Background: The public health response to an influenza pandemic or other large-scale health emergency may include mass prophylaxis using multiple points of dispensing (PODs) to deliver countermeasures rapidly to affected populations. Computer models created to date to determine “optimal” staffing levels at PODs typically assume stable patient demand for service. The authors investigated POD function under dynamic and uncertain operational environments.

Methods: The authors constructed a Monte Carlo simulation model of mass prophylaxis (the Dynamic POD Simulator, or D-PODS) to assess the consequences of nonstationary patient arrival patterns on POD function under a variety of POD layouts and staffing plans. Compared are the performance of a standard POD layout under steady-state and variable patient arrival rates that may mimic real-life variation in patient demand.

Results: To achieve similar performance, PODs functioning under nonstationary patient arrival rates require higher staffing levels than would be predicted using the assumption of stationary arrival rates. Furthermore, PODs may develop severe bottlenecks unless staffing levels vary over time to meet changing patient arrival patterns. Efficient POD networks therefore require command and control systems capable of dynamically adjusting intra- and inter-POD staff levels to meet demand. In addition, under real-world operating conditions of heightened uncertainty, fewer large PODs will require a smaller total staff than many small PODs to achieve comparable performance.

Conclusions: Modeling environments that capture the effects of fundamental uncertainties in public health disasters are essential for the realistic evaluation of response mechanisms and policies. D-PODS quantifies POD operational efficiency under more realistic conditions than have been modeled previously. The authors’ experiments demonstrate that effective POD staffing plans must be responsive to variation and uncertainty in POD arrival patterns. These experiments highlight the need for command and control systems to be created to manage emergency response successfully. (Disaster Med Public Health Preparedness. 2009;3(Suppl 2):S121–S131)

We screened tuberculosis (TB) contacts as an outbreak investigation with tuberculin skin test (TST) and interferon-gamma release assay (IGRA). We evaluated adverse events and TB incidence in all persons screened after rifampicin (RFP) prophylaxis, and specifically assessed the new TB cases in relation to initial TST and IGRA results. The 180 contacts were divided into four groups: TST+/IGRA+ (n=101), TST+/IGRA− (n=22), TST−/IGRA+ (n=16), and TST–/IGRA– (n=41). RFP treatment (4 months) was prescribed only to the TST+/IGRA+ group. Of 87 contacts who initiated prophylaxis, adverse events occurred in 21 contacts (24·1%) including hepatotoxicity (11·5%), flu-like syndrome (5·7%), and thrombocytopenia (3·4%). TB developed in two TST+/IGRA+ subjects after completion of prophylaxis, including one multidrug-resistant (MDR)-TB case during 21·8 months of follow-up. Adverse events were frequent, and development of TB including MDR-TB occurred after RFP prophylaxis.

Summary

Background and objectives: Antibiotic therapy alters the diagnostic value of protected brush specimens. With protected brush specimens alone, diagnosing pneumonia requires 24 or 48 h. Addition of direct Gram staining shortens this delay. Antibiotic prophylaxis, recommended after major surgery, may influence the contribution of Gram staining to diagnosing postoperative pneumonia. Methods: During a 1-yr period, we retrospectively studied all patients on mechanical ventilation suspected of having postoperative pneumonia who had undergone fibreoptic bronchoscopy with protected brush specimens. Postoperative pneumonia was diagnosed when quantitative protected brush specimens culture results yielded 103 colony-forming units mL−1. Results: Fifty patients were clinically suspected of having postoperative pneumonia after cardiac (n = 42), vascular (n = 5) or thoracic (n = 3) surgery. Eleven (22%) samples were obtained during antibiotic prophylaxis. Twenty-two (44%) episodes were microbiologically proven. Gram-stain sensitivity was 95.5%, with 82.1% specificity, 80.7% positive-predictive value and 95.8% negative-predictive value. Concordance between direct Gram-stain-identified pathogens and Gram stain of cultured pathogens was significantly less frequent during antibiotic prophylaxis (63.6%) than afterwards (94.9%) (P < 0.05). Conclusion: Antibiotic prophylaxis diminished the diagnostic value of Gram staining of protected brush specimens. When protected brush specimens was performed during antibiotic prophylaxis, Gram staining accurately enabled early exclusion of postoperative pneumonia because of its excellent negative-predictive value. After antibiotic prophylaxis, Gram staining permitted early diagnosis of postoperative pneumonia identification of the responsible pathogen.

This study was designed to evaluate the effects of a prophylactic antibiotic regimen on the incidence of wound infection after clean neck dissections. A prospective series of 57 patients undergoing clean neck dissections with the use of perioperative ampicillin-sulbactam for 24 hours was compared with an historical control group of 51 patients undergoing clean neck dissections with no perioperative antibiotic use. The outcome variable was the incidence of post-operative wound infection. The two groups were similar for factors reported to influence the rate of post-operative wound infection. Wound infection occurred in one patient (1.7 per cent) in the study group and in seven patients (13.3 per cent) in the control group, the difference was statistically significant (p = 0.02). These data suggest that the use of a perioperative antibiotic for 24 hours in patients undergoing clean neck dissection results in significant reduction in the incidence of post-operative wound infection.