Over 1 billion people globally are estimated to be infected with Toxoplasma gondii with severe or unknown consequences and no safe and effective therapies are available against congenital or persistent chronic infection. We propose that atovaquone and diclazuril synergistically protect against fetal-maternal toxoplasmosis.

METHODS: Programmed pregnant mice were treated with atovaquone and diclazuril monotherapy, or combined (atovaquone + diclazuril) therapy and infected with tachyzoites (0, 300, 600) and the course of infection was studied.

RESULTS: Infected dams with low dose (300) developed moderate toxoplasmosis complications and treatments were similarly effective with minor differences between monotherapies. In contrast, major differences were observed amongst varied treatments during high-dose (600) infection and severe related- toxoplasmosis complications as follows. Dams developed hydrothorax, ascities and excess weight gain. Combined therapy (P < 0.01) and to a lesser extent diclazuril monotherapy (P < 0.05) protected dams from excess weight, hydrothorax, and ascities. Infected dams exhibited splenomegaly, hepatomegaly and severe hepatitis. Combined therapy synergistically normalized pathology (P < 0.001) and to a lesser degree monotherapy (diclazuril P < 0.01, and atovaquone P < 0.05) protected dams from hepatitis and splemomegaly. Additionally, behavioral response to pain stimuli and fetal weight and fetal numbers were significantly preserved in treated dams.

CONCLUSIONS: This is the first report describing combined atovaquone and diclazuril therapy (a) to be safe in pregnancy, (b) to exert novel synergistic effects, and (c) to protect dams and their nested fetuses against adverse effects of severe toxoplasmosis.

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Published in International Journal of Clinical Medicine, v. 5, no. 15, p. 921-932.

Copyright © 2014 by author and Scientific Research Publishing Inc.

This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/

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Dr. Thomas Tobin from Maxwell H. Gluck Equine Center, College of Agriculture, University of KY, provided a portion of funding from Kentucky Science and Technology KSTC 721-RFP-006 and the concept of diclazuril in congenital toxoplasmosis [28]. . . . This investigation was supported by the Grant from National Institutes of Health NIH-DE019177 (Dr. Helieh S. Oz).