Cholera Disease Research Report
Karla Obasi
HEA 341
Disease Research Report
December 9, 2010
CHOLERA
Disease Defined Cholera is an infection of the small intestine that causes a large amount of watery diarrhea. Cholera is a bacterial disease (caused by the bacterium Vibrio cholerae) usually spread through contaminated water. The bacteria, which are found in fecal-contaminated food and water and in raw or undercooked seafood, produce a toxin that affects the intestines causing diarrhea, vomiting, and severe fluid and electrolyte loss. This overwhelming dehydration is the outstanding characteristic of the disease and is the main cause of death. Cholera has a short incubation period (two or three days) and runs a quick course. In untreated cases the death rate is high, averaging 50%, and as high as 90% in epidemics, but with effective treatment the death rate is less than 1%.
Historical Perspective During 1883, cholera was epidemic in Egypt. A German physician and bacteriologist, Robert Koch traveled with a group of German colleagues from Berlin to Alexandria, Egypt in August, 1883. Following necropsies, they found a bacillus in the intestinal mucosa in persons who died of cholera, but not of other diseases. He reasoned that the bacillus was related to the cholera process, but was not sure if it was causal or consequential. He stipulated that the time sequence could only be resolved by isolating the organism, growing it in pure culture, and reproducing a similar disease in animals. He was not able to obtain such a pure culture, but did try to infect animals with choleraic material. None became infected. His thoughts and early findings were sent in a dispatch to the German government and shared with the German press. On January 7th 1884, Koch announced in a dispatch that he had successfully isolated the bacillus in pure culture. One month later he wrote again, stating that the bacillus was not straight like other bacilli, but "a little bent, like a comma." He also noted that the
HEA 341
Disease Research Report
December 9, 2010
CHOLERA
Disease Defined Cholera is an infection of the small intestine that causes a large amount of watery diarrhea. Cholera is a bacterial disease (caused by the bacterium Vibrio cholerae) usually spread through contaminated water. The bacteria, which are found in fecal-contaminated food and water and in raw or undercooked seafood, produce a toxin that affects the intestines causing diarrhea, vomiting, and severe fluid and electrolyte loss. This overwhelming dehydration is the outstanding characteristic of the disease and is the main cause of death. Cholera has a short incubation period (two or three days) and runs a quick course. In untreated cases the death rate is high, averaging 50%, and as high as 90% in epidemics, but with effective treatment the death rate is less than 1%.
Historical Perspective During 1883, cholera was epidemic in Egypt. A German physician and bacteriologist, Robert Koch traveled with a group of German colleagues from Berlin to Alexandria, Egypt in August, 1883. Following necropsies, they found a bacillus in the intestinal mucosa in persons who died of cholera, but not of other diseases. He reasoned that the bacillus was related to the cholera process, but was not sure if it was causal or consequential. He stipulated that the time sequence could only be resolved by isolating the organism, growing it in pure culture, and reproducing a similar disease in animals. He was not able to obtain such a pure culture, but did try to infect animals with choleraic material. None became infected. His thoughts and early findings were sent in a dispatch to the German government and shared with the German press. On January 7th 1884, Koch announced in a dispatch that he had successfully isolated the bacillus in pure culture. One month later he wrote again, stating that the bacillus was not straight like other bacilli, but "a little bent, like a comma." He also noted that the
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