Since the Spanish flu emerged as a pandemic in 1918, many invisible viral enemies have threatened the world. Although each new virus is spread differently, causing different symptoms and with varying mortality rates, public health officials build on these experiences to fight the current COVID-19 pandemic.
The H1N1 flu (swine flu) emerged in June 2009 in Mexico and spread globally through August 2010, when the World Health Organization declared the end of the pandemic. In that short time, there were 60.8 million cases affecting 24% of the global population. The mortality rate was 0.02% with 12,500 deaths.
In 2014, Ebola emerged as a very deadly virus with an average mortality rate of 50 percent. By the time the pandemic ended in March 2016, there had been over 28,000 cases worldwide. In comparison, the first case of the novel COVID-19 appeared in December 2019 and as of April 28, 2020, there have been nearly 3 million cases and close to 212,000 deaths. As this pandemic continues the mortality rate changes daily due to the variability of mass testing and reporting.
The symptoms of these modern viruses vary. For instance, the H1N1 flu virus causes fever, chills, cough and body aches. COVID-19 causes fever, chills, repeated shaking with chills, cough, shortness of breath, muscle pain, headache, sore throat, a new loss of taste or smell, and it can mimic influenza. For the most severe cases of COVID-19, patients require intensive care and ventilators. In contrast, Ebola causes extreme symptoms, including vomiting, diarrhea and bleeding. This meant people were less likely to be out in public spreading the virus, making it easier to identify and isolate these patients.
One major difference between Ebola and COVID-19 is the method of spread. Ebola is spread during the last stage of the disease through blood and sweat. In contrast, COVID-19 spreads more easily through breathing, coughing or talking in close contact. According to an early study from China, approximately 80 percent of COVID-19 cases are mild, meaning they show few or no symptoms.
The impact of these widespread viruses varies by age group and underlying health conditions. For example, people over the age of 65 and people of any age with underlying health conditions are at a higher risk of severe illness from COVID-19. The H1N1 virus affected both children and adults. By the end of the H1N1 pandemic, 80 percent of deaths were people younger than 65.
In conclusion, regardless of the mortality rate or the number of confirmed cases, each virus has devastating worldwide impact. Undoubtedly, scientists will continue to learn more about how COVID-19 stacks up against other viruses.