From SARS and MERS to COVID-19: Still ill-prepared to combat pandemic-prone diseases
Although the two prior epidemics of coronavirus—Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS)—had died down, their lessons remain unheeded, as is demonstrated by the explosive spread of the novel coronavirus (COVID-19) that has recently earned pandemic status, according to a recent study.
“Inadequate risk assessment regarding the urgency of the situation, and limited reporting on the virus within China has, in part, led to the rapid spread of COVID-19 throughout mainland China and into proximal and distant countries,” said lead researcher Noah Peeri, a doctoral candidate at the University of North Texas Health Science Center in Fort Worth, Texas, US.
Peeri and his team used data from the Centers for Disease Control and Prevention (CDC) and conducted a comprehensive review of existing literature to consider experiences with deadly coronaviruses and pinpoint areas for improvement in preparedness plans, as well as provide a critical assessment of the risk factors and actionable items for stopping their spread.
“Coronaviruses are zoonotic and are a large family of viruses that cause illness ranging from the common cold to more severe diseases, such as MERS and SARS,” Peeri wrote. [Nat Rev Microbiol 2016;14:523-534; Lancet 2020;395:497-506]
Major animal reservoir hosts for MERS and SARS are bats and dromedary camels, respectively. COVID-19 is suspected to be transmitted to humans via contaminated bats, similar to SARS. Another important commonality between COVID-19 and SARS is that both have emerged from wholesale live-animal markets in China. This may signal the need for closure of such markets, Peeri said, pointing out that this measure would be the strongest deterrent to another zoonotic disease outbreak. [Int J Epidemiol 2020;doi:10.1093/ije/dyaa033]
For all three viruses, human-to-human transmission is believed to have occurred via exposure to respiratory droplets or secretions of infected individuals.
“Compared with SARS and MERS, COVID-19 has spread more rapidly, due in part to increased globalization and the focus of the epidemic… The availability of connecting flights, the timing of the outbreak during the Chinese New Year, and the massive rail transit hub located in Wuhan, [the epicentre of the outbreak], have enabled the virus to perforate throughout China, and eventually, globally,” Peeri said. [Lancet 2020;395:689-697]
Control measures were implemented, although not promptly enough. On January 23, Wuhan was placed on lockdown, as Chinese authorities suspended airline and railway departures in order to contain the virus. Two days later, travel restrictions were imposed on 18 more cities, affecting nearly 60 million people. All these happened almost 2 months after the first official case of the virus was confirmed (December 8), and millions of people had crossed the affected region since, oblivious to the risks involved. Nevertheless, China was quick to publish the genetic sequence of the virus—less than a week after isolating it from a patient—which, in turn, facilitated faster diagnoses on a global scale. https://www.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19-final-report.pdf]
“[T]he length of time it took for China's state-controlled media to reveal the nature of the illness was too great,” Peeri said. “This can be attributed to a failure of proper risk assessment and management by the Chinese government and health ministry.”
Risk assessment should be able to resolve the unknowns and control the impact of the virus accordingly. What must be done, according to Peeri, is to evaluate the current standard of epidemiologic surveillance, as well as identify risk factors for human-to-human transmission from asymptomatic cases.
“Since there is no specific treatment for coronaviruses, there is an urgent need for global surveillance of humans infected with COVID-19. The combined role of internet of things (IoT) and related technologies can play a vital role in preventing the spread of zoonotic infectious diseases,” he pointed out. [https://www.who.int/health-topics/coronavirus]
Smart disease surveillance systems could help plot the spread of infection by enabling simultaneous reporting and monitoring, end-to-end connectivity, data assortment and analysis, tracking and alerts. Remote medical assistance, on the other hand, may facilitate detection and control of zoonotic infectious disease outbreaks.
Such a technology should prove useful in monitoring live-animal markets in China, to ensure strict implementation of health and hygiene protocols that limit contact between live animals and humans. This is because permanent closure seems unlikely, given that these markets have been historically considered to be vital to communities across the country, Peeri explained.
Around the world, aside from personal protection and travel-related interventions, more and more governments are using social distancing—avoiding mass gatherings and maintaining distance of approximately 6 feet from others when possible—to slow down the rate of infection. The idea is to prevent surges in illness that could swamp healthcare systems and to provide time for vaccines and treatments to be developed. [https://www.cdc.gov/coronavirus/2019-ncov/php/risk-assessment.html; Lancet 2020;doi:10.1016/S0140-6736(20)30567-5]
In terms of treatment, initial reports stated that most COVID-19–infected patients received oral oseltamivir (75 mg twice daily) in combination with antibiotics; those with severe illness were given corticosteroids (40–120 mg/day) to reduce lung inflammation. Some hospitals have been giving prophylactic antibiotics to avoid secondary infection. [Lancet 2020;395:497-506]
Only so much preparation can be done in the face of a pandemic-prone disease. Not all countries can impose stringent measures China adopted, or be well prepared as Singapore and Hong Kong, both of which were shaken by SARS and have used its hard-worn lessons to manage COVID-19 well. [Lancet 2020;395:848-850]
Peeri and his team called for development of effective methods to provide early and timely detection of zoonotic diseases, which could potentially reduce morbidity and mortality. “Future research should attempt to address the uses and implications of IoT technologies for mapping the spread of infection.”
As of March 15, there are 152,428 confirmed cases of COVID-19 across 141 territories with 5,720 deaths, with no indication of abatement. Although less deadly, the virus has exceeded both the SARS and MERS in transmissibility, with the World Health Organization declaring the outbreak a pandemic on March 11. SARS, which also originated in China, infected a total of 8,096 people in 29 countries and killed 774 in a span of 8 months, whereas MERS, which had its origins in Saudi Arabia, infected 2,494 people and killed 858 over about 7 years of observation. [https://experience.arcgis.com/experience/685d0ace521648f8a5beeeee1b9125cd; https://www.who.int/csr/sars/country/table2004_04_21/en/; https://www.who.int/emergencies/mers-cov/en/]