Special Feature

Oral Rehydration Therapy Shows Effectiveness in Controlling Cholera in Haiti

By Stan Deresinski, MD, FACP, Clinical Professor of Medicine, Stanford, Associate Chief of Infectious Diseases, Santa Clara Valley Medical Center, is Editor for Infectious Disease Alert.

In 1854, London was rocked by a cholera epidemic that killed approximately 10,000 people. Using what are now considered classical epidemiological methods, Dr. John Snow traced the source of at least 500 of the infections to a single water pump at Broad Street, validating his theory that cholera was a water-borne disease 29 years before the etiologic agent was discovered by Robert Koch; removing the pump handle stopped the outbreak in that area. Although this demonstration provided all humans needed to know to prevent future cases of cholera, there have been four pandemics since that time, with the last one (the 7th pandemic) one still ongoing. A minor variant of the strain of Vibrio cholerae, responsible for the current pandemic, caused a Western Hemisphere outbreak that began in 1991 in Peru and spread across Central and South America. Through at least the last century, however, no cases of cholera had occurred in Haiti — until now.

A posting on a blog from the Hôpital Albert Schweitzer in the Artibonite valley on October 20, 2010, described the first evidence of the epidemic:1,2

"During the day yesterday [i.e., October 19], reports came in to us at HAS that there was a suspected outbreak of severe diarrhea and vomiting, with most of the cases in the Artibonite region. By the late afternoon, HAS began to accept an influx of such cases, all with similar symptoms, and we reviewed charts from Monday and Sunday [i.e., October 17-18] to identify possible earlier cases. A total of 30 patients had been received by the middle of the night on Wednesday [i.e., October 20], mostly adults and primarily male. The patients came from localities near the Artibonite River, and many reported that they had drunk water from the river. The regional director. . . came to HAS and reported that there were many cases in Petite Riviere (i.e., in the mid-artibonite valley, down river from Mirebalais). HAS staff, who had been to the hospital in St. Marc [i.e., coastal community near the termination of the Artibonite river], reported that there was a large crowd outside the hospital, with an estimated 60 patients there."

The outbreak in Haiti was officially confirmed on October 21, 2010, and, as of December 3, 2010, 91,770 cases were reported, with almost one-half having been hospitalized and 2,071 (2.3%) having died. Almost one-half of all cases were reported from Artibonie Department, where the epidemic started, although this aread accounts for only 16% of the population of Haiti. Almost half the deaths in that Department occurred in the community and, among these, the median interval from onset of symptoms to death was 12 hours, with one individual reported to have died only two hours after onset. Only approximately one-fourth of those who died in the community received oral rehydration therapy, which is highly effective if initiated early enough. The implicated strain is a hybrid of the El Tor biotype and the classic toxin type, with the former being associated with longer environmental persistence and the latter possibly with more severe disease. Some evidence suggests that the strain originated in Nepal.

The key to the control of cholera is largely the same as it was in the time of John Snow — provision of safe drinking water and improved hygiene. In addition, WHO and PAHO are considering the use of cholera vaccination in Haiti.3 Two such vaccines are available — Dukoral and Shanchol —and their value in the current circumstance is being debated.

References

  1. Rawson I. Blogger Post, Hôpital Albert Schweitzer Haiti, October 20, 2010.
  2. Frerichs RR. Cholera in Haiti and the modern "John Snow". http://www.ph.ucla.edu/epi/snow/cholera_haiti.html
  3. McNeil DG Jr. Use of cholera vaccine in Haiti is now viewed as viable. http://www.nytimes.com/2010/12/11/world/americas/11cholera.html?partner=rss&emc=rss