Edith R. Lederman

Pyogenic liver abscess with a focus on Klebsiella pneumoniae as a primary pathogen: an emerging disease with unique clinical characteristics.

OBJECTIVES:Pyogenic liver abscess is a common intraabdominal infection. Historically, Escherichia coli (E. coli) has been the predominant causative agent. Klebsiella liver abscess (KLA) was first reported in Taiwan and has surpassed E. coli as the number one isolate from patients with hepatic abscesses in that country and reports from other countries, including the United States, have increased. We examined the microbiologic trends of pyogenic liver abscess at our institution to determine if a similar shift in etiologic agents was occurring.METHODS:We examined all cases of liver abscess at our institution from 1999 to 2003 via a retrospective chart review of inpatient records and reviewed the English literature via a MEDLINE search for all U.S. cases of KLA.RESULTS:Since 1966, only 12 cases of KLA have been reported in the United States. We report six cases of KLA at our institution alone; 2 patients were not Asian, and 4 were not diabetic. Klebsiella pneumoniae (K. pneumoniae) was the most common cause of pyogenic hepatic abscess at our institution over the last 5-yr period. When comparing Klebsiella versus other causes of pyogenic liver abscess, there were no significant differences in demographics or laboratory findings; however, most of our Klebsiella cases occurred among Filipinos. Review of the 18 cases of K. pneumoniae liver abscess in the United States showed that Klebsiella cases occurred predominantly among middle-aged men; 83% had concurrent bacteremia and 28% had metastatic complications. An increasing number of cases were reported from the United States since the mid-1990s.CONCLUSIONS:These data suggest that KLA may represent an emerging disease in Western countries, such as the United States. The diagnosis of K. pneumoniae should be considered in all cases of liver abscess, and appropriate antibiotic therapy and a diagnostic work-up for metastatic complications should be employed.

Infections associated with tumor necrosis factor-α antagonists

Abstract: Tumor necrosis factor (TNF)-α antagonists are promising therapeutic agents for patients with severe autoimmune and rheumatologic conditions. Unfortunately, their use has been associated with an increased rate of tuberculosis, endemic mycoses, and intracellular bacterial infections. Infliximab, 1 of 3 available drugs in this novel class, appears to be associated with the greatest risk of infection, likely because of its long half-life and induction of monocyte apoptosis. Prospective trials are necessary to determine the exact risk associated with these agents, particularly the newer TNF-α antagonists. More specific TNF-α blockers, which reduce inflammation while maintaining adequate immunity, are needed. In the meantime, a thorough work-up is mandatory for all febrile illness occurring in TNF-α blocker recipients. We present 4 patients who developed severe infections during TNF-α antagonist therapy, review the literature, and discuss current guidelines for surveillance and prophylaxis. Abbreviations: AIDS = acquired immunodeficiency syndrome, FDA = United States Food and Drug Administration, HIV = human immunodeficiency virus, PPD = purified protein derivative, RA = rheumatoid arthritis, TB = tuberculosis, TH1 = T-helper type 1, TNF = tumor necrosis factor, WBC = white blood cell count.

Coccidioidomycosis: a descriptive survey of a reemerging disease. Clinical characteristics and current controversies.

Abstract: Coccidioidomycosis is a fungal disease with protean manifestations endemic to the Lower Sonoran Life Zone, which includes the hot deserts of the southwestern United States and areas of Mexico. Two hundred and twenty-three patients were found to have coccidioidomycosis at our institution from 1994-2002, the largest reported cohort of coccidioidomycosis patients since the 1950s. Of these patients, 58% presented with isolated pulmonary disease, 14% had high (>1:16) complement fixation titers without clear evidence of dissemination, 22% had definite disseminated disease, and 5% had unclassified disease. Enzyme immunoassay was a reliable diagnostic tool in those with symptomatic disease, but had a low specificity in those who were asymptomatic. Complement fixation titers of ≥1:16 were associated with dissemination to bone or skin but were not helpful in evaluating central nervous system disease. Thirteen percent of patients with high complement fixation titers (>1:16) without clear evidence of dissemination on presentation and 7% of those with isolated pulmonary disease eventually progressed to disseminated disease; 30% of Filipino patients with pulmonary disease progressed to disseminated disease. Nonwhite race was a predictor for dissemination; African American patients more often developed disseminated bony disease while Filipinos were more likely to develop cutaneous or central nervous system disease. Relapse of disseminated coccidioidomycosis occurred in 24% of patients; the risk was highest (71%) among those with central nervous system disease. Azole therapy was generally inferior to amphotericin B in disseminated disease. Predictors of permanent disability included African American or Filipino race, central nervous system disease, and bony disease. Abbreviations:, CF = complement fixation, CNS = central nervous system, CSF = cerebrospinal fluid, CT = computed tomography, EIA = enzyme immunoassay, LDH = lactate dehydrogenase, MRI = magnetic resonance imaging, OR = odds ratio, VP = ventriculo-peritoneal.

