PubMed | EpiX Analytics, University of California at Davis and U.S. Department of Agriculture
Type: Journal Article | Journal: Risk analysis : an official publication of the Society for Risk Analysis | Year: 2016
Our objective was to evaluate the effect that complexity in the form of different levels of spatial, population, and contact heterogeneity has in the predictions of a mechanistic epidemic model. A model that simulates the spatiotemporal spread of infectious diseases between animal populations was developed. Sixteen scenarios of foot-and-mouth disease infection in cattle were analyzed, involving combinations of the following factors: multiple production-types (PT) with heterogeneous contact and population structure versus single PT, random versus actual spatial distribution of population units, high versus low infectivity, and no vaccination versus preemptive vaccination. The epidemic size and duration was larger for scenarios with multiple PT versus single PT. Ignoring the actual unit locations did not affect the epidemic size in scenarios with multiple PT/high infectivity, but resulted in smaller epidemic sizes in scenarios using multiple PT/low infectivity. In conclusion, when modeling fast-spreading epidemics, knowing the actual locations of population units may not be as relevant as collecting information on population and contact heterogeneity. In contrast, both population and spatial heterogeneity might be important to model slower spreading epidemic diseases. Our findings can be used to inform data collection and modeling efforts to inform health policy and planning.
Groenendaal H.,EpiX Analytics |
Zagmutt F.J.,EpiX Analytics |
Patton E.A.,Trade and Consumer Protection |
Wells S.J.,University of Minnesota
Journal of Dairy Science | Year: 2015
Johne's disease (JD), or paratuberculosis, is a chronic enteric disease of ruminants, caused by infection with Mycobacterium avium ssp. paratuberculosis (MAP). Johne's disease causes considerable economic losses to the US dairy industry, estimated to be over $200 million annually. Available control strategies include management measures to improve calf hygiene, test-and-cull strategies, and vaccination. Although the first 2 strategies have shown to reduce the prevalence of MAP, they require dedicated and long-term efforts from dairy producers, with often relatively slow progress. As a result, uptake of both strategies has not been as wide as expected given the economic benefits especially of improved hygiene. Vaccination has also been found to reduce the prevalence and economic losses of JD, but most economic estimates have been based on simulation of hypothetical vaccines. In addition, if an animal is vaccinated, cross-reactivity between MAP antibodies and bovine tuberculosis (BTB) antigens may occur, decreasing the specificity of BTB tests. Therefore, MAP vaccination would cause additional indirect costs to the BTB surveillance and control program. The objective of the present study was to use data from a MAP vaccine trial together with an epidemiologic and economic model to estimate the direct on-farm benefits of MAP vaccination and to estimate the indirect costs of MAP vaccination due to the cross-reactivity with BTB tests. Direct economic benefits of MAP vaccination were estimated at $8.03 (90% predictive interval: -$25.97 to $41.36) per adult animal per year, all accruing to the dairy producers. This estimate is likely an underestimation of the true direct benefits of MAP vaccination. In addition, indirect economic costs due to cross-reactivity were $2.14 per adult animal per year, making MAP vaccination economically attractive. Only in regions or states with a high frequency of BTB testing (because of, for example, Mycobacterium bovis outbreaks in a wild deer population) and areas where typically small groups of animals are BTB tested would MAP vaccination not be economically attractive. © 2015 American Dairy Science Association.
Zagmutt F.J.,EpiX Analytics |
Sempier S.H.,Mississippi Alabama Sea Grant Consortium |
Hanson T.R.,03 Swingle Hall
Risk Analysis | Year: 2013
Emerging diseases (ED) can have devastating effects on agriculture. Consequently, agricultural insurance for ED can develop if basic insurability criteria are met, including the capability to estimate the severity of ED outbreaks with associated uncertainty. The U.S. farm-raised channel catfish (Ictalurus punctatus) industry was used to evaluate the feasibility of using a disease spread simulation modeling framework to estimate the potential losses from new ED for agricultural insurance purposes. Two stochastic models were used to simulate the spread of ED between and within channel catfish ponds in Mississippi (MS) under high, medium, and low disease impact scenarios. The mean (95% prediction interval (PI)) proportion of ponds infected within disease-impacted farms was 7.6% (3.8%, 22.8%), 24.5% (3.8%, 72.0%), and 45.6% (4.0%, 92.3%), and the mean (95% PI) proportion of fish mortalities in ponds affected by the disease was 9.8% (1.4%, 26.7%), 49.2% (4.7%, 60.7%), and 88.3% (85.9%, 90.5%) for the low, medium, and high impact scenarios, respectively. The farm-level mortality losses from an ED were up to 40.3% of the total farm inventory and can be used for insurance premium rate development. Disease spread modeling provides a systematic way to organize the current knowledge on the ED perils and, ultimately, use this information to help develop actuarially sound agricultural insurance policies and premiums. However, the estimates obtained will include a large amount of uncertainty driven by the stochastic nature of disease outbreaks, by the uncertainty in the frequency of future ED occurrences, and by the often sparse data available from past outbreaks. © 2013 Society for Risk Analysis.
