by Charles Bankhead, Senior Editor, MedPage Today July 20, 2020
As the COVID-19 pandemic rages on with “essentially no end in sight,” the clinical and epidemiologic toll has provided a grim reminder of how unpredictable and potentially dangerous coronavirus infections can be, according to Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases.
Borrowing from the title of an article he co-authored earlier this year, Fauci reemphasized the point that coronavirus infections are “more than just the common cold.” Historically, misperceptions about the potential seriousness of coronavirus infections probably owed to the recognition that the viruses cause up to 30% of all common colds.
“The issue of the possibility of a coronavirus being a pandemic came upon us in 2002 with the severe acute respiratory syndrome [SARS] and then again in 2012 with MERS [Middle Eastern respiratory syndrome],” Fauci said during a virtual meeting on COVID-19 and cancer, sponsored by the American Association for Cancer Research.
Same Family, Striking Differences
Though SARS and MERS originated from the same viral family as COVID-19, they lacked the “absolute overwhelming efficiency and capability of spreading from human to human.” As a result, first-line preventive measures, such as physical separation, mask wearing, and quarantine, brought the outbreaks under control in a relatively short period of time, in the case of SARS, or maintained a fairly stable rate of infection.
Providing a frame of reference, Fauci noted that the SARS outbreak started in China in November 2002. Originally diagnosed as an atypical pneumonia or influenza, the pandemic did not begin in earnest until an infected person traveled from China to Hong Kong and stayed in a hotel where 19 other people subsequently became infected. From there, the infection spread to multiple countries (including 27 cases in the United States and 251 in Canada).
By July 31, 2003, the worldwide SARS toll reached 8,096 cases and 774 deaths. China accounted for a majority of cases (5,327) and the most deaths (349), followed by Hong Kong (1,755; 299), Taiwan (346; 37); and Singapore (238; 33). Many countries had one or a few isolated cases, and most of South America, Africa, and the Middle East were unaffected. The infection virtually disappeared by the end of July 2003.
“In essence, the outbreak was controlled by purely public health measures, without any drugs and without any vaccines,” said Fauci.
The first MERS case was reported in November 2012 and came from Saudi Arabia. Unlike SARS, the caseload remained modest until a spike occurred in the first quarter of 2014, followed a return to baseline rates. Also unlike SARS, the MERS caseload has continued to spike periodically right up to 2020, said Fauci. A third key difference from SARS is that MERS has a high case fatality rate (34%). As of March 2020, the MERS toll stood at 2,519 cases and 866 deaths. About 80% of all cases came from Saudi Arabia.
No End in Sight
In contrast to SARS and MERS, COVID-19 has led to almost 15 million infections worldwide and more than 600,000 deaths. The current daily caseload approaches 250,000, and about 5,000 people a day are dying of the infection. Although the pandemic has touched virtually every country in the world, the U.S. has emerged as the global leader in cases (almost 14 million) and deaths (143,500).
Beyond the morbidity and mortality burden, the spectrum of the disease remains striking, said Fauci. In 40%-45% of cases, patients have no symptoms, despite testing positive for exposure to the virus. From there, symptoms run the gamut from mild (uncomplicated upper respiratory tract infection) to critical illness (acute respiratory distress, septic shock, multiorgan system failure). Patients who are asymptomatic or have mild/moderate symptoms account for about 80% of all cases.
The large percentage of patients with asymptomatic infection confounds efforts to determine the true infection-related mortality, he said. A widely cited study from China showed a case-fatality rate of 2.3% in 44,672 infected patients. “If you count all of the people who are asymptomatic, it’s likely that the total fatality rate is around 1% or less.”
With regard to infection prevention, in the absence of an effective vaccine, Fauci said, “The bottom-line common denominator is physical distancing.” Citing NIH evidence-based guidelines for COVID-19, he recommended the following public health measures:
- Social/physical distancing and stay-at-home orders
- Closure of schools, venues, and nonessential businesses
- Bans on public gatherings
- Travel restrictions with infection screening
- Aggressive case identification and isolation
- Contact tracing and quarantine
From a personal prevention perspective, the guidelines recommend diligent hand washing, social distancing, use of face masks, covering sneezes and coughs, avoiding face touching, and regular cleaning/disinfection of frequently touched objects.
Fauci touched briefly on vaccine development and noted that at least one candidate vaccine will begin phase III testing by the end of July.
“It’s one of several, so there’s no statement as to what is better than the other,” he said. “This one temporally happens to be ahead, and a phase I trial showed some very promising data, published just a few days ago.”
In a nod to his virtual audience of cancer specialists, Fauci noted that fear of COVID-19 infection has interfered with routine cancer screening. Resulting delays in diagnosis and treatment are predicted to have downstream consequences in the form of 10,000 excess deaths from breast and colon cancer over the next decade.
In closing, Fauci referenced an article he and colleagues published more than a decade ago, addressing the perpetual challenge of emerging infections.
“We’ve always had emerging infectious diseases,” he said. “We will continue to have them in the future. Just as emerging infections provide for us a perpetual challenge, we need to be perpetually prepared.”