Figure 1: A Shewanella haliotis severe soft tissue infection developed in the left leg of a 52-year-old female who had undergone orthotopic liver transplantation six months earlier and had handled fresh seafood in a market a week before (A, black arrow). Progressive, painful swelling of the left leg created a compartment syndrome with the loss of distal pulses and required emergent surgical decompression by fasciotomy (B). Two sets of blood cultures and fluid cultures from the left leg confirmed S. haliotis infection in an immunocompromised patient. 13
intracerebral lesions; one patient inNewZealandwith spinal osteomyelitis; and one veterinary laboratory worker with a mild form of brucellosis. 2,4 The diagnosis of brucellosis can be by slow-growing culture from blood or biopsies, serological demonstration of Brucella antibodies (ELISA) for the more commonly en- countered strains, and PCR assays for separation and specia- tion of the terrestrial and marine mammal strains. Invasive brucellosis and neurobrucellosis will require prolonged treatment (2-12 months) with a combination of intravenous rifampin, doxycycline, and gentamicin for a week or more followed by six or more weeks of oral doxycycline and rifampin. 1 For persons exposed to stranded marine mam- mals or their carcasses, a three-week course of antimicrobial prophylaxis with oral doxycycline and rifampin has been recommended by the CDC in addition to symptom surveil- lance with daily fever checks for 24 weeks. 1 For children and others who cannot take doxycycline, a three-week course of trimethoprim-sulfamethoxazole and rifampin is recommended. 1 On October 27, 2011, six months after the Deepwater Horizon BP oil spill off the Louisiana coast in April 2010, the National Oceanic and Atmospheric Administration (NOAA) confirmed that 5 of the 21 tested bottle-nosed dolphins among the 580 dolphins that died in the northern Gulf of Mexico in 2010-2011 had marine mammal brucel- losis. 5 NOAA scientists concluded that severe environ- mental stress, including crude oil exposures, could have compromised the animal’s immune systems, making them more susceptible to a zoonotic infectious disease common in marine mammals. 5 As a result, the NOAA advises that anyone who encounters a stranded or dead dolphin in the
antibiotic susceptibilities, and biochemical and molecular signatures (Table 1). NEWLY EMERGING CAUSES OF MARINE INFECTIONS Marine Mammal Brucella Species Brucellosis, or undulant fever, is a zoonotic infectious disease caused by several species-specific strains of Brucella , which are small, gram-negative, non-motile, non-spore- forming, rod-shaped coccobacilli. Brucellosis is rare in the United States, with an average of 113 cases reported to the CDC annually over the period 2000-2009. 1 Most cases in the United States are caused by consuming unpasteurized milk or cheese from infected cattle ( B. abortus ) or goats ( B. melitensis ), hunting feral swine ( B. suis ), and occupational exposures among laboratory workers handling Brucella species. 1,2 New zoonotic reservoirs of Brucella strains have now been identified in pinnipeds (seals, sea lions, and walruses) and cetaceans (dolphins, porpoises, and whales), collectively referred to as marine mammal Brucella species and tentatively classified as B. pinnepediae and B. cetaceae, respectively. 2 Seroprevalence studies have now identified marine mammal Brucella species strains in both seals and porpoises stranded and dying along the New England Coast. 3 In humans, brucellosis can cause fever, febrile sweat- ing, headache, weakness, myalgia, back pain, and rarely, invasive granulomatous disease in bone, liver, and the cen- tral nervous system (neurobrucellosis). 2 Four human cases of marine mammal brucellosis have been reported since 2001 with two cases in males from coastal Peru treated in the United States for neurobrucellosis with granulomatous
J La State Med Soc VOL 166 May/June 2014 105
Made with FlippingBook - Online catalogs