By Dady Chery
An article by Dr. Renaud Piarroux and his colleagues from France, Haiti, and the United States combines the epidemiological information about Haiti’s cholera outbreak, together with molecular biology evidence, some of it from the United Nations fact-finding panel and unpublished until now, to make an ironclad scientific case about the UN Nepalese base in Mirebalais being the source of Haiti’s cholera contamination. This is not all. The epidemic is attributed directly to an inadequate medical surveillance of the UN Nepalese troops together with the appalling sanitation at a UN base near Mirebalais.
The article notes that the cholera epidemic that first reached Haiti in October 2010 actually began in Nepal the previous July. During Summer and Fall 2010, Nepal recorded 1,790 cholera cases. This situation was recognized by the World Health Organization, the U.S. Embassy in Kathmandu (Nepal’s capital), and at least one Nepalese newspaper as representing a serious epidemic. Nevertheless, in the midst of this epidemic, the UN brought 1,280 of its Nepalese personnel to Kathmandu for three months of training and then gave them a 10-day leave after this training to go to their homes in Nepal, thus exposing the largest group of South Asians serving in MINUSTAH to cholera before sending them on to Haiti.
Dr. Piarroux and his colleagues believe that the exposure of the troops probably occurred during the 10-day leave, although it could have happened during the three months of training.
The troops received their only medical examinations in Kathmandu before their home leave. They were not examined after their 10-day home leave in Nepal or on arrival in Haiti. Furthermore, the examinations of the troops in Kathmandu after their training appears to have been quite cursory and routine. The medical exams did not include stool tests because, according to the UN, since the exams were negative, no laboratory tests were needed, as was policy.
The cholera-exposed Nepalese soldiers settled into a camp near Mirebalais and two other smaller camps in neighboring towns. Septic wastewater was collected from all three camps and dumped into an open septic pit near the Mirebalais camp, uphill of a river. Local people, including Mirebalais’ Mayor complained formally in a letter to the UN about the seepage of foul-smelling waste fluids downhill into the river but got no response. They, together with journalists documented the leakage from the pipes into the river as well as the disposal of wastes from tanker trucks into the pit near the UN Mirebalais camp. Ultimately even the UN’s own investigative panel of scientists acknowledged that the poor sanitation in the Mirebalais camp had allowed fecal contamination of a river that had been a local source of water for cooking and drinking.
The camps’ medical records were provided only to a set of UN panelists, who reported not finding evidence of cases of severe diarrhea and dehydration in these records. Dr. Piarroux and his colleagues note that
“ [the UN panel] made no mention of mild or moderate diarrhea cases. In addition, no review was made of medical records of Nepalese troops assigned to the two other neighboring camps.”
The UN Panel did conclude that
“the evidence overwhelmingly supports the conclusion that the source of the Haiti cholera outbreak was due to contamination of the Meye Tributary of the Artibonite River with a pathogenic strain of current South Asian type Vibrio cholerae as a result of human activity.”
To which, Piarroux and his colleagues respond:
“We agree, but feel our findings support more specific conclusions.”
Indeed. Haiti’s cholera represents the best studied case so far of an epidemic. The evidence from epidemiological and molecular biological studies is overwhelming, and it all leads directly to the Nepalese troops and the MINUSTAH camps. I summarize below the evidence in the recent paper.
During October 19–24, 2010 a team of Haitian epidemiologists carried out a field investigation in the Mirebalais region, and from November 7–27 a French-Haitian research team traveled to the most affected areas for another field investigation.
The epidemiologists documented what had also been noted by Haitian residents and visiting journalists, namely the MINUSTAH Mirebalais camp’s unsanitary conditions, including a discharge of sewage from a pipe into Meille River water used by local people for cooking and drinking. They pinpointed the first cholera cluster to an area near Mirebalais between October 16 – 19.
The first reports of acute watery diarrhea in a patient came on October 18 from Cuban doctors at the Mirebalais Community Hospital and was followed the same day by 28 new admissions and two deaths. When a Haitian team from the Ministry of Public Health and Population (MSPP) investigated further, they discovered that the first cases had actually occurred on October 14. In other words, the first cholera cases appeared in Haiti five days after the arrival of the first group of Nepalese troops. The research team identified the first hospitalized patients as being a family from Meille village, together with their neighbors (10 other cases on October 19).
