An agent-based model for the transmission dynamics of Toxoplasma gondii.
Summary of "An agent-based model for the transmission dynamics of Toxoplasma gondii."
Toxoplasma gondii (T. gondii) is a unicellular protozoan that infects up to one-third of the world's human population. Numerous studies revealed that a latent infection of T. gondii can cause life-threatening encephalitis in immunocompromised people and also has significant effects on the behavior of healthy people and animals. However, the overall transmission of T. gondii has not been well understood although many factors affecting this process have been found out by different biologists separately. Here we synthesize what is currently known about the natural history of T. gondii by developing a prototype agent-based model to mimic the transmission process of T. gondii in a farm system. The present model takes into account the complete life cycle of T. gondii, which includes the transitions of the parasite from cats to environment through feces, from contaminated environment to mice through oocysts, from mice to cats through tissue cysts, from environment to cats through oocysts as well as the vertical transmission among mice. Although the current model does not explicitly include humans and other end-receivers, the effect of the transition to end-receivers is estimated by a developed infection risk index. The current model can also be extended to include human activities and thus be used to investigate the influences of human management on disease control. Simulation results reveal that most cats are infected through preying on infected mice while mice are infected through vertical transmission more often than through infection with oocysts, which clearly suggests the important role of mice during the transmission of T. gondii. Furthermore, our simulation results show that decreasing the number of mice on a farm can lead to the eradication of the disease and thus can lower the infection risk of other intermediate hosts on the farm. In addition, with the assumption that the relation between virulence and transmission satisfies a normal function, we show that intermediate virulent lineages (type II) can sustain the disease most efficiently, which can qualitatively agree with the fact that the evolution of the parasite favors intermediate virulence. The effects of other related factors on transmission, including the latent period and imprudent behavior of mice, and prevention strategies are also studied based on the present model.
Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, TN 37996-2030, United States; School of Civil Engineering and Mechanics, Huazhong University of Science & Technology, Wuhan 430074, China.
This article was published in the following journal.
Name: Journal of theoretical biology
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/22004993
- DOI: http://dx.doi.org/10.1016/j.jtbi.2011.10.006
Medical and Biotech [MESH] Definitions
The acquired form of infection by Toxoplasma gondii in animals and man.
A genus of protozoa parasitic to birds and mammals. T. gondii is one of the most common infectious pathogenic animal parasites of man.
A macrolide antibiotic produced by Streptomyces ambofaciens. The drug is effective against gram-positive aerobic pathogens, N. gonorrhoeae, and staphylococci. It is used to treat infections caused by bacteria and Toxoplasma gondii.
Infections of the BRAIN caused by the protozoan TOXOPLASMA gondii that primarily arise in individuals with IMMUNOLOGIC DEFICIENCY SYNDROMES (see also AIDS-RELATED OPPORTUNISTIC INFECTIONS). The infection may involve the brain diffusely or form discrete abscesses. Clinical manifestations include SEIZURES, altered mentation, headache, focal neurologic deficits, and INTRACRANIAL HYPERTENSION. (From Joynt, Clinical Neurology, 1998, Ch27, pp41-3)
Prenatal protozoal infection with TOXOPLASMA gondii which is associated with injury to the developing fetal nervous system. The severity of this condition is related to the stage of pregnancy during which the infection occurs; first trimester infections are associated with a greater degree of neurologic dysfunction. Clinical features include HYDROCEPHALUS; MICROCEPHALY; deafness; cerebral calcifications; SEIZURES; and psychomotor retardation. Signs of a systemic infection may also be present at birth, including fever, rash, and hepatosplenomegaly. (From Adams et al., Principles of Neurology, 6th ed, p735)
We compared the transplacental-transmission ability of Toxoplasma gondii and Neospora caninum in cattle. One uninfected pregnant heifer served as control, while three were inoculated with N. caninum K...
Introduction: Toxoplasma gondii, the agent that causes toxoplasmosis, is an opportunistic parasite that infects many mammalian species. It is an obligate intracellular parasite that causes severe cong...
Toxoplasma gondii of warm-blooded animals and humans is an important pathogenic agent throughout the world. Soil is increasingly recognized as an important source in the transmission of Toxoplasma. To...
Two studies, of a natural infection and an experimental infection, were performed in order to study congenital transmission of Toxoplasma gondii in cattle. In the first study, 50 fetuses were harveste...
The shortfalls of the current treatment options against infections with the parasite Toxoplasma gondii (T. gondii) necessitates the development of non-toxic and well-tolerated alternatives. To address...
To evaluate pyrimethamine as a prophylactic agent against toxoplasmic encephalitis in individuals who are coinfected with HIV and latent Toxoplasma gondii. Toxoplasmic encephalitis is a m...
We investigate whether the add-on specific antitoxoplasmatic medication has positive effects in individuals with schizophrenia or major depression seropositive for Toxoplasma gondii (TG) i...
With a HIV incidence much higher in the DFA than in European French territory, this disease is a major public health problem in these areas, especially in French Guiana. Cerebral toxoplas...
To compare pyrimethamine and intravenous (IV) clindamycin vs. pyrimethamine and sulfonamides in the treatment of AIDS patients with central nervous system (CNS) Toxoplasma gondii.
To evaluate the effectiveness and toxicity of oral azithromycin and pyrimethamine as acute therapy for toxoplasmic encephalitis in AIDS patients. To assess the toxicity and effectiveness o...