Background & Aims : Sixty nine species of ticks in order Metastigmata may cause tick paralysis. A neurotoxin, which is found in tick salvia, is believed to be responsible for the paralysis. About 4-5 days after tick attachment paralysis occurs. The cause of the paralysis is blockage of transmission at the neuromuscular junction, due to the reduction of release of acetylcholine, and / or interaction in acetylcholine synthesis. There are differences in the clinical symptoms of paralysis produced by ticks. Generally, it is identified by a flaccid, ascending, acute & a febrile paralysis of limbs. Respiratory failure is the common cause of the death in tick paralysis. Recovery depends on the stage of paralysis. In mild forms recovery is rapid & which follows tick removal.

  Materials & Methods : This survey was tried to determine the capacity of Ornithodoros lahorensis ticks in producing tick paralysis in rat. After collection of O. lahorensis from infested farms and kept them in laboratory condition, 6 male rats were infested with female adult and larval ticks separately. After two weeks clinical, physical and electromyographical examinations were done.

  Results: The results indicated no sign of paralysis in physical and clinical examination in two groups of rats (infested to adult and larva ticks). Also the electromyography in infested rats was normal.

  Conclusion: O . lahorensis cann ot produce paralysis in rat.

  Source: Urmia Med J 2011: 22(2): 162 ISSN: 1027-3727