Onchocerciasis (River Blindness) Ada C. Quiñones, MPH student Walden University Pu6165-1 Instructor: Dr Rebecca Heick Summer,2010 Welcome Everyone! My name is Ada Quiñones. I am a MPH student at Walden University. As part of my program, I am doing a Service-Based Learning Project and I chose the topic “River Blindness”. The Scientist (2010) Online Image, August 7,2010 Retrieved from: www.thescientist.com

Goal The goal of this presentation is to convince different health organizations to work together in order to find effective methods for reducing the incidence and prevalence of River Blindness worldwide. Although onchocerciasis (River Blindness) is currently a major cause of blindness in the world, it is a preventable disease. Countries affected with this disease need support to fully eradicate it worldwide. The goal of this presentation is to convince different health organizations to work together in order to find effective methods for reducing the incidence and prevalence of River Blindness worldwide.

The intended audience includes individuals from: The Carter Center River Blindness Program World Health Organization(WHO) Centers for Disease Control and Prevention: Division of Parasitic Diseases (CDC) The International Eyes Foundation Program Mectizan Donation Programs Lions Club International General Public Some organizations are currently working for the prevention, treatment and eradication of River Blindness. Among some of the many organizations are the following: The Carter Center River Blindness Program World Health Organization(WHO) Centers for Disease Control and Prevention: Division of Parasitic Diseases (CDC) The International Eyes Foundation Program Mectizan Donation Programs Lions Club International

Objective Educate the general public about Onchocerciasis (River Blindness) Educate the public about potential health impact Convince professionals of the need for public health interventions Educating health professionals along with other sectors in relation to the disease is the beginning to work for disease eradication. Spreading the word in relation to the magnitude and implications of this condition generates knowledge to other sectors that could, therefore, become involved to work together for the eradication of River Blindness.

Introduction River Blindness is primarily an African disease, common in central Africa, especially in villages near rivers and streams. OCP/World Health Organization(1997) Online Image, August 7,2010 Retrieved from: https://apps.who.int/ocp/slides/index.htm Onchocerciasis, commonly known as river blindness, is a parasitic infection afflicting 18 million people worldwide. (Terranova et al, 2007). The causative organism, Onchocerca volvulus, is a filarial nematode transmitted by infested blackflies of the genus Similum, which are found near freely flowing waterway(Robert & Janovy,1996). Simulium kaffaense has been identified as the vector in Ethiopia and East Africa( Boatin & Richards,2006). Blindness transmission is most intense in remote African rural agricultural villages, located near rapidly flowing streams(CDC,2008). O. volvulus is almost exclusively a parasite of man. Adult worms live in nodules in a human body where the female worms produce high numbers of first-stage larvae known as microfilariae (WHO,2010). Centers for Disease Control and Prevention[CDC]September, 2008). Onchocerciasis Retrieved from: http://www.cdc.gov/ncidod/dpd/parasites/onchocerciasis/factsht_onchocerciasis.htm#prevention sis/factshtonchocerciasis.htm#what

These flies breed in fast-flowing streams and rivers, increasing the risk of infection to individuals living nearby, hence the common name of “ River Blindness". Adult Black Fly (Simulium yahense) with Onchocerca volvulus emerging from the insect's antenna. The parasite is responsible for the disease known as River Blindness in Africa. Image provided courtesy of the USDA under Public Domain. http://serc.carleton.edu/microbelife/k12/microbes_within/resources.html A parasitic disease, it is caused by a large tissue roundworm that spreads from person to person through the bites of black flies. These flies breed in fast-flowing streams and rivers, increasing the risk of infection to individuals living nearby, hence the common name of “ River Blindness". Centers for Disease Control and Prevention[CDC]September, 2008). Onchocerciasis Retrieved from: http://www.cdc.gov/ncidod/dpd/parasites/onchocerciasis/factsht_onchocerciasis.htm#prevention sis/factshtonchocerciasis.htm#what

