title: The effect of antimalarial chloroquine therapy and prophylaxis on concurrent infection with Onchocerca volvulus in Ecuador.
abstract: The effect of chloroquine phosphate on Onchocerca volvulus in vivo was studied in Ecuadorians undergoing treatment for malaria. All persons with a diagnosis of acute malaria and treated with 2500 mg of chloroquine over 3 d showed a 100% reduction of dermal O. volvulus microfilariae 7 d after treatment. However, 28 d after treatment the microfilarial densities returned to their pre-treatment levels and at 35 d they had increased to 121.6% of their pre-treatment values. Treatment did not appear to have any effect on the adult O. volvulus examined histologically in extirpated nodules. Patients treated for acute malaria and subsequently kept on a prophylactic regimen of 500 mg chloroquine weekly showed a reduction of 56.7% from pre-treatment microfilarial density after 27 weeks. Patients who underwent nodulectomy as well as treatment for acute malaria and were given 500 mg of chloroquine prophylactically for 27 weeks showed a reduction in dermal microfilarial density of 93.6%. Symptoms of onchocerciasis were reduced in the latter group of patients, with the elimination of all acute dermatological changes within 6 weeks. Ocular examination of these surgically and chemotherapeutically treated individuals revealed reductions of 94.9% of microfilariae in the anterior chamber, 95.9% of live microfilariae in the cornea, and 95.1% of dead microfilariae in the cornea. There was a reduction of 69.8% in corneal fluffy opacities. No alteration in the visual acuity or in visible lesions in the posterior segment was recorded. The results suggest that a complex interaction between chloroquine and O. volvulus takes place in vivo, which can be beneficial to the patient over a long period.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Onchocerciasis Project, Community Development Vozandes, Hospital Vozandes, Quito, Ecuador.
authors.forename: R H
authors.initials: RH
authors.lastname: Guderian
authors.forename: M
authors.initials: M
authors.lastname: Anselmi
authors.forename: B J
authors.initials: BJ
authors.lastname: Beck
authors.forename: C D
authors.initials: CD
authors.lastname: Mackenzie
authors.forename: J F
authors.initials: JF
authors.lastname: Williams
authors.forename: J R
authors.initials: JR
authors.lastname: Proaño
authors.forename: P J
authors.initials: PJ
authors.lastname: Cooper
mesh_terms: D000208:Acute Disease; D000328:Adult; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D002738:Chloroquine / Q000031:analogs & derivatives* / Q000494:pharmacology; D005123:Eye / Q000469:parasitology; D006801:Humans; D008288:Malaria / Q000150:complications* / Q000188:drug therapy; D008297:Male; D009854:Onchocerca / Q000187:drug effects*; D009855:Onchocerciasis / Q000150:complications / Q000469:parasitology*; D015827:Onchocerciasis, Ocular / Q000469:parasitology; D012867:Skin / Q000469:parasitology
chemical_list: D000962:Antimalarials; C023676:chloroquine diphosphate; D002738:Chloroquine