Medical Care

Traditionally, DEC was used to kill microfilariae. It is not in wide use now because of the severe reactions mentioned above in the Mazzotti test.

The standard treatment now includes ivermectin given as a single dose and repeated every 6-12 months for 10 years. Ivermectin works by paralyzing the microfilariae over 6 months. It has no effect on adult worms.^{[10, 11]}

Ivermectin has been shown to delay the development of optic atrophy, reduce the visual field loss, and decrease the severity of keratitis. More advanced chorioretinal and keratitis lesions and angle-closure glaucoma are not treated with ivermectin. Iridocyclitis can result from ivermectin therapy and can be treated with steroids and cycloplegic drops. In addition, some ivermectin-resistant strains of O volvulus have recently appeared.^[12]

Moxidectin is an antiparasitic drug that was approved by the FDA in June 2018 to treat onchocerciasis in patients aged 12 years or older. The WHO initiated clinical trials for use in onchocerciasis treatment in 2009. Moxidectin is closely related to ivermectin but yields a more sustained reduction in microfilarial levels. FDA approval was based on a double-blind, parallel group, superiority trial (n=1472) that compared moxidectin (8 mg PO once) with ivermectin (150 mcg/kg PO once). The trial took place in Ghana, Liberia, and the Democratic Republic of the Congo. Results showed skin microfilarial loads (ie, parasite transmission reservoir) were lower from month 1 to month 18 after moxidectin treatment than after ivermectin treatment, with an 86% difference at month 12. Moxidectin would therefore be expected to reduce parasite transmission between treatment rounds more than ivermectin could, thus accelerating progress toward elimination.^[13]

Doxycycline has been used against Wolbachia and has been shown to decrease microfilarial loads.^[14]Animal models treated with doxycycline have had a decrease in posttreatment corneal thickness and stromal haze.^[14]

Other drugs currently under investigation include rifampin and azithromycin.

Surgical Care

Surgical treatments are usually directed against preventing the loss of vision caused by Ovolvulus. These include the following:

Cataract extraction for visually significant cataracts
Trabeculectomy or drainage implants for glaucoma management
Penetrating keratoplasty for corneal pathology
Vitrectomies or laser photocoagulation for chorioretinal lesions

Consultations

Infectious disease physicians and ophthalmologists should be involved in the care of all patients with onchocerciasis.

Diet

There are no dietary restrictions for affected patients.

Activity

Depending on the severity of disease, patients with severe vision loss may need assistance with activities of daily living. Otherwise, patients should have as much activity as tolerated.