Geography Distribution Thirty countries of Africa Americas Ecuador Mexico Brazil Venezuela Colombia Yemen Global Distribution: Onchocerciasis is locally transmitted in thirty countries of Africa, 13 foci in the Americas (Mexico, Guatemala, Ecuador, Colombia, Venezuela, Brazil) and in Yemen(CDC,2008). Onchocerciasis in casual travelers is rare; the infection is transmitted in rural areas, and, unlike malaria, contracting onchocerciasis requires more than one infectious bite.(CDC,2008). Through it probably originated in Africa, and remains a major health problem there, River Blindness has spread to other countries, such as Saudi Arabia, Yemen, Brazil, Columbia, Venezuela, Ecuador, Guatemala and Mexico. (Robert & Janovy,1996). It is thought that slaves brought from Africa to Central and South America introduced the worm to those regions (Robert & Janovy,1996). Unite for Sight Inc. Online Image, August 7,2010 Retrieved from: www.uniteforsight.org Centers for Disease Control and Prevention[CDC]September, 2008). Onchocerciasis Retrieved from: http://www.cdc.gov/ncidod/dpd/parasites/onchocerciasis/factsht_onchocerciasis.htm#prevention sis/factshtonchocerciasis.htm#what

Life cycle The disease spreads from person to person by the bite of a black fly. When a black fly bites a person who has onchocerciasis, microscopic worms (called microfilariae) in the infected person's skin infect the black fly (Rea et al,2010). The microfilariae develop over 2 weeks to a stage where they are infectious to humans. An infectious black fly will typically inject one or two larvae to transmit the disease to another person (Rea et al,2010). Since the worms can only increase their numbers in the human by first mating and then cycling their microfilariae through the black fly, the intensity of human infection (number of worms in an individual) is related to the number of infectious bites sustained by an individual(Rea et al,2010) Blindness is almost always in persons with intense infection (Murray et al ,2007). Centers for Disease Control and Prevention[[CDC](2008) Online Image, August 7,2010 Retrieved from: http://www.dpd.cdc.gov/dpdx

Onchocerca volvulus Onchocerca volvulus was probably introduced to the Americas by African slaves . Humans appear to be the only natural definitive host. Adult worms move under the skin, where they become encapsulated by host reaction.   OCP/World Health Organization(1997) Online Imagen, August 7,2010 Retrieved from:https://apps.who.int/ocp/slides/index.htm Onchocerca volvulus microfilaria were found by O’Neil in 1875, and the adult worms were detected by Leuckart in 1983 in nodules removed from the scalp and chest of a West African native(Garcia,2007). The worms characteristically are knotted together in pairs or groups in the subcutaneous tissue. They are slender and blunt at both ends(Roberts & Janovy,1996). Lips and a buccal capsule are absent. (Robert & Janovy,1996). Males are 19 to 42cm long by 130 to 210 μm wide; females are 33.5 to 50.0 cm long by 270 to 400 μm wide. ( Robert & Janovy,1996). Robert, L.S., & Janovy ,J.(1996). Foundations of Parasitology (5th ed). USA: Wm.C. Brown publishers

Symptoms Infected persons may be without symptoms. Those with symptoms will usually have one or more of the three manifestations: Skin rash Eye lesions Subcutaneous bumps under the skin The most serious manifestation consists of lesions in the eye that can progress to blindness.(CDC,2008). Centers for Disease Control and Prevention[CDC] 2008). Onchocerciasis Retrieved from: http://www.cdc.gov/ncidod/dpd/parasites/onchocerciasis/factshtonchocerciasis.htm#what Robert, L.S., & Janovy ,J.(1996). Foundations of Parasitology (5th ed). USA: Wm.C. Brown publishers The normal incubation period of onchocerciasis ranges from nine to 24 months after the bite of an infected black fly. Each female worm can reproduce millions of microfilariae during her lifetime. Worms can live for 10-15 years.(CDC,2008) Symptoms occur between one to three years after initial infection. Early indications of onchocerciasis include fever, joint pain and skin welts (hives). Nearly 10% of infected individuals are asymptomatic

