Epidemiologic Investigation of a Cluster of Neuroinvasive Bacillus cereus Infections in 5 Patients With Acute Myelogenous Leukemia

Background. Five neuroinvasive Bacillus cereus infections (4 fatal) occurred in hospitalized patients with acute myelogenous leukemia (AML) during a 9-month period, prompting an investigation by infection control and public health officials. Methods. Medical records of case-patients were reviewed and a matched case-control study was performed. Infection control practices were observed. Multiple environmental, food, and medication samples common to AML patients were cultured. Multilocus sequence typing was performed for case and environmental B cereus isolates. Results. All 5 case-patients received chemotherapy and had early-onset neutropenic fevers that resolved with empiric antibiotics. Fever recurred at a median of 17 days (range, 9–20) with headaches and abrupt neurological deterioration. Case-patients had B cereus identified in central nervous system (CNS) samples by (1) polymerase chain reaction or culture or (2) bacilli seen on CNS pathology stains with high-grade B cereus bacteremia. Two case-patients also had colonic ulcers with abundant bacilli on autopsy. No infection control breaches were observed. On case-control analysis, bananas were the only significant exposure shared by all 5 case-patients (odds ratio, 9.3; P = .04). Five environmental or food isolates tested positive for B cereus, including a homogenized banana peel isolate and the shelf of a kitchen cart where bananas were stored. Multilocus sequence typing confirmed that all case and environmental strains were genetically distinct. Multilocus sequence typing-based phylogenetic analysis revealed that the organisms clustered in 2 separate clades. Conclusions. The investigation of this neuroinvasive B cereus cluster did not identify a single point source but was suggestive of a possible dietary exposure. Our experience underscores the potential virulence of B cereus in immunocompromised hosts

Demand and Supply Dynamics for Sequentially Released Products in International Markets: The Case of Motion Pictures

We develop an econometric model to study a setting in which a new product is launched first in its domestic market and only at a later stage in foreign markets, and where the product's performance (“demand”) and availability (“supply”) are highly interdependent over time within and across markets. Integrating literature on international diffusion, “success-breeds-success” trends, and the theatrical motion picture industry—the focus of the empirical analysis—we develop a dynamic simultanenous-equations model of the drivers and interrelationship of the behavior of consumers (“audiences”) and retailers (“exhibitors”). Our findings emphasize the importance of considering the endogeneity and simultaneity of audience and exhibitor behavior, and challenge conventional wisdom on the determinants of box office performance (which is predominantly based on modeling frameworks that fail to account for the interdependence of performance and availability). Specifically, we find that variables such as movie attributes and advertising expenditures, which are usually assumed to influence audiences directly, mostly influence revenuesdirectly, namely through their impact on exhibitors' screen allocations. In addition, consistent with the idea that the “buzz” for a movie is perishable, we find that the longer is the time lag between releases, the weaker is the relationship between domestic and foreign market performance—an effect mostly driven by foreign exhibitors' screen allocations.Dynamic Simultaneous Equations Modeling, International Release Strategies, Entertainment Marketing, Motion Picture Distribution and Exhibition, Channel Management