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Interview With Author Of “Deadly River”---

Officials Accused Of Covering Up The Source Of The Outbreak

French Epidemiologist Anointed As  “Modern Day John Snow”

Ralph Frerichs, well-known UCLA epidemiologist and creator of an extensive website on John Snow, has spent four years writing a book about the introduction of cholera in Haiti and the medical detective work of French epidemiologist Renaud Piarroux. The Epidemiology Monitor first wrote about Frerichs and his involvement with the cholera outbreak back in 2013.

Back then, Frerichs told the Monitor he got “terribly intrigued” by the failure of early investigators to pinpoint conclusively the source of the outbreak. He felt that something was not quite right with the reports he was reading because “I could not believe they could not wrap it up. They were omitting all the basic things and tip-toeing around the findings.”

In 2013, Frerichs was uncertain about whether or not Piarroux was truly a John Snow equivalent. He told us Piarroux was a worthy candidate but he wanted to wait until after the book was finished to decide. His hesitation has now disappeared as he told the Monitor this month, “I am now calling Dr. Renaud Piarroux the ‘modern John Snow’ for his excellent epidemiological manner and skills as described in the book. (See Side by Side Comparison Table in this issue). When he faced the source of the initial outbreak and immediately recognized that the personnel were serving one of the most powerful organizations in the world, he did not flinch.  I was hesitant in case other candidates appeared, but alas, none did.  Piarroux was the man, a worthy hero.” 

We interviewed Frerichs to get his perspective now that the book has been published.

EM:  Deciding to write a book is a big commitment or big decision. What tipped you to decide to write this book?

Frerichs: I first became aware of the Haiti cholera outbreak in October 2010 shortly after it began.  At the time I was still teaching a summer course on epidemiology at UCLA and was looking for interesting outbreak examples to share with my students.  I was initially surprised when epidemiologists and others at CDC and PAHO commented that they were too busy to find the source, and that the origin of what would soon become the world’s largest cholera outbreak might never be identified. Shortly thereafter, I decided to add a section to the John Snow website on the Haitian cholera outbreak, and included comments here and there about news items and related articles. In early November 2010 French epidemiologist Renaud Piarroux arrived in Port-au-Prince, requested by the Haitian government.  In January 2011, I wrote Piarroux in Marseille, having read his consultant report.  We immediately  hit it off.  He shared with me both his findings and correspondences, deepening my interest.  After his seminal article appeared in Emerging Infectious Diseases, we noticed that there was still confusion about how cholera came to Haiti, so we addressed this in an article that summarized the etiological roll of Nepalese peacekeepers of the United Nations.  The story kept getting bigger, and eventually we decided to write a book that covered much more than was possible in a journal article.  While we both labored equally on the book, Piarroux was personally more comfortable having me be the story-teller and him being the main subject. Furthermore, our publisher thought this was the best arrangement.  

EM:  What was the most striking thing you learned in the process of writing the book?

Frerichs: We eventually understood all aspects of how cholera came to Haiti and following an explosive and seemingly simultaneous phase in Artibonite River communities, then spread throughout the country.  Making these discoveries was standard practice for an epidemiologist versed in field and web research, requiring some digging, but nothing too far out of the ordinary. What took more digging was understanding the unusual reactions of UN and CDC officials, adding dark clouds to what should have been a clear-lighted investigation. As smart people misled, the obfuscating paths required major unraveling, presented both in the book and in a supplemental website of visuals at   

EM:   What is a good short statement of your main conclusion after writing the book? 

Frerichs: Outbreak investigations always involve finding out what took place, identifying the source and understanding the disease spread. This information is then used both for control programs and for prevention of future outbreaks.  The cholera outbreak in Haiti was no different.  When investigators were unable or unwilling to identify the source, control programs in Haiti suffered, going in multiple directions without fundamental understanding, lacking total effectiveness. 

EM:  Is this the same as what you consider to be the main message from the book?

Frerichs: I like best a passage from the book’s introduction.

“What this book offers is an in-depth portrait of how scientific investigation is  conducted when it is done right. It explores a quest for scientific truth and dissects a scientific disagreement involving world-renowned cholera experts who find themselves embroiled in turmoil in a poverty-stricken country. It describes the impact of political maneuvering by powerful organizations such as the United Nations and its peacekeeping troops in Haiti, as well as by the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC). In so doing, it raises issues about how the world’s wealthy nations and international institutions respond when their interests clash with the needs of the world’s most vulnerable people. In an era when there is more focus than ever before on global and population health, the story poses critical questions and offers insights not only about how to eliminate cholera in Haiti but about how nations and international organizations such as the UN, WHO, and CDC deal with deadly emerging infectious diseases.”

EM: Has the link to the Nepalese peacekeepers been conclusively established beyond a shadow of a doubt? If not, how would you describe the strength of the evidence pointing to them as the source?

Frerichs: Much of the evidence was presented in Piarroux’s first article in Emerging Infectious Diseases (1) and in the molecular article of Hendriksen et al in MBio (2). The recent work of others and additional map graphics were added and summarized in Clinical Microbiology and Infection strengthening the case all the more (3). These three articles provided sufficient evidence of Nepalese peacekeepers as the source for most scientific readers, leaving only a few diehard skeptics.  

