1. PUBH-8165-1 Environmental Health
TOPIC: Onchocerciasis
Presented By:
Christopher Arori
Public Health Student
Instructor: Dr. Shana Morrell
April, 2009
Walden University

2. Learning Goals
After the presentation on onchocerciasis, the audience should be able to:
Define the disease process
Know its significance
Identify the signs and symptoms of the disease
List risk factors associated with the illness
Identify people at risk
Describe the overall impact of the disease to society
Understand the effective control and prevention measures available
Understand the current and future outlook of the disease based on research
The learning goals in this presentation would be to cover areas about this disease (river blindness), to demonstrate how serious it can be, understand how it is caused, how it spreads and who are the people likely to be most affected.

3. Agenda What is Onchocerciasis? Its significance What causes it?
Risk factors
People at risk
Social-Economic Impact
Control and Prevention Measures
Future Outlook
Key Goals of the Presentation
Information
To Manage and Implement Control Measures
Expected Learning Outcomes
Audience to be able to Share the Disease Information with their Communities
References
Onchocercias, or a river blindness, can cause serious illness. The purpose of this presentation is to better inform those living in areas of Africa where this disease is endemic, so that they may learn how to prevent and combat this disease. Local public health entities can provide technical information on how to fight the spread of the disease. There is not much that can be done without financial resources to initiate and carry out community projects to eliminate onchocerciasis. Today, we will start by discussing the causes and significance of river blindness, who is at risk, and some of the prevention and control measures.

4. Onchocerciasis Defined
Caused by a parasitic worm (Onchocerca vulvulus)
Spread to humans by the bite of an infected black fly (species of female Simulium flies) , after multiple bites (CDC, 2008).
Often times called river blindness
Occurs along fast flowing rivers and streams in Africa, Latin America, and Yemen (WHO,2009).
References
Center for Disease Control & Prevention (2008)
World Health Organization, (2009 )
Definition: According to the Center for Disease Control and Prevention (CDC), onchocerciasis is defined as a disease caused by a parasitic worm (Onchocerca Vulvulus) and is spread to humans by the bite of an infected black fly, after multiple bites (CDC, 2008). The black flies usually live along fast flowing streams/rivers (CDC, 2008). And since the disease is usually common along the rivers and streams, it is sometimes referred to as river blindness illness. Most of the countries south of the Sahara, Africa are appropriate environments for the deadly black fly (WHO, 2009). The Savanna and rain forest vegetation with numerous rivers and stream in the region provide breeding reservoirs for the vectors (Dozier, Onwuliri, & Nwoke, 2004).
References:
Dozier, I.N.S., Onwuliri, C.0.E., & Nwoke, B.E.B., (2004). Onchocerciasis in Imo state, Nigeria (2): the
prevalence, intensity and distribution in the upper Imo river basin. International Journal of Environmental Health Research, 14 (5),
WHO, 2009
CDC, 2008

5. Significance Affects 17.7 million people worldwide
About 270,000 become blind
500, 000 people have visual impairment
99 % of those cases are in Africa
Social-economic underdevelopment results from such impairements
Fertile land is abandoned
Income generating capacity is compromised
(CDC,2008)
References
Center for Disease Control and Prevention (2008)
Significance: Onchocerciasis as a parasitic disease affects a lot of people who live along rivers and streams in more than 35 countries worldwide including Africa, Latin America, and Yemen (Stingl, 2009). The data shows that the global prevalence of persons with onchocercias is over 17.7million, 270,000 people have become blind due to the disease process, 500,000 people have developed visual impairment and out of those numbers, 99% are in Africa (CDC, 2008). A study conducted in Cameroon Village indicated that out of 181 research subjects examined 35.3 % and 64% developed generalized and partial seizures respectively associated with river blindness (Prischich, De Rinaldis, Bruno, Egeo, Santori, & Zappaterreno, “et al”, 2008). The black fly is dangerous in spreading river blindness if it is not contained. Research Indicates that onchocerciasis is the second leading cause of blindness in the world (Park, Dickerson, & Janda, 2008). Such visual impairments disables many inhabitants of those regions and hence they become non-productive economically. Households are not able to support themselves in terms of finance, food, shelter, and clothing. The ultimate effect is the spread of poverty and malnutrition.
References
Prischich, F., De Rinaldis, M., Bruno, F., Egeo, G., Santori, C.; Zappaterreno, A., & “et al”, (2008). High prevalence of epilepsy in a village in the Littoral Province of Cameroon. Epilepsy Research, 82 (2/3),

6. Signs and Symptoms Skin rash Eye lesions Bumps under the skin
Chronic dermatitis, edema, chronic thickened skin (Lizard skin)
Disfigurement of the human body,
Eye lesions may progress to partial and full-prone blindness (CDC, 2008; WHO, 2009).
References
Center for Disease Control & Prevention (2008)
World Health organization (2009)
Signs and symptoms: It is extremely important to understand what to look for when one has been infected by river blindness. There is not any other way to seek for medical attention if you do not understand what the signs and symptoms of onchocerciasis are. The incubation period after the black fly bites a person, it takes over 9-24 months for an individual to develop symptoms such as skin rash, eye lesions, and bumps under the skin and over time the infected person may develop chronic dermatitis, edema, chronic thickened skin (Lizard skin), disfigurement of the human body, and eye lesions may progress to partial and full-prone blindness (CDC, 2008; WHO, 2009).