Medication

CDC. Parasites - Onchocerciasis (also known as River Blindness). CDC. Available at http://www.cdc.gov/parasites/onchocerciasis/disease.html. Accessed: 25th July 2014.
Cantey PT, Roy SL, Boakye D, Mwingira U, Ottesen EA, Hopkins AD, et al. Transitioning from river blindness control to elimination: steps toward stopping treatment. Int Health. 2018 Mar 1. 10 (suppl_1):i7-i13. [QxMD MEDLINE Link]. [Full Text].
Yaya G, Kobangué L, Kémata B, Gallé D, Grésenguet G. [Elimination or control of the onchocerciasis in Africa? Case of Gami village in Central African Republic]. Bull Soc Pathol Exot. 2014 Aug. 107(3):188-93. [QxMD MEDLINE Link].
World Health Organization. Prevention of Blindness and Visual Impairment. Onchocerciasis Control Programme (OCP). World Health Organization. Available at http://www.who.int/blindness/partnerships/onchocerciasis_OCP/en/. Accessed: 25th July 2014.
Little MP, Breitling LP, Basáñez MG, Alley ES, Boatin BA. Association between microfilarial load and excess mortality in onchocerciasis: an epidemiological study. Lancet. 2004 May 8. 363(9420):1514-21. [QxMD MEDLINE Link].
Cooper PJ, Proaño R, Beltran C, Anselmi M, Guderian RH. Onchocerciasis in Ecuador: ocular findings in Onchocerca volvulus infected individuals. Br J Ophthalmol. 1995 Feb. 79(2):157-62. [QxMD MEDLINE Link].
Kayembe DL, Kasonga DL, Kayembe PK, Mwanza JC, Boussinesq M. Profile of eye lesions and vision loss: a cross-sectional study in Lusambo, a forest-savanna area hyperendemic for onchocerciasis in the Democratic Republic of Congo. Trop Med Int Health. 2003 Jan. 8(1):83-9. [QxMD MEDLINE Link].
Vingtain P, Thillaye I. Longitudinal study of microfilarial infestation and humoral immune response to filarial and retinal antigens in onchocerciasis patients treated with ivermectin. Ophthalmic Res. 1988.
Thiele EA, Cama VA, Lakwo T, Mekasha S, Abanyie F, Sleshi M, et al. Detection of Onchocerca volvulus in Skin Snips by Microscopy and Real-Time Polymerase Chain Reaction: Implications for Monitoring and Evaluation Activities. Am J Trop Med Hyg. 2016 Apr. 94 (4):906-11. [QxMD MEDLINE Link].
Turner HC, Walker M, Churcher TS, Basáñez MG. Modelling the impact of ivermectin on River Blindness and its burden of morbidity and mortality in African Savannah: EpiOncho projections. Parasit Vectors. 2014 May 26. 7:241. [QxMD MEDLINE Link]. [Full Text].
Banla M, Tchalim S, Karabou PK, Gantin RG, Agba AI, Kére-Banla A, et al. Sustainable control of onchocerciasis: ocular pathology in onchocerciasis patients treated annually with ivermectin for 23 years: a cohort study. PLoS One. 2014. 9(6):e98411. [QxMD MEDLINE Link]. [Full Text].
Osei-Atweneboana MY, Awadzi K, Attah SK, Boakye DA, Gyapong JO, Prichard RK. Phenotypic evidence of emerging ivermectin resistance in Onchocerca volvulus. PLoS Negl Trop Dis. 2011 Mar 29. 5(3):e998. [QxMD MEDLINE Link]. [Full Text].
Opoku NO, Bakajika DK, Kanza EM, Howard H, Mambandu GL, Nyathirombo A, et al. Single dose moxidectin versus ivermectin for Onchocerca volvulus infection in Ghana, Liberia, and the Democratic Republic of the Congo: a randomised, controlled, double-blind phase 3 trial. Lancet. 2018 Jan 17. [QxMD MEDLINE Link]. [Full Text].
Hoerauf A, Mand S, Adjei O, Fleischer B, Büttner DW. Depletion of wolbachia endobacteria in Onchocerca volvulus by doxycycline and microfilaridermia after ivermectin treatment. Lancet. 2001 May 5. 357(9266):1415-6. [QxMD MEDLINE Link].
World Health Organization. African Programme for Onchocerciacis Control (APOC). Available at http://www.who.int/apoc/onchocerciasis/ocp/en/. Accessed: 25th July 2014.
