What do all these have in Common….China

The virus emerged in China in the winter of 1957 and spread rapidly worldwide via ships, aeroplanes, and trains. In April, it sparked a major epidemic in Hong Kong, where about 250 000 people were infected, and by June India had seen over a million cases. Shortly afterwards, it made landfall in the UK, and by September outbreaks were being reported in England, Wales, and Scotland. General practitioners were “amazed at the extraordinary infectivity of the disease” and the suddenness with which it attacked younger age groups. Yet, while some members of the College of General Practitioners called for the UK Government to issue a warning about the dangers presented by the virus and coordinate a national response, the ministry of health demurred. Instead, the virus was permitted to run its course.

The 1957 outbreak was not caused by a coronavirus—the first human coronavirus would not be discovered until 1965—but by an influenza virus. However, in 1957, no one could be sure that the virus that had been isolated in Hong Kong was a new pandemic strain or simply a descendant of the previous 1918–19 pandemic influenza virus.

1957 flu pandemic, also called Asian flu pandemic of 1957 or Asian flu of 1957, outbreak of influenza that was first identified in February 1957 in East Asia and that subsequently spread to countries worldwide. The 1957 flu pandemic was the second major influenza pandemic to occur in the 20th century; it followed the influenza pandemic of 1918–19 and preceded the 1968 flu pandemic. The 1957 flu outbreak caused an estimated one million to two million deaths worldwide and is generally considered to have been the least severe of the three influenza pandemics of the 20th century.
The 1957 outbreak was caused by a virus known as influenza A subtype H2N2. Research has indicated that this virus was a reassortant (mixed species) strain, originating from strains of avian influenza and human influenza viruses. 

After 10 years of evolution, the 1957 flu virus disappeared.

The first recorded instance of the outbreak appeared on 13 July 1968 in British Hong Kong. There is an unconfirmed possibility that the outbreak actually began in Mainland China before it spread to Hong Kong.
The outbreak in Hong Kong, where the population density was greater than 6,000 people per square kilometre, reached its maximum intensity in two weeks. The outbreak lasted around six weeks, affecting about 15% of the population (some 500,000 people infected), but the mortality rate was low and the clinical symptoms were mild.

There were two waves of the flu in mainland China, one between July–September in 1968 and the other between June–December in 1970. The reported data were very limited due to the Cultural Revolution, but retrospective analysis of flu activity between 1968–1992 shows that flu infection was the most serious in 1968, implying that most areas in China were affected at the time.

The first classical swine influenza A H1N1 viruses were isolated in Mainland China in 1991. To aid surveillance of swine influenza viruses as part of pandemic preparedness, we sought to identify their origin.

On March 17 2009, the first case of a novel H1N1 influenza virus infection, also known as swine flu, was documented in Mexico. It rapidly spread throughout Mexico and the US and was declared a full pandemic by the WHO on June 11 2009. 

Swine flu circulated around the world in two waves until August 10 2010, when the WHO officially declared the pandemic over. By comparing the coronavirus pandemic with the 2009-2010 H1N1 pandemic and looking at modern forecast models, we might be able to better assess what to expect over the coming weeks to months.

As of March 22, we are in week 16 of the COVID-19 pandemic, roughly equivalent to July 8 2009 of the H1N1 pandemic. These two points in time offer a useful comparison as the number of cases in both the US and UK were at nearly identical levels in both pandemics.

The comparison highlights four important differences. First, with the 2009 H1N1 pandemic beginning in North America, the US had the highest number of cases at week 16. This contrasts with the COVID-19 pandemic with the highest number of cases reflecting the virus’s origins in China.

The first documented case of COVID-19 is thought to have appeared on December 1 2019 in Wuhan, China. Four months later, the world is in the middle of a pandemic with little idea of what comes next. Yet this is not the first pandemic to occur in recent years.