Tetanus is a paralyzing infectious bacterial disease caused by the neurotoxin produced by C. tetani. It affects humans and animals, but there is no documented direct transmission from animal to human. Prevention in humans is based on an anti-tetanus vaccine (recommended at birth, with a booster every ten years) and on the prophylactic administration of anti-tetanus immunoglobulin in case of an at-risk wound. Tetanus leads to death in approximately 30% of the cases.
Clostridium tetani, bacterium responsible for tetanus
Clostridia are ubiquitous bacteria (present everywhere in the environment). Some species can affect human and animals through the production of powerful toxins. Among these, C. tetani produces a muscle-contracting toxin that is responsible for tetanus. It is a neurotoxin, meaning that it acts on the nervous system.
How is the diagnosis made?
The clinical diagnosis of tetanus is based on clinical characteristics rather than laboratory confirmation (WHO). The laboratory’s role is therefore secondary, although it provides conclusive confirmation of the diagnosis. A serum sample must be taken as early as possible (within 3 days of the symptoms appearing) and before administering antitoxins. A negative result does not allow to exclude tetanus.
What analyses are performed in the laboratory?
The tetanus toxin is detected in the serum by means of a mouse bioassay (lethality test). The level of anti-tetanus antibodies in serum can also be determined at the laboratory to check the vaccination status of individuals/patients.
The laboratory is recognized as the National Reference Laboratory (NRL).