Sauerbrey M, Rakers LJ, Richards FO. Progress toward elimination of onchocerciasis in the Americas. Int Health. 2018 Mar 1. 10 (suppl_1):i71-i78. [QxMD MEDLINE Link]. [Full Text].
The Carter Center. River Blindness Elimination Program. The Carter Center. Available at http://www.cartercenter.org/health/river_blindness/index.html. Accessed: 25th July 2014.
Greene BM, Gbakima AA, Albiez EJ, Taylor HR. Humoral and cellular immune responses to Onchocerca volvulus infection in humans. Rev Infect Dis. 1985 Nov-Dec. 7(6):789-95. [QxMD MEDLINE Link].
Ament CS, Young LH. Ocular manifestations of helminthic infections: onchocersiasis, cysticercosis, toxocariasis, and diffuse unilateral subacute neuroretinitis. Int Ophthalmol Clin. 2006 Spring. 46(2):1-10. [QxMD MEDLINE Link].
Awadzi K, Edwards G, Opoku NO, Ardrey AE, Favager S, Addy ET, et al. The safety, tolerability and pharmacokinetics of levamisole alone, levamisole plus ivermectin, and levamisole plus albendazole, and their efficacy against Onchocerca volvulus. Ann Trop Med Parasitol. 2004 Sep. 98(6):595-614. [QxMD MEDLINE Link].
Ayong LS, Tume CB, Wembe FE, Simo G, Asonganyi T, Lando G, et al. Development and evaluation of an antigen detection dipstick assay for the diagnosis of human onchocerciasis. Trop Med Int Health. 2005 Mar. 10(3):228-33. [QxMD MEDLINE Link].
Babalola OE. The peculiar challenges of blindness prevention in Nigeria: a review article. Afr J Med Med Sci. 2011 Dec. 40(4):309-19. [QxMD MEDLINE Link].
Basáñez MG, Pion SD, Churcher TS. River blindness: a success story under threat?World Health Organization. Prevention of blindness and visual impairment: priority eye diseases. PLoS Med. 2006. 3:e371.
Berger RB, Blackwell NM, Lass JH, Diaconu E, Pearlman E. IL-4 and IL-13 regulation of ICAM-1 expression and eosinophil recruitment in Onchocerca volvulus keratitis. Invest Ophthalmol Vis Sci. 2002 Sep. 43(9):2992-7. [QxMD MEDLINE Link].
Brattig NW. Pathogenesis and host responses in human onchocerciasis: impact of Onchocerca filariae and Wolbachia endobacteria. Microbes Infect. 2004 Jan. 6(1):113-28. [QxMD MEDLINE Link].
CDC. Progress toward elimination of onchocerciasis in the Americas - 1993-2012. MMWR Morb Mortal Wkly Rep. 2013 May 24. 62(20):405-8. [QxMD MEDLINE Link].
Cooper PJ, Guderian RH, Proaño R, Taylor DW. Absence of cellular responses to a putative autoantigen in onchocercal chorioretinopathy. Cellular autoimmunity in onchocercal chorioretinopathy. Invest Ophthalmol Vis Sci. 1996 Feb. 37(2):405-12. [QxMD MEDLINE Link].
Cupp EW, Sauerbrey M, Richards F. Elimination of human onchocerciasis: history of progress and current feasibility using ivermectin (Mectizan(®)) monotherapy. Acta Trop. 2011 Sep. 120 Suppl 1:S100-8. [QxMD MEDLINE Link].
Dadzie Y, Neira M, Hopkins D. Final report of the Conference on the eradicability of Onchocerciasis. Filaria J. 2003 Feb 7. 2(1):2. [QxMD MEDLINE Link]. [Full Text].
Diemert DJ. Tissue Nematode Infections. Goldman’s Cecil Medicine. 2011. 193-200.
Ejere HO, Schwartz E, Wormald R, Evans JR. Ivermectin for onchocercal eye disease (river blindness). Cochrane Database Syst Rev. 2012 Aug 15. 8:CD002219. [QxMD MEDLINE Link].
Etya’ale D, Taylor HR. Onchocerciasis. Duane's Ophthalmology. Lippincott Williams & Wilkins; 2006. 5: Chapter 62. [Full Text].
Globisch D, Moreno AY, Hixon MS, Nunes AA, Denery JR, Specht S. Onchocerca volvulus-neurotransmitter tyramine is a biomarker for river blindness. Proc Natl Acad Sci U S A. 2013 Mar 12. 110(11):4218-23. [QxMD MEDLINE Link].
