domingo, 8 de mayo de 2011

Understanding the cholera epidemic, Haiti. Emerg Infect Dis. 2011 Jul

Suggested citation for this article: Piarroux R, Barrais R, Faucher B, Haus R, Piarroux M, Gaudart J, et al. Understanding the cholera epidemic, Haiti. Emerg Infect Dis. 2011 Jul; [Epub ahead of print]
Understanding the Cholera Epidemic, Haiti






Renaud Piarroux, Robert Barrais, Benoît Faucher, Rachel Haus, Martine Piarroux, Jean Gaudart, Roc Magloire, and Didier Raoult

Author affiliations: Université de la Méditerranée, Marseilles, France (R. Piarroux, B. Faucher, J. Gaudart, D. Raoult); Ministère de la Santé Publique et de la Population, Port-au-Prince, Haiti (R. Barrais, R. Magloire); Service de Santé des Armées, Paris, France (R. Haus); and Martine Piarroux Université de Franche-Comté, Besançon, France (M. Piarroux)


After onset of the cholera epidemic in Haiti in mid-October 2010, a team of researchers from France and Haiti implemented field investigations and built a database of daily cases to facilitate identification of communes most affected. Several models were used to identify spatio-temporal clusters, assess relative risk associated with the epidemic’s spread, and investigate causes of its rapid expansion in Artibonite Department. Spatio-temporal analyses highlighted 5 significant clusters (p<0.001): 1 near Mirebalais (October 16–19) next to a United Nations camp with deficient sanitation, 1 along the Artibonite River (October 20–28), and 3 caused by the centrifugal epidemic spread during November. The regression model indicated that cholera more severely affected communes in the coastal plain (risk ratio = 4.91) along the Artibonite River downstream of Mirebalais (risk ratio = 4.60). Our findings strongly suggest that contamination of the Artibonite and 1 of its tributaries downstream from a military camp triggered the epidemic. On October 21, 2010, the Haitian Ministry of Public Health and Population (MSPP) reported a cholera epidemic caused by Vibrio cholerae O1, serotype Ogawa, biotype El Tor (1). This epidemic was surprising as no cholera outbreak had been reported in Haiti for more than a century (1,2). Numerous media rapidly related the epidemic to the deadly earthquake that Haiti had experienced 9 months earlier. However, simultaneously, a rumor held recently incoming Nepalese soldiers responsible for importing cholera, along with accusations of illegal dumping of waste tank contents (3). A cholera outbreak was indeed reported in Nepal’s capital city of... full-text: 16 pages http://www.cdc.gov/eid/content/17/7/pdfs/11-0059.pdf?source=govdelivery




Suggested citation for this article: Dowell SF, Braden CR. Implications of the introduction of cholera to Haiti. Emerg Infect Dis. 2011 Jul; [Epub ahead of print]

Implications of the Introduction of Cholera to Haiti
Scott F. Dowell and Christopher R. Braden


Author affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, USA

With more than 250,000 cases and 4,000 deaths in the first 6 months, the cholera epidemic in Haiti has been one of the most explosive and deadly in recent history. It is also one of the best documented, with detailed surveillance information available from the beginning of the epidemic, which allowed its spread to all parts of the country to be traced. Piarroux et al. make good use of this information, along with their own careful field investigations, to trace the epidemic to its beginning and propose an explanation for its origins (1).

Multiple lines of evidence indicate that Vibrio cholerae was newly introduced into Haiti. Cholera had not been documented in Haiti for at least several generations. Although there was a reference to a small number of “cholera” cases during the American occupation in 1928 (2), there was no culture confirmation, and the likelihood is these represented cases of severe diarrhea caused by other pathogens. In the current situation, 14 V. cholerae isolates from the Artibonite Department early in the epidemic were indistinguishable by multiple phenotypic and molecular characterization methods, which indicated the infections were due to a single clone of V. cholerae introduced into Haiti in 1 event (3). Piarroux et al. present strong evidence that the earliest cases of cholera occurred in the upper Artibonite valley, near the town of Mirebalais. Within days of the Mirebalais cases, hundreds of additional cases were reported in the lower Artibonite valley, more than 50 km away, and over the next 2 days in neighboring departments outside the Artibonite valley. This rapid spread is characteristic of cholera transmission in a mobile, immunologically naive population with widespread exposure to sewage-contaminated drinking water. The mobility of the population ensured transmission of the pathogen to all 10 departments of Haiti within weeks, and the uniformly poor water and sanitation infrastructure...

full-text: 4 pages
http://www.cdc.gov/eid/content/17/7/pdfs/11-0625.pdf?source=govdelivery

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