Clinical Presentation Onchocercomas Skin changes Ocular envolment Immune System Effect OCP/World Health Organization(1997) Online Imagen, August 7,2010 Retrieved from: https://apps.who.int/ocp/slides/index.htm Onchocercoma: Subcutaneous nodules (onchocercomas) are a significant indicator of infection and appear in 30% of all cases. Nodules develop over a 18-month span and vary in size and number. Nodule location depends on the location of the black fly bite. In Africa the nodules are mainly found on the lower trunk and pelvic region while in the Americas the head and neck are the most affected regions (Robert & Janovy, 1996). Cutaneous Presentation: The skin is the principal site of infection.  Intense irritation and itching of skin occurs as the body responds to O. volvulus antigens (Garcia,2007).  This inflammation eventually leads to the thickening and cracking of skin. Chronically infected skin loses its elasticity and becomes hypertrophic or thickened.(Garcia,2007). Loss of elasticity occurs due to the thickening of skin and eventually atrophy of skin and wrinkling occurs. In Africa patients ,may exhibit localized areas of spotty depigmentation surrounded by slightly hyperpigmented zones occurring mainly on the shins; this condition known as leopard skin (Garcia,2007). Ocular involment: A major complication of onchocerciasis has been ocular lesion leading to bilateral blindness (Garcia,2007). Inmune System Effect: Individuals with chronic onchocerciasis have an abundance of T cells producing IL-4 and IL-5. and they have markedly high levels of antigen-specific IgE and IgG4 antibodies and eosinophilia(Gacia,2007). OCP/World Health Organization(1997) Online Imagen, August 7,2010 Retrieved from: https://apps.who.int/ocp/slides/index.htm OCP/World Health Organization(1997) Online Imagen, August 7,2010 Retrieved from: https://apps.who.int/ocp/slides/index.htm Garcia, L.S.(2007). Diagnostic medical parasitology (5thed) .Washington, D.C: ASM Press

Incidence and Prevalence Onchocerciasis is the second leading cause of preventable blindness in the world. More than 17.7 million people worldwide are infected, and 109 million people are at risk. Visual impairments occur in 500,000 of these people, including 270,00 cases of blindness. Over 90% of the disease occurs in Africa, with the rest occurring in six countries in Latin America, Yemen and the Arabian Peninsula . Approximately 17.7 million people worldwide are infected with river blindness; 500,000 are visually impaired; and another 270,000 are blind due to the disease in 37 endemic countries( WHO,2010). Approximately 123 million people live in endemic areas worldwide and are therefore at risk of infection; more than 99 percent of those infected live in Africa, and Nigeria is the most river blindness-endemic country in the world. (The Carter Center,2010). Onchocerciasis is a major cause of blindness in many African countries. As a public health problem, the disease is most closely associated with West and Central Africa, but it is also prevalent in Yemen and six countries in Latin America. Onchocerciasis has in the past greatly reduced the economic productivity in infected areas and left vast tracts of arable land abandoned. It is estimated that there are about half a million blind people due to river blindness.(WHO,2010). Centers for Disease Control and Prevention[CDC]September, 2008). Onchocerciasis Retrieved from: http://www.cdc.gov/ncidod/dpd/parasites/onchocerciasis/factsht_onchocerciasis.htm#prevention sis/factshtonchocerciasis.htm#what

Mortality and Morbidity Within the human body, the adult female worm (macrofilaria) produces thousands of baby or larval worms (microfilariae), which migrate in the skin and the eye and are the cause of morbidity.(WHO,2007). While mortality rates for onchocerciasis are null, the personal costs, and social and economic burdens are high(WHO,2007). Within the human body, the adult female worm (macrofilaria) produces thousands of baby or larval worms (microfilariae), which migrate in the skin and the eye and are the cause of morbidity. (WHO,2007). While mortality rates for onchocerciasis are null, the personal costs, and social and economic burdens are high(WHO,2007). In 1995, an estimated 270,000 people were blinded and another 500,000 had severe visual impairment as a result of the disease. A multi-country study showed that more than 30% of the population in endemic areas have onchocercal dermatitis. In a survey of skin disease in 7 endemic sites in 5 African countries, 40-50% of adults reported troublesome itching. Blindness is not associated with excess mortality. However, increasing microfilarial load is associated with mortality in both males and females.

Socio-economic Impact Hinders agriculture productivity Generate massive economic losses Imposes a disproportionate disease burden on poor rural communities It creates stigma Onchocerciasis causes and perpetuates poverty World Health Organization [WHO], (2010). Onchocerciasis. Retrieved from: http://www.who.int/topics/onchocerciasis/en/ Onchocerciasis (river blindness) is a serious public health problem with important socioeconomic consequences. The presence of onchocercal skin lesions is unsightly and has a psychosocial effect on the affected (Wagbatsoma & Okojie,2004). The affected ARE socially withdrawn, probably due to the frustration of their health condition. There is a need to improve people’s attitude towards the disease and improve disease awareness through appropriate health education, which will encourage the acceptance of Ivermectin as adequate treatment and compliance to the treatment regimen to reduce morbidity and promote self-esteem. (Wagbatsoma & Okojie,2004). The river blindness person and his/her family face serious social challenges. Directly interferes with many daily activities. In the case of adults, the possibilities for gainful employment are severely limited as is their participation in many activities(WHO,2010). To this is often added a loss of social status and self esteem. Nevertheless, it is clear that they diminish the quality of life not only for blind persons, but for their families as well(WHO,2010). In addition to its direct impact on people, the disease has also had detrimental effects on agricultural production in the affected countries because people no longer are willing to cultivate fertile bottomland near rivers (Moller,2005).

