Table 1.
Characteristics of known tick paralysis toxins.
| Characteristic | I. holocyclus | R. evertsi evertsi | A. walkerae | D. andersoni |
|---|---|---|---|---|
| Life stage that cause paralysis | Nymphs and adults | Adults | Larvae | Adults |
| Mechanism of toxin | Inhibits synaptic vesicle (acetylcholine) release when binding to the synaptosomes at neuromuscular junction | Impair the conduction of impulses along the peripheral nerve fibers (nodes of Ranvier) | Inhibits Ca2+ dependent synaptic vesicle release and desensitizing its receptor | Motor polyneuropahty with limited participation of the afferent pathways |
| Size | 40–80 kDa; HT-1 = 5kDa |
68–70 kDa 74 kDa |
11 kDa/range of 11–115 kDa 80–100 kDa/32 and 60 kDa | 37–43 kDa |
| Recovery after tick removal | Prolonged (Days to weeks) with initial deterioration of host’s condition | Within hours to two days | Within hours | Within hours |
| Antiserum therapy | Useful in early stage of paralysis | None available | None available | None available |
| Immunity | Full | Limited | Partial | Dose dependent immunity |
| Isoelectric point | 8.86 4.5–5 |
6 | 4.5 | Unknown |
| Protease digestion | Resistant | Inactivate toxin | Unknown | Unknown |