The origin evidence is now established beyond a shadow of a doubt, at least in my eyes.  Keep in mind, however, that the evidence we presented has not, and likely will not, be presented in a court of law or face a trial by jury.  Instead, the evidence in its totality is there for reputable scientists to consider.  Neither Piarroux nor I have heard any plausible alternative explanations, and doubt that any will be forthcoming, at least not ones that will stand the test of scientific evidentiary scrutiny.   

EM: What are the main reasons why you think epidemiologists will enjoy or benefit from reading the book. 

Frerichs: What is not to like when you have a good medical detective story with flawed agencies and a dramatic power imbalance, presented in an exotic setting; a French epidemiologist of high character, courage and grit; and a coverup by unlikely persons and organizations who imply they are following a higher good, but instead are deluding the very people they purport to help, thereby diminishing themselves and losing trust?  

I have had quite a literary journey with this book, now going on for five years.  I hope your readers will find it of interest and value the contents, including of course the website with visuals where the damning evidence is made more plain at:  and at the

Cornell University Press website

(1) Piarroux, Renaud, Robert Barrais, Benoît Faucher, Rachel Haus, Martine Piarroux, Jean Gaudart, Roc Magloire, and Didier Raoult. “Understanding the Cholera Epidemic, Haiti.” Emerging Infectious Diseases 17, no. 7 (2011): 1161–68

(2) Hendriksen, Rene S., Lance B. Price, James M. Schupp, John D. Gillece, Rolf S. Kaas, David M. Engelthaler, Valeria Bortolaia, Talima Pearson, Andrew E. Waters, Bishnu Prasa Upadhyay, Sirjana Devi Shrestha, Shailaja Adhikari, Geeta Shakya, Paul S. Keim and Frank M. Aarestrup. “Population Genetics of Vibrio cholerae from Nepal in 2010: Evidence on the Origin of the Haitian Outbreak.” MBio 2, no. 4 (2011): e00157-11. 

(3) (Frerichs, Ralph R., Paul S. Keim, Robert Barrais, and Renaud Piarroux. “Nepalese Origin of Cholera Epidemic in Haiti.” Clinical Microbiology and Infection 18, no. 6 (2012): E158–163.) 

Expert  Anoints Shoe-Leather French Epidemiologist As
The Modern Day John Snow


John Snow

Renaud Piarroux

Cholera origin theories
  Miasma and germ theories Environmental and human activity theories
Occupation and avocation
  Physician, working as an anesthesiologist; in his spare time, studied and researched cholera and cholera epidemics Physician with PhD in microbiology and cellular biology, working as parasitologist and mycologist; in his spare time, studied and researched cholera and cholera epidemics
Personal characteristics
  Never married, aged 41 in 1854; strong iconoclastic character willing to challenge prevailing cholera theory; exhibited intelligence, creativity, courage, resolve and ability to work with others. Married with three children, aged 50 in 2010; strong iconoclastic character willing to challenge prevailing cholera theory; exhibited intelligence, creativity, courage, resolve and ability to work with others.
Early interest in cholera
  During his apprentice years, Snow in 1831 was sent to provide medical assistance in Killingworth where the miners from the local colliery and their families were victims of a deadly cholera outbreak. While volunteering in 1994 with Médecins du Monde to provide pediatric care in a refugee camp in Goma, Zaire (later DR Congo), Piarroux encountered a massive cholera epidemic, causing tens of thousands of deaths in a six-week span.  
Research publications on cholera
  Published widely, including: Snow, John. On the mode of communication of cholera. 2nd edition, much enlarged. London, J. Churchill, 1855, 162 pp; and Snow, John. On the outbreak of cholera at Abbey-Row, West Ham. Med. Times and Gazette, n. s. vol. 15, Oct. 24, 1857, pp. 417-419. Published widely, including: Piarroux, Renaud et al. Understanding the Cholera Epidemic, Haiti. Emerging Infectious Diseases 17, no. 7 (2011): 1161–68; and Piarroux, Renaud, and Benoît Faucher. Cholera Epidemics in 2010: Respective Roles

of Environment, Strain Changes, and Human-Driven Dissemination. Clinical

Microbiology and Infection 18, no. 3 (2012): 231–38.

Effective use of maps
  Used spot map derived from government mortality statistics to focus on the Broad Street neighborhood pump as the

likely source of a cholera outbreak

Used spot maps and spatial-temporal statistical software with data derived from commune-specific surveillance program to focus on the Nepalese UN camp as the likely source of the cholera outbreak
Research on cholera control
  Lobbied to remove handle from Broad Street pump; researched delivery of household water from River Thames, with input above and within tidal region of resident-polluted river.  Lobbied to establish commune-specific cholera reporting system that used computer-generated local maps to guide control efforts; conducted research on cholera elimination strategy based on local search and containment of cholera cases during dry season.
Immediate versus longer-term goals
  Favored immediate cholera control rather than wait for social and sanitary reform as a grand goal. Favored immediate cholera elimination rather than wait for national water and sanitation program, or continuing mass-immunization program, both only partially funded by international agencies.


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