DIAGN MICROBIOLINFECTDIS 1992;15:161-164

161

The Fortuitous Diagnosis of Cholera in a Two-Year-Old Girl Jeremy D. Gradon, Larry I. Lutwick, Roomi Chavda, and Michael Levi

We are reporting the fortuitous diagnosis of a case of cholera and the unusual failure of the commercial bacteriologic media that led to the unexpected isolation of Vibrio cholerae. The case demonstrates the need for communication between the

medical staff and laboratory personnel when an uncommon disease, such as cholera, is suspected. This case also alerts the clinician to the possibility of multiple enteric pathogens coinfecting a traveller.

INTRODUCTION

formed stool for which she was given local "overthe-counter" antibiotics including trimethoprimsulfamethoxazole (SXT) and tetracycline with resolution of her symptoms. None of her close contacts had significant diarrhea. On the airplane back to New York (7 July 1990), severe diarrhea developed, and immediately upon disembarking she was brought to the emergency room. She was a dehydrated child with sunken eyes and dry mucous membranes who passed multiple clear liquid stools. Her white cell count was 13,000/mm 3 (70% polymorphonuclear leukocytes, 10% bands, and 20% lymphocytes), potassium 1.9 meq/dl, bicarbonate 13 meq/dl, and glucose of 90 mg/dl. Stool microscopy showed no white or red blood cells. Inadvertently, no travel history or patient information was provided on the slip that accompanied the stool specimen to the microbiology laboratory. As a consequence, the stool was plated onto all the routine plates, but not onto specific media for the isolation of Vibrio cholerae. The patient was begun on intravenous fluid replacement and potassium supplementation. Two days after submission of the stool specimen, the microbiology laboratory presumptively identified a stool isolate as V. cholerae. The organism was resistant to ampicillin and SXT. Blood and urine cultures were negative. The patient made an uneventful recovery and was discharged on 14 July. Epidemiologic follow-up of the other passengers who had been on the same flight as our patient did not detect any other cases of cholera (New York City Department of Health, personal communication). The patient was followed up in the outpatient

Cholera is a rarely reported disease in the United States. In 1990, only four cases were reported to the Centers for Disease Control (CDC), one of which came from our institution. We wish to describe that case, the unusual circumstances surrounding the laboratory diagnosis, and the associated gastrointestinal tract pathogens isolated from this patient. The importance of physician-laboratory communication, quality control of culture media, and the high index of suspicion for multiple infection in patients from areas of high endemicity are highlighted by this case.

CASE REPORT The patient, a 2-year-old girl who was born in New York to parents of Pakistani descent and had not left the Brooklyn area until 2 months prior to her hospital admission, was admitted with severe diarrhea. She had been taken to Karachi, Pakistan, did not travel to rural areas, and ate and drank only at her relatives homes. She had intermittent bouts of diarrhea with From the Divisionof InfectiousDiseases and Microbiology Laboratory, MaimonidesMedicalCenter, Brooklyn,New York, USA. Address reprint requests to Dr. J.D. Gradon, Division of Infectious Diseases and MicrobiologyLaboratory,MaimonidesMedical Center, 4802 Tenth Avenue, Brooklyn,NY 11219, USA. Received 4 February 1991; revised and accepted 2 April 1991. © 1992 Elsevier Science Publishing Co., Inc. 655 Avenue of the Americas, New York, NY 10010 0732-8893/92/$5.00

162

J.D. Gradon et al.