Higazi TB, Filiano A, Katholi CR, Dadzie Y, Remme JH, Unnasch TR. Wolbachia endosymbiont levels in severe and mild strains of Onchocerca volvulus. Mol Biochem Parasitol. 2005 May. 141(1):109-12. [QxMD MEDLINE Link].
Mbanefo EC, Eneanya CI, Nwaorgu OC, Otiji MO, Oguoma VM, Ogolo BA. Onchocerciasis in Anambra State, Southeast Nigeria: endemicity and clinical manifestations. Postgrad Med J. 2010 Oct. 86(1020):578-83. [QxMD MEDLINE Link].
McKechnie NM, Gürr W, Yamada H, Copland D, Braun G. Antigenic mimicry: Onchocerca volvulus antigen-specific T cells and ocular inflammation. Invest Ophthalmol Vis Sci. 2002 Feb. 43(2):411-8. [QxMD MEDLINE Link].
Mcleod SD. Parasitic Keratitis. Yanoff & Duke. Yanoff & Duker: Ophthalmology. 2008. 274-8.
Murdoch ME. Onchocerciasis. UpToDate. Available at http://www.uptodate.com/contents/onchocerciasis. Accessed: 25th July 2014.
Murdoch ME, Asuzu MC, Hagan M, Makunde WH, Ngoumou P, Ogbuagu KF, et al. Onchocerciasis: the clinical and epidemiological burden of skin disease in Africa. Ann Trop Med Parasitol. 2002 Apr. 96(3):283-96. [QxMD MEDLINE Link].
Ndyomugyenyi R, Tukesiga E, Büttner DW, Garms R. The impact of ivermectin treatment alone and when in parallel with Simulium neavei elimination on onchocerciasis in Uganda. Trop Med Int Health. 2004 Aug. 9(8):882-6. [QxMD MEDLINE Link].
Nguyen JC, Murphy ME, Nutman TB, Neafie RC, Maturo S, Burke DS, et al. Cutaneous onchocerciasis in an American traveler. Int J Dermatol. 2005 Feb. 44(2):125-8. [QxMD MEDLINE Link].
Norman FF, Pérez de Ayala A, Pérez-Molina JA, Monge-Maillo B, Zamarrón P, López-Vélez R. Neglected tropical diseases outside the tropics. PLoS Negl Trop Dis. 2010 Jul 27. 4(7):e762. [QxMD MEDLINE Link]. [Full Text].
Otranto D, Sakru N, Testini G, Gürlü VP, Yakar K, Lia RP, et al. Case report: First evidence of human zoonotic infection by Onchocerca lupi (Spirurida, Onchocercidae). Am J Trop Med Hyg. 2011 Jan. 84(1):55-8. [QxMD MEDLINE Link]. [Full Text].
Pearlman E, Hall LR, Higgins AW, Bardenstein DS, Diaconu E, Hazlett FE, et al. The role of eosinophils and neutrophils in helminth-induced keratitis. Invest Ophthalmol Vis Sci. 1998 Jun. 39(7):1176-82. [QxMD MEDLINE Link].
Remme J, Dadzie KY, Rolland A, Thylefors B. Ocular onchocerciasis and intensity of infection in the community. I. West African savanna. Trop Med Parasitol. 1989 Sep. 40(3):340-7. [QxMD MEDLINE Link].
Remme JHF, World Health Organization, Geneva. The global burden of onchocerciasis in 1990. 2004.
Rowe SG, Durand M. Blackflies and whitewater: onchocerciasis and the eye. Int Ophthalmol Clin. 1998 Winter. 38(1):231-40. [QxMD MEDLINE Link].
Saint André Av, Blackwell NM, Hall LR, Hoerauf A, Brattig NW, Volkmann L, et al. The role of endosymbiotic Wolbachia bacteria in the pathogenesis of river blindness. Science. 2002 Mar 8. 295(5561):1892-5. [QxMD MEDLINE Link].
World Health Organization. A new drug for river blindness? Research and Training in Tropical Diseases (TDR) News. World Health Organization TDR News. Available at http://www.who.int/tdr/publications/documents/tdrnews-issue-79.pdf. Accessed: 25th July 2014.
World Health Organization. Prevention of Blindness and Visual Impairment. Priority eye diseases. WHO. Available at http://www.who.int/blindness/causes/priority/en/index1.html. Accessed: 25th July 2014.
Zimmerman PA, Dadzie KY, De Sole G, Remme J, Alley ES, Unnasch TR. Onchocerca volvulus DNA probe classification correlates with epidemiologic patterns of blindness. J Infect Dis. 1992 May. 165(5):964-8. [QxMD MEDLINE Link].

