Quantitative tip culture methods and the diagnosis of central venous catheter-related infections.

The diagnostic usefulness of two quantitative catheter culture methods was compared in a prospective study of central venous arterial catheters. The roll-plate method followed by sonication was used to culture 177 catheters from 85 patients, and the sonication method was used to culture 136 catheters from 68 patients. All patients were evaluated for catheter-related infections. Catheter-related infections were associated with greater than or equal to 100 colony-forming units (CFU) isolated from catheter tips by either roll plate (p = 0.01) or sonication (p less than 0.001). The sensitivity, specificity, and positive and negative predictive values of greater than or equal to 10(3) CFU by roll plate for catheter-related septicemia were 56%, 97%, 63%, and 96% compared with 93%, 95%, 76%, and 99%, respectively, for the same level by sonication. For central venous and arterial catheters, the sonication method can distinguish infection from contamination and is superior to the roll-plate method in that it may offer a more sensitive and predictive alternative in the diagnosis of catheter-related septicemia.

Optimal duration of therapy for catheter-related Staphylococcus aureus bacteremia: a study of 55 cases and review.

Over the last two decades, the optimal duration of therapy for catheter-related Staphylococcus aureus bacteremia has become the subject of controversy. A review of the literature revealed an occasional association between relapse of the infection and a short course of therapy (less than 10 days of iv antibiotic therapy). From records kept between 1983 and 1989 at the University of Florida's affiliated hospitals, we identified 55 patients with catheter-related S. aureus bacteremia. Nine patients (16%) developed acute early complications (e.g., endocarditis or osteomyelitis) while receiving antibiotics. The results of multivariate analysis showed that an early complicated course was characterized by fever and/or bacteremia that persisted for greater than 3 days after catheter removal (P = .02). The remaining 46 patients were followed up for at least 3 months. During follow-up, three of the 18 patients treated for less than 10 days with iv antibiotics developed relapsing septicemia, whereas none of the 28 patients treated for a longer period developed this condition (P = .05). Fever and/or bacteremia that persists for greater than 3 days after catheter removal and initiation of antibiotic therapy suggests an acutely complicated course requiring prolonged treatment. The duration of iv antibiotic therapy in uncomplicated cases should not be less than 10 days but need not be greater than 2 weeks.

Acute bacterial sialadenitis: a study of 29 cases and review.

Acute bacterial parotitis (ABP) used to be described as a nosocomial postoperative infection associated with a high mortality. A review of the literature on acute bacterial sialadenitis (ABS) revealed Staphylococcus aureus as the most common pathogen. Between 1970 and 1988, 17 patients with ABP and 12 with acute bacterial submandibular sialadenitis (ABSS) were admitted to a university hospital. Cultures of purulent discharge from the salivary ducts of these patients revealed S. aureus in 53% and viridans streptococci in 31%. During the study period, only six nosocomial cases of ABP occurred out of 289,234 admissions. S. aureus was the organism isolated most frequently in the nosocomial cases. There were no deaths, and all patients recovered following antibiotic treatment without surgical drainage. Advances in antimicrobial therapy and fluid management of hospitalized patients have made nosocomial ABS a rare disease with a favorable prognosis. S. aureus remains the most common pathogen causing ABS even in nosocomially infected patients who are not critically ill.