zithromax and Onchocerciasis

The effects of azithromycin treatment on the presence of Wolbachia endobacteria and on the embryogenesis and microfilariae production of Onchocerca volvulus were studied. In 2002, in an endemic area in Ghana, 37 onchocerciasis patients were treated for 6 weeks with azithromycin: 23 patients received 250 mg every day, and 14 took 1,200 mg once a week. After 6 and/or 12 months, all palpable worm nodules were extirpated from 31 treated and nine additional untreated patients, and the presence of Wolbachia and embryogenesis were assessed by immunohistology. In nodules taken 6 months after treatment with either dose and 12 months after 1,200 mg/week, the Wolbachia loads of the worms were not different from those of untreated worms. However, 12 months after the 250-mg/day azithromycin regimen, significantly less female worms (65% compared to 92% untreated ones) presented many Wolbachia, although the reduction was less pronounced than observed in other studies after treatment with doxycycline. Embryogenesis and microfilariae production were not reduced. It is concluded that azithromycin administered alone for 6 weeks at 250 mg/day or 1,200 mg/week is not suitable for treatment of human onchocerciasis. But daily azithromycin should be studied in combination with other drugs and with other doses.

Topics: Adolescent; Adult; Animals; Anti-Bacterial Agents; Azithromycin; Endemic Diseases; Female; Ghana; Humans; Male; Middle Aged; Onchocerca volvulus; Onchocerciasis; Symbiosis; Treatment Outcome; Wolbachia

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.

Topics: Adolescent; Adult; Animals; Anthelmintics; Anti-Bacterial Agents; Azithromycin; Child; Child, Preschool; Drug Therapy, Combination; Female; Humans; Ivermectin; Male; Middle Aged; Onchocerca volvulus; Onchocerciasis; Rifampin; Wolbachia

Trachoma is the world's most frequent cause of blindness from an infectious agent. The disease caused by infection is associated with lack of access to sanitation and low hygiene standards. Trachoma is controlled through the Surgery, Antibiotics, Facial cleanliness, and Environmental improvement (SAFE) strategy, which delivers azithromycin (AZM) mass drug administration (MDA) in endemic areas. The putative vector Musca sorbens principally reproduce in human faecal matter left in the environment due to open defecation. Ivermectin (IVM) is on the WHO's essential medicines list and is administered as preventative chemotherapy against two neglected tropical diseases (NTDs)-onchocerciasis, as an annual or bi-annual treatment, and lymphatic filariasis, as an annual treatment in combination with albendazole. Ivermectin has a known inhibitive effect on insects that reproduce in dung. To assess if IVM could be a viable vector control tool against M. sorbens, this study evaluates existing data from trachoma, onchocerciasis and lymphatic filariasis mass drug administration (MDA) operations in Ethiopia. Persistent and recrudescent trachoma in evaluation units (EUs) were examined for whether AZM MDA in EUs was accompanied by IVM MDA, and whether co-administration was associated with greater likelihood of trachoma control. Results show an association suggesting that EUs that received both IVM and AZM MDA benefit from improved control of trachoma in persistent or recrudescent areas, when compared to EUs that received AZM MDA. This initial investigation supports the potential for ivermectin's use to support SAFE. Findings warrant further work to validate ivermectin's impact on M. sorbens reproduction through controlled lab and field-based studies.

Topics: Animals; Anti-Bacterial Agents; Azithromycin; Chlamydia trachomatis; Elephantiasis, Filarial; Humans; Ivermectin; Muscidae; Onchocerciasis; Trachoma