An outbreak of cameline filariasis in the Sudan

Sheathed microfilariae (mean length 278 +/- 10 microns SEM; mean width 7.2 +/- 0.8 microns) were detected in the blood of 7/14 housed camels (Camelus dromedarius). Microfilaraemic camels of either sex were inappetent, lethargic, reluctant to move and exhibited weakness in the hind limbs; some remained in sternal recumbency. Cardiac disorders, orchitis and skin nodules were conspicuously absent. The microfilariae showed a biphasic pattern in the blood that peaked at 20:00 and plateaued between 04:00 and 06:00. Adult filarial worms were recovered from the mesenteric and femoral arteries. Marked clinical improvement within 1-2 weeks was seen in three camels treated at 10:00 with a single subcutaneous injection of 0.2 mg/kg of ivermectin. These camels became amicrofilaraemic 2-5 days after treatment and remained so for the length of the observation period (133 days). Treatment of two camels at the time of high microfilaraemia (06:30) resulted in adverse reaction and death.