Lymphatic Filariasis, abbreviated as LF, also known as elephantiasis, is a disease caused by the burrowing of parasitic worms inside of the human lymphatic system. The parasitic nematode worms are called filariae, and the species of worms that tend to burrow in the lymph system are the Wuchereria bancrofti, Brugia malayi and Brugia timori. Like many other parasitic worms, male worms are of smaller stature, ranging from three to four centimeters in length, and females around eight to ten centimeters.
The lymphatic helminthes survive only in the lymphatic system, colonize and build “nests” in lymph vessels and nodes, disrupting the bodies natural response to foreign pathogens. As phagocytes move throughout the body to destroy pathogens, their microscopic journeys are blocked by the nesting worms. As lymph, or lymphatic fluids attempt to get past the helminth, the fluid stretches the vessels and begins to build up, resulting in an enlargement of the area. The area is filled with lymph, and tissue fluid from swelling, which can grow in some cases to over one hundred pounds. The disfigurement causes excessive pain in many cases, and are usually associated with “infection-like symptoms” such as fever and swelling because of the bodies’ response to the foreign parasite.
Many victims of the disfiguring infection do not realize they are infected until years after the contraction of the filariae. Host often notice lymphedema (swelling of the extremities) or hydrocele (swelling of scrotum) in their adult years; leading scientists to believe that the disease is often contracted at a younger age, and the parasites gradually cause enough damage to result in such large build ups of fluid.
Image showing the disfiguring effects of Lymphatic Filariasis on lower extremities
Not only do the parasites cause swelling of the breast, extremities, and scrotum, but they also cause proteinuria and hematuria due to damage of the kidneys. The devastating parasites are found in mosquitoes all over the world. More specifically the Brugia malayi are most often located areas of east and south Asia, India, Indonesia, Malaysia and Thailand. The Wuchereria bancrofti are commonly found in rural Africa and Pacific Islands. The reason that these areas are hotbeds for Lymphatic Filariasis infection is due to poverty rates and access to preventative and post-infection treatments.
In areas of low poverty, it is rare that people will have a steady, filtered water supply, a sewage or waste system, and closed bathrooms. With areas covered in defecation, bugs, rabid animals and infectious pathogens are common. In areas of low poverty, people are often not educated on how to safely prepare a meal by boiling water and food to eliminate pathogens before consumption. For LF, mosquitoes are the carrier, and starter of the “Lymphatic Filariasis cycle.” When mosquitoes bite an infected human, they consume the microfilaria or parasitic larvae, which will then develop and migrate to the mosquito’s’ mouth. When that mosquito goes and bites another person, it drops off those larvae into another human, thus creating another LF cycle.
Especially in destitute areas, where mosquitoes can feast, people are at high risk of infection. It is hard for people to contract LF after just one bite because of the small amount of parasitic larvae in each bite. Often, people require multiple bites over a short period of time to contract the disease from mosquitoes. Once the larvae develop in the bloodstream and settle in the lymphatic system, they lay eggs which will continue in their parent’s trails; burrowing, and nesting in their human hosts’ only real internal defense system.
Treatment for the disease is fairly basic when taking preventative measures. Sadly this is not the case for those already infected with the disease. Once infected, there are antiparasitic medicines which can be administered every few months to hopefully eliminate adult, full sized worms. In areas of extreme poverty often people are unable to get these medicines. To lessen the negative effects of LF, sufferers should wash their infected body part with soap and clean water to eliminate bacteria and infected tissue. In addition, the swollen body part should be massaged and elevated to dissipate swelling and improve lymph flow.
For those who do not have the disease, and are looking for preventative measures, MDA, or mass drug administration is the most feasible and cost efficient option. A cocktail of albendazole and medicines like ivermectin (commonly used to treat worms in dogs) or diethylcarbamazine citrate can be administered twice a year and effectively lessen the density of microfilariae in the bloodstream, and stop the transmission of larvae to mosquitoes, essentially stopping the LF cycle. With over one billion people at risk for contracting this disease and 120 million people already infected, it is estimated that over 600 million albendazole tablets are donated each year for MDA. Because the disease is so disfiguring and debilitating it actually gives people an incentive to take the donated tablets even if they do not know much about the medicine, if it lessens the chance of them getting infections. Simple tactics people can use to lessen their chance of infection is sleeping under a mosquito net, cleaning any open sores, and wearing mosquito repellent frequently.