“Based on the estimations and projections from the AIR Pandemic Model, we estimate that this may represent a moderately conservative projection of cases; the vast majority will be asymptomatic or have mild symptoms,” said Dr. Narges Dorratoltaj, principal scientist at AIR Worldwide. “The difference between the low and high ends of the range is driven by a few factors. Uncertainty in the reported number of confirmed cases and the transmissibility of the virus play a significant role. Specifically, the lower end of the range represents a scenario where a) the true number of cases is relatively closer to what has been reported than estimated, and b) the possibility that containment measures (such as isolation and quarantine) become more successful than they have been to date. If such containment measures—driven by international and/or local authorities—are successful, this could restrict the human-to-human transmission sufficiently to bring the eventual number of cases to or even below the low end of the modeled projected range of cases.”
AIR’s model-based estimates account for uncertainty and underreporting. Mild to moderate symptoms are the types of cases least likely to be captured in the official numbers, but even for severe cases and deaths, it is likely that there will be significant underreporting.
COVID-19, the disease caused by the newly emergent SARS-CoV-2 virus, was declared a pandemic on March 11 by the World Health Organization (WHO), and by March 27, more than half a million people had contracted the disease. According to the WHO, as of 4:00 a.m. ET on April 1, 2020, there were 783,360 confirmed cases of COVID-19 and 37,203 deaths worldwide; actual counts are likely to be higher due to underreporting. Efforts at containment have shown success in slowing the spread of the virus in China as well as in a handful of other countries such as South Korea. The epicenter of the disease shifted to Europe on March 13, with transmissions and deaths increasing substantially in several European countries, particularly in Italy, Spain, Germany, France, and the UK. Cases across Africa have expanded to nearly 5,800 in 49 countries, and increases are expected in more countries worldwide. On March 24, the WHO warned that the United States was seeing a “very large acceleration” in infections, and by the end of last week, the U.S. had become the newest epicenter of the pandemic.
This is the first pandemic caused by a coronavirus, according to the WHO. The virus responds well to comprehensive containment measures, as reported in China and South Korea. Governments around the world have moved to reduce their citizens' movements and tighten borders. India proactively imposed a 21-day lockdown as of March 24. In addition, flights have been canceled; bars and restaurants have been closed; conferences, festivals, concerts, and sporting events have been canceled or postponed, including the postponement of the Tokyo Olympics to the spring of 2021; and further closures of schools and universities have been announced, with some extending through the end of the school year.
On March 13, Europe became the epicenter of the pandemic, having outpaced China in new cases. On March 16, the European Union instituted a 30-day ban on nonessential travel to at least 26 European countries from the rest of the world. Italy has been hit particularly hard, with 22% of their population aged 65 or older and more vulnerable to the virus. The Italian government placed the country under quarantine on March 9. France and Spain also implemented lockdowns after March 15. Spain’s death toll has risen sharply over the previous two weeks; Spain and Italy together now make up more than half the world’s deaths from the virus, although the growth of new cases has decelerated slightly over the last three days. Several other countries have followed with lockdowns, including Austria, Belgium, and Portugal, while Germany has issued strict social distancing measures. The UK began a lockdown last Monday, which was extended this Sunday as confirmed cases rose to 19,522, with deaths at 1,228. France has warned of growing impacts to healthcare systems from the outbreak, particularly around Paris.
On March 23, as deaths in the United States surpassed 100 in a single day, the U.S. Surgeon General warned that the outbreak would likely worsen due to insufficient mitigation measures and poor public adherence to social distancing. The WHO warning followed on the 24th, but by the 26th, the U.S. had become the pandemic epicenter, overtaking China’s case numbers. Several states responded with stronger public guidelines and by closing nonessential businesses to slow the disease spread. On Sunday, March 29, the President extended country-wide distancing guidelines through April. The sharp increase of cases and hospitalizations has reportedly begun to overwhelm the health systems in some states, including New York, where more than 1,000 people have died as of the morning of March 30, according to state officials. The U.S. State Department issued a Level 4 “do not travel” advisory—the highest level—and partial border closures with Canada and Mexico have gone into effect.
More countries have reported a shortage of ventilators for those in danger of respiratory failure—a major cause of death from this disease—as well as shortages of other critical equipment. Many hospitalized patients require lengthy treatment to recover, adding to the strain on healthcare systems. Some antivirals originally developed against other viral infections such as Ebola, HIV, or malaria, are being repurposed and tested in COVID-19 clinical trials. Researchers and scientists across the world are working to develop effective treatment and a vaccine for COVID-19. During the week of March 16, clinical trials to test coronavirus vaccines started; however, a successful vaccine will not be available for a year or more. Further symptoms and outbreak numbers are being tracked by new methods, such as phone apps and social media tracing, while private and public entities worldwide are directing their efforts toward combatting the virus.
Dr. Dorratoltaj noted, “There is high uncertainty around the fatality of the disease; however, it is estimated that COVID-19 has a higher case fatality rate (CFR) compared to seasonal flu (~0.1%) and a lower CFR compared to the 2003 SARS outbreak (~5.0%-10.0%). The current estimation for the average CFR ranges between 0.5% and 4%. According to the CCDC, among more than 72,000 patient records, with 86% of cases between 30 and 79 years old, current estimation for CFR ranges between 0.5% and 4%. CFR is estimated to be more than 5% for individuals with pre-existing conditions such as cardiovascular disease, diabetes, chronic respiratory conditions, hypertension, and cancer, and more than 8% for people older than 70 years old.”
Currently there is no specific treatment available for this disease other than supportive care. There are some antivirals and other treatments currently being used to treat patients. So far, fatality is most common in older patients, with more than 80% of deaths occurring in people over 60 years of age, more than 40% of whom have one or more pre-existing known co-morbidities, including cardiovascular disease, diabetes, and malignancies. It is also important to note that people who are more than 60 years old are generally at higher risk for any type of pneumonia and not just COVID-19 pneumonia. For these reasons, an overall increase in cases of the virus does not imply a commensurate increase in fatalities.
In countries with robust healthcare systems, any imported cases would most likely be contained with few or no transmissions to additional people—provided that cases are rapidly identified, and appropriate infection control protocols are followed. However, the current increase in the number of cases in some countries outside of China shows that there has been silent transmission that started in clusters and expanded to communities before health officials were able to contain them completely.
AIR continues to monitor the COVID-19 outbreak and will provide updates as warranted.
About AIR Worldwide
AIR Worldwide (AIR) provides risk-modeling solutions that make individuals, businesses, and society more resilient to extreme events. In 1987, AIR Worldwide founded the catastrophe modeling industry and today models the risk from natural catastrophes, terrorism, pandemics, casualty catastrophes, and cyber incidents. Insurance, reinsurance, financial, corporate, and government clients rely on AIR’s advanced science, software, and consulting services for catastrophe risk management, insurance-linked securities, longevity modeling, site-specific engineering analyses, and agricultural risk management. AIR Worldwide, a Verisk (Nasdaq:VRSK) business, is headquartered in Boston, with additional offices in North America, Europe, and Asia. For more information, please visit www.air-worldwide.com.