A hospital epidemiology perspective on what we’ve discovered from the infection prevention response to COVID-19
Looking at some of the lessons learned from the response to the early phases of the COVID-19 pandemic from the perspective of the hospital epidemiologist, we can improve preparedness for future events by understanding how our hospitals used contemporary knowledge and guidance to construct their initial response to COVID-19 and modify this response based on the evolving data. We frame our comments based on the historical context provided by two recent global infectious threats, as our response to these threats shaped our preparedness efforts for COVID-19.
In April 2009, a novel influenza strain was first reported in Mexico and quickly spread worldwide. The 2009 H1N1 influenza pandemic was particularly concerning because of early reports of more severe manifestations and mortality in younger adults compared to typical seasonal influenza.
To prepare for this new strain, we had the advantage of having considerable knowledge on the modes of transmission of influenza, which is mostly through direct contact and droplets and potentially airborne transmission in special settings. Given the low level of population immunity to 2009 H1N1 influenza, the U.S. Centers for Disease Control and Prevention initially (until it was determined that 2009 H1N1 influenza was not particularly severe and it became endemic) recommended use of N95 respirators for which supply was not adequate, even with tapping the national stockpile.
After the 2009 H1N1 influenza pandemic subsided, the national stockpile of 100 million N95 respirators was not completely restocked. Emory’s pandemic preparedness work group weighed the advantages and disadvantages (including cost) of stockpiling at the organizational level and ultimately developed a stockpile of oseltamivir for the next severe influenza. Much of this local stockpile expired and was never used.
The 2014-2015 outbreak of Ebola in West Africa triggered a reassessment of hospital preparedness in the U.S. after several patients were repatriated to the U.S. for medical care. In addition, a patient admitted to a Texas hospital was diagnosed with Ebola after admission, resulting in exposure to several healthcare personnel.
Traditional and social media outlets overestimated the potential for an uncontrolled outbreak in the U.S. by conflating this risk with the high case fatality rate and the importance of meticulous infection prevention when providing patient care. In reality, Ebola has a low reproductive number, in part because transmission was known to occur from contact and not the respiratory route and did not pose a risk for uncontrolled transmission domestically.
In the aftermath, the U.S. government allocated funding to improve preparedness for a serious communicable disease outbreak such as Ebola. In Atlanta, Emory University Hospital became a national Ebola treatment center, and Emory University Hospital Midtown, Grady Healthcare and Children’s Healthcare of Atlanta, among others, applied for and received government funds to enhance preparation to manage a small number of patients with a serious communicable disease, such as Ebola, who might enter or be referred to our facilities. These efforts focused on a preparedness plan for the anticipated rare patient and included training a group of providers with high-level PPE training and developing dedicated physical spaces with anterooms and special ventilation designed to care for a small number of patients.
However, we were unprepared for COVID-19, the next outbreak. A large part of the challenge related to COVID-19 can be attributed to the unknowns of dealing with a new and formidable pathogen with uncertain clinical manifestations and unclear routes of transmission compounded by politicization and external guidance that underestimated transmissibility in COVID-19.
In addition, our preparedness suffered from recent bias based on our two most recent experiences in U.S. hospitals. These were of a respiratory pathogen (H1N1 influenza) and a viral hemorrhagic fever (Ebola), both of which had clear symptoms and had more defined modes of transmission. COVID-19, the most significant global pandemic since the influenza pandemic of 1918, initially had an unclear mode of transmission, attack rate and clinical manifestations.
Shortly after the first description of COVID-19, the cause was identified and the virus rapidly sequenced. SARS-CoV-2, as it was eventually named, was similar to both typical human coronaviruses causing the common cold, but also to more severe coronaviruses including MERS-CoV and SARS-CoV-1. Extrapolating from other coronaviruses, the route of transmission was thought to be respiratory droplets occurring early in the illness and mostly through people with symptoms.
Hampered by access to easy testing and with non-specific symptoms, initial diagnostics were focused on those with symptoms and travel to a known “hotspot.” Early signals that transmission occurred from asymptomatic persons were missed. Eventually, the major role of transmission in individuals with no or mild symptoms became clear, but only after significant spread of the virus had already occurred.
The first case of COVID-19 was detected in Georgia on March 2, 2020, but in retrospect, there were likely undetected local cases that fit the epidemiologic and clinical profile weeks earlier. It took weeks to move away from screening and risk stratification based on travel history, another legacy of the Ebola experience where transmission was thought not to be local. In the hospital, lack of appreciation of asymptomatic viral shedding resulted in inadvertent transmission, including from healthcare worker to healthcare worker.
Early problems with test development limited labs from developing a broader testing capacity, but the synergy between the testing void and unexpected asymptomatic transmission created huge challenges. When testing became more widely available, clinical utility was limited because PCR testing was based in large labs and had relatively long turn-around-times. Lower fidelity tests with more rapid turnaround times, especially those that are inexpensive and point of care, will be a practical adjunct to improve patient flow and care.
When dealing with a pathogen of unknown transmissibility and variable clinical severity, the default infection prevention approach is to use more extensive PPE than may be needed in case the organism turns out to be more transmissible than initially suspected and to allay the concerns of healthcare workers faced with the unknown. This presupposes an adequate PPE supply.
The possibility of PPE shortages was considered during previous national pandemic response planning efforts. This huge need for supplies to respond to a pathogen such as pandemic flu or COVID-19 was codified in detailed preparedness plans but not prioritized at a national level, especially after our Ebola experience shifted focus to special biocontainment units that required a large amount of complex PPE for a small number of healthcare workers.
While it is not feasible for hospitals or health systems to stockpile pandemic-level quantities of supplies in perpetuity, we have learned lessons that should help in the future, such as ways to extend use and reprocess PPE to ensure availability to keep our healthcare workers safe.
During the early phases of this (and any) outbreak, effective and transparent communication is essential along with messaging that guidance will change as new information is accumulated. Even with this knowledge and experience from past outbreaks, effective communication to healthcare workers continues to be a challenge. The dynamic nature of our knowledge necessitated frequent changes to processes and practices, including universal masking, use of eye protection, implementation of social distancing and implementing extended and re-use of PPE while maintaining trust among our healthcare workers fearful of this new pathogen.
Misinformation, particularly through social media and word of mouth, was rampant and complicated communication efforts. The challenge will be to maintain these efforts and morale as fatigue accumulates during subsequent waves. In this regard, our past experiences haven’t fully prepared us for what we are likely to see.
Perhaps the most important lesson is an appreciation of how much our institutional response depends on a coherent governmental response, particularly at the federal level, that provides timely data, science-based public health guidance, clear communication that inspires trust and fiscal leadership. Struggles with testing capacity and sourcing PPE that have consumed so much effort at the institutional level were compounded by failure at the national level to ensure an adequate supply chain.
Importantly, our hospitals and staff in Atlanta were excessively stressed by caring for thousands of patients with COVID-19 resulting from uncontrolled community transmission, much of which could have been prevented if leaders had consistently promoted and supported evidence-based infection prevention measures.