Clinical Applications

The Case of the Missionary Health Care Worker in Africa

Jenny, a twenty-two year old college graduate, has recently decided to spend two years as a missionary in a coastal African village. As part of her duties, she will work in the missionary clinic that has recently been established in the village. This clinic will provide routine medical care and a travelling physician and nurse will visit once each week. Jenny feels fortunate to have the opportunity to use the information that was presented to her in various classes she completed while in college. After completing a 4-month intensive training period (language classes, medical preparation for work in the clinic, and cultural enrichment), she departed for Africa.

Upon her arrival, Jenny found that she would be spending most of her time in the clinic since the village had been without routine medical care for the past 2 years. The previous clinic was closed due to flooding and insufficient funds to rebuild. Initially, Jenny found that she was very dependent upon the physician’s weekly visits since her training was limited. Gradually, she found that she was beginning to call upon her training (both clinical and classroom) and she felt comfortable diagnosing and treating some of the more routine cases. One morning, a mother came in with her five-year-old child. The mother reported that the child had been unable to eat or drink anything for the past day because of vomiting. In addition, her child was experiencing severe diarrhea. Jenny asked the mother if any other family members were exhibiting similar symptoms, to which the mother replied that a few other members of the family had similar symptoms, however, not as severe. Jenny’s first thought was that the symptoms were very similar to those she had exhibited following a bout of food poisoning while in college. Since the villagers had no refrigeration and poor sanitation, Jenny gave the mother an electrolyte solution containing glucose similar to Gatorade® and told the mother to have the affected children consume this solution and nothing else for the next 24 hours. After that time, if the children were no longer vomiting, she could start feeding them tea and broth. Jenny also cautioned the mother that if the children did not seem to be getting better after 24 hours to bring the children back to the clinic.

The next morning Jenny opened the clinic to find the mother, and not just the child she had seen the previous day, but three more of the woman’s children. All of the children were exhibiting similar symptoms that now included muscle cramping and excessive thirst in addition to diarrhea and vomiting. When checking the vital signs of the children, Jenny noticed increases in both the pulse and respiratory rates accompanied by decreased blood pressures. Uncertain as to the appropriate course of action, Jenny contacted the physician by radio. Upon conveying the histories and information to the physician, Jenny received instructions to keep the children at the clinic, start intravenous (IV) infusion with lactated Ringer’s solution, and allow the children to drink as much of the electrolyte solution with glucose as they would like. The physician also gave Jenny a list of laboratory tests to run on the blood, urine and stool samples that she should collect. Jenny started the IV infusions and gave each child some of the electrolyte solution. After this, she obtained stool, blood and urine samples from each child and asked the mother to leave the children with her for care and observation. The mother agreed and said she would return later that night to help with the children.

The results of the tests run indicated severe metabolic acidosis, an increased hematocrit, hypokalemia, and the presence of Vibrio cholerae bacteria in the stool samples. Based on the results of these tests, the physician and Jenny diagnosed the children with cholera and obtained a more detailed history in an attempt to determine whether these individuals were the only ones exposed or whether these cases were the first of a possible epidemic. Jenny and the physician found that the family had recently visited relatives in a distant village where similar symptoms had been present in a number of families that had all celebrated a recent shellfish harvest.

The physician prescribed continued IV infusions with lactated Ringer’s solution and electrolyte fluid replacement by mouth. The children were not allowed to consume other foods or drinks, especially coffee or any other beverages containing caffeine. The children were also told that once the vomiting stopped they could start consuming solid foods. The children were all treated with antibiotics and stool samples were taken from other family members to determine whether or not they were infected with Vibrio cholerae. Infected, asymptomatic individuals were treated with antibiotics. The physician later explained to Jenny that caffeine was prohibited because the toxin produced by the bacteria (termed choleragen) binds to the surface of the epithelial cells of the small intestine and activates adenylate cyclase. In addition, the toxin interferes with the active transport of sodium ions in the intestinal lumen.

1		Why did Jenny initially suspect that the child and the other family members were experiencing food poisoning?
2		Why did Jenny initially prescribe an electrolyte solution containing glucose?
3		Upon further evaluation on the second day why would the children present with an increased pulse and respiratory rate but a decreased blood pressure?
4		Why did the children present with metabolic acidosis?
5		Why were the children experiencing muscle cramping and complaining of excessive thirst on the second day?
6		Why were the children not allowed to consume any caffeine containing beverages?
7		Why does the effect of the cholera toxin on the epithelial sodium transport protein contribute to both the diarrhea and metabolic acidosis?