FILARIASIS By Micaela Yanez OUTLINE Introduction of Filariasis History Transmission Epidemiology Progress of Lymphatic Filariasis The Disease Symptoms and Treatments WHAT IS FILARIASIS A disease that affects humans and animals and is caused by nematode parasites of the order Filariidae. Of the 100 described filarial parasites only 8 species cause infection in humans. The 8 filarial parasites are classified by the location they inhabit in host
CLASSIFICATION OF FILARIAL PARASITES 1 st group- Cutaneous (of the skin) Loa loa Onchocerca volvulus Mansonella streptocerca 2 nd group- Lymphatic (Lymphatic system) Wuchereria bancrofti Brugia malayi Brugia timori 3 rd group- Body Cavity Mansonella perstans Mansonella Ozzardi LYMPHATIC FILARIASIS "a parasitic disease caused by threadlike worms living in the human lymphatic system." The "threadlike worm" that can cause lymphatic filariasis is a blood-dwelling filarial nematode, from the aschelminth phyla 3 known species: Wuchereria bancrofti Brugia malayi Brugia timori WHAT ARE THE DIFFERENCE? Differences between W. bancrofti, B. malayi and B. timori reside in epidemiology, vectors, reservoirs, symptoms, but mainly species morphology.
WUCHERERIA BANCROFTI well-documented most widespread cause of lymphatic filariasis morphologically significantly different from the other species Wuchereria bancrofti in a blood smear BRUGIA MALAYI Vector and reservoir Transmitted by Mansonia mosquitos Animal reservoirs Morphology differences BRUGIA TIMORI Least common Least studied More similar to W. bancrofti that to B. malayi Vector Anopheles barbirostris No known animal reservoirs Symptoms and morphology resembles B. malayi Larger then B. malayi
HISTORY OF LYMPHATIC FILARIASIS Timeline of discovery 2000BC Pharaoh Mentuhotep II 500 AD Nok civilization in West Africa Greek and Roman civilization 1588-1592 symptoms 1849- symptoms 1863 and 1866- microfilariae 1876- adult worm 1877- life cycle 1900- transmission TRANSMISSION A wide range of mosquitoes can transmit the parasite, depending on the geographic area. In Africa, the most common vector is Anopheles In the Americas, it is Culex quinquefasciatus, and Aedes Mansonia can transmit the infection in the Pacific and in Asia. Anopheles Mansonia titillans Culex quinquefasciatus Aedes TRANSMISSION
EPIDEMIOLOGY Endemic in approx. 80 countries 120 million infected 40 million seriously incapacitated or disfigured India, Indonesia, Nigeria, & Bangladesh =70% 1/3 of infected live in India 1/3 of infected live in Africa Remainder are in South Asia, the Pacific and South America EPIDEMIOLOGY Most of the infections worldwide are caused by Wuchereria bancrofti. In Asia, the disease can also be caused by Brugia malayi and Brugia timori. Microfilaria of Wuchereria bancrofti, top image. Microfilaria of Brugia malayi, bottom image. (CDC Photos; DPDx)
PROGRESSION OF LYMPHATIC FILARIASIS 3 STAGES OF PROGRESSION * Prepatent Period * Incubation Period * Chronic Stage of Lymphatic Filariasis Adult W. bancrofti worms with the smaller male on the left and larger female on the right THE DISEASE Elephantiasis The individuals above are all infected with W. bancrofti. DIAGNOSIS ICT Test X-Ray Detection Blood Test
PREVENTION AND TREATMENT there is no known vaccine or cure for lymphatic filariasis Diethylcarbamazine (DEC) is a popular microfilaricide, and has been used in Mass Drug Treatment programs. symptoms are often treated with antihistamines, and antibiotics ERADICATION Lymphatic filariasis is one of seven diseases worldwide that the WHO has targeted for eradication Global Alliance to Eliminate Lymphatic Filariasis REVIEW What is filariasis How its transmitted Where its found The disease Treatment, Prevention, and Eradication
REFERENCES Center for Disease Control and Prevention. 2007. Lymphatic Filariasis. Accessed online at http://www.cdc.gov/ncidod/dpd/parasites/lymphaticfilariasis/ Dreyer, G., Noroes, J., Figueredo-Silva, J., and Piessens, W.F. 2000. Pathogenesis of Lymphatic Disease in Bancroftian Filariasis: A clinical Perspective. Parasitology Today. 16:545-550. John, David T. and William A. Petri Jr. "Brugia malayi." Medical Parasitology. 9th ed. St. Louis, Missouri: Saunders Elsevier, 2006. 285-289. John, David T. and William A. Petri Jr. "Wuchereria bancrofti." Medical Parasitology. 9th ed. St. Louis, Missouri: Saunders Elsevier, 2006. 274-285. John, David T. and William A. Petri Jr. "Wuchereria bancrofti." Medical Parasitology. 9th ed. St. Louis, Missouri: Saunders Elsevier, 2006. 274-285. John, David T. and William A. Petri Jr. "Brugia timori." Medical Parasitology. 9th ed. St. Louis, Missouri: Saunders Elsevier, 2006. 287-289. Melrose, Wayne D. 2002. Lymphatic filariasis: new insights into an old disease. International Journal of Parasitology. 32:947/960. The Global Alliance to Eliminate Lymphatic Filariasis. Accessed April 2009 at http://www.filariasis.org/.