Influenza Pandemics of the 20th and 21st Century
Influenza pandemics have affected the world’s population, its economy, political and cultural perceptions.
Influenza virus symptoms are described in texts as early as 2,400 years ago. The first real evidence of the disease goes back to 1580 Russia, when a pandemic surged through Europe and Africa. In Rome, the pathogen killed 8,000 people and nearly destroyed several cities in what is now Spain.
In recent years, globalization has made the spread of a disease such as COVID-19 difficult to contain. However, at the same time, international cooperation and advances in research and medicine have made it less likely a repeat of the death toll experienced during the Spanish flu will happen again.
Nonetheless, it’s important to continue learning about disease control and treatments, as well as staying vigilant while funding research and development in medicine.
This article deals briefly with the pandemics that struck the world in the 20th and 21st centuries. Its intention is to look back in history in order to understand the present and plan for the future. It is not meant to frighten or to sensationalize past or current events. Knowledge is power.
The Spanish Flu — Silent Killer of the 20th Century
Just a few months before World War One — the “War to End All Wars” — came to an end in November of 1918, a microscopic assassin made itself known in British and American army barracks during the spring of that year. It killed swiftly and efficiently. Young and otherwise healthy soldiers often crowded into military bases in the United States and along the Western Front in Europe began to report to infirmaries with typical flu symptoms. They first reported fever, aching, and nausea, but these symptoms were soon followed by a deadly pneumonia that filled their lungs with bloody fluids. The foamy blood many of them coughed up signaled an impending death as they would soon take their last breath.
The United States had just joined the war the previous year and the spring of 1918 represented a crucial time for the Allied Forces. Victory laid ahead. Divulging the news of any weakness could embolden the enemy and prolong the war. Hence, the information that scores of soldiers were falling ill was kept a secret. This was perhaps the main reason for the virus’ rapid spread throughout Europe and eventually the rest of the world.
Spain Thought to be the Origin
By May of 1918, the influenza virus had made its way to Spain, ultimately killing a total of 260,000 people — an astonishing 1% of the Spanish population. Spain, a neutral country not involved in the armed struggle and therefore unencumbered by wartime censorship, began reporting on the deadly virus immediately. When Alfonso XIII, King of Spain contracted the virus, the news of the deadly illness spread quickly. Therefore, the impression that the pandemic had started in Spain prompted European and U.S. media to label the virus the ‘Spanish flu.’
Epidemiologists in the past hypothesized that the original outbreak started in either a British army base in Étaples, France or at Fort Riley in Kansas, where the first cases were reported. However, more recent experts believe the virus, known today as the H1N1 with genes of avian origin, most likely originated somewhere in northern China in late 1917. From there, it is believed, quickly moved to western Europe with the 140,000 Chinese laborers employed by the French and British governments as they sought to hire a work force that could free up troops for combat duty.
Perhaps 100 Million Dead
The world’s population in 1918 was a mere 1.8 billion. World War One was responsible for the death of 16 million people. However, by the time the pandemic was under control in December of 1920, at least 50 million people had been killed by the Spanish flu. Some estimates are as high as 100 million. The virus claimed more lives in a single year than all the casualties from the war.
It is also estimated that one-third of the world’s population, or 500 million people, became infected with the virus. This represents the most severe pandemic in recent history and one which brought the world to its knees. In the U.S. it forced schools, churches, theaters and public meetings to shut down. Within the period of a year, 675,000 Americans had lost their lives.
The Young Were Targets
For the most part, flu viruses target the old and very young among a population. The Spanish flu, however, presented an entirely different problem: the majority of the deaths occurred among those between the ages of 20 and 40. Their strong immune system would work against them by overreacting in an attempt to fight off the virus and as a result the lungs would be destroyed.
With no effective drugs, vaccines or antibiotics that could fight secondary infections, the only defense against the virus was to avoid contact with an infected person. Citizens were ordered to wear masks in public and instructed to wash their hands often. Large urban settings with mass transportation and consumption proved difficult areas to control a fast-moving virus such as this one. Those cities that were able to quickly minimize public gatherings lost fewer lives. Consequently, New York City was hit particularly hard, with 851 people dying from the flu in a single day.
Perfect Conditions for Rapid Spread
During the war, conditions on the ground were optimum for the transmission of a deadly virus. Troops living in packed barracks with sleeping arrangements close to one another; hundreds of thousands of troops in transit through camps every day; camps that were also home to poultry and piggery; camps with infected soldiers in contact with local villages; most importantly, the unwillingness of governments to disseminate information about the flu because of wartime secrecy.
The war itself was a contributing factor to the lethal nature of the virus. Possibly, the soldiers’ immune systems were already weakened by malnutrition, exposure to chemical attacks, and long hours in combat. All of this increasing their susceptibility to the virus and the inability to fight back secondary infections.
