Cholera clinical presentation

The average incubation period for V. cholerae infection is 1 to 3 days. The clinical presentation can vary from asymptomatic to life-threatening dehydration owing to watery diarrhea. The onset of diarrhea is abrupt and is followed rapidly or sometimes preceded by vomiting. Initial stools generally do not have the rice water appearance that is classically noted with cholera. Fever occurs in less than 5% of patients, and the physical examination correlates weU with the severity of dehydration. In the most severe state, this disease can progress to death in 2 to 4 hours if not treated. In some cases, fluid accumulates within the intestinal lumen causing abdominal distension and ileus and may cause intravascular depletion without diarrhea. Patients may lose up to 1 liter of isotonic fluid every hour. 

B. Clinical Features. Cholera may present as mild diarrhea or as a fulminant disease characterized by profuse watery diarrhea with fluid losses exceeding 5 to 10 liters or more per day. Without... 

Commonly implicated water-borne pathogens include Vibrio cholerae, Cryptosporidium parvum and hepatitis A. The pathophysiology and clinical presentation of these, and numerous other examples, are well described in the wider literature. However, they are also relevant from a biological weapons perspective due to the capacity to cause widespread illness by their intentional release into water supplies. Natural epidemics also occur sporadically throughout the world. Most UK cases are imported by infected travellers. 

Four hundred adults presenting with acute watery diarrhea were entered into a randomized, placebo controlled, double blind clinical trial of berberine, tetracycline, and tetracycline + berberine to study the antisecretory and vibriostatic effects of the alkaloid. Of 18S patients with cholera, those given tetracycline or tetracycline + berberine had considerably reduced volume and frequency of diarrheal stools, duration of diarrhea, and volumes of required intravenous and oral rehydration fluid. Berberine did not produce an antisecretory effect, but analysis by factorial design equations showed a reduction in diarrheal stools by one liter and a reduction in cyclic AMP concentrations in stools by 77% in the groups given berberine. Many fewer patients given tetracycline or tetracycline + berberine excreted vibrios in their stools after 24 hours in comparison with those given berberine alone. Neither tetracycline nor berberine had any benefit over placebo in 215 patients with noncholera diarrhea [219]. 

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