Susannah J. Eykyn

Endogenous bacterial endophthalmitis: a 17-year prospective series and review of 267 reported cases.

Endogenous bacterial endophthalmitis is a rare but serious condition that occurs when bacteria cross the blood-ocular barrier and multiply within the eye. We provide an overview of endogenous bacterial endophthalmitis by reviewing 267 reported cases and integrating this with our experience of an additional 19 cases. The majority of patients with endogenous bacterial endophthalmitis are initially misdiagnosed and many have an underlying disease known to predispose to infection. This condition is often previously undiagnosed. Blood cultures are the most frequent means of establishing the diagnosis. The most common Gram positive organisms are Staphylococcus aureus, group B streptococci, Streptococcus pneumoniae,and Listeria monocytogenes. The most common Gram negative organisms are Klebsiella spp., Escherichia coli, Pseudomonas aeruginosa, and Neisseria meningitidis. Gram negative organisms are responsible for the majority of cases reported from East Asian hospitals, but Gram positive organisms are more common in North America and Europe. The visual outcome is poor with most cases leading to blindness in the affected eye. Many patients have extraocular foci of infection, with an associated mortality rate of 5%. The outcome of endogenous bacterial endophthalmitis has not improved in 55 years and clinicians need to have a high level of awareness of this commonly misdiagnosed condition.

Staphylococcus aureus Native Valve Infective Endocarditis: Report of 566 Episodes from the International Collaboration on Endocarditis Merged Database

BACKGROUND Staphylococcus aureus native valve infective endocarditis (SA-NVIE) is not completely understood. The objective of this investigation was to describe the characteristics of a large, international cohort of patients with SA-NVIE. METHODS The International Collaboration on Endocarditis Merged Database (ICE-MD) is a combination of 7 existing electronic databases from 5 countries that contains data on 2212 cases of definite infective endocarditis (IE). RESULTS Of patients with native valve IE, 566 patients [corrected] had IE due to S. aureus, and 1074 patients had IE due to pathogens other than S. aureus (non-SA-NVIE). Patients with S. aureus IE were more likely to die (20% vs. 12%; P < .001), to experience an embolic event (61% [corrected] vs. 31%; P < .001), or to have a central nervous system event (21% [corrected] vs. 13%; P < .001) and were less likely to undergo surgery (26% vs. 39%; P < .001) than were patients with non-SA-NVIE. Multivariate analysis of prognostic factors of mortality identified age (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1-1.7), periannular abscess (OR, 2.4; 95% CI, 1.0 [corrected] -5.6), heart failure (OR, 3.9; 95% CI, 2.3-6.7), and absence of surgical therapy (OR, 2.3; 95% CI, 1.3-4.2) as variables that were independently associated with mortality in patients with SA-NVIE. After adjusting for patient-, pathogen-, and treatment-specific characteristics by multivariate analysis, geographical region was also found to be associated with mortality in patients with SA-NVIE (P < .001). CONCLUSIONS S. aureus is an important and common cause of IE. The outcome of SA-NVIE is worse than that of non-SA-NVIE. Several clinical parameters are independently associated with mortality for patients with SA-NVIE. The clinical characteristics and outcome of SA-NVIE vary significantly by geographic region, although the reasons for such regional variations in outcomes of SA-NVIE are unknown and are probably multifactorial. A large, prospective, multinational cohort study of patients with IE is now under way to further investigate these observations.

Is Methicillin-Resistant Staphylococcus aureus More Virulent than Methicillin-Susceptible S. aureus? A Comparative Cohort Study of British Patients with Nosocomial Infection and Bacteremia

Staphylococcus aureus is the most common cause of hospital-acquired bacteremia. From 1995 through 2000, data on age, sex, patient specialty at time of first bacteremia, primary and secondary sites of infection, delay in initiating antimicrobial therapy, and patient outcome were prospectively recorded for 815 patients with nosocomial S. aureus bacteremia. The proportion of patients whose death was attributable to methicillin-resistant S. aureus (MRSA) was significantly higher than that for methicillin-susceptible S. aureus (MSSA) (11.8% vs. 5.1%; odds ratio [OR], 2.49; 95% confidence interval [CI], 1.46-4.24; P<.001). After adjustment for host variables, the OR decreased to 1.72 (95% CI, 0.92-3.20; P=.09). There was no significant difference between rates of disseminated infection (7.1% vs. 6.2% for MRSA-infected patients and MSSA-infected patients, respectively; P=.63), though the rate of death due to disseminated infection was significantly higher than death due to uncomplicated infection (37% vs. 10% for MRSA-infected patients [P<.001] and 37% vs. 3% for MSSA-infected patients [P<.001]). There was a strong statistical trend toward death due to nosocomial MRSA infection and bacteremia, compared with MSSA.

Pneumococcal bacteraemia: 325 episodes diagnosed at St Thomas's Hospital.

