No depletion of Wolbachia from Onchocerca volvulus after a short course of rifampin and/or azithromycin.
Endosymbionic Wolbachia bacteria inside adult Onchocerca volvulus worms (causing river blindness) are necessary for female worm fertility. We evaluated whether rifampin and/or azithromycin used in a five-day course could kill Wolbachia. In an open-label trial in Guatemala, 73 patients with 134 palpable onchocercal nodules were randomized into four treatment groups: rifampin, azithromycin, a combination of the two drugs, and controls (multivitamins). After five days of antibiotic treatment, all participants received a single dose of ivermectin on day 6. Nine months after treatment, the nodules were removed and the worms were examined. Skin snips to determine microfilariae were obtained at baseline and nine months. There were no significant differences between any of the treatment groups in the condition of the worms in the nodules, the presence of Wolbachia surface protein, or the number of microfilariae in skin. Short courses with these antibiotics will not clear Wolbachia from O. volvulus.
Richards
Frank O
FO
Centers For Disease Control and Prevention, Atlanta, Georgia 30333, USA. frichards@cdc.gov
Amann
Josef
J
Arana
Byron
B
Punkosdy
George
G
Klein
Robert
R
Blanco
Carlos
C
Lopez
Beatriz
B
Mendoza
Carlos
C
Domínguez
Alfredo
A
Guarner
Jeannette
J
Maguire
James H
JH
Eberhard
Mark
M
D000293:Adolescent; D000328:Adult; D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017963:Azithromycin / Q000008:administration & dosage* / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007559:Ivermectin / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D017181:Onchocerca volvulus / Q000187:drug effects / Q000382:microbiology*; D009855:Onchocerciasis / Q000188:drug therapy / Q000469:parasitology; D012293:Rifampin / Q000008:administration & dosage* / Q000627:therapeutic use*; D020577:Wolbachia / Q000187:drug effects*
D000871:Anthelmintics; D000900:Anti-Bacterial Agents; D007559:Ivermectin; D017963:Azithromycin; D012293:Rifampin