7. Risk Factors Poor communication about the disease.
Lack of Ivermectin therapy and drug resistance to the medication (Achim, Sabine, Yeboah, Marcelle, Alexander, Sabine, & et al, 2009).
lack of interest in onchocerciasis prevention and research by local entities(Loewenberg, 2008).
Lack of specific information about the disease.
The presence of the vectors, black flies
References
Achim H., Sabine S., Yeboah M., Marcelle B., Alexander D., Sabine M., & “et al” (2009). Efficacy of 5- week doxycycline treatment on adult Onchocerca volvulus. Parasitological Research, 104 (2),
Loewenberg, S. (2008). Tanzania's fight against onchocerciasis. Lancet, 372 (9651),
Risk factors: Not covering up areas of known black fly populations. There has to be open communications to let the affected communities know the areas which are at a high risk.
Lack of Ivermectin therapy and drug resistance to the medication (Achim, Sabine, Yeboah, Marcelle, Alexander, Sabine, & “et al” 2009).
A global lack of interest in onchocerciasis prevention and research (Loewenberg, 2008).
Little or uncertain information to work with is often a common problem. We should all be engaged to combat the disease, river blindness. The presence of the vectors, black flies continue to be a problem along the river banks in many regions of Africa, America, and Yemen
Who are at risk
The local people, particularly those who live along the streams and rivers of Africa, Latin America, and Yemen are exposed to river blindness (Stingl, 2009). The other secondary groups entail adventure travelers, missionaries, and peace corps volunteers (CDC, 2008).
The indigenous populations live along the rivers because of fertile soils and engage in farming activities (Dozier, Onwuliri, & Nwoke, 2004). But as we shall see later in this presentation, the black fly usually will end up forcing the majority of people to relocate from the river banks to high altitude due to the disease process, river blindness.
References
Achim H., Sabine S., Yeboah M., Marcelle B., Alexander D., Sabine M., & “et al” (2009). Efficacy of 5-week doxycycline treatment on adult Onchocerca volvulus. Parasitological Research, 104 (2),
Loewenberg, S. (2008). Tanzania's fight against onchocerciasis. Lancet, 372 (9651),
Stingl, P. (2009). Onchocerciasis: developments in diagnosis, treatment and control.
International Journal of Dermatology, 48 (4),

8. Social-Economic Impact
Socioeconomic underdevelopment
Fertile land is abandoned
Kids drop out of schools
Income generating capacity is compromised
Social stigma is persistent due to the disfigurement of human body
(CDC, 2008)
References
Center for Disease Control & Prevention, 2008
Socio-economic impact: Society is healthy and productive if its inhabitants are in good health in all spheres of life. Any deviation from such physical, emotional, spiritual, political health will lead to lack of productivity and finally to poverty, in my opinion. Communities who are affected by the disease herein presented usually end up experiencing numerous social-economic problems, namely:
Socioeconomic underdevelopment; fertile land is abandoned as many people relocate to high altitudes to avoid areas which are invested by the black fly. Kids drop out of schools due to frequent illnesses associated with black fly bites.
Income generating capacity is compromised due to abandoning of fertile lands for crops. Income from agricultural products is diminished.
Social stigma is persistent due to the disfigurement of the human body, particularly if you think of the swelling of the lower extremities with necrotic tissue and lizard like appearance.
(CDC, 2008)

9. Prevention and Control Measures
Clearing forests along river basins/banks
Applying DDT sparingly
Aerial spraying, by using environmentally friendly larvicides such as Temephos and carbamates pyrethroids (organo- phosphorus insecticides).
Use of Medications such as Ivermectin (WHO, 2009)
References
World Health Organization, 2009
Prevention: Regardless of how competent we may be, environmental health professionals cannot be expected to solve problems alone. But it takes a joint effort through partnerships, communities, coalitions and a holistic approach to solve the problems. Consequently, onchocerciasis can be solved only and only if we work together to teach communities and all stakeholders involved to eliminate the hyper-endemic by 2015 as postulated by the African Development Bank Group (2009). The ADPG proposed and approved a program worth $ 24.5 million to launch a campaign against onchocerciasis in terms of Ivermectin administration, monitoring, surveillance, implementation of strategies, evaluation and research activities (African Development Bank Group, 2009).
Medication administration such as Ivermectin and Doxycycline 200mg/day continue to show promising signs of treating the helminthes associated with river blindness (Hoerauf, Specht, Büttner, Pfarr, Mand, Büttner, & “et al” 2008).
References
Hoerauf, A.; Specht, S.; Büttner, M.; Pfarr, K.; Mand, & “et al” (2008). Wolbachia endobacteria depletion by doxycycline as antifilarial therapy has macrofilaricidal activity in onchocerciasis: a randomized placebo-controlled study. Medical Microbiology & Immunology, 197 (3),
Moeller, D.W (2005). Environmental Health. 3rd Ed. Harvard University Press, inc. MA