Media Gallery

of 0

Author

Debora E Garcia-Zalisnak, MD Resident Physician, Department of Ophthalmology, Eastern Virginia Medical School

Debora E Garcia-Zalisnak, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Ophthalmology, American College of Physicians

Disclosure: Nothing to disclose.

Coauthor(s)

John D Sheppard, Jr, MD, MMSc Professor of Ophthalmology, Microbiology and Molecular Biology, Clinical Director, Thomas R Lee Center for Ocular Pharmacology, Ophthalmology Residency Research Program Director, Eastern Virginia Medical School; President, Virginia Eye Consultants

John D Sheppard, Jr, MD, MMSc is a member of the following medical societies: American Academy of Ophthalmology, American Society for Microbiology, American Society of Cataract and Refractive Surgery, American Uveitis Society, Association for Research in Vision and Ophthalmology

Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: 1-800-DOCTORS; AbbVie; Alcon; Aldeyra; Allergan; Alphaeon; ArcScan; Baush+Lomb; Bio-Tissue; Clearside; EyeGate; Hovione; Mededicus; NovaBay; Omeros; Pentavision; Portage; Santen; Science Based Health; Senju; Shire; Sun Pharma; TearLab;TearScience;Topivert<br/>Serve(d) as a speaker or a member of a speakers bureau for: AbbVie; Alcon; Allergan; Bausch+Lomb; Bio-tissue; EyeGate;Hovione;LayerBio; NovaBay;Omeros;Portage; Santen; Shire; Stemnion; Sun Pharma;TearLab;TearScience; Topivert <br/>Received research grant from: Alcon; Aldeyra; allergan; Baush+ Lomb; EyeGate; Hovione; Kala; Ocular Therapeutix;Pfizer; RPS; Santen;Senju;Shire;Topcon; Xoma.

Specialty Editor Board

Simon K Law, MD, PharmD Clinical Professor of Health Sciences, Department of Ophthalmology, Jules Stein Eye Institute, University of California, Los Angeles, David Geffen School of Medicine

Simon K Law, MD, PharmD is a member of the following medical societies: American Academy of Ophthalmology, Association for Research in Vision and Ophthalmology, American Glaucoma Society

Disclosure: Nothing to disclose.

R Christopher Walton, MD Adjunct Professor, Department of Ophthalmology, University of Texas Health Science Center at San Antonio

R Christopher Walton, MD is a member of the following medical societies: American Academy of Ophthalmology, American Uveitis Society

Disclosure: Nothing to disclose.

Chief Editor

Hampton Roy, Sr, MD † Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences

Hampton Roy, Sr, MD is a member of the following medical societies: American Academy of Ophthalmology, American College of Surgeons, Pan-American Association of Ophthalmology

Disclosure: Nothing to disclose.

Acknowledgements

Deborah R Eezzuduemhoi, MD Assistant Professor, Department of Ophthalmology and Visual Sciences, Texas Tech University, Health Sciences Center School of Medicine

Deborah R Eezzuduemhoi, MD is a member of the following medical societies: American Academy of Ophthalmology, American Academy of Pediatrics, and Women in Ophthalmology, Inc

Disclosure: Nothing to disclose.

Deborah Wilson, MD Director of Glaucoma Service, Assistant Professor, Department of Ophthalmology, Georgetown University Medical Center

Deborah Wilson, MD is a member of the following medical societies: American Academy of Ophthalmology and American College of Physicians

Disclosure: Nothing to disclose.