The virus surged through the world like a wild forest fire. It killed victims within a couple of days with frightening symptoms. First, was the lack of oxygen that would turn victim’s faces blue, starting with the ears. This was followed by bloody fluids that would fill the victim’s lungs. Finally, suffocation and death would soon follow.
The pandemic began to unfold sometime in January of 1918 and ended in December of 1920. It swept over the world in three waves from March 1918 to the Spring of 1919. However, it is believed the 1918 Influenza virus had been around in a less virulent form long before March of 1918. The virus began to kill its victims as it underwent several mutations. First killing hundreds, then thousands, eventually hundreds of thousands, becoming a global pandemic.
Much Deadlier Than the War
In the United States, officials attempted to deal with the overwhelming number of sick people. During the pandemic, 25% of Americans contracted the flu and 675,000 lost their lives. Consequently, the life expectancy in the United States dropped by 12 years in just one year. By the end of World War One on November 11, 1918, a total of 53,000 American troops had died in combat, compared to 57,000 who had succumbed to the flu.
Asian Flu of 1957
The Asian flu pandemic of 1957 was first identified in February of the same year in East Asia, subsequently spreading worldwide. It was the second major influenza pandemic in the 20th century following the Spanish flu of 1918–19. It was caused by influenza A subtype H2N2, a reassortant (mixed species) strain of avian and human influenza combined. After ten years of evolution, this particular virus disappeared and was replaced by the new influenza A subtype H3N3, which gave rise to the Hong Kong flu pandemic.
The virus first spread throughout China and surrounding countries in the first months of the outbreak, reaching the United States by midsummer of 1957. During the initial months of the first reported cases in the U.S., its impact on the population was minimal. Toward the end of 1957 a second wave of the illness hit the Northern Hemisphere, including the U.S. and the United Kingdom. The second surge of the pandemic mainly affected children, the elderly, and pregnant women.
By March of 1958, an estimated 69,800 people had died in the United States. Estimates of worldwide deaths varied between one million to four million, however the WHO estimates about two million. In 1957, an influenza vaccine was developed, which greatly contained its outbreak.
Hong Kong Flu of 1968
In July of 1968 an influenza outbreak originating in China became the third such pandemic of the 20th century, lasting until 1970. The pandemic was the result of a virus known as influenza A subtype H3N2, suspected of having evolved from the strain that caused the 1957 pandemic and known as the H2N2 or Asian flu.
Although those who had been exposed to the earlier 1957 Asian flu maintained immune protection to the 1968 virus, deaths worldwide were estimated at one million. Fatalities in the United States were 116,000.
There were also other reasons for fewer people dying in this pandemic than in the two previous events: the pandemic did not gain momentum until the winter school holidays, limiting its spread; improved medical care; widespread availability of improved antibiotics which were effective against secondary bacterial infections.
1977 Russian Flu — True Pandemic?
While the 1977 Russian flu outbreak was considered a pandemic, it was a benign H1N1 strain primarily affecting people born after the 1950s. This was a population who did not have exposure to previous H1N1 viruses and consequently no immunity to it.
The Russian flu began in May of 1977 in northern China and spread rapidly through children and those younger than 23 years of age on a worldwide basis. Also called the ‘red’ flu, it was originally thought to have originated in Russia, however, researchers eventually placed the origin in China.
Swine Flu Around the World
The 2009 Flu Pandemic or Swine Flu
The second influenza pandemic involving the H1N1 virus made its initial appearance in the state of Veracruz, Mexico sometime in April of 2009, and lasted until the end of 2010. Epidemiologists described it as a new strain of the H1N1 virus which combined bird, swine and human flu with the Eurasian pig flu virus. This led to the term “swine flu.” Evidence suggest the virus to have been present in the area for months before it was officially recognized as an epidemic.
The new virus was isolated by American and Canadian laboratories in late April of the same year. It was soon traced to a 5-year-old boy in the rural town of La Gloria, Mexico who contracted the illness on March 9th. The World Health Organization (WHO) declared its first-ever “public health emergency of international concern.” (PHEIC) in late April. In June, the WHO and the U.S. Center for Disease Control and Prevention (CDC) declared the outbreak a pandemic.
It is estimated that approximately 20% of the global population at the time (about 6.8 billion) contracted the illness, representing between 700 million to 1.4 billion cases of the flu. In absolute terms this figure represented a much higher number of infections than the Spanish flu; however, substantially fewer fatalities ranged between 150,000 to 570,000 globally. While the Spanish flu’s fatality rate was approximately 3%, the swine flu of 2009 exhibited less than 1%.
Prior to the pandemic announcement, the Mexican government closed most of Mexico City’s public and private facilities as a way of containing the spread of the virus. In spite of these measures, the epidemic continued to spread globally. In the United States, Barack Obama sought an extra $1.5 billion from Congress in April in order to help build stockpiles of antiviral drugs, work on vaccines and strengthen international cooperation with other countries.
As tension built among national governments, Japan cancelled visa-free travel from Mexico and the U.S. The European Union as well as other governments advised against non-essential travel to Mexico. Malaysia’s government asked the World Health Organization to ban outbound travel from Mexico as a way to stop the spread of the virus.