Prevention Black flies bite during the day. The best prevention is to avoid infective bites of the black fly by: Using insecticides such as DEET Wearing long sleeve shirts and pants. Treatment of streams and river with insecticides has successfully reduced or eliminated transmission. A significant problem in vector control has been the development of resistance to larvicide. The solution to this problem is the rotational use of different larvicide during the treatment campaign . (Garcia,2007). In areas where application of insecticides would be difficult, surgical removal of nodules has been used as a means of controlling as well as preventing blindness. (Garcia,2007). No vaccine or recommended drug is available to prevent onchocerciasis (CDC,2008). Centers for Disease Control and Prevention[CDC]September, 2008). Onchocerciasis Retrieved from: http://www.cdc.gov/ncidod/dpd/parasites/onchocerciasis/factsht_onchocerciasis.htm#prevention sis/factshtonchocerciasis.htm#what

Diagnostics Serologic testing for antibodies Bloodless skin snips PCR (Polymerase Chain Reaction) Slit lamp examination Mazzoti test Garcia, L.S.(2007). Diagnostic medical parasitology (5thed) .Washington, D.C: ASM Press Serologic testing for antibodies is available, but a positive result does not necessarily indicate an active case of onchocerciasis.(CDC,2008). The best methods of diagnostics is the demonstration of microfilariae in bloodless skin snips (Robert & Janovy,1996). Assay using PCR to detect onchocercal DNA in skin snip specimens are now use in laboratories and are highly sensitive and specific (Murray et al., 2007). Slit-lamp examination of the eye in the anterior chamber or retroillumination to detect corneal microfilariae can be performed(Garcia,2007). The Mazztto test can be used when results with skin snips are negative; however, there may be severe reactions in patients with heavy microfilarial burdens (Garcia,2007). A single oral dose of 25 to 50mg of DEC is given, individuals often develop intense pruritus within few hours. (Garcia,2007).

Traveler Risk Risk of infection is greater in: Adventure travelers Missionaries, Peace Corps volunteers Onchocerciasis in casual travelers is rare; the infection is transmitted in rural areas, and, unlike malaria, contracting onchocerciasis requires more than one infectious bite(CDc,2008). Thus, risk of infection is greater in adventure travelers, missionaries, and Peace Corps volunteers who are likely to have intense and prolonged exposure to black fly bites(CDC,2008). The disease is most intensely transmitted in remote African rural agricultural villages, located near rapidly flowing streams(CDC,2008). Centers for Disease Control and Prevention[CDC]September, 2008). Onchocerciasis Retrieved from: http://www.cdc.gov/ncidod/dpd/parasites/onchocerciasis/factsht_onchocerciasis.htm#prevention sis/factshtonchocerciasis.htm#what

Treatment Surgical Removal Ivermectin Removal of enlarged regional lymph glands DEC Suramin Amocarzine Mebendazole and flubendanzole OCP/World Health Organization(1997) Online Imagen, August 7,2010 Retrieved from: https://apps.who.int/ocp/slides/index.htm Surgical removal of detectable nodules, especially in the head region is simple and easy to perform. It reduces the risk and severity of ocular complication (Garcia,2007). Ivermectin is administered as an oral dose of 150 micrograms per kilogram (maximum 12 mg) every 6-12 months (CDC,2008). It markedly reduces microfilaria numbers within 48 h and blocks the release of microfilaria numbers from the uterus of the adult female worm for up to 6 month (Garcia,2007). The drug should probably not be given to pregnant women or children under 5 years (Thylefors et al., 2008). Ivermectin does not kill the adult parasites, but reduces the numbers of microfilariae in skin so the disease does not progress.(CDC,2008). DEC is an effective microfilaricidal drug, but it may precipitate serious dermal and systematic complications. (Garcia,2007). Suramin is effective in eliminating adult filarial worms as well as the microfilariae(Garcia,2007). Mebendazole and Flubendazole are effective microfilaricidal drug; they are useful alternative to DEC, and fewer ocular side effects. (Garcia,2007). Robert, L.S., & Janovy ,J.(1996). Foundations of Parasitology (5th ed). USA: Wm.C. Brown Centers for Disease Control and Prevention[CDC]September, 2008). Onchocerciasis Retrieved from: http://www.cdc.gov/ncidod/dpd/parasites/onchocerciasis/factsht_onchocerciasis.htm#prevention sis/factshtonchocerciasis.htm#what Garcia, L.S.(2007). Diagnostic medical parasitology (5thed) .Washington, D.C: ASM Press publishers

