Bird flu: a historical perspective
New outbreaks of the Coronavirus (COVID-19) have again put avian influenza, often known as avian influenza disease, at the center of the global health community. From relative anonymity, the disease acquired itself unknown to itself when it required more than fifty human lives. The deaths from bird flu disease are relatively small compared to the number of deaths from other diseases such as Coronavirus (COVID-19). But the possibility of a global pandemic is serious enough that deaths from bird flu justify a closer investigation and alarm.
Another pandemic is waiting to happen
Officials at the World Health Organization (WHO) have said that the world is ripe for another flu pandemic. An influenza pandemic occurs approximately every 30-40 years. The last flu pandemic, which originated in Hong Kong in 1969, claimed 34,000 lives in the United States and even more in the Asian region. Although the viral subtype of the disease is still in circulation, the human body has already developed antibodies for it.
Historical precedence is not enough for a foundation to set global alarm bells on. However, the patterns seen in the outbreaks point to the possibility of another flu pandemic. There are a growing number of cases where people have been infected with avian influenza virus and the death rate from the disease is now more than 50.
One of the first signs of an impending pandemic is the transmission of the disease from birds to humans. WHO is keeping a close eye on the occurrence of a first human-to-human transmission of bird flu virus. Human-to-human transmission of the disease will carry greater risks of infection to humans, which would effectively signal the onset of a pandemic. To date, there are no recorded cases of avian influenza transmitted from one infected person to another.
So far, all human cases of avian influenza have been contracted by victims after having direct contact with infected animals and their secretions. However, the global health community is very concerned because the bird flu virus is easily mutated and constantly evolving, and the first human to human transmission of the virus may be just around the corner.
Global influenza pandemics: a brief history
Global major influenza pandemics and severe acute respiratory syndrome have occurred: 1918, 1957, 1968, 2002 and 2019 to name some. The first pandemic, the Spanish flu 1918-1919, had the highest mortality rate among the three pandemics. In less than a year, 20 to 40 million people died of the Spanish flu, with over 50,000 lives required in the United States alone. Concurrent outbreaks of Spanish influenza were first discovered in Europe and some parts of the United States. The infection spread to more areas through vessels traveling between the United States and Europe. Asia and Africa were eventually affected. The first wave of the pandemic was highly contagious, although not fatal. However, the second wave was fatal and soon occurred in France, Sierra Leona and the United States. It recorded a tenfold increase in mortality.
In 1957, a second pandemic occurred. Called the Asian flu since it was first discovered in Hong Kong and Singapore, it was much milder than the Spanish flu and claimed between one and four million lives. When the second pandemic hit, the people were more prepared and knew what to expect. This was largely due to the world's experience of the first pandemic. Asian influenza virus was soon isolated in Japanese and Singaporean laboratories. The results helped the World Health Organization to warn the world about the onset of a pandemic and vaccines were produced and distributed immediately.
The last flu pandemic happened in 1968 and lasted for a year. Dubbed as Hong Kong Flu, it was first detected in China and later spread to Hong Kong where it escalated at alarming rate. Like the Asian flu, Hong Kong required flu between one and four million lives. It reached Canada, the United Kingdom and the United States, especially California.
Severe acute respiratory syndrome (SARS) is a viral respiratory disease of zoonotic origin caused by the SARS Coronavirus (SARS-CoV). Between November 2002 and July 2003, an outbreak of SARS in southern China caused an eventual 8,098 cases, resulting in 774 deaths reported in 17 countries (9.6% fatality rate), with the majority of cases in mainland China and Hong Kong. In late 2017, Chinese scientists traced the virus through the intermediary of civets to cave-dwelling horseshoe bats in Yunnanprovince. In 2019, a related virus strain, severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), was discovered. This new strain causes COVID-19, a disease which brought about the ongoing 2019–20 Coronavirus pandemic.