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Raj Persaud in conversation - the podcasts

Mar 23, 2020

You can also listen to this interview on a free app on iTunes and Google Play Store entitled 'Raj Persaud in conversation', which includes a lot of free information on the latest research findings in psychology, psychiatry, neuroscience and mental health, plus interviews with top experts from around the world. Download it free from these links. Don't forget to check out the bonus content button on the app.


The Psychology of the Virus Super-Spreader


Covid-19 like many infections, can produce such mild symptoms, or maybe none at all, in some, so that they don’t realise they are infected; they then spread the contagion without realising it. This means that Covid-19 may be particularly prone to the disturbing phenomenon of the ‘super-spreader’.

An illustration that appeared in 1909 in The New York American June 20, 1909
Mary Mallon (1870-1938) nicknamed “Typhoid Mary”
Source: An illustration that appeared in 1909 in The New York American June 20, 1909

Officialdom doesn’t seem keen so far on disseminating the ‘super-spreader’ theories over Covid-19, maybe because they don’t want the general public to feel ‘off the hook’ to make mass personal changes. This may happen if they don’t feel personal responsibility for contagion; which they won’t if they can blame a few ‘super-spreaders’ instead.


But maybe the opposite is true, if the public better grasped the concept of the ‘super-spreader’, maybe they would adhere more to public health restrictions?

Why can there be such large variability between countries and regions, as to the spread and virulence of a particular infectious disease? It is tempting to see the answers in, for example, differences between varying Government policies, but there are other biological factors which can be in play as well, such as genetic susceptibility, or the age profile of a population.


However, one phenomenon which may not be receiving as much attention as it deserves, given it’s potential to explain variable rates of spread of infections, is the idea of the ‘super-spreader’.

‘Super-spreading’ refers to the frightening spectacle when just a single patient infects such a huge number of contacts, that the usual or average rate of spread from more typical individuals, becomes dwarfed.


There is a strand of thinking in epidemiology that the controversial role of ‘super-spreaders’ needs to be better understood if modelling of epidemics is to become more accurate, and official response better targeted.

‘Supers-spreaders’ might be out in the community spreading the disease for an extended period of time before being detected by conventional methods.


In a study entitled ‘MERS, SARS, and Ebola: The Role of Super-Spreaders in Infectious Disease’, the authors point to the role of so-called ‘super-spreaders’ in past epidemics.

Published in the academic journal Cell Host & Microbe, the study quotes the example of the 2015 MERS-CoV outbreak in South Korea, which began from a single case who had travelled from the Middle East. Middle East Respiratory Syndrome coronavirus (MERS-CoV) emerged as a new virus resulting in severe respiratory disease plus renal failure. The case fatality rate was up to 38%.

The authors of this study into ‘super-spreaders’ were based at the Chinese Academy of Sciences, Beijing, Shenzhen Third People’s Hospital, Shenzhen, and the Chinese Center for Disease Control and Prevention, Beijing, China.

MERS-CoV cases typically occur in the Middle East, where dromedary camels harbour the virus.


Between May and July 2015, an outbreak of MERS-CoV in South Korea killed 36 people out of 186 confirmed cases. Twenty-nine secondary infections in South Korea have been traced to a single index patient who travelled from the Middle East. Two of these secondary cases were apparently responsible for 106 subsequent infections, out of 166 known cases at the time.


So, according to this study, the MERS-CoV outbreak in South Korea was driven primarily by three infected individuals, and approximately 75% of cases can be traced back to three super-spreaders who have each infected a disproportionately high number of contacts.

This study also documented ‘super-spreading’ during the SARS-CoV outbreak in 2003. The index patient of the Hong Kong epidemic was treated at Prince of Wales Hospital and was associated with at least 125 secondary cases.


Similar events, according to the study, were observed with the 2014-15 Ebola outbreak, centred in Western Africa. In Sierra Leone, the funeral of a traditional healer that died from EBOV directly infected 13 others and was ultimately linked to more than 300 cases. The authors point out that ‘super-spreading’ has also been documented in measles and TB outbreaks.