Additional Resource Higher Institute of Health of Bengo http://www.portalangop.co.ao/motix/en_us/noticias/saude/2010/5/25/Bengo-hosts- seminar-fight-against-river-blindness,7ace8f84-fb33-464b-a0ca-5745d6202bb7.html   The Carter Center River Blindness program http://www.cartercenter.org/health/river_blindness/index.html World Health Organization (WHO) http://www.who.int/topics/onchocerciasis/en/ Breakthroughs magazine http://nature.berkeley.edu/breakthroughs/break_feature1_su08.php Lions club international http://www.lionsclubs.org/EN/lci-foundation/our- programs/sightfirst/initiatives/lcif-gr-river-blindness.php The international eyes foundation program http://www.iefusa.org/riverblind.shtml MAP International http://www.map.org/site/PageServer?pagename=SP_Uganda_River_Blindness Mectizan Donation Program http://www.merck.com/corporate-responsibility/access/access-developing-emerging/mectizan-donation-riverblindness/ Centers for Disease Control and Prevention[ http://www.cdc.gov/ncidod/dpd/parasites/onchocerciasis/factshtonchocerciasis.htm#what

Reference Centers for Disease Control and Prevention[[CDC].(2008). Onchocerciasis Retrieved from: http://www.cdc.gov/ncidod/dpd/parasites/onchocerciasis/factshtonchocerciasis.htm# what Basáñez, M.G., Sébastien, D.S.,Churcher, T.S., Breitling L.P., Little,M.P., Boussinesq, M. (2006). River Blindness: A success story under threat? Plos Medicine,3(9), 1454-1460 Boatin,B.A., & Richard F.O Jr. (2006). Control of Onchocerciasis. Advance in Parasitology 61. 349-394. Gárcia, L.S.(2007). Filarial nematodes.In Gárcia,L.S., Diagnostic Medical Parasitology (5thed.) (pp341-348). Washington, D.C: ASM Press/ Hall, L.R., & Pearlam,E. (1999). Pathogenesis of Onchorcercal keratitis (River Blindness). Clinical Microbiology Reviews,12 (3), 445-453. Moller, D. W.(2005).Rodents and Insects. In Moeller,D.W. Environmental Health (3rd ed.). (pp 258).Boston: Harvard University Press. Murray, P.R., Baron, E.J., Jorgensen, J.H., Landry, M.J., & Pealler, M.A.(2007).Manual of Clinical Microbiology, D. C: ASM Press Rea, P.A., Zhang,V., & Baras, Y.S. (2010) .Ivermectin and River Blindness. American Scientist,98. 294-303

Reference Robert, L.S., & Janovy ,J.(1996). Nematodes:Filaroidea, In Robert, L.S., & Janovy, J., Foundations of Parasitology (5th ed).(pp. 452-456). USA: Wm.C. Brown publishers Terranova, M., Padovese, V., Klaus, S., and Morrone, A.(2007). Onchocerciasis in Tigray. International Society of Dermatology, 46, 39-41 Thylefors, B., Alleman, M. M.,& Twum-Danso, N.A.Y. (2008). Operational lessons from 20 years of the Mectizan donation program for the control of Onchocerciasis. Tropical Medicine and international health, 13(5), 689- 696 Wagbatsoma, V.A., & Okojie, O.H. (May, 2004). Psychosocial effects of river blindness in a rural community in Nigeria. The Journal of the Royal Society for the Promotion of Health 124 ,134-136,   World Health Organization [WHO], (1979). Environmental Health Criteria 9: DDT and its derivates. World Health Organization [WHO], (2010). Onchocerciasis. Retrieved from: http://www.who.int/topics/onchocerciasis/en/

Thank you