Macrofilaricidal effect of 4 weeks of treatment with doxycycline on Wuchereria bancrofti.

OBJECTIVE: To evaluate the efficacy of doxycycline as a macrofilaricidal agent against Wuchereria bancrofti.

METHOD: In the Western Region of Ghana, 18 patients infected with W. bancrofti were recruited and treated with 200 mg doxycycline per day for 4 weeks. Seven untreated patients served as controls. Four months after doxycycline treatment, all patients received 150 mug/kg ivermectin. Patients were monitored for Wolbachia and microfilaria loads, antigenaemia and filarial dance sign (FDS).

RESULTS: Four months after doxycycline treatment, cases had a significantly lower Wolbachia load than controls; and 24 months after treatment, microfilaraemia, antigenaemia and frequency of FDS were significantly lower in cases than controls. Most importantly, 4 weeks of doxycycline killed 80% of macrofilariae, which is comparable with the results of a 6-week regimen. Circulating filarial antigenaemia and FDS were strongly correlated.

CONCLUSION: A 4-week regimen of doxycycline seems sufficient to kill adult W. bancrofti and could be advantageous for the treatment of individual patients, e.g. in outpatient clinics.