Epidemiology of meningitis with a negative CSF Gram stain: under-utilization of available diagnostic tests.

Meningitis with a negative cerebrospinal fluid Gram stain (CSF-GS) poses a diagnostic challenge as more than 50% of patients remain without an aetiology. The introduction of polymerase chain reaction (PCR) and arboviral serologies have increased diagnostic capabilities, yet large scale epidemiological studies evaluating their use in clinical practice are lacking. We conducted a prospective observational study in New Orleans between November 1999 and September 2008 (early era) when PCR was not widely available, and in Houston between November 2008 and June 2013 (modern era), when PCR was commonly used. Patients presenting with meningitis and negative CSF-GS were followed for 4 weeks. All investigations, PCR used, and results were recorded as they became available. In 323 patients enrolled, PCR provided the highest diagnostic yield (24·2%) but was ordered for 128 (39·6%) patients; followed by serology for arboviruses (15%) that was ordered for 100 (31%) of all patients. The yield of blood cultures was (10·3%) and that of CSF cultures was 4%; the yield for all other tests was <10%. Overall, 65% of the patients remained without a diagnosis at 4 weeks: 72·1% in early era vs. 53·4% (P < 0·01) in modern era; this change was attributed to diagnosing more viral pathogens, 8·3% and 26·3% (P < 0·01), respectively. The introduction of PCR and arboviral serologies has improved the yield of diagnosing patients with meningitis and a negative CSF-GS, but both tests are being under-utilized.

Outpatient parenteral antimicrobial therapy for the treatment of methicillin-susceptible Staphylococcus aureus: a comparison of cefazolin and ceftriaxone.

PURPOSE: Although the antistaphylococcal penicillins remain the drugs of choice for methicillin-susceptible Staphylococcus aureus (MSSA) infections, cefazolin and ceftriaxone are often prescribed due to their less frequent dosing and reduced cost. The purpose of this study was to compare clinical outcomes and adverse events in patients receiving outpatient parenteral antimicrobial therapy (OPAT) with ceftriaxone or cefazolin for the treatment of MSSA infections. METHODS: A retrospective study was carried out of 122 patients evaluated at Ben Taub and Lyndon B. Johnson General Hospitals in Houston, Texas, between January 1, 2006, and March 31, 2012, with a documented MSSA infection who received cefazolin or ceftriaxone as OPAT. A favorable clinical outcome was determined by their primary care physician's assessment at follow-up in the clinic. RESULTS: Out of 122 patients, 78 (64 %) were treated with cefazolin and 44 (36 %) with ceftriaxone. Patients were predominantly young (median age 46 years), male (54.2 %), and Hispanic (51.2 %). Patients were similar in terms of baseline demographics, types of infections, and management of infections. Favorable clinical outcomes were similar between cefazolin and ceftriaxone (67.9 versus 79.8 %, p = 0.17), along with a similar incidence of adverse events and complications (5.1 versus 2.3 %, p = 0.65, and 26.9 versus 18.2 %, p = 0.38, respectively). CONCLUSIONS: OPAT with either cefazolin or ceftriaxone is similar in terms of favorable outcomes, adverse events, and complications when treating MSSA infections. A randomized clinical trial is needed in order to confirm these results.