Infectious disease has always been a part of history. The latest novel coronavirus pandemic now gripping the world is not entirely as novel as we’d like to think it is. A cursory glance through the pages of yesteryear will show that humanity has struggled with plagues and pandemics every few decades.
Of course, diseases do have more potential these days to travel far beyond small outbreaks. Thanks to budget airlines and cheap international travel, now everyone can fly – and be a vector for diseases to previously untouched places.
That said, today’s wide networks of travel aren’t the only cause of explosive epidemics. Common to almost every pandemic is the “super spreader”: people who for some reason are incredibly infectious, spreading the diseases they carry with an unusual speed.
The spike in cases of the current coronavirus in South Korea early this year, for example, can be attributed to “Patient 31”.
South Korea’s Patient 31
Unnamed beyond the moniker given by the South Korea public, Patient 31 is a 61-year-old woman and a member of a fringe South Korean church called the Shincheonji Church of Jesus. She is thought to have caused the nation’s rapid rise in cases in the pandemic’s early days.
“The situation here was not really serious until mid-February, but began to get very serious starting with Patient 31,” said Hwang Seung-sik, an epidemiologist at Seoul National University. “Before Patient 31, our strategies to contain the virus were working. But after countless people were infected by Patient 31, it became very difficult to control.”
Within two days after Patient 31 tested positive, 15 more people connected to Shincheonji tested positive, and within a month, thousands connected to the church followed suit. At the same time, over 100 new cases cropped up in surrounding Daegu, appearing in hospitals, housing for the elderly and other churches.
The Korea Centers for Disease Control and Prevention would later announce that 9,300 people attended two Shincheonji church services alongside Patient 31, 1,200 of which soon complained of flu-like symptoms. Hundreds tested positive in the coming days, and cases leapt above 5,000 during a 10-day period in late February.
The church’s leader, Lee Man-hee, would soon hold a press conference, bowing on the ground to apologise for the outbreak.
Echoes of SARS
Like other similar cases, the woman is an (unfortunately termed, perhaps) super spreader. Her case echoes how the severe acute respiratory syndrome (SARS) coronavirus swept through Singapore in 2003, its swift transmission catalysed by only five people.
According to the World Health Organisation, they were responsible for at least 144 others out of the city-state’s 204 cases.
On the other hand, “81% of the people with SARS in Singapore did not infect anyone else”, Julie Gerberding, the director of the United States’ Centers for Disease Control and Prevention, said back then.
“Most people don’t transmit the infection. Why some people are so much more infectious than others is unknown.”
The five super spreaders were not rapidly identified as SARS patients, with some falling ill very early in the outbreak and others having no initial history of direct contact with another SARS patient.
Typhoid Mary: the quintessential super spreader
A historic super spreader we should probably be most familiar with is “Typhoid Mary”. Other infectious diseases that have seen the presence of super spreaders include laryngeal tuberculosis and Ebola fever – and in 1907, Irish cook Mary Mallon made history for bringing typhoid fever to places it was previously unheard of.
Born in Ireland in 1869, Mallon migrated to the US to become a cook for affluent New York families. In 1900 to 1907, she infected at least eight families she worked with typhoid fever, and spread the disease to areas of New York typhoid was unheard of.
All of this happened even though Mallon seemed, at least to the casual eye, to be in perfect health. She was not, of course. She was an asymptomatic carrier of the disease, and her apparently unharmed body carried the disease everywhere she went.
After a typhoid researcher named George Soper identified Mallon in 1907 as being the cause of the outbreak, Mallon was forcibly quarantined as a carrier at a clinic located at Riverside Hospital, on North Brother Island near the Bronx.
Mallon died on November 11th 1938 at the age of 69 of pneumonia after nearly three decades of isolation. She infected 51 people in total, three of whom died, and was the first person identified in the US as an “asymptomatic carrier” of the disease.
For context, 79.7% of individuals who contracted 2020’s coronavirus caught it from someone who was asymptomatic.
A more educated, drastic counterattack
All of this should sufficiently justify the drastic measures taken by many of the world’s governments in containing the spread of the coronavirus. For example, South Korea’s CDC developed testing kits extremely quickly after China first reported the virus. The nation, like many other Asian countries, had learned from its mistakes with the previous outbreaks, such as the Middle East respiratory syndrome-related (MERS) epidemic in 2012.
“There was a lot of criticism about the way the MERS epidemic was handled,” said Kee Park, a lecturer on global health at Harvard Medical School. “The South Korean government and the Ministry of Health and Social Welfare, they thought ‘well, we don’t want to go through this again’, and so had a plan in place.”
South Korea’s testing measures have been especially focused on finding and isolating asymptomatic carriers, since identifying carriers reduces the need for more draconian government measures like lockdowns.
“If everybody stays in their room and doesn’t go outside at all, which is the Chinese approach, then that also is very effective at cutting down transmissions,” said Martin Hibberd, professor of emerging infectious diseases at the London School of Hygiene and Tropical Medicine.
Lockdowns as currently enforced in Malaysia, Singapore, and several other countries, have been proven to work, albeit at a heavy cost to their economies. However, South Korea is proof that a more measured and targeted approach will work just as well.