TABLE 1 Pathogens Detected in Patient Pathogen

Vibrio cholerae Rotavirus Giardia lamblia Campylobacter jejuni Salmonella typhi

Identification Date (1990) 7 July 29 July 15 August 17 August 27 August

Site Stool Stool Stool Stool Stool & blood

clinic. She remained free of diarrhea, and the following pathogens were detected in her stool: rotavirus by stool ELISA (Kallsted, Austin, TX) on 29 July, Giardia lamblia cysts by visualization in the stool on 15 August, and Campylobacter jejuni was grown from her stool on 17 August (Table 1). Stool cultures on family members were performed, and her parents and her one sibling were also found to have C. jejuni in their stool at that time. Because she was doing well clinically, no specific therapy was administered for these organisms. She was readmitted to the hospital on 27 August 1990 with a complaint of fever, malaise, and anorexia. Her diarrhea had not recurred and she had not left her parent's home in Brooklyn. She had been eating food prepared by her mother only. No one else in the family was ill. Physical examination revealed a sickly looking girl with a temperature of 102°F, and a pulse rate of 72. Her lungs were clear and abdomen soft with no splenomegaly. She had a single rose spot on her anterior abdominal wall. Laboratory testing revealed a white blood cell count of 8700/mIn3 with a normal manual differential. Blood, urine, and sputum cultures were obtained in the emergency room as part of a routine sepsis workup. The stool and blood cultures grew a group-D salmonella, which was identified as Salmonella typhi. The organism was found to be resistant to ampicillin and SXT, and she was treated with intravenous cefotaxime. She made a full, uneventful recovery and was discharged home. She remains well on followup. MICROBIOLOGY On 9 July, a routine stool culture was submitted to the microbiology laboratory. In our laboratory, stool is inoculated onto the following agar media: trypticase soy agar with 5% sheep blood [blood-agar plates (BAP)], MacConkey, Hekton-Enteric, Campy-Blood with five antibiotics and GN broth (BBL Microbiology Systems, Cockeysville, MD). Routine protocol requires technicians to examine culture plates at 24 and 48 hr for Salmonella spp., Shigella spp., Yersinia

enterocolitica, C. jejuni, ~-hemolytic oxidase-positive Gram-negative rods (to rule out Aeromonas hydrophila), pure or heavy growth of a Staphylococcus aureus or yeast, and the absence or presence of normal enteric flora. Identification and susceptibility testing are done using standard methods. The presence of ~-lactamase production was determined by the nitrocefin disk method. After 48 hr of incubation, the stool cultures demonstrated normal enteric flora. The Campy-Blood agar plate revealed one large (5 mm) mucoid colony, resembling a Pseudomonas spp. Organisms from this colony were indophenol oxidase-positive and a Gram stain revealed large, curved Gram-negative bacilli. To determine the identification of this organism, we performed a subculture on to thiocitrate-bile-saltsucrose (TCBS) and triple sugar iron agars (BBL), Campy-Blood agar, BAP, and it was inoculated into an AP120 E (Analytab, Plainview, NY). Bauer-Kirby disk diffusion susceptibility tests were performed. At a later time, broth dilution (Microscan, West Sacramento, CA) antimicrobial susceptibility tests were also performed. Following 18 hr of incubation, the subculture produced yellow (sucrose positive) mucoid colonies on TCBS, an acid over acid triple sugar-iron agar (TSI), and was identified as V. cholerae (5146124, excellent identification) by the API 20 E. The infectious disease and infection control services of our hospital and N e w York City (NYC) Department of Health were notified of the case. The organism was forwarded to the NYC Department of Health Laboratories for confirmation and toxin testing. Disk susceptibility and minimum inhibitory concentration (MIC) testing demonstrated organism resistance to trimethoprim-sulfamethoxazole (MIC >8/152), trimethoprim (MIC >8 ~g/ml), polymyxin B (disk susceptibility only), and susceptibility to cephalosporins (cephalothin MIC -< 4 p~g/ml), ureidopenicillins, aminoglycosides, and quinolones (ciprofloxacin MIC -8 ~xg/ml), sulfamethoxazole (MIC >256 ~g/ml), mezlocillin (MIC >64 p~g/ml), and susceptibility to the cephalosporins (cephalothin MIC = 8~g/ml), aminoglycosides and quinolones (ciprofloxacin MIC -