Question

Case Study - Cholera A 25 year old woman is brought into a clinic in Bangladesh during the monsoon season. She is almost comatose, her pulse is weak and she is experiencing tachycardia. She has severe diarrhea, and is producing watery stool at a rate of 950 ml/hr. Her skin appears shriveled, and when a fold of skin is pinched it remains so for several minutes. Microscopic examination of the patient’s stool reveals the presence of a large number of Vibrio cholerae bacteria. The patient cannot drink, so intravenous isotonic NaCl is administered. When the patient is conscious, she is given an oral rehydration solution to drink. It contains NaCl, KCl, NaHCO3 and glucose. After 5 days she is sufficiently recovered to leave the hospital.

1. How did she most likely encounter the bacteria?

2. Why does she exhibit weak pulse and tachycardia? Why is she almost comatose?

3. How did the cholera toxin enter the cells and how did it affect intracellular signal transduction pathways and membrane transport.

4. How do intravenous fluids immediately improve the patient’s condition? Why isotonic NaCl?

5. What is the rationale for the ingredients in the oral rehydration solution?

6. Why does the patient recover in 5 days with this treatment and without antibiotics?

Answer 1

Answer 1:

She has most likely encountered the bacteria Vibrio Cholerae through fecal oral route. She might have taken contaminated food or water which has lead to this condition of her.

Answer 2:

Since she is having severe diarrhoea with watery stool, she is continuously loosing water and electrolytes from the body which has caused dehydration. The excessive loss of water from the body has caused the blood volume to reduce which has lead to hypovolemia. The reduced blood volume has caused reduction in blood pressure. Hence, all of these has lead to weak pulse, tachycardia and an almost comatose condition because if she is left untreated then she might lead into shock or even die.