Outbreak Detection with Wun-Ju Shieh

Dr. Wun-Ju Shieh, worked as a pathologist and infectious diseases expert with the CDC from 1995-2020. He recounts his experiences conducting high risk autopsies on the frontlines of outbreaks including Ebola, H1N1 influenza, monkeypox and SARS-CoV-1 and 2. He also addresses key questions about factors contributing to the (re)emergence and spread of pathogens and discusses whether outbreaks are becoming more frequent or simply more widely publicized.

Ashley's Biggest Takeaways:

• Pathologists are a group of medical doctors serving behind the line of the daily hospital activities.
• Pathology service can be divided into atomic pathology and clinical pathology. The field covers all the laboratory diagnostic work in the hospital, and clinical microbiology or medical microbiology is actually a subdivision within the clinical pathology service.
• Usually, a pathologist working in a hospital will examine and dissect tissue specimens from surgery or biopsy.
• The pathologist also performs autopsies as requested to determine or confirm the cause of death.
• Serving as first a clinician in Taiwan and then a pathologist in the United States has provided Shieh with the unique experience of evaluating patients from both the outside-in and the inside-out!
• Even when a major outbreak of a known etiologic agent is taking place, confirmatory diagnosis is necessary for subsequent quarantine, control and prevention of the outbreak.
• During major disease outbreaks, other pathogens do not go away, and we must simultaneously facilitate their timely diagnosis to ensure effective patient treatment and care.
• SARS-CoV-2 appears to be transmitted more easily than SARS-CoV-1. One possible explanation for this is that the amount of viral load appears to be the highest in the upper respiratory tract of those with COVID-19, shortly after the symptoms develop. This indicates that people with COVID-19 may be transmitting the virus early in infection, just as their symptoms are developing…or even before they appear or without symptoms.
• SARS-CoV-1 viral loads peak much later in the illness.
• Asymptomatic transmission is rarely seen with SARS-CoV-1 infection.
• Almost 99% of SARS-CoV-1 patients developed prominent fever when they started to carry infectivity. Temperature monitoring was therefore, very effective at detecting sick patients and facilitating prompt quarantining procedures, which effectively contained/minimized transmission of the virus.
• This was not as effective for SARS-CoV-2, despite early attempts at temperature. monitoring.
• SARS-CoV-2 was much harder to contain both because of the milder display of host symptoms and the demonstration of higher viral transmissibility.