The U.S. and Mexico: Addressing a shared legacy of neglected tropical diseases and poverty

We are building a strong evidence base that neglected tropical diseases (NTDs) are now widespread among the poorest people living in the United States. NTDs are unique poverty-related infections that cause long-term and debilitating effects. While they don’t command the same attention of higher profile infections such as influenza, the NTDs are considered the most common afflictions of the world’s poor and a major factor underlying their ill health.

Our studies now indicate that NTDs are also found among the poor in the southern United States. We estimate that 12 million Americans, most of them impoverished, live with an NTD. They are likely diseases you have never heard of — Chagas disease, cysticercosis, toxocariasis, toxoplasmosis, and trichomoniasis — in addition to viruses transmitted by mosquitoes, including dengue and West Nile virus infection.

As the 2016 U.S. presidential campaign heats up, there is a strong temptation to blame immigrants coming across our southern border as the source of our American NTDs. But we have found that in most cases transmission of these diseases currently occurs within the U.S. For example, there are millions of African-Americans who live in poverty with these diseases and who have never left the country.

The fact that 12 million impoverished Americans are affected suggests that NTDs rank among our nation’s most common health disparities. They occur at the confluence of extreme poverty and our warm subtropical climate.

NTDs are not unique to the U.S. Instead they are found wherever extreme poverty combines with suitable climate conditions. In Mexico, NTDs are also widespread but not necessarily along its border with the U.S. Instead, NTDs concentrate in Mexico’s poorest southern states such as Chiapas, Oaxaca and Guerrero, or in the Mayan villages on the Yucatan Peninsula. Many of the NTDs are same as those found in the poorest parts of Texas or elsewhere along the U.S. Gulf Coast.

There are opportunities to jointly address the NTDs shared between the U.S. and Mexico. First and foremost, we need to conduct programs to actively determine exactly how widespread these diseases are and who might be at greatest risk. This year the Texas legislature passed the first NTD bill ever in the U.S., which will help to facilitate epidemiological surveillance activities in our state, but there are needs to conduct similar activities across the southern U.S., as well as in Mexico. We also need to better understand how NTDs are actually transmitted and how poverty contributes to disease transmission. We need to make diagnostics and treatments more available and affordable. For instance, less than 1 percent of people living with Chagas disease in either the U.S. or Mexico are diagnosed and treated for their illness. We need programs to make physicians and other health care providers aware of these diseases and how to manage and treat them, while simultaneously shaping policies on disease prevention in poor and vulnerable towns, districts, and regions. Finally, there is an important research and development agenda, as in many cases we do not yet have in-hand drugs, diagnostics and vaccines for many NTDs.

On September 29-30, Rice University’s Baker Institute, together with the National School of Tropical Medicine, will host a high-level summit to address these and related issues on the NTDs shared between the U.S. and Mexico. The summit will bring together government officials, policymakers, scientists and public health experts from both countries. By doing a “deep dive” on these diseases we hope to make progress toward reducing the health and economic impact of these horrific and all-too-common health disparities.

The authors of the blog are Baker Institute experts Peter J. Hotez, M.D., Ph.D., fellow in disease and poverty;  Jennifer Herricks, Ph.D., posdoctoral fellow; and Kirstin R.W. Matthews, Ph.D., fellow in science and technology policy. Dr. Hotez is also dean of the National School of Tropical Medicine at Baylor College of Medicine.