10. Prevention and Control Measures
Lack of precise information about the dangers of the black fly bites (Dozier, Onwuliri, & Nwoke, 2004)
Application of DEET (30% proof) to all open areas
Utilizing long sleeves attire and trouser bottoms when in outdoors
Wearing a head net if necessary
Avoiding camping near fast flowing rivers in black fly invested areas
References
Dozier, I.N.S., Onwuliri, C.0.E., & Nwoke, B.E.B., (2004). Onchocerciasis in Imo state, Nigeria (2): the prevalence, intensity and distribution in the upper Imo river basin. International Journal of Environmental Health Research, 14 (5),
World Health Organization (2009)
Center for Disease Control and Prevention (2008)
Prevention: There has also been an effort by the local governments via their health departments to control the black flies and also giving free onchocerciasis treatment medications such as Ivermectin to their people (Dozier, Onwuliri, & Nwoke, 2004). Some drug companies like Merck have been able to donate free anthelminth treatments over 570 million for the last 20 years (Thylefors, Alleman, & Twum-Danso, 2008). Very impressive.

11. Future outlook
Onchocerciasis, a parasitic condition along the river basins, will soon be eliminated.
One of the problems which can be seen is the issue of resistance to drugs and insecticides by the vectors (Humans &Insects).
Research needs to be conducted to figure out how to address the resistance problems
There is a need to develop potent medications to wipe out river blindness from the nations affected.
Although much has been accomplished to prevent and control river blindness, we all need still to be vigilant in the surveillance of the condition. There is the need to do more research on new medications as well as the current ones to evaluate there efficacy in the treatment of onchcerciasis. It is recommended that we continue to clear forests along the streams and rivers to control and disrupt reservoirs for the black fly.

12. Bibliography for further reading
Achim H.; Sabine S.; Yeboah M.; Marcelle B.; Alexander D.; Sabine M.& et al (2009). Efficacy of 5-week doxycycline treatment on adult Onchocerca volvulus. Parasitological Research, 104 (2), Churcher, T.S. & Basáñez, M-G. (2009) Sampling strategies to detect anthelmintic resistance: the perspective of human onchocerciasis. Trends in Parasitological, 25 (1), Dozie, I.N.S.; Onwuliri, C.O.E.; & Nwoke, B.E.B. (2004). Onchocerciasis in Imo state, Nigeria (2): the prevalence, intensity and distribution in the upper Imo river basin. International Journal of Environmental Health Research, 14 (5), Hoerauf, A.; Specht, S.; Büttner, M.; Pfarr, K.; Mand, & “et al” (2008). Wolbachia endobacteria depletion by doxycycline as antifilarial therapy has macrofilaricidal activity in onchocerciasis: a randomized placebo-controlled study. Medical Microbiology & Immunology, 197 (3), Loewenberg, S. (2008). Tanzania's fight against onchocerciasis. Lancet, 372 (9651), McGeary, R.P.; Bennett, A.J.; Tran, Q.B.; Cosgrove, K.L.; & Ross, B.P. (2008).Suramin: Clinical Uses and Structure-Activity Relationships.Mini Reviews in Medicinal Chemistry, 8 (13), Park, J.; Dickerson, T.J.; & Janda, K.D. (2008). Major sperm protein as a diagnostic antigen for onchocerciasis. Bioorganic & Medicinal Chemistry, 16 (15), Prischich, F.; De Rinaldis, M.; Bruno, F.; Egeo, G.; Santori, C.; Zappaterreno, A. & et al (2008). High prevalence of epilepsy in a village in the Littoral Province of Cameroon. Epilepsy Research, 82 (2/3), Sabine S.; Sabine M.; Yeboah M.; Peter K.; Dietrich B.; Achim H.(2008).Efficacy of 2- and 4-week rifampicin treatment on the Wolbachia of Onchocerca volvulus. Parasitological Research, 103 (6), Stingl, P. (2009). Onchocerciasis: developments in diagnosis, treatment and control.International Journal of Dermatology, 48 (4), 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 & International Health, 13 (5), The Center for Disease Control and prevention, (2008) World Health Organization, (2009)
The reference page is provided for you as a resource for some more information about Onchocercias concerning its outbreak, risk factors, what is done by the scientific community to control the problem and what could be done to prevent the spread of the disease.