The authors contend that initial stages of all of the outbreaks mentioned above involved at least one super-spreading event. Super-spreaders the authors argue, may become the key difference between an infection cluster and an epidemic.

In a study entitled, ‘Transmission potential of COVID-19 in South Korea’, published at medRxiv as a preprint, the authors point out that the epicentre of the South Korean COVID-19 outbreak has been identified in Daegu, where the rapid spread has been attributed one super-spreading event that has led to at least 40 secondary cases stemming from church services in that city.


In another study entitled, ‘Spatial and temporal dynamics of superspreading events in the 2014–2015 West Africa Ebola epidemic’, published in PNAS, (Proceedings of the National Academy of Sciences  of the United States of America), the authors argue that had the super-spreaders been identified and quarantined promptly, around 61% of the Ebola infections could have been prevented. The authors argue their findings highlight the key role of super-spreaders in driving epidemic growth.


While there are many factors that may explain the still mysterious phenomenon of ‘super-spreading’, individual behaviour might play a key role.

A classic example that arises from experience of previous outbreaks includes so-called “doctor shopping”. This can comprise visiting multiple hospitals to treat the same ailments, even traveling to other countries to visit new clinics.

Different health care systems may promote contrasting doctor-shopping behaviours.For example, privatised healthcare lends itself more readily to ‘doctor-shopping’, as the individual patient can decide to consult as many different physicians as they can afford. Indeed, in non-pandemic times this may be a key advantage used to promote fee-for-service systems.


Yet a more centralised, state-controlled system, like the UK’s NHS (National Health Service) is better equipped to prevent this. In the NHS you can’t very easily consult any other Family Practice, beyond the one you are registered with. Also, you can’t see any specialist you desire, unless you have been formally referred by your General Practitioner.


During normal times these limitations might be irritating, but in a pandemic these restrictions may curtail ‘super-spreading’.

However, it is not clear that any healthcare system, no matter how well organised, can do much against an extremely determined ‘super-spreader’, unless extremely draconian powers of incarceration are invoked.

This is precisely what happened in the case of perhaps the first documented case, and most famous individual ‘super-spreader’ in history, an Irish immigrant cook who disseminated Typhoid fever in the New York area, subsequently becoming notoriously referred to as ‘Typhoid Mary’.Her story is important as it may be a prophetic foretelling of our own future. It could be many recalcitrant spreaders who refuse to conform to public health advice, may yet find themselves similarly imprisoned.


Between 1900 and 1907, Mary Mallon moved as cook from household to household, infecting some 22 people with typhoid fever. At this time this was a disease with a ten-per-cent mortality rate.

Several attempts were made to enlist her cooperation in being tested, and to comply with quarantine advice, which she resolutely ignored. Eventually the authorities concluded that she represented such a threat to the public’s health, she had to be incarcerated, and therefore isolated against her will on a quarantine island in the East River.


The police and doctors were involved in the frantic physical chase to capture her. Such was the struggle from the intransigent cook, that the doctor had to be involved in the forcible physical restraint involved in subduing the patient in the ambulance, removing her from her freedom.

Mary Mallon was released over three years later having grudgingly promised to comply with restrictions, including promising not to return to cooking, and signing in regularly with the authorities.


However, such was her actual resolution to return to cooking against medical advice, she eventually slipped away again from surveillance, only to resurface 5 years later, when she was discovered to be cooking at the Sloan Maternity Hospital in New York City, where 25 new cases of typhoid fever had just been reported.


One lesson that might be learned from her case was that finding her alternative viable employment might have prevented the second tragic outbreak.

Mallon was sent back to her secluded bungalow on North Brother Island, for the rest of her life. She died on Nov. 11, 1938, after more than 26 years of compulsory isolation. In the end, she had infected at least 51 people, 3 of whom died.


Yet as Janet Brooks points out in her investigation entitled, ‘The Sad and Tragic Life of Typhoid Mary’ published in the Canadian Medical Association Journal, by the time she died, New York health officials had identified more than 400 other healthy carriers of Typhoid, yet no one else was forcibly confined.


