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Biomedical subjects

R Shonkwiler

Publications and source records attributed to R Shonkwiler.

5 recordsLinked to original sources

A gonorrhea model treating sensitive and resistant strains in a multigroup population.

In recent years gonorrhea infection with antibiotic-resistant strains, especially PPNG, has become a significant public health problem. Drawing on the gonorrhea model of Lajmanovich and Yorke, a multigroup model that embraces both resistant and sensitive strains of the organism is introduced. It is shown that, like the Lajmanovich and Yorke (single-strain) model, in the general case the sensitive-resistant model has a unique globally asymptotic equilibrium. As a function of the interplay between contact rates, cure rates, and reversion rates, the equilibrium can lead to endemic infection with sensitive infection only, resistant infection only, or both, or to elimination of sensitive and resistant infection.

Gonorrhea

A validation study of a simulation model for common source epidemics.

We consider an environment and a population of individuals who are susceptible to a disease caused by a pathogen spread from a common source. We view the sequence of events resulting in the illness of some individuals as consisting of three components: the introduction of the pathogens and their dispersion through the environment, the movement of susceptible individuals through the environment, and the physiological effects of exposure of susceptible individuals to various pathogen levels. We identify four important parameters: two for each of the first and third components. A computer simulation of a model with these features is developed and implemented to study a 1977 outbreak of toxoplasmosis. Questions of parameter estimation and model validation are considered in detail.

Computer Simulation