It shares a common zinc protease motif (His-Glu-Xaa-Xaa-His) that researchers hypothesized was essential for target cleavage until this was more recently confirmed by experiment: when all zinc was removed from the neuron with heavy metal chelators, the toxin was inhibited, only to be reactivated when the zinc was added back in. The light chain binds to VAMP and cleaves it between Gln76 and Phe77. Without VAMP, vesicles holding the neurotransmitters needed for motor neuron regulation (GABA and glycine) cannot be released, causing the above-mentioned deregulation of motor neurons and muscle tension. Diagnosis
There are currently no blood tests for diagnosing tetanus. The diagnosis is based on the presentation of tetanus symptoms and does not depend upon isolation of the bacterium, which is recovered from the wound in only 30% of cases and can be isolated from people without tetanus. Laboratory identification of C. tetani can be demonstrated only by production of tetanospasmin in mice. Having recently experienced head trauma may indicate cephalic tetanus if no other diagnosis has been made.The "spatula test" is a clinical test for tetanus that involves touching the posterior pharyngeal wall with a soft-tipped instrument and observing the effect. A positive test result is the involuntary contraction of the jaw (biting down on the "spatula") and a negative test result would normally be a gag reflex attempting to expel the foreign object.
In 1998 in Uganda, 3,433 tetanus cases were recorded in newborn babies; of these, 2,403 died. After a major public health effort, Uganda in 2011 was certified as having eliminated maternal and neonatal tetanus. Post-exposure prophylaxis
Tetanus toxoid can be given in case of suspected exposure to tetanus. In such cases, it can be given with or without tetanus immunoglobulin (also called tetanus antibodies or tetanus antitoxin). It can be given as intravenous therapy or by intramuscular injection.The guidelines for such events in the United States for non-pregnant people 11 years and older are as follows:

Treatment
Mild tetanus
Mild cases of tetanus can be treated with:
Tetanus immunoglobulin (TIG), also called tetanus antibodies or tetanus antitoxin. It can be given as intravenous therapy or by intramuscular injection. Antibiotic therapy to reduce toxin production. Metronidazole intravenous (IV) is a preferred treatment. Benzodiazepines can be used to control muscle spasms. Options include diazepam and lorazepam, oral or IV. Severe tetanus
Severe cases will require admission to intensive care. In addition to the measures listed above for mild tetanus:
Human tetanus immunoglobulin injected intrathecally (which increases clinical improvement from 4% to 35%)
Tracheotomy and mechanical ventilation for 3 to 4 weeks.