Onchocerca fasciata Railliet and Henry, 1910 and its nodule development in camels in Saudi Arabia.

A total of 192 male camels of three age groups (young, adult and old) from Saudi Arabia were examined for Onchocerca fasciata infection by detection of microfilariae in skin snips and nodules in the nuchal ligaments and subcutaneous tissues of the neck and shoulder. The overall prevalence rates were 10.9 and 33.3%, respectively. The prevalence rate by the skin snip technique and the number of microfilariae per gram of skin were higher in young and adult camels than in old camels. However, the prevalence rate by the detection of nodules and the number of nodules per infected camel, increased with increase in age of the camels. An increase in size and weight of nodules was reported with an increase in age of the camels. Nodules varied in diameter from 2 to 36 mm and in weight from 0.5 to 5.0 g. The overall percentage of soft viable and calcified nodules was 42.5 and 57.5%, respectively. The viability of worms decreased, but calcification increased with increased age of the camels. Four levels of degeneration and calcification of worms were described following scanning electron microscopy.