Eliminating Neglected Tropical Diseases

June 17th, 2010, by PETER J. HOTEZ

Most Americans are surprised to learn that the most common causes of illnesses among poor people living in the Western Hemisphere are caused by a group of parasitic infections known collectively as the neglected tropical diseases or “NTDs.”
Worldwide, approximately one billion people live on either no money or next to no money — below the World Bank poverty figure of US$1.25 per day. Most of these people are the families of subsistence farmers and urban slum dwellers. Approximately 100 million of the “bottom billion” live in the Latin American and Caribbean (LAC) region; most of them are likely either African Americans or Native Americans (indigenous populations).

Recent studies published in the Public Library of Science have shown that most of the bottom 100 million living in the LAC region are afflicted with one or more NTDs. For instance, almost all are infected with parasitic whipworms — a condition known as trichuriasis — which is associated with colitis and other forms of inflammatory bowel disease. Approximately 50 million people living in poverty have hookworms, which cause intestinal blood loss; 2-7 million people have schistosomiasis — a parasitic worm infection associated with flatworms in the blood vessels, while almost one million people have lymphatic filariasis, also known as elephantiasis, a disfiguring condition of the limbs and genitals. The health consequences of these huge numbers of poor people infected with NTDs is significant.
Our studies indicate that even though the NTDs are not well known by the lay community or even by many health care providers, their chronic disabling health impact actually exceeds much better known conditions such as HIV/AIDS. Moreover, the NTDs have been shown to actually cause poverty because of their ability to impair child development and intellect (hookworm reduces future wage earning by 40% or more), worker productivity, and pregnancy outcome. Indeed, the NTDs represent a stealth reason why the bottom 100 million in LAC cannot escape poverty.
Where did the NTDs come from? Based on recorded history, the NTDs were introduced into the LAC region, especially in Brazil and the sugar plantations of the Caribbean, through the Atlantic slave trade. Through 400 years of the Middle Passage, the NTDs previously and currently endemic to West Africa established in the LAC region. The medical historian Todd Savitt, as well as my colleagues at the CDC and the Pan American Health Organization, have pointed out that the NTDs also represent a historic legacy of slavery.
The good news is that today we can forever wipe out some of these legacies of slavery through low-cost treatments, which can be provided on an annual basis. In many cases, the treatments delivered through mass drug administration can be provided for only 50 cents a person per year. For that purpose we have established the Global Network for Neglected Tropical Diseases to provide large scale support for NTDs treatments.
In the LAC region, these treatments are delivered through a hemisphere-wide initiative supported jointly with the Inter-American Development Bank and the Pan American Health Organization. In addition, we have established mechanisms for treating the poorest people in sub-Saharan Africa where the greatest number of people with NTDs live.
What about the United States? No surprise to anyone, the U.S. still has major pockets of poverty in areas such as the Mississippi Delta and our inner cities. Today, millions of African Americans who live in these areas also suffer from parasitic infections — we call them neglected infections of poverty or NIoPs — although they differ from the ones in the LAC region. For instance, an estimated 3 million African Americans, mostly children, suffer from toxocariasis — a parasitic worm infection associated with asthma and developmental delays — while almost a million African American women have trichomoniasis in their genital tract. Many Hispanic Americans living in poverty also suffer from Chagas disease associated with heart defects and cysticercosis — a brain parasitic infection associated with seizures.

Dr. Peter Hotez is president of the Sabin Vaccine Institute and Distinguished Research Professor at The George Washington University. He is also the author of “Forgotten People, Forgotten Diseases.”

Last modified: April 26, 2011 at 10:56 am