Patient Profile:
F.N. is a 69-year-old gentleman who has a history of end stage renal disease secondary to hypertensive nephrosclerosis. He started outpatient peritoneal dialysis in March 1997, and switched to hemodialysis in February 1998 due to pseudomonas peritonitis. His past medical history is significant for ischemic cardiomyopathy, COPD anemia, GERD, BPH, and gout. Mr. N. was born in India, moved to the United States in 1988, and speaks minimal English.

F.N. left for a 2-month vacation in India on 1/7/05 and returned to the United States on 3/6/05. He presented to the outpatient dialysis center on 3/7/05 and appeared to be stable with no complaints. He returned for outpatient hemodialysis on 3/9/05 and complained of nausea, vomiting, diarrhea, and chills. He was afebrile at the dialysis center. Blood pressures pre- and postdialyses were normal. Blood cultures were drawn and his white blood count was mildly elevated at 13.2. He was seen by the nephrologist rounding at the center and was instructed to take Imodium and Compazine as needed for presumed gastroenteritis. An outpatient chest x-ray was negative for acute disease. The following day F.N. was still symptomatic with diarrhea and abdominal cramping and was seen in the nephrology office on 3/10/05. A stool culture was sent to the lab on 3/11/05. He was still complaining of diarrhea on 3/14/05, and he was started on Flagyl 250 mg p.o. three times a day and Questran 1 package p.o. twice a day, standard treatment for suspected c-dificile colitis.

On 3/14/05 F.N.’s family and the nephrology office were notified that the stool culture was positive for Shigella flexneri. The Flagyl and Questran were stopped and Ciprofloxacin 500 mg p.o. daily for 5 days was prescribed on 3/15/05. F.N. was instructed on extra handwashing and the need to clean high touch areas at home. The outpatient dialysis center was also notified of the culture results and need for aggressive handwashing.

1. The current episode of acute diarrhea will resolve with proper therapy.
   
2. The patient will tolerate outpatient pharmacologic treatment.
   

Discussion:
Shigella gastroenteritis is an enteric bacterial infection more common in developing countries. Fever is usually present at the time of diagnosis. Shigella transmission can occur from contaminated food or water or through direct person-to-person spread, and the mode of transmission may vary depending on the geographic region. Shigella outbreaks have been associated with swimming pools and day care participation. Children with documented Shigella should be excluded from day care until negative stool cultures are obtained (Reisdorff & Pflug, 2004). Strict hand washing is key, and infected children should be separated from non-infected children. Foodborne transmission (with cold salads) has also been recognized. In the developing world, inadequate sewage disposal has lead to an increase in Shigella transmission (Ahmed, Clemens, Ansaruzzaman & Haque, 1997). The infection is usually self-limited and, if untreated, the disease averages 7 days in length (Maurelli & Lampel, 1995). A stool culture is necessary to confirm the diagnosis (Harris, Dupont, & Hornick, 1972).

Antibiotics have been shown to reduce the duration of fever and diarrhea to approximately 2 days (Dupont, 1995). Shigella usually affects the gastrointestinal tract but can lead to bacteremia (Struelens et al., 1985). Drugs of choice are third-generation cephalosporins and fluroquinolones (Reisdorff & Pflug, 2004). Azithromycin has also been used with success; however, resistance to ampicillin and Bactrim is increasing (Braunwald et al., 2002).

Most cases of acute diarrhea are presumed to be of viral origin since a pathogen can be detected in only 2%-6% of cases. The average incidence of confirmed shigella infection in the United States from 1986-1996 was 11 cases per 100,000 population, but these rates may be underestimates since many patients do not see their medical provider or have a stool culture (Preliminary FoodNet Data, 2004). High fever, abdominal cramps and diarrhea usually characterize shigella gastroenteritis. Stools are typically small in volume, mucoid, and bloody (Acheson & Keusch, 1995).

In F.N.’s case, the intended patient outcomes were met and he was able to avoid being hospitalized. He completed the prescribed 5-day course of Cipro and reported at dialysis on 3/18/05 that his diarrhea had resolved and he was feeling well. Interestingly, his wife did not develop Shigella gastroenteritis and no other contacts, either at home or in the dialysis facility, became ill.

Summary
The clue to this patient’s correct diagnosis was his recent return from India. He usually visits there on an annual basis and the occurrence of posttravel infection has been noted in his medical records.

This case study shows the importance of assessing patients for fever, abdominal cramps and diarrhea after recent travel outside of the United States. Shigella gastroenteritis should be in the differential diagnosis for patients with the above clinical presentation. The keys for diagnosis and prompt treatment of this disorder are to obtain the history, recognize symptoms, and order stool cultures.

References

Acheson, D.W., & Keusch, G.T. (1995). Shigella and enteroinvasive escherichia coli. In M. J. Blaser, P. D. Smith, J. I. Ravdin, H.B. Greenberg, & R. L. Guerrant (Eds.), Infections of the gastrointestinal tract. (p. 765). New York: Raven Press.

Ahmed, F., Clemens, J.D., Ansaruzzaman, M., & Haque, E. (1997). Epidemiology of shigellosis among children exposed to cases of shigella dysentery: A multivariate assessment. American Journal of Tropical Medicine Hygiene, 56, 258.

Braunwald, E., Faucim, A.S., Kasper, D.L., Hauser, S.L., Longo, D.L., & Jameson, J.L. (2002). Infectious diarrhea. In Harrison’s Manual of Medicine, (15th ed.) (p. 359). New York: McGraw-Hill.

Dupont, H.L. (1995). Shigella species. In G.L Mandell, J.E Bennett, & R. Dolin (Eds.), Principles and practice of infectious diseases, (4th ed.). New York: Churchill Livingstone.

Harris, J.C., Dupont, H.L., & Hornick, R.B. (1972). Fecal leukocytes in diarrheal illness. Annals of Internal Medicine, 76, 697.

Maurelli, A.T., & Lampel, K.A. (1995). Shigella. In Y.H. Hui, J.R. Gorham, K.D. Murrell, & D.O. Cliver (Eds.), Foodborne disease handbook (p.321). New York: Marcel Dekker.

Preliminary FoodNet Data On The Incidence Of Infection With Pathogens Transmitted Commonly Through Food-Selected Sites, United States 2003. (2004, April 30). Morbidity and Mortality Weekly Report, pp. 338-343.

Reisdorff, E.J., & Pflug, V.J. (2004) Infectious diarrhea. In G. Bosker (Ed.), Textbook of primary and acute care medicine (2nd ed.) (p.1151). Atlanta, GA: Thompson American Health Consultants.

Struelens, M.J., Patte, D., Kabir, I., Salam, A., Nath, S.K., & Butler, T. (1985). Shigella septicemia: Prevalence, presentation, risk factors, and outcome. Journal of Infectious Disease, 152, 784.