1. Provided by David Mann, Division of Outbreak Investigation, Maryland Department of Health and Mental Hygiene.

From August 14, 1998 to August 21, 1998 six outbreaks were reported to the Maryland Department of Health and Mental Hygiene. From long term care facilities: two outbreaks of Scabies. one outbreak of gastroenteritis.

Foodborne outbreaks: two outbreaks of food service facility-associated gastroenteritis of unknown etiology.

2. The Johns Hopkins Hospital. Information provided by Dr. May Arroyo, Department of Pathology.

Case Presentation: A 56 year old white male, status post total right hip replacement secondary to arthritis,

presented to the ED with a two week history of inability to walk secondary to weakness of the right leg. He had initially experienced several days of nausea, vomiting, and progressive fatigue, and subsequently developed pain and weakness in the lower extremities. The pain in the left lower extremity had resolved after several days. However, the patient still complained of pain along the anterior aspect of the right thigh, and weakness of the right leg. He also reported an erythematous rash along the medial aspect of both lower extremities of two weeks duration. Past medical history was significant for childhood polio, malaria, Dengue fever, and heavy alcohol use. The patient is an electrical engineer employed in Indonesia. Physical examination was significant for a temperature of 101^oF, lower extremity edema, a punctate, nonblanching, erythematous rash on the medial aspect of the lower extremities, a normal neurological exam, and decrease strength of the right lower extremity. Pertinent laboratory findings included: white blood cells 15,000/mm³, hematocrit 30.9%, sedimentation rate 103 mm/hr, alkaline phosphatase 186 IU/L, aspartate aminotransferase 80 IU/L, and amylase 107 IU/L. Blood cultures were negative. The right hip joint was aspirated and the joint aspirate was sent to microbiology.

Organism: Gram stain of the joint aspirate revealed numerous neutrophils and rare straight and curved gram negative organisms. Cultures grew Vibrio vulnificus. V. vulnificus is a ubiquitous, lactose fermenting, gram negative, facultative anaerobic rod which grows in warm coastal waters and estuaries with low salinity (1,2,3). The organism is transmitted via two mechanisms: through ingestion of contaminated undercooked seafood and raw oysters, and by direct exposure of a wound to contaminated seawater or brackish water. The organism grows optimally in 0.5 to 2% NaCl and a temperature range of 25-37^oC. V. vulnificus, as with other Vibrio species, can persists in a viable, albeit non-culturable, state at low temperatures (4). In the U.S., V. vulnificus has been harvested from oysters growing in the Gulf of Mexico, Chesapeake Bay, Pacific Coast, and New England (5). Contamination of food with V. vulnificus does not impart a change in odor or taste to the food item (1).

The propositus denied exposure to saltwater or ingestion of raw oysters or non-potable water. He reported, however, habitually rinsing his mouth with faucet tap water and frequent ingestion of Mylanta.

V. vulnificus produces several enzymes which promote tissue destruction: a collagenase, elastolytic protease, hemolytic cytotoxin, and a metalloprotease (2).

Clinical presentation: V. vulnificus causes mild gastroenteritis, wound infection, and septicemia. Patients with chronic liver disease, immunosuppression, and conditions associated with iron overload are particularly susceptible to fatal septicemia (1,2,3). The syndrome generally presents as fever, nausea, and myalgias within 24-48 hours of ingesting the contaminated food. Diarrhea is not usually observed. The organism reaches the bloodstream by invading the intestinal mucosa. Sepsis generally develops within 36 hours and is characterized by a mortality rate exceeding 50%.

Skin lesions develop within 24 hours following exposure of broken skin to contaminated water or shellfish. The lesions vary from hemorrhagic bullae to necrotic ulcers and can quickly progress to a compartment syndrome and septicemia. Isolated cases of pneumonia, meningitis, spontaneous cellulitis, and endometritis have been reported (2,3).

Laboratory diagnosis: Vibrio species are fastidious organisms which are sensitive to drying and acid pH. They are often hemolytic on sheep blood agar and oxidase positive (4). Other oxidase positive gram negative rods include Aeromonas spp and Plesiomonas spp. Growth on all media is enhanced in the presence of 1% NaCl. V. vulnificus,

V. mimicus, and V. parahaemolyticum can be distinguished from other Vibrio species by the formation of blue-green colonies on TCBS (thiosulfate citrate bile sucrose) agar. V. vulnificus can be distinguished from V. parahaemolyticus by its ability to utilize lactose and salicin (4).

Treatment: Doxycycline is recommended for V. vulnificus and other Vibrio species.

References:

(1) CDC. Vibrio vulnificus infections associated with eating raw oysters-Los Angeles, 1996. JAMA 276:937;1996.

(2) Stabellini, N. Camerani, A., Lambertini, D., Rossi, M.R., Virgili, A., and Gilli, P. Fatal sepsis from Vibrio vulnificus in a hemodialyzed patient. Nephron 78:221;1998.

(3) Vollberg, C.M., and Herrefa, J.L. Vibrio vulnificus infection: An important cause of septicemia in patients with cirrhosis. South. Med. J. 90:1040;1997.

(4) Koneman, E.W., Allen, S.D., Janda, W.M., Schreckenberger, P.C., and Winn, W.C. Jr. 1997. Curved gram-negative bacilli and oxidase-positive fermenters: Campylobacteraceae and Vibrionaceae, pp.321-361. Clinical Microbiology, 5th edition, Lippincott-Raven Publishers, Philadelphia.

(5) Wright, A.C., Hill, R.L., Johnson, J.A., Roghman, M, Colwell, R.R., and Morris, J.G. Jr. Distribution of Vibrio vulnificus in the Chesapeake Bay. Appl. and Environ. Micro. 62:717;1996.