Toxocariasis: A neglected infection for the Anthropocene epoch

While ascariasis, trichuriasis, and hookworm infection dominate global efforts to control human soil-transmitted helminth infections, a picture is unfolding to suggest that toxocariasis is now a fourth and perhaps equally important parasitic disease. Toxocara eggs are widespread in the environment and practically ubiquitous in the soils of many subtropical and tropical regions of Asia, Africa, and the Americas. Human zoonotic infection is also highly prevalent in these areas, based on serologic studies to detect anti-Toxocara antibodies. The relevance of these findings to human and animal disease burden estimates is still largely unknown, but some studies implicate exposure to Toxocara eggs and larvae to both pulmonary disease leading to asthma, and neurologic disease resulting in epilepsy and cognitive delays. On that basis, human toxocariasis may emerge as one of the most important neglected parasitic infections of humans. With anticipated global warming and urbanization associated with our modern human-transformed geological epoch, known as the Anthropocene, it is likely that toxocariasis will become a dominant infection and one widely prevalent in our future and projected mega-cities.