Fall 1999 Issue
A Shameful Disease
The CDC Foundation joins the fight to eradicate lymphatic filariasis, the world’s second-leading cause of permanent disability
A young woman in southeast Asia sees her chances of ever getting married evaporate. Two brothers in Haiti are deeply embarrassed about their mother’s appearance. An African man endures the hidden shame of a disfiguring illness he wants no one to know about.
These are the people who suffer from lymphatic filariasis (LF), a parasitic disease with horrifying physical and social consequences. Ranked by the World Health Organization as the world’s second-leading cause of permanent disability, lymphatic filariasis affects 120 million people in tropical areas all over the globe.
“It is truly a terrible disease,” says Dr. David Addiss, deputy chief of the Epidemiology Branch in CDC’s Division of Parasitic Diseases. “We’re working in a community in Haiti where 50 percent of the population is infected.”
Dr. Addiss is one of several CDC scientists providing technical expertise to countries asking for help. His involvement stems from CDC’s role as a World Health Organization collaborating center for eliminating lymphatic filariasis. Therein lies the good news: Lymphatic filariasis can be eliminated. The challenge comes in mobilizing communities to implement disciplined, long-term treatment programs.
It’s a mammoth task, particularly in developing countries with little or no public health infrastructure, and the CDC Foundation is joining CDC in taking up the fight.
People contract lymphatic filariasis when bitten by a mosquito infected with a parasitic worm. After the bite, tiny worms crawl through the hole in the skin, looking for lymphatic vessel tissue in which to settle.
“In lymphatic filariasis, the worms develop into adults, and the victim’s lymphatic vessels become dilated and flabby,” says Dr. Addiss. “The lymphatic system is designed to flush waste from the human body, so any damage to the system can cause a build-up of excess fluid.” In women, he explains, this lymphatic damage can lead to elephantiasis, a massive swelling of the legs. In men, the worms tend to live in the scrotal area, causing fluid to form around the testicles, which fosters hydrocele and other debilitating genital diseases.
The physical, psychological, and social effects of LF are devastating. In weakening the lymphatic system, the disease inhibits the body’s main defense against bacterial infections. The pooling of fluid in a victim’s legs gives bacteria a hospitable place to grow, and the impaired defense system can’t fight off the infection. Repeat infections cause further damage, making the sufferer even more susceptible to new infections and swelling.
“Ultimately, the only way to stop this vicious cycle is to interrupt the life cycle of the worm,” says Dr. Addiss. “And we now have the drugs to do that.”
The worms can only reproduce inside the human body. After the adults mate, millions of microfilaria, the worms’ “offspring,” begin to circulate in the victim’s blood. Mosquitoes ingest these microfilaria when they bite an infected person, then spread the infection to other people they bite.
In January 1998, the pharmaceutical company SmithKline Beecham announced a massive donation program of albendazole, a drug that, when combined with other drugs, suppresses microfilaria. If every person infected or at risk for lymphatic filariasis could be treated with the drug once a year for five to ten years - the life span of the worms - the parasite could be eradicated. Another effective method is to fortify ordinary table salt, which people consume every day, with the drug DEC.
“Everyone involved with this disease is excited about the possibilities for eradication,” says Dr. Addiss. “The first step was to bring the right people together on a global level. What we needed was a meeting of the minds between experts in lymphatic filariasis and the professionals who develop manuals for disease elimination programs.”
With the help of the CDC Foundation, that meeting took place in July. Through a grant from the SmithKline Beecham Foundation, some of the world’s top experts in lymphatic filariasis gathered at CDC to examine the critical components of programs to eliminate lymphatic filariasis. The product from that meeting is a guidebook to help managers of elimination efforts initialize and sustain their programs, as well as deliver drug treatments to communities that need them.
These guiding materials are needed. “People with lymphatic filariasis frequently are ostracized from their spouses, children and communities,” says Julie Bettinger, an Association of Schools of Public Health Fellow with the CDC. “They feel a sense of shame. Many don’t want to come out of their homes … They lose their families, their jobs and their chance for an education.”
Now, there is new cause for hope. “Scientifically, we’ve got the tools to get rid of this horrible disease,” Dr. Addis says. “We know how to interrupt its transmission, just as we’ve done with smallpox. It’s a matter now of taking those tools and applying them. And learning as we go.”