Haiti Cholera Outbreak Largest in Recent Memory

The cholera outbreak in Haiti accounted for 57% of all cholera cases and 45% of cholera deaths reported to the World Health Organization (WHO; Geneva, Switzerland) in 2010 and 2011, according to a new study.

Researchers at the US Centers for Disease Control and Prevention (CDC; Atlanta, GA, USA) reported the findings of the Haitian National Cholera Surveillance System (NCSS) set up in October 2010—nearly 10 months after the devastating earthquake that shattered the country—when Haiti was stricken by epidemic cholera, which has so far sickened more than 600,000 people and killed nearly 7,500. The cholera was possibly inadvertently introduced by troops from Southeast Asia who formed part of the earthquake relief effort, as the strain involved is similar to the one circulating in Asia, and different from those found in Latin America and the USA.

Within 29 days of the first report, cases of Vibrio cholerae (serotype Ogawa, biotype El Tor) were confirmed in all 10 administrative departments in Haiti. Through October 20, 2012, the Haiti Public Health Ministry reported 604,634 cases of infection, 329,697 hospitalizations, and 7,436 deaths from cholera. The ministry isolated V. cholerae O1 from 1,675 of 2,703 stool specimens tested (62%). The cumulative attack rate was 5.1% at the end of the first year, and 6.1% at the end of the second year.

The researchers reported that the cumulative case fatality rate consistently trended downward, reaching 1.2% at the close of year two, with departmental cumulative rates ranging from 0.6% to 4.6%. Within three months after the start of the epidemic, the rolling 14-day case fatality rate was 1% and remained at or below this level with few, brief exceptions. Overall, the cholera epidemic in Haiti accounted for 57% of all cholera cases and 53% of all cholera deaths reported to the WHO in 2010, and 58% of all cholera cases and 37% of all cholera deaths in 2011.

“The earthquake had seriously damaged the country's health care, water and sanitation systems, which had already been precarious; only 63% of Haiti's 9.8 million people had access to an improved drinking water source, just 12% got piped and treated water, and only 17% had adequate sanitation,” concluded lead author Ezra Barzilay, MD, and colleagues of the CDC. “The international goal in a cholera outbreak is a case fatality rate of no more than 1%. That was made more challenging because of these conditions.”

Related Links:
World Health Organization
US Centers for Disease Control and Prevention