Was Mary Mallon discriminated against? Was it something to do with being an Irish single woman with no husband nor parents to fight her corner, or did she suffer from some kind of intransigent personality type, or even disorder, which meant she was more prone to conflict with the authorities?

Could this personality type identify behavioural super-spreaders today?


Before they imprisoned her, Mary Mallon was quick to wield a carving fork whenever approached by health officials who first tried to reason with her. Once incarcerated she wrote violently threatening letters to her doctors, explaining that if ever released, she would get a gun and kill them. This was not an immediately obviously sensible tactic over securing her freedom, and might suggest the possibility of an undiagnosed mental illness.


Author Susan Campbell Bartoletti, in her biography of Mary Mallon, entitled, ‘Terrible Typhoid Mary – The Deadliest Cook in America’, points out that she could have been let out of her imprisonment much earlier, if she had just played the politics, and agreed to the terms the authorities demanded, from the beginning.


She could have simply agreed not to cook, and she could then have slipped away from their surveillance, once released. Her problem really was that she was too honest.

Paradoxically could extreme sincerity might also be a sign of a psychiatric disorder? It was the key argument many anti-psychiatrists in the 1960’s deployed against the incarceration of psychiatric patients, which is that they landed themselves in trouble because they were too ‘authentic’ or honest when answering the doctor’s questions.


This is one of the underlying themes of films like Jack Nicholson’s ‘One Flew Over The Cuckoo’s Nest’.

If it was her persistent personal rigidity, in denying there was anything wrong with her cooking, maybe Mary Mallon could not apparently grasp the concept of being a ‘healthy carrier’, which trapped her into dogged conflict with the authorities, and left her to languish for the rest of her life in enforced quarantine.


Maybe there seemed to be a pride issue involved in that she may have regarded Typhoid as a disease associated with being ‘dirty’, with not washing her hands properly after leaving the toilet before cooking, yet she was a proud ‘clean’ cook. Perhaps the doctors failed in their attempt to explain the science to a scarcely educated kitchen worker because of the cultural and class divide between them?


Maybe they are failing again with the public as they are making the same mistake in not grasping how to bridge the chasm in understanding between the epidemiologists and the public?

Or is there, in fact, a little of Mary Mallon in all of us who buck the Government’s injunctions? We rebel when attempts are made to prevent us from doing what we love, because we don’t see the link between our own personal behaviour, and how it’s going to stop a pandemic?


The story of possibly the first documented ‘super-spreader’ in history, suggests that even today, a failure to grasp the science behind infections and disease, by just one person, could prove deadly to society.



MERS, SARS, and Ebola: The Role of Super-Spreaders in Infectious Disease. Gary Wong, Wenjun Liu, Yingxia Liu, Boping Zhou, Yuhai Bi, George F.Gao Cell Host & Microbe Volume 18, Issue 4, 14 October 2015, Pages 398-401


Transmission potential of COVID-19 in South Korea. Eunha Shim, Amna Tariq, Wongyeong Choi, Yiseul Lee, Gerardo Chowell. medRxiv preprint doi:


‘Spatial and temporal dynamics of superspreading events in the 2014–2015 West Africa Ebola epidemic’. Max S. Y. Lau, Benjamin Douglas Dalziel, Sebastian Funk, Amanda McClelland, Amanda Tiffany, Steven Riley, C. Jessica E. Metcalf, and Bryan T. Grenfell. PNAS February 28, 2017 114 (9) 2337-2342


Typhoid Mary: Captive to the Public’s Health By Judith Walzer Leavitt ISBN 0-8070-2102-4, Beacon Press, Boston, Massachusetts


The sad and tragic life of Typhoid Mary. J Brooks. CMAJ. 1996 Mar 15; 154(6): 915–916.

‘Terrible Typhoid Mary: A True Story of the Deadliest Cook in America’ by Susan Campbell Bartoletti. Houghton Mifflin Harcourt Publishers.


