from the gulf states (184). Risk factors for infection include liver disease (most commonly
alcoholic), hemachromatosis, HIV infection, steroid use, malignancy, and achlorhydria (181).
V. vulnificushas been associated with two distinct syndromes: septicemia and wound
infection (185,186). A third syndrome of gastrointestinal illness has also been suggested (187).
Primary septicemia is a fulminant illness that occurs after the consumption of contaminated
raw shellfish. Consumption of raw oysters within 14 days preceding the illness has been
reported in 96% of the cases (188). Wound infection occurs after a pre-existing or newly
acquired wound is exposed to contaminated seawater.
The onset of symptoms is abrupt. The most common presenting signs and symptoms are
fever, chills, shock, and secondary bullae (186). Skin lesions are seen in 65% of patients and are
an early sign of septicemia. The most characteristic skin manifestation is erythema, followed by
a rapid development of indurated plaques. These plaques then become violaceous in color,
vesiculate, and then form bullae. The necrotic skin eventually sloughs off, leaving large ulcers
(Fig. 10) (189). Gangrene of a limb can develop because of blood-vessel occlusion (190).
Diagnosis is aided by clinical presentation and history. The bacteria can be readily
cultured from blood and cutaneous lesions (191). A real-time PCR assay has also been reported
(192).
The mortality rate for septicemia is about 53% and is higher in patients who present with
hypotension and leucopenia (193). Median duration from hospitalization to death is about 1.6
days (186). Failure to initiate antibiotics promptly is associated with higher mortality (184).
Debridement of involved tissue is usually necessary.
Rickettsia akari
Rickettsialpox, which was first described in 1946 in New York City, is caused byR. akari(194).
R. akariinfects house mice (Mus musculus) and is transmitted to humans by the house mouse-
associated mite,Liponyssoides sanguineus(195). Most cases have occurred in large metropolitan
areas of the northeastern United States (195,196).
Rickettsialpox has an incubation period of 9 to 14 days (197). The initial lesion develops
into an eschar at the site of inoculation. Local lymph nodes around the eschar may become
enlarged and tender. Approximately one week following the development of the eschar,
Figure 10 Skin lesions associated with V. vulnificus
septicemia in a 75-year-old patient with liver cirrhosis.
Source: Courtesy of CDC/From Ref. 184.Fever and Rash in Critical Care 39