Rumors and innuendos began to circulate within social media and other sources of information. China angrily denied some Mexican media reports that the swine flu had originated in China and spread to Mexico through people traveling through the United States. Up to this time, China had been heavily criticized for its handling of the avian flu and SARS, specifically for its intentional cover-up which allowed those diseases to spread throughout the world.
Tensions between the U.S. and Russia also intensified as Moscow placed a partial ban on American meat, prompting Washington to correctly deny any connection with the pandemic. Sporting events worldwide were canceled, such as the A1 Grand Prix car race in Mexico City; China also announced its gold medal-winning national diving team would not take part in the FINA Diving Gran Prix in Fort Lauderdale, Florida.
Financial markets were affected during the pandemic. Certain segments of the market, such as the travel industry were negatively impacted. Hardest hit were stocks with connections to the Mexican travel and tourism industries. In contrast, shares of pharmaceutical companies experienced a short term lift.
Signs and Symptoms of Swine Flu
In pigs, an influenza infection produces fever, sneezing, coughing, difficulty breathing, lethargy, decreased appetite and weight loss. The mortality rate is usually low, at less than 4%. Due to certain receptors in swine to which avian and mammalian influenza viruses can bind, a virus is able to evolve and mutate into different forms. Hence, pigs are considered a “mixing vessel” which allow strains of diseases to change and evolve, eventually able to be passed on to other mammals, including humans.
Zoonotic or direct transmission of swine flu from pigs to humans is rare but possible. As of today, there are only 50 cases known to have occurred since first recorded in 1958. These transmissions resulted in six deaths. While these numbers seem low, experts believe the true rate of zoonotic infection of swine flu to be much higher, as most cases cause very mild symptoms and are most likely not reported.
In humans to human transmission, (not zoonotic) the symptoms of swine flu H1N1 virus are similar to all other influenza-like illnesses which include fever, cough, sore throat, watery eyes, body aches, shortness of breath, headache, weight loss, chills, runny nose, sneezing, dizziness and abdominal pain. In the 2009 outbreak diarrhea and vomiting were also reported by some patients.
Proper hand washing techniques to prevent spreading of the virus. Experts suggest washing hands for as long as one can sing the “happy birthday song” twice, or at least 20 seconds. Avoid touching the eyes, mouth or nose. Stay away from those who display flu-like symptoms as well as when displaying symptoms.
2019–20 Coronavirus Outbreak
The 2019–20 coronavirus outbreak is caused by the SARS-CoV-2 virus (severe acute respiratory syndrome coronavirus 2). The disease is referred to as COVID-19 and it is an “influenza-like” ailment. While it is not the flu, it is worthwhile discussing it.
The SARS-CoV-2 was first identified in Wuhan, Hubei, China and it is thought to have a zoonotic origin involving bats initially with pangolins as an intermediate host. The first person reported to have fallen ill was on December 1st, 2019; however. a public notice of the outbreak was not released until December 31st.
The initial notice out of the city government to residents stated that there was no clear evidence of human-to-human transmission. A week later, in January 7th, 2020 the Communist Party Politburo Standing Committee began discussions of possible prevention methods and control. The slow initial response of the government has been severely criticized.
While it has not been declared a pandemic as of yet (March 4, 2020), it is an ongoing public health emergency of global proportion. In fact, the likelihood of it being declared a global pandemic rests perhaps within days.
The three criteria used by the CDC to classify an outbreak a pandemic are: a disease that kills; is capable of person-to-person transmission; and that involves a worldwide spread.
As of March 3, WHO officials have said that within the previous 24 hours, COVID-19’s cases outside of China were almost nine times higher than inside the country.
Similarly to influenza, the virus spreads in people through respiratory droplets produced in sneezing and coughing. Incubation period ranges from two to fourteen days; typically, five days. Symptoms have been known to include fever, cough, muscle aches and shortness of breath. Those infected may be asymptomatic (no symptoms) or exhibit mild symptoms. In any case, those contracting the virus are contagious until the pathogen is no longer in their bodies.
Complications can include pneumonia and acute respiratory distress syndrome (respiratory failure due to rapid inflammation in the lungs.)
Currently, there are no available vaccines. The National Institute of Health (NIH) announced on February 25th that clinical trial of remdesivir, an antiviral medication to treat COVID-19 has begun. Mateon Therapeutics headquartered in San Francisco, California announced in March 2nd it has launched an antiviral response program focused on COVID-19. A group of German scientists have identified a drug called comastat mesylate, which they believe may work to combat the disease. Other efforts to find antiviral drugs include the possibility of using the hepatitis C (HCV) medicine Ganovo (danoprevir) and the HIV drug ritonavir.
In the meantime, it is best to avoid infection by thorough hand washing, maintaining distance from sick people and monitoring plus self-isolation for two weeks for those who suspect of being infected.