What happens when a person's reputation has been forever damaged? With archival photographs and text among other primary sources, this riveting biography of Mary Mallon by the Sibert medalist and Newbery Honor winner Susan Bartoletti looks beyond the tabloid scandal of Mary's controversial life. How she was treated by medical and legal officials reveals a lesser-known story of human and constitutional rights, entangled with the science of pathology and enduring questions about who Mary Mallon really was. How did her name become synonymous with deadly disease? And who is really responsible for the lasting legacy of Typhoid Mary? This thorough exploration includes an author's note, timeline, annotated source notes, and bibliography.


Awards: Newbery Honor, Carolyn Field Award, Lamplighter Award, Parents Gold Choice Award, Outstanding Pennsylvania Author of the Year, Children's Book Guild Award for Body of Nonfiction Work

Susan Campbell Bartoletti was born in Harrisburg, Pennsylvania, in 1958 and grew up in rural Pennsylvania, a place she has used as a setting in her young adult novels and nonfiction books. A student, author, and teacher, Bartoletti uses historical elements as the backbone of many of her works, and she has won many awards for her ability to combine historical facts with her unique writing style.


Susan Campbell Bartoletti was born Susan Campbell in Harrisburg, Pennsylvania, on November 18, 1958. Two months after her birth, her father was killed in a car accident. Her mother later remarried after Bartoletti finished kindergarten, and the family moved to the outskirts of Scranton, Pennsylvania. She loved growing up in the countryside of rural Pennsylvania, and she later used this setting in many of her works. As a young girl, Bartoletti enjoyed reading, drawing, horseback riding, playing piano, and listening to the Beatles. By the eighth grade, she was editor of her newspaper and had discovered her passion for art and writing. She decided to pursue her career as soon as possible, and after her junior year of high school, she left to attend college early. Bartoletti attended Marywood College and majored in art at first. After realizing the stiff competition in the field and receiving praise from her creative writing professor, Campbell switched gears and decided to major in English and secondary education instead. After her sophomore year, she married Joseph Bartoletti, and the couple later had two children, Brandy and Joey. Bartoletti received her BA in 1979 and obtained her first teaching job at the age of 20. She began teaching English at North Pocono Middle School and remained there for 18 years. She also co-advised the school's award-winning literary magazine for 15 years. While teaching, she simultaneously earned her MA in English at the University of Scranton in 1982. Bartoletti became involved in many different activities, including the Children's Literature Association, the National Council of Teachers of English, and the Rutgers Council on Children's Literature. She also found time to write more. Her first picture book, Silver at Night, was published in 1994. This was an autobiographical work about her husband's grandfather, an Italian immigrant who spent nearly half a century in the coal mines. Bartoletti wanted a lot of her writing to focus on historical events, particularly labor history in her native Pennsylvania. In 1996, her work Growing Up in Coal Country was published. This book focused on the working and living conditions of Pennsylvania coal towns and won her numerous awards including the Carolyn Field Award, the Lamplighter Award, and the Parents Gold Choice Award. She remained ambitious, and as she was writing and teaching eighth grade English she became an instructor in children's literature at the University of Scranton. In 1998, Bartoletti decided to stop teaching at the middle school in order to pursue her writing career and earn her PhD in creative writing. She attended Binghamton University with a full fellowship, where she won the Excellence in Research award for her doctoral dissertation.

In 1999, Susan wrote a book concerning child labor laws and the hardships children endured as they were forced to work in big industries. Kids on Strike! discussed the problems of child labor and the actions to strike against them. The pictures within the work reveal children suffering from sleep deprivation and missing fingers and showed the world just how tragic child labor was. She also focused on another historical tragedy in 2001 when she finished writing Black Potatoes: The Story of the Great Irish Famine, 1845-1850. This work tells the story of the Great Potato Famine in which one million Irish died from starvation and disease, and two million had to leave Ireland to escape death. That same year, the Pennsylvania Library Association named Bartoletti the Outstanding Pennsylvania Author of the Year. In the midst of all the attention, Bartoletti wrote yet another book titled The Flag Maker (2004). This was a story about Caroline Pickersgill and her mother, Mary, sewing a large-enough American flag for the British to see it during a major battle in the War of 1812. She was inspired to write about it after she saw the 80-pound masterpiece in the Smithsonian Institute in Washington, DC.

