Part II: The public health response
The recipe for the cholera disaster in Haiti involved three key ingredients, said Scott F. Dowell, MD, MPH, during his presentation to infectious diseases (ID) experts at the 49th Annual Meeting of the Infectious Diseases Society of America Sunday in Boston.
The long distances patients have to travel to get care, poor water treatment and sanitation across Haiti, and the fact that the Haitian population hasn’t been exposed to cholera for at least 100 years all contributed to an inability to control the epidemic that has taken already taken the lives of more than 6,600 people.
“Without antibiotic [treatment], diarrhea with cholera lasts up to six days,” said Stephen B Calderwood, MD, of Massachusetts General Hospital. Antibiotics shorten the duration of diarrhea and fluid loss, he said, and the key to treating cholera is getting hydration in, either via oral fluids or IV when dehydration is severe, before the patient goes into shock. Left untreated, the mortality of cholera is quite high, Calderwood said.
Fifty-five percent of the approximately ten million residents of the island nation are living in extreme poverty, and Haiti has the lowest gross domestic product (GDP) in the western hemisphere, Dowell said. Not surprisingly, water treatment and sanitation in the country lags behind most Latin American countries by about 20 years.
Since cholera had not been seen on the island nation for about a century, after the earthquake what is known as a “pre-decision brief” was distributed to the public health system in anticipation of ID outbreaks, that stated “cholera is unlikely to occur… is absent in the Caribbean… (and) if diarrhea deaths occur among adults testing should be done,” Dowell said. They were terribly wrong.
The outbreak started about ten months after the January 2010 quake, and the World Health Organization estimates that since then about 470,000 cases of cholera have occurred in Haiti and more than 6,600 people have died. Public health experts were tasked with responding to a substantial outbreak in poor country ravaged by a recent natural disaster – clinics were overwhelmed, unprepared non-governmental organizations were suddenly performing cholera care, and there were severe supply shortages, Dowell said.
One of the first tasks was to boost national laboratory capacity and function to look at stool cultures for Vibrio Cholerae. That effort has been highly effective. Before the earthquake, one national lab looked at about four culture specimens per month – and now that number has jumped to 180 specimens per month, Dowell said. The labs are also now equipped with rapid testing for cholera.
“Physicians rapidly gained cholera treatment experience, but they still needed guidance,” Dowell said, such as how to staff a night shift, and how to keep up with rapid fluid volume losses.
A study on cholera risk factors conducted in Haiti found that not treating the drinking water was the main risk component. “This has been a critically important message to get out – treat your drinking water,” Dowell said. A mortality study also helped map out the appropriate public health strategy in the country – finding that the mean time from disease onset to community death was 12 hours, meaning treatment had to happen fast. Also helpful in determining a public health strategy, the study found that only 23 percent of those who died drank oral rehydrating solution, and of those who sought medical care, 13 percent died en route, 13 percent died at home after discharge, and 74 percent died at the health facility. Of hospital deaths, more than half died after overnight admission.
So while this has been the largest and most deadly cholera outbreak in recent history, Dowell said, it has also been the best documented – with daily national surveillance, study of origin, and the impact of interventions being studied and monitored. The massive Haitian and international clinical response has also had an overwhelming impact, reducing mortality from three to one percent, and saving more than 7,000 lives, Dowell said.
“Elimination of the threat of epidemic cholera is still possible for Haiti, and the key ingredient for that will be clean, chlorinated water and latrines.”