A group of international ophthalmology and infectious disease experts is calling for toxoplasmosis to be formally recognized by the World Health Organization (WHO) as a neglected tropical disease (NTD), arguing that the condition meets the WHO’s criteria and that failure to act is perpetuating preventable vision loss, disability, and congenital disease.
Writing in PLOS Neglected Tropical Diseases, João Marcello Furtado and colleagues set out the case for toxoplasmosis as a condition that is common, controllable, disproportionately affects vulnerable populations, and remains underrepresented in research and policy. For ophthalmologists, the argument carries particular weight: toxoplasmosis is described as the leading intraocular infection worldwide and a major contributor to visual impairment and blindness.
Toxoplasma gondii is usually transmitted to humans through ingestion of raw or undercooked meat containing tissue cysts, or through food and water contaminated with oocysts shed by cats. Most infections are mild or subclinical, but the consequences can be severe. When newly acquired infection occurs during pregnancy, transplacental transmission can lead to miscarriage or lifelong neurological and visual impairment. Ocular toxoplasmosis can also cause recurrent retinochoroiditis and sight-threatening inflammation.
The paper authors argue that toxoplasmosis satisfies the first WHO criterion for NTD designation: a disproportionate burden in populations affected by poverty. Risk is higher where access to safe water, sanitation, food safety systems, prenatal care, and specialist services is limited. Congenital infection can entrench disadvantage, as children with visual or neurological impairment may face barriers to education, employment, and economic participation. Families already under socioeconomic pressure may also carry the long-term costs of repeated medical visits, rehabilitation, and lost income.
The disease also has a strong tropical and subtropical dimension. Warm temperatures, humidity, and rainfall support oocyst survival and environmental contamination. The authors highlight South America in particular, where virulent parasite genotypes circulate and rates of ocular disease are among the highest globally.
Crucially, toxoplasmosis is not inevitable. Prevention and control could be strengthened through measures already embedded in public health: safer food handling, improved water and sanitation, better environmental management, strengthened antenatal care, maternal screening, earlier diagnosis, and treatment. The authors stress that although toxoplasmosis may lack a single “hero intervention” such as mass drug administration that characterizes previous NTD designations, it still fits naturally within a One Health model that links human health, veterinary practice, agriculture, food safety, and environmental protection.
Another core argument is neglect. The paper notes that toxoplasmosis receives less research funding per disability-adjusted life-year (DALY) than some established NTDs, despite an estimated 190,000 congenital infections each year and around 1.68 million DALYs, largely driven by congenital disease. There is no licensed human vaccine, diagnostic access remains uneven, serological testing can be expensive and poorly standardized in low-resource settings, and treatment protocols still lack robust comparative evidence.
Official NTD recognition, the paper authors argue, would not be merely symbolic. It could place toxoplasmosis within WHO monitoring systems, unlock targeted research and implementation funding, support technical guidance for Ministries of Health, and help integrate prevention into maternal-child health, primary care, food safety, and One Health programs.
The paper also acknowledges potential risks, including pressure on already limited NTD resources. But the authors conclude that the scale of preventable congenital infection, visual impairment, and long-term disability makes the case for recognition compelling. For eye care professionals, the message is direct: toxoplasmosis is not just an infectious disease problem. It is a global vision health problem hiding in plain sight.