One of Bartoletti's most compelling books was written in 2005. Hitler Youth: Growing Up in Hitler's Shadow is a story about young Germans devoting their lives to Hitler and his Nazi regime. The book also incorporated stories about young people resisting the movement, a dangerous and often fatal move. The photographs in the book put the impact of Hitler's campaign in perspective and are difficult to look at. One of the first photos was a 1934 photo taken during German Youth Day in Potsdam where a young boy is shown raising his hand in the Nazi salute. In 2006, Hitler Youth became a Newbery Honor Book selection.

On her website and in interviews, Bartoletti mentions that she is often asked if she writes the works she does, which often delve into difficult and complex topics, "to show kids today how good they have it." The answer is no. She hopes that her works give "readers courage — courage to question and to think critically about history; courage to consider and respond to their social, political, and existential responsibilities; and, most of all, courage to stand up."

In 2009, she won the Washington Post's Children's Book Guild Award for Body of Nonfiction Work. Bartoletti also won the Carolyn W. Field Award in 2009 for her novel The Boy Who DaredThe Boy Who Dared earned Bartoletti many more honors and distinctions, including American Library Association Book of Distinction and Best Book for Young Adults, Booklist Top 10 Historical Fiction for Youth, and International Reading Association Notable Book for an Important Society. In 2010, she published They Called Themselves the K.K.K.: The Birth of an American Terrorist Group, which was a Junior Library Guild Selection. This children's book also earned recognition and was placed on the Best Children's Book of the Year List for the School Library JournalKirkus, and Publisher's Weekly.

Susan Campbell Bartoletti has served as a professor of children's literature for the Pennsylvania State University's World Campus and, at the time of this writing, lives in Moscow, Pennsylvania, where she continues to write and publish.

Selected Works:


  • Growing Up in Coal Country. Boston: Houghton Mifflin, 1996.
  • Kids on Strike! Boston: Houghton Mifflin, 1999.
  • Black Potatoes: The Story of the Great Irish Famine, 1845-1850. Boston: Houghton Mifflin, 2001.
  • Hitler Youth: Growing Up in Hitler's Shadow. New York: Scholastic Nonfiction, 2005.
  • They Called Themselves the K.K.K.: The Birth of an American Terrorist Group. New York: Houghton Mifflin, 2010.
  • (Coedited with Marc Aronson.) 1968. Somerville: Candlewick, 2018.


  • No Man's Land: A Young Soldier's Story. New York: Blue Sky Press, 1999.
  • A Coal Miner's Bride: The Diary of Anetka Kaminska. New York: Scholastic, 2000.
  • The Boy Who Dared. New York: Scholastic Press, 2008.

Picture Books

  • Silver at Night. New York: Crown, 1994.
  • Dancing with Dziadziu. San Diego: Harcourt Brace, 1997.
  • The Christmas Promise. New York: Blue Sky Press, 2001.
  • Nobody's Nosier Than a Cat. New York: Hyperion Books for Children, 2003.
  • The Flag Maker: A Story of the Star Spangled Banner. Boston: Houghton Mifflin, 2004.
  • Nobody's Diggier Than a Dog. New York: Hyperion Books for Children, 2005.
  • Naamah and the Ark at Night. Cambridge, MA: Candlewick, 2011.
  • "Biography: Susan Campbell Bartoletti." Scholastic. 4 December 2011. <>.
  • Heller, Steven. "Hitler Youth." New York Times Book Review 14 Aug. 2005: 16.
  • Kohlepp, Peg. "History Unfurled; A Kids' Salute to the Illustrious History of the Red, White, and Blue." Times-Picayune 4 July 2004: 4.
  • "Librarians Find Meat in 'Potatoes'" Lancaster Sunday News 17 Nov. 2002: 6.
  • Myers, Alison Green. Faculty Interview: Susan Campbell Bartoletti. Highlights Foundation. 6 September 2017. 12 July 2018. <>.
  • Susan Campbell Bartoletti. 2010. 4 December 2011 and 12 July 2018. <>.
  • "Susan Campbell Bartoletti." The Gale Literary Databases: Contemporary Authors Online. 8 Oct. 2010. 4 Dec. 2011.