Calls to Elevate Toxoplasmosis Concern

Researchers from around the globe are advocating for a serious reconsideration of the parasite Toxoplasma gondii, which spreads through cat feces and contaminated food and water. Their latest paper suggests that the World Health Organization (WHO) should formally identify T. gondii as a neglected tropical disease.

This infection, known as toxoplasmosis, affects approximately 1 in 10 Americans and can lead to serious health issues, including blindness. Disturbingly, it may also influence personality traits. The researchers believe that recognizing T. gondii in this way could enhance both research efforts and preventative measures in the regions most at risk.

Justine Smith, a senior author and ophthalmologist at Flinders University in Australia, remarked that while progress is being made against other neglected tropical diseases, toxoplasmosis seems to be overlooked.

The Toxoplasmosis Challenge

T. gondii is a single-celled protozoan parasite infamous for its life cycle. Cats are its primary hosts, but it first takes residence in rodents, which then become prey for cats. This parasite can infect nearly all warm-blooded animals, including humans. We typically catch it from handling infected cat feces, eating contaminated food, or consuming undercooked meat.

Unlike rodents, humans cannot spread toxo further. Once contracted, the parasite tends to remain dormant in the body for life, often without causing significant issues. However, it’s not entirely benign, as João Furtado, a fellow ophthalmologist from the University of São Paulo in Brazil, pointed out.

“Most infections are mild and go unnoticed,” he explained. “But if a woman is infected during pregnancy, that can lead to serious complications, as the parasite can be transmitted to the fetus. This can cause miscarriage or long-term visual impairment.”

In other cases, the parasite can move to the eyes and cause retinal inflammation, known as ocular toxoplasmosis, which is a leading cause of retinal infections worldwide. Left untreated, it could result in lasting vision loss.

Interestingly, toxo seems to alter the behavior of infected rodents, making them less fearful and bolder, which increases their chances of being captured by cats. Some studies hint at the potential for toxo to affect larger animals, including humans, possibly even increasing the risk of conditions like schizophrenia or brain cancer.

The Case for Recognition

According to the research team, toxo meets all the WHO’s criteria for a neglected tropical disease: it affects those living in poverty disproportionately, presents a significant burden in tropical regions, is preventable and treatable, yet receives insufficient attention in terms of research.

Labeling toxo as such could lead to improved funding and resources aimed at addressing it, potentially resulting in vaccines and better treatment options. “Right now, there’s no commercial vaccine available,” Smith noted. “The medications we have can help manage flare-ups but do not cure the infection.”

Increased funding could support essential preventative measures, such as enhancing sanitation and food safety, particularly for communities at higher risks, like pregnant women. The paper was published recently in the journal PLOS Neglected Tropical Diseases.

Despite being labeled a tropical disease, T. gondii is widespread, with an estimated 10% of Americans infected. The parasite poses a more significant risk in places like Brazil, where it can affect up to 80% of impoverished populations needing urgent assistance.

Regardless of where one lives, there are ways to mitigate the risk of exposure. Furtado emphasized, “Toxoplasmosis is quite common, but much of it is preventable. There’s no need for panic, and cat owners shouldn’t feel the need to abandon their pets. The issue extends beyond cats.”

He suggests simple actions—like cooking meat thoroughly, washing fruits and vegetables, and practicing good hygiene after handling cat litter or soil—can be effective. At the same time, he believes that responsibility shouldn’t rest solely on individuals.

“Safe food systems, clean water, sanitation, prenatal care, timely diagnosis, and treatment are collective responsibilities,” he asserted. “That’s why toxoplasmosis should be regarded not only as an individual health issue but also as a public health challenge.”