Onchocerciasis - An Overview - Amrita Institute of Medical Sciences ...

Amrita Journal of MedicineTable 1: Treatment regimens for Onchocerca volvulus infectionsDrug Adult Dose Pediatric DoseIvermectinDoxycycline150 μg/kg PO in one dose every 6months for 15 years200 mg PO daily for 6 weeks150 μg/kg PO in one dose every 6months for 15 years200 mg PO daily for 6 weeksThe typical dosage and duration of treatment usingthese agents is summarized in Table 1. It is importantto note that doxycycline is not standard therapy and itsapplication depends upon the opinion of the doctorin prescribing it as a treatment option. If the patientis unable to tolerate 200 mg of oral doxycycline dailythat is required to kill adult worms, 100 mg PO daily issufficient to sterilize female nematodes.PREVENTION & CONTROLThere are no vaccines or medications to preventgetting infected with o. volvulus. Personal protectionmeasures against insect bites are the only preventionefforts one can take to avoid the infection. These includewearing full-sleeve shirts and long pants duringthe day when blackflies bite, applying a spray or lotionof 30-50% of N,N-Diethyl-meta-toluamide (DEET) onexposed skin and wearing permethrin-treated clothing.Large-scale onchocerciasis control measures havebeen initiated and successfully operating for morethan three decades. Beginning in 1974, onchocerciasiscontrol program (OCP) for effective vector controlwas implemented in West Africa. With the availabilityof the inexpensive ivermectin (Mectizan®), MectizanDonation Program (MDP) was established in 1987to oversee Merck’s donation of the drug for effectivecontrol of onchocerciasis to needy communities worldwide.The enormous success of this program resultedin a partnership of GlaxoSmithKline with Merck whichsubsequently included elimination of lymphatic filariasiswithin the mandate of the MDP and began donatingalbendazole along with ivermectin. In 1992, a Non-Governmental Development Organization (NGDO)Coordination Group for onchocerciasis control wasformed under the supervision of WHO to promoteworldwide interest in and garner support for the use ofivermectin in endemic countries to eliminate this publichealth menace.Under the aegis of WHO, African Program for OnchocerciasisControl (APOC) was set up in 1995 witha goal of eliminating onchocerciasis as a disease ofpublic health importance in Africa. Community-DirectedTreatment with Ivermectin (CDTI) involving active communityparticipation is at the core of APOC’s strategywith over one million Community Directed Distributors(CDDs) delivering over half a billion treatments in morethan 146,000 African communities since the inceptionof the program. This strategy has been so popular andeffective that it is now being extended to include deliveryof other health interventions.The Carter Centre, a NGDO, has since 1996, assistednational Ministries of Health in eleven African andSouth/Central American countries by imparting healtheducation and distributing ivermectin. The centre is alsothe sponsoring agency for the Onchocerciasis EliminationProgram of the Americas (OEPA), a partnershipprogram including the governments of the six endemiccountries, Pan American Health Organization (PAHO), aprivate sector (Merck & Co. Inc.), a specialized researchinstitution (Centres for Disease Control and Prevention,CDC) and another NGDO, Lions Club InternationalFoundation. With the continued thrust under the OEPAumbrella 19 , the blindness attributable to the infection hasbeen eliminated from Colombia (2007), Ecuador (2009),followed by Mexico and Guatemala (2011); and theprogram efforts remain focused in Brazil and Venezuela.CONCLUSIONSOnchocerciasis was included on the priority diseaselist of VISION 2020, a global initiative for theelimination of avoidable blindness - a joint program ofWHO and the International Agency for the Preventionof Blindness (IAPB) with an international membershipof NGDOs, professional associations, eye care institutionsand corporations. With the clearly demonstrablesuccess of burgeoning partnerships, it seems likely thatonchocerciasis shall be eliminated in most, if not in allthe endemic communities in the world 20 and the goalof removing this condition from the priority disease listof VISION 2020 seems increasingly within reach.REFERENCES1. Report of a WHO Expert Committee on onchocerciasiscontrol. WHO Technical Report Series 1995;852.2. Murdoch ME, Asuzu MC, Hagan M, et al. Onchocerciasis:the clinical and epidemiological burden of skin disease inAfrica. Ann Trop Med Parasitol 2002;96:283-96.8