An Investigation of a Major Outbreak of Rift Valley Fever in Kenya: 2006–2007

An outbreak of Rift Valley fever (RVF) occurred in Kenya during November 2006 through March 2007. We characterized the magnitude of the outbreak through disease surveillance and serosurveys, and investigated contributing factors to enhance strategies for forecasting to prevent or minimize the impact of future outbreaks. Of 700 suspected cases, 392 met probable or confirmed case definitions; demographic data were available for 340 (87%), including 90 (26.4%) deaths. Male cases were more likely to die than females, Case Fatality Rate Ratio 1.8 (95% Confidence Interval [CI] 1.3-3.8). Serosurveys suggested an attack rate up to 13% of residents in heavily affected areas. Genetic sequencing showed high homology among viruses from this and earlier RVF outbreaks. Case areas were more likely than non-case areas to have soil types that retain surface moisture. The outbreak had a devastatingly high case-fatality rate for hospitalized patients. However, there were up to 180,000 infected mildly ill or asymptomatic people within highly affected areas. Soil type data may add specificity to climate-based forecasting models for RVF.

Klebsiella Liver Abscess: A Coast-to-Coast Phenomenon

!30 years of age are at higher risk of developing acute hepatitis A than are those aged 140 years (OR, 5.5; 95% CI, 1.2– 23.3). Patients who acquired HIV infection during sex had higher rates of natural hepatitis A immunity than did those who acquired HIV infection parenterally (61% vs. 38%; ). P p .13 These data support the recommendation of hepatitis A vaccination for patients with HIV infection in developed countries, particularly white patients aged !30 years, because most are not naturally immune. On the other hand, for recent immigrants from Africa and Latin America with HIV infection, prescreening for hepatitis A virus IgG antibody is recommended before routine hepatitis A vaccination, because a large proportion of such patients are naturally immune.

History of U.S. Military Contributions to the Study of Parasitic Diseases

U.S. military researchers have made major contributions to the discovery, diagnosis, treatment, and prevention of a number of parasitic diseases. We review the paramount U.S. military contributions to the understanding of leishmaniasis, filariasis, schistosomiasis, trypanosomiasis, gastrointestinal parasites, intestinal capillariasis, and angiostrongyliasis.

Outbreak of Clostridium perfringens food-borne illness associated with a Mardi Gras celebration

Abstract: Clostridium perfringens is a preventable cause of food-borne illness. We report an outbreak of C. perfringens food-borne illness linked to the consumption of gumbo at a hospital party. Twenty-nine (74%) of 39 exposed individuals developed abdominal cramping and diarrhea 9 hours after ingestion of the gumbo. Culture of the gumbo revealed C. perfringens. A case-control study revealed a statistically significant association between gumbo consumption and illness (P < 0.001). Interviews revealed improper food handling techniques with respect to serving temperatures and refrigeration.

Purpura-Producing Streptococcus pneumoniae

Abstract: Clinical manifestations of purpura-producing Streptococcus pneumoniae may mimic meningococcemia. The pathogenesis of S. pneumoniae purpura has been elucidated, but clinical cases of benign purpura due to this organism are rare. We report the first case of purpura-producing S. pneumoniae occurring in the setting of uncomplicated community-acquired pneumonia in an immunocompetent adult.