still spread the virus unknowingly to others.  

The virulence of the disease, when coupled with the danger of new outbreaks carried by asymptomatic patients, highlights the critical importance of effective diagnostics in identifying active and silent carriers of the infection. In a series of recent interviews and webinars with leading healthcare professionals from China, we learned about the essential role that lab diagnostics are playing in the country. Below are some of our key takeaways.

Lessons from China

Since the COVID-19 outbreak began around November 2019 in China, the country helped to develop many of the diagnostic protocols that are used globally today. At first, RT-PCR testing was not available in many Chinese hospitals, so some had to rely on chest x-rays and clinical evaluations to diagnose patients, according to Dr Bi Jie Hu, a Professor and Head of Department of Infectious Diseases and Hospital Infection Management at Zhongshan Hospital in Shanghai, China (see COVID-19 pneumonia experience from China: diagnosis, treatment and PPE, a webinar that was hosted by the Asia Pacific Association of Critical Care Medicine). 

As a major tertiary teaching hospital that is affiliated with Fudan University in Shanghai, Zhongshan was fortunate to have relatively early access to RT-PCR testing. This allowed the hopsital to implement PCR testing at multiple points in the patient care process. During discharge, for example, PCR tests were conducted on two separate respiratory specimens with a sampling interval of at least one day, as well as on a stool specimen, in order to make absolutely sure that the patient was no longer contagious and could leave the hospital without putting others at risk. 

At the Third Affiliated Hospital of Sun Yat-sen University in Guangzhou, aggressive testing also applies to patients showing no symptoms, according to Dr Bo Hu, who directs the hospital’s laboratory medicine department. “If the RNA test is positive, we need to send the patient to the isolation ward for 14 days to see what happens,” he explains.

In Wuhan, the initial epicenter of the outbreak, life has resumed for most citizens since the citywide lockdown ended in early April, but hospitals remain cautious against new outbreaks that could reemerge at any time. By casting a wide net and testing aggressively, local laboratories enable hospital workers to identify every individual who can potentially spread the virus further, providing the foundation for containment.

Managing COVID-19 Patients

Beyond simply identifying those with COVID-19, laboratory diagnostics are also central in the management of severe and critical cases, providing insight into disease progression that enables clinicians to tailor interventions to the needs of individual patients.

One important role is to assess the prevalence of co-morbidities and their potential impact on COVID-19 patients. According to a March 2020 study in JAMA [3] on mortality of adult inpatients with COVID-19 in Wuhan, heart disease was highly correlated with adverse clinical outcomes. Roughly 46% of non-survivors showed elevated troponin levels, compared to just 1% of survivors, suggesting that troponin testing could play an important role in the diagnostic pathway.

“The data are very consistent with what I saw in the ICU ward of my hospital,” said Dr Ning Zhou, Deputy Chief Physician in the Department of Cardiovascular Medicine at Tonghi Hospital in Wuhan. “This is a matter of great concern for cardiologists” (see COVID-19 in Wuhan: local cardiologist shares frontline experience, a webinar that was co-hosed by the Asia Pacific Society of Cardiology).

Blood gas monitoring can also have a life-or-death impact on some COVID-19 patients. “For patients with novel coronavirus pneumonia, especially the severe patients, blood gas and electrolyte balance is greatly affected,” says Dr Xuefeng Wang, Director of the Laboratory Department of Shanghai Jiao Tong University School of Medicine in Shanghai, China (see Blood gas testing, POC and biosafety protections in COVID-19 management, a video interview hosted by Roche Diagnostics, for advice on managing quality and biosafety for blood gas analysis in the core lab and at the point of care).

Next Steps for Containment

The global number of COVID-19 cases has exceeded 3 million and is continuing to rise. Compared to the West, some countries in Asia have found success in minimizing the outbreak by adopting aggressive tactics. China shut down entire cities, while South Korea implemented widespread virus testing and contact-tracing.

Many governments were caught without a concrete national strategy to deal with pandemics and thus were slow in their outbreak response. Countries that maintain a strong healthcare system with sufficient capacity to test, isolate and treat infected patients are likely to stay one step ahead of the virus.

[1] Petrosillo, N., et al., 2020. COVID-19, SARS and MERS: are they closely related? Clinical Microbiology and Infection, 26(6), pp.729-734

[2] Day, M., 2020. Covid-19: four fifths of cases are asymptomatic, China figures indicate. The BMJ, 369, pp.1375

[3] Zhou, F., et al., 2020. Clinical course and risk factors for mortality of adult and adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. The Lancet, 395(10229), pp.1054-1062.