amebiasis or bowel perforation in enteric fever. Risk factors for intestinal perforation in typhoid
fever were a short duration of symptoms (within 2 weeks of illness onset), inadequate antibiotic
therapy, male gender, and leukopenia in a case-control study in Turkey (95). Enteric fever is
most commonly due toSalmonella typhi,but also can be caused byS. paratyphiorBrucellaspecies
(96,97). In the United States, the total number of typhoid fever cases has decreased. A larger
proportion (69%) has been imported during foreign travel especially from Mexico and India (98).
Typhoid fever may also present with other clinical syndromes requiring ICU admission
including ARDS, lower gastrointestinal bleeding, splenic rupture, and coma (95,97,99,100).
Confirmatory diagnosis of typhoid fever requires blood culture isolation that is positive in
approximately 80% of cases or approximately 90% with bone marrow culture (97,101). Stool and
urine cultures are occasionally positive, 37% and 7%, respectively, but do not constitute
definitive evidence of systemic infection. Widespread multidrug-resistantS. typhi(resistant to
ampicillin, chloramphenicol, and TMP/SMX) has been documented in many areas of Asia,
Africa, and the Middle East requiring the use of fluoroquinolones, as first-line therapy, or
alternatives such as third-generation cephalosporins or azithromycin (94,97,102,103). Adjunctive
therapy with high-dose corticosteroids has been shown to decrease mortality in severely ill
typhoid fever patients with delirium, obtundation, coma, or shock (104). The majority (95%) of
amebic liver abscesses will present within the first two to five years after leaving the endemic
region (93,105,106). Diarrhea is present in less than half with amebic trophozoites or cysts in
<30%. The differential diagnosis must also include bacterial liver abscess, echinococcal cyst, and
hepatoma. Ultrasound and CT imaging will assist in defining the hepatic lesions and highly
sensitive and specific serology will often confirm extraintestinal amebiasis (often negative in the
first seven days) (93). Therapy with parenteral metronidazole results in mortality rates of<1% in
uncomplicated liver abscesses (93). However, complicated amebic liver abscesses with extension
into the thoracic cavity, peritoneum, or pericardium have case-fatality rates of 6.2%, 18.4%, and
29.6%, respectively (105).
Dysentery and Severe Gastrointestinal Fluid Losses
Dysentery is characterized by a toxic appearance, fever, lower abdominal pain, tenesmus, and
frequent small-volume loose stools containing blood and/or mucus with large numbers of
fecal leukocytes on microscopic exam. Etiologies of dysentery can be divided into amebic
(Entamoeba histolytica)versus bacillary [Shigellaspp. especiallyS. dysenteriaeandS. flexneri,
Campylobacter jejuni, nontyphoidal Salmonella spp., Yersinia enterocolitica, enteroinvasive
Escherichia coliand enterohemorrhagicE. coli(EHEC)] (106). Shigellosis is the most common
etiology and is associated with fatality rates as high as 9% in indigenous populations in
endemic regions and 20% duringS. dysenteriaeepidemics (107). Complications can include
bacteremia, intestinal perforation, dehydration, toxic megacolon, ileus, rectal prolapse,
hemolytic uremic syndrome (also well documented with EHEC strains such as O157:H7),
altered consciousness, and seizures. Predictive factors associated with increased risk of death
in shigellosis (age older than one year, diminished serum total protein, thrombocytopenia, and
altered consciousness) reflect the importance of sepsis in shigellosis-related deaths (108).
Diarrhea-related mortality in noninflammatory diarrhea has been significantly reduced
globally with the institution of oral rehydration therapy. Dysentery-related deaths have not
been significantly reduced and require antimicrobial therapy and supportive intensive care in
addition to appropriate rehydration (106,107,109,110). The majority of noninflammatory
diarrhea cases in returning travelers present as mild or moderate illness due to bacterial agents
such as ETEC,Campylobacter jejuni,and, less commonly, protozoal agents such asGiardia
lamblia.Noninflammatory diarrhea due to cholera may present in a returning traveler with life-
threatening dehydrating illness with profound fluid and electrolyte deficits (111). Imported
Vibrio choleraeis rare in the United States; however, an appreciation of regional risks of
epidemic strains (El Tor in South/Central America and Africa, non-O1V. choleraeO139 in
Southeast Asia and the Indian subcontinent) is important (111).
Fulminant Hepatitis
Fulminant hepatitis manifests as severe acute liver failure with jaundice and hepatic
encephalopathy (112). Viral hepatitis accounts for the majority (approx. 75%) of fulminant
330 Wood-Morris et al.