No abstract

No abstract

BackgroundMeasles cases continue to occur among susceptible individuals despite the elimination of endemic measles transmission in the United States. Clustering of disease susceptibility can threaten herd immunity and impact the likelihood of disease outbreaks in a highly vaccinated population. Previous studies have examined the role of contact tracing to control infectious diseases among clustered populations, but have not explicitly modeled the public health response using an agent-based model.MethodsWe developed an agent-based simulation model of measles transmission using the Framework for Reconstructing Epidemiological Dynamics (FRED) and the Synthetic Population Database maintained by RTI International. The simulation of measles transmission was based on interactions among individuals in different places: households, schools, daycares, workplaces, and neighborhoods. The model simulated different levels of immunity clustering, vaccination coverage, and contact investigations with delays caused by individuals’ behaviors and/or the delay in a health department’s response. We examined the effects of these characteristics on the probability of uncontrolled measles outbreaks and the outbreak size in 365 days after the introduction of one index case into a synthetic population.ResultsWe found that large measles outbreaks can be prevented with contact investigations and moderate contact rates by having (1) a very high vaccination coverage (≥ 95%) with a moderate to low level of immunity clustering (≤ 0.5) for individuals aged less than or equal to 18 years, or (2) a moderate vaccination coverage (85% or 90%) with no immunity clustering for individuals (≤18 years of age), a short intervention delay, and a high probability that a contact can be traced. Without contact investigations, measles outbreaks may be prevented by the highest vaccination coverage with no immunity clustering for individuals (≤18 years of age) with moderate contact rates; but for the highest contact rates, even the highest coverage with no immunity clustering for individuals (≤18 years of age) cannot completely prevent measles outbreaks.ConclusionsThe simulation results demonstrated the importance of vaccination coverage, clustering of immunity, and contact investigations in preventing uncontrolled measles outbreaks.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-015-1766-6) contains supplementary material, which is available to authorized users.

No abstract

Objective To compare the relative effectiveness of methotrexate and mycophenolate mofetil for non-infectious intermediate uveitis, posterior uveitis, or panuveitis. Design Multicenter, block-randomized, observer-masked clinical trial Participants Eighty patients with non-infectious intermediate, posterior or panuveitis requiring corticosteroid-sparing therapy at Aravind Eye Hospitals in Madurai and Coimbatore, India. Intervention Patients were randomized to receive 25mg weekly oral methotrexate or 1g twice daily oral mycophenolate mofetil and were monitored monthly for 6 months. Oral prednisone and topical corticosteroids were tapered. Main Outcome Measures Masked examiners assessed the primary outcome of treatment success, defined by achieving the following at 5 and 6 months: (1) ≤0.5+ anterior chamber cells, ≤0.5+ vitreous cells, ≤0.5+ vitreous haze and no active retinal/choroidal lesions in both eyes, (2) ≤ 10 mg of prednisone and ≤ 2 drops of prednisolone acetate 1% a day and (3) no declaration of treatment failure due to intolerability or safety. Additional outcomes included time to sustained corticosteroid-sparing control of inflammation, change in best spectacle-corrected visual acuity, resolution of macular edema, adverse events, subgroup analysis by anatomic location, and medication adherence. Results Forty-one patients were randomized to methotrexate and 39 to mycophenolate mofetil. A total of 67 patients (35 methotrexate, 32 mycophenolate mofetil) contributed to the primary outcome. Sixty-nine percent of patients achieved treatment success with methotrexate and 47% with mycophenolate mofetil (p=0.09). Treatment failure due to adverse events or tolerability was not significantly different by treatment arm (p=0.99). There were no statistically significant differences between treatment groups in time to corticosteroid-sparing control of inflammation (p=0.44), change in best spectacle-corrected visual acuity (p=0.68), and resolution of macular edema (p=0.31). Conclusions There was no statistically significant difference in corticosteroid-sparing control of inflammation between patients receiving methotrexate or mycophenolate mofetil. However, there was a 22% difference in treatment success favoring methotrexate.