Three hundred and twenty five episodes of pneumococcal bacteraemia occurred at St Thomass Hospital during 1970-84, accounting for 13.3% of all episodes of bacteraemia. Twice as many cases occurred in male as in female patients, and common predisposing factors included chronic chest disease, alcoholism, haematological malignancies, cirrhosis, and sickle cell anaemia. Mortality was 28.6% overall but only 11.8% among patients who received antibiotic treatment for at least 24 hours. Most patients (261) had pneumonia, 26 had meningitis, and eight were children with occult bacteraemia. The commonest serotype of pneumococcus in adults was type 3 (39 episodes), and these strains were associated with a high mortality. Other factors determining a fatal outcome included underlying disease (such as cirrhosis, malignancy, and chronic chest disease) and extrapulmonary infection. Almost half the survivors were treated for 10 days or less and became afebrile within 48 hours.

Suggested Modifications to the Duke Criteria for the Clinical Diagnosis of Native Valve and Prosthetic Valve Endocarditis: Analysis of 118 Pathologically Proven Cases

We analyzed 118 consecutive cases of pathologically proven infective endocarditis (100 cases of native valve endocarditis [NVE] and 18 cases of prosthetic valve endocarditis [PVE]) with use of the Beth Israel criteria, the Duke criteria, and our suggested modifications of the Duke criteria; we found improved diagnostic sensitivity with our modifications. These modifications included the following additional minor criteria: the presence of newly diagnosed clubbing, splenomegaly, splinter hemorrhages, and petechiae; a high erythrocyte sedimentation rate; a high C-reactive protein level; and the presence of central nonfeeding lines, peripheral lines, and microscopic hematuria. Analysis of the pathologically proven cases of NVE showed that 64% were probable by the Beth Israel criteria, 83% were definite by the Duke criteria, and 94% were definite by our modified Duke criteria. For the pathologically proven cases of PVE, 50% were probable by the Beth Israel criteria, 50% were definite by the Duke criteria, and 89% were definite by our modified Duke criteria. All cases of NVE and PVE rejected by the Duke criteria remained rejected by our modifications. Therefore, our modifications improved diagnostic sensitivity while retaining specificity.

Native Valve Endocarditis Due to Coagulase-Negative Staphylococci: Report of 99 Episodes from the International Collaboration on Endocarditis Merged Database

Using a large cohort of patients from the International Collaboration on Endocarditis Merged Database, we compared coagulase-negative staphylococcal (CoNS) native-valve endocarditis (NVE) to NVE caused by more common pathogens. Rates of heart failure and mortality were similar between patients with CoNS NVE and patients with Staphylococcus aureus NVE, but rates for both groups were significantly higher than rates for patients with NVE due to viridans streptococci. These results emphasize the importance of CoNS as a cause of NVE and the potential for serious complications with this infection.

Necrobacillosis: a forgotten disease

Over four years five previously healthy young adults developed necrobacillosis , a severe septicaemic illness caused by Fusobacterium necrophorum. The infections were characterised by sore throat followed by rigors and the formation of metastatic abscesses and all caused considerable diagnostic confusion.

EPIDEMIC MULTIRESISTANT ESCHERICHIA COLI INFECTION IN WEST LAMBETH HEALTH DISTRICT

A year-long outbreak of multiresistant Escherichia coli K52 H1, predominantly serogroup O15, is reported from south east London. Most patients had urinary tract infections, some with septicaemia; but some cases of septicaemia were associated with pneumonia, meningitis, and endocarditis--unusual infections for E coli. 3 of these patients died. The organism was acquired in the community, and its source is still being investigated.

Prognostic Factors in 61 Cases of Staphylococcus aureus Prosthetic Valve Infective Endocarditis from the International Collaboration on Endocarditis Merged Database

Staphylococcus aureus prosthetic valve infective endocarditis (SA-PVIE) is associated with a high mortality rate, but prognostic factors have not been clearly elucidated. The International Collaboration on Endocarditis merged database (ICE-MD) contained 2212 cases of definite infective endocarditis (as defined using the Duke criteria), 61 of which were SA-PVIE. Overall mortality rate was 47.5%, stroke was associated with an increased risk of death, and early valve replacement was not associated with a significant survival benefit in the whole population; however, patients who developed cardiac complications and underwent early valve replacement had the lowest mortality rate (28.6%).

Microbiology of pyogenic liver abscess.

Sixteen patients with pyogenic liver abscesses were studied over 10 years to discover the causative organisms of the condition. Pus was subjected to Gram-negative smear or gas-liquid chromatography to detect volatile acids characteristic of anaerobes and then cultured. All isolates were identified by conventional methods and tested for sensitivity to appropriate antimicrobial agents. Bacteria were grown from the liver abscesses in all 16 patients. Streptococcus milleri Lancefield group F was the commonest organism isolated from the pyogenic liver abscesses, being found in 13 patients. If Strep milleri is isolated care should be taken not to mistake it for an anaerobe, and finding the organism in the blood should alert the clinician to the possible presence of a liver abscesses.