Zagmutt F.J.,EpiX Analytics |
Carroll C.A.,Teva Neuroscience
International Journal of Neuroscience | Year: 2015
Purpose/Aim of the Study: Trials of dimethyl fumarate (DMF) and teriflunomide, two new oral therapies for relapsing-remitting multiple sclerosis (RRMS) were recently published [1, 2, 3]. A comparison of their safety against glatiramer acetate-a prevalent injectable treatment-is relevant to inform therapy-switching decisions. The study objective was to conduct a systematic review and mixed treatment comparison of total AEs in RCTs of dimethyl fumarate 240 mg bid (DMF2) or tid (DMF3), glatiramer acetate 20 mg injectable daily (GA), and teriflunomide 7 mg (TERI7) or 14 mg (TERI14) daily in RRMS patients. Materials and Methods: Articles were selected following Cochrane guidelines. A network meta-analysis was used to compare the odds of patients experiencing at least one AE between drugs, using placebo as baseline. Drugs were compared using the odds ratio (OR), credible interval (CrI), and confidence in OR ≥1 (PrOR). The mean rank (best = 1) and corresponding Surface-Under-Cumulative-Ranking (SUCRA) (best = 100%) were reported. Results: 3737 patients from three RCTs were included for analysis. Patients receiving GA exhibited the lowest AEs (DMF2 [OR = 2.67, PrOR = 98.7%], DMF3 [OR = 1.92, PrOR = 95.3%], Teri7 [OR = 2.74, PrOR = 95.2%], Teri14 [OR = 3.03, PrOR = 96.4%]), and equivalent to PB (OR = 1.60; PrOR = 94.3%). No other significant differences were found. GA also ranked with the lowest AEs (rank = 1.2, SUCRA = 96.0%), whereas DMF2 and Teri14 ranked highest (rank = 4.8). Conclusions: RRMS patients treated with glatiramer have the lowest odds of experiencing AEs, while patients taking DMF or teriflunomide have similar, higher odds of developing AEs, suggesting that patients treated with glatiramer may have higher QoL than patients under DMF or teriflunomide. © 2014 Taylor and Francis.
PubMed | EpiX Analytics
Type: Journal Article | Journal: The International journal of neuroscience | Year: 2012
The comparative safety profiles of monotherapeutic treatments for Parkinsons disease (PD) can provide valuable therapeutic information. The objective of this study was to perform an indirect comparison of Adverse Events (AEs) and Dropout Rates (DRs) among clinical trials of pramipexole, ropinirole, and rasagiline. Outcomes analyzed included DRs, total AEs, and AE categories: Cognitive (CG), Gastrointestinal (GI), and Sleep/Fatigue (SF). The odds-ratio (OR) and Credible Interval (CrI) of outcomes between products using placebo as common comparator was calculated using indirect meta-analytical methods. AEs incidences for subjects receiving rasagiline were not significantly different from placebo, whereas DRs were significantly lower than for placebo (OR = 0.55; 95% CrI = 0.34-0.88). Patients receiving pramipexole or ropinirole had higher incidence of all AEs and DRs than patients taking rasagiline, except for the nonsignificant incidence of CG for ropinirole vs. rasagiline (1.76; 0.69-4.70). The incidence of GI (2.11; 1.13-4.06) and SF (2.75; 1.42-5.47) was significantly higher for ropinirole than for pramipexole, whereas the incidence of CG was significantly lower for ropinirole than for pramipexole (0.22; 0.07-0.69). Findings suggest that subjects with early PD treated with rasagiline have fewer AEs and DRs than those treated with pramipexole or ropinirole. GI and SF AEs were highest for subjects treated with ropinirole, while individuals treated with pramipexole exhibited the highest incidence of cognitive AEs.
PubMed | Lane College, EpiX Analytics and University of Edinburgh
Type: | Journal: Scientific reports | Year: 2015
The expanding distribution of African swine fever (ASF) is threatening the pig industry worldwide. Most outbreaks occur in backyard and small-scale herds, where poor farmers often attempt to limit the diseases economic consequences by the emergency sale of their pigs. The risk of African swine fever virus (ASFV) release via this emergency sale was investigated. Simulation modeling was used to study ASFV transmission in backyard and small-scale farms as well as the emergency sale of pigs, and the potential impact of improving farmers and traders clinical diagnosis ability-its timeliness and/or accuracy-was assessed. The risk of ASFV release was shown to be high, and improving farmers clinical diagnosis ability does not appear sufficient to effectively reduce this risk. Estimates obtained also showed that the distribution of herd size within the backyard and small-scale sectors influences the relative contribution of these farms to the risk of release of infected pigs. These findings can inform surveillance and control programs.