Cerebrospinal setariosis with Setaria marshalli and Setaria digitata infection in cattle.

Setaria digitata and S. marshalli larvae were observed in the cerebrospinal cavity of 2 paralyzed cattle in Taiwan. The 2 affected cattle showed quadriplegia and lumbar paralysis, respectively. At necropsy, which was performed 7 days after the 7-month-old cattle became quadriplegic, three and nineteen S. marshalli larvae as well as two female adult worms were found in the cranial cavity, spinal cavity and peritoneal cavity of the cattle, respectively. Necropsy on the other 8-month-old cattle was also performed 3 days after it showed lumbar paralysis, and ten S. digitata larvae were found in the spinal cavity. In both cattle, many mononuclear inflammatory cells mixed with a few eosinophils were seen accumulated in the connective tissue around the root of the spinal nerves. Infiltration of eosinophils and mononuclear inflammatory cells into the epidura and arachnoidea of the brain were also observed. The major inflammatory cell was lymphocytes, but neutrophils and eosinophils were also present. The number of cells in the cerebrospinal fluid collected initially from the two affected cattle were 105/0.01 ml and 143/ 0.01 ml, respectively. This is the first report of cerebrospinal setariosis in cattle associated with S. marshalli.

Development of a diagnostic DNA probe to detect Setaria digitata: the causative parasite of cerebrospinal nematodiasis in goats, sheep and horses.

Two repetitive sequences (IpSdM and IpSdS) have been cloned and sequenced from the genome of Setaria digitata. When IpSdM (214 bp) and IpSdS (201 bp) were aligned, a high degree of homology (85%) was observed, indicating that they belong to the same family of repeats. IpSdM represents a complete repeating element while IpSdS consists of two partial repeating elements arranged in tandem. The elements are present in about 10 000 copies comprising 2.8% of the S. digitata genome. As a diagnostic probe IpSdM detects as little as 100 pg DNA of both S. digitata and S. labiato-papillosa. It can also detect a single microfilaria and a L3 larva making it a valuable tool to monitor cattle and mosquito vector populations in the prevention of cerebrospinal nematodiasis.