An estimated 2,000 people in the Artibonite region have been struck by a killer diarrhea epidemic caused by Cholera Vibrio. Like the other islands in the Caribbean, during the past 100 years, Haiti has been sheltered from this disease. The world is known to have gone through seven cholera pandemics. The last one struck Asia in 1961, then Africa in 1970, and arrived to the Americas in 1991 where it spread from Peru and infected one million people in South America between 1991-1993, killing one percent of those affected. At the onset of the epidemic in Latin America, 30% of affected people died. As knowledge of the disease became more widespread, the mortality dropped to 1%. The medical community became more aware of the rapid and vigorous rehydration needed to save the lives of affected people.
Usually people get cholera from ingesting sewage or from eating or drinking food or water infected with cholera containing feces. Cholera lives at the mouth of rivers where the oceanic tides brings salt into the river. The bacteria, Cholera Vibrio, needs a high concentration of salt for its biological functions. It replicates best when the water temperature is greater than 20 degree Celcius. It usually strikes in the summer or fall. The incubation period or the time from ingestion of the bacteria to disease symptoms is 24 to 48 hours. Once ingested, the bacteria are usually killed by the acid in one’s stomach. However, if the bolus ingested is sufficiently large, then some make it past the stomach into the intestines where they invade the intestinal wall and cause the body’s salt to accumulate in the intestine’s lumen. The accumulated salt pulls a large volume of water out of the body into the intestines. The accumulated water in the intestines produces a watery diarrhea in which the victim can lose more than 250cc /kg of stool within the first 24 hours. This large volume loss can cause palpitations, sunken eyes, hypotension, coma and eventually death. Death usually occurs when the volume loss exceeds 10% of total body weight. To survive the infection as fluid is being lost through the diarrhea, an equal volume of fluid has to be replaced rapidly either orally or intravenously.
The seventh Cholera pandemic did not affect the Caribbean until now. The strain causing the disease has to be studied to know whether it is a new strain or one of the virulent ones that became endemic in various parts of the world. Before this episode, cholera was not known to have occurred in Haiti during the past one hundred years. Haitian adults have no immunity against it. This makes people of all ages in Haiti susceptible to the infection. Anyone can get the infection, but people with blood type O are even more susceptible.
The key to surviving the infection is prompt recognition of the symptoms. Cholera causes a non-bloody, watery diarrhea without fever. It rarely causes vomiting. The World Health Organization has released salt tablets with a bit of sugar to add to clean water to orally replace the water and electrolytes lost from the diarrhea. In the absence of these salted tablets, people can prepare their own rehydration fluid by adding ½ teaspoon of salt and 6 level teaspoons of sugar in 5 cups of clean water. Again, it is crucial that an equal volume of water lost in the diarrhea be replaced rapidly to avoid death. While fluid is being replaced, the patient can continue to eat a regular diet and young children can continue to breastfeed. By eating or by breastfeeding, the body is able to replenish other elements like potassium and bicarbonate lost in the diarrhea. Antibiotics like doxycycline, tetracycline, azithromycin, erythromycin, or ciprofloxacin are among the medications that can reduce the duration of the infection. Nonetheless, the mainstay of therapy is aggressive fluid replacement. In the absence of salt and sugar, plain clean water can be lifesaving as well.
Given the potential severity of the infection, preventive measures are crucial. Efforts to control its spread depend heavily on understanding how the infection is acquired and how it spreads. It is vital that people only use clean water for drinking and cooking. Cholera is not heat resistant, so it is destroyed when food is cooked until well done. Frequent hand washing with soap helps to prevent human to human transmission. It is vital that people have adequate feces disposal. The most common source of cholera epidemic is the ingestion of foods or water contaminated with sewage. For this reason, the infection is more likely after rainstorms and floods.
Like other regions affected by cholera, Haiti can combat the infection by providing rapid rehydration to those affected and by educating the population on preventive measures. According to the CDC, “the most effective measures to prevent transmission of acute watery diarrhea are provision of safe (chlorinated) water; safe water storage; appropriate disposal of feces; and hand washing with soap after caring for patients, toileting, cleaning other persons after toileting, or before preparing, serving, or eating food”.
References:
CDC: Acute watery diarrhea and cholera: Haiti pre-decision brief for public health action. March 2, 2010
World Health Organization website essays on cholera, visited on 10/22/2010
Griffith and colleagues: Review of reported cholera outbreaks worldwide, 1995-2005. Am Jour Trop Med Hyg 75 (5) 2006, pp 973-977
Harrison’s Internal Medicine 14th Edition
Posted on 10/25/2010
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