Laboratory analyses confirmed that these patients had been infected with Vibrio cholerae O1, serotype Ogawa, biotype El Tor.
After analyzing their data, the French and Haitian researchers wrote,
“Our epidemiologic study provides several additional arguments confirming an importation of cholera in Haiti. There was an exact correlation in time and places between the arrival of a Nepalese battalion from an area experiencing a cholera outbreak and the appearance of the first cases in Meille a few days after. The remoteness of Meille in central Haiti and the absence of report of other incomers make it unlikely that a cholera strain might have been brought there another way.”
Several days after the initial infections from the Meille water, seven communes of the lower Artibonite River simultaneously became contaminated (bottom row, October 20-22). This second wave of infections could not be explained by the movement of people on roads from Mirebalais but was consistent with a propagation of the epidemic via the Artibonite River. A dramatic drop in the cases after two days also suggested the kind of dilution of the cholera that might have occurred in a river. Piarroux and his colleagues have been cautious in interpretating this explosion, but they note that it would be compatible with a massive dumping of choleric waste from a septic tank into the river.
Three alternative approaches have been used to study the cholera in Haiti. All of them could be likened to getting a volume of the complete Shakespeare works and trying to find out if another volume is identical.
1. “Variable-number tandem-repeat” (VNTR) or “multiple-locus VNTR analysis” (MLVA) would be somewhat analogous to searching for a series of short phrases in both volumes to see if they all occur on the same pages, in the same places. This is the least expensive approach.
2. “Partial genome sequencing” is analogous to picking a single page (a gene in this case), or a defined small set of pages and comparing every letter in each of those pages in the two volumes to see if they match. For this kind of analysis, it is good to pick pages that would likely be the most variable ones. One might choose to compare for example, the first few pages of the two volumes of Shakespeare’s works, since the introductions to different volumes tend to differ.
3. “Complete genome sequence typing” (WGST) is equivalent to comparing every letter of every word on every page of both large volumes. This is the most thorough approach and also the most expensive one.
Interestingly, using the first and second approaches a panel of scientists appointed by the UN was first to confirm by molecular genetics that the Haitian and Nepalese cholera were identical, although their results have never been published. In a July 19, 2011 correspondence to Dr. Dong Wook Kim of the International Vaccine Institute in Korea a UN researcher wrote:
“A careful analysis of the MLVA results and the ctxB gene indicated that the [Vibrio cholera] strains isolated in Haiti and Nepal during 2009 [corrected to 2010] were a perfect match.”
In other words, according to the UN researcher, a comparison of Haiti’s cholera to Nepal’s, using approaches 1 and 2 above, discovered the strains to be a perfect match.
Another research group studied the cholera from 24 different Nepalese individuals in five different districts in Nepal and used WGST to compare these cholera to the bacteria from three Haitians. This scientific team found the cholera from one group of Nepalese to be identical to the cholera in the three Haitians to within 1 or 2 base pairs . To continue the analogy: they compared several volumes as large as the complete Shakespeare and found them to be identical except for a 1-2 letter difference.
Piarroux and his colleagues conclude:
“the onset of cholera in Haiti was not due to climatic factors and was not the direct consequence of the January 2010 earthquake. All of the scientific evidence shows that cholera was brought by a contingent of soldiers traveling from a country experiencing a cholera epidemic. Understanding what triggered the epidemic is important for preventing future occurrences, and acknowledges the right of Haitians to understand the events that lead to their cholera devastation.”
According to MSPP, from October 2010 to January, 2012 there were over 526,524 suspected cases of cholera and 7,025 deaths due to the infection in Haiti. So far, the UN has shown no inclination to restore clean water to the country.
1. R. R. Frerichs, P.S. Keim, R. Barrais, and R. Piarroux (2012) Nepalese origin of cholera epidemic in Haiti. Clinical Microbiology and Infection, Vol 18, E158-E163.
Source: Haiti Chery
Copyright © 2012, 2013 by Dady Chery. All rights reserved. Dady Chery is a journalist, playwright, essayist and poet, who writes in English, French and her native Creole. She is the Editor of Haiti Chery and author of We Have Dared to Be Free: Haiti’s Struggle Against Occupation.
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