Clostridium tetani is a clinically important bacterium. It is a Gram-positive, sporulating obligate anaerobe, notorious for producing Tetanus. The organism is found in soil and in the intestinal tracts and faeces of animals.

SYMPTOMS

Tetanus has been known since ancient times when the link was made between wounds and painful, fatal muscle spasm. It was once known as "Lockjaw", after the early symptoms which involve spasms of the masseter muscle. This is followed by progressive rigidity and violent spasms of the trunk and limb muscles. Death usually follows and results from interference with the respiratory muscles and breathing process.

TOXINS

Most cases of tetanus result from small puncture wounds with C. tetani spores that germinate and produce toxin. The infection remains localised, but systemic damage results from the production of exotoxins, released when the spores germinate and grow. Tetanus toxin “Tetanospasmin” is one of the most potent toxins known, third only to botulinum toxin and diphtheria toxin. This powerful neurotoxin enters peripheral nerves and travel to the Central Nervous System. Here it interferes with the release of neurotransmitters, causing muscle contraction and spasm.

TREATMENT

Treatment of established Tetanus can be achieved with:

• Human tetanus immunoglobulin, (containing antitoxins) to neutralise the toxin.
• Large doses of antibiotics to halt toxin production.

IMMUNISATION

Immunisation is accomplished with tetanus toxoid, as part of the DPT (Diphtheria, Typhoid, Polio) vaccine. In the UK three injections are given in the first year of life, followed by a Preschool and School Leaver boosters. Following such a schedule the individual is usually considered protected for life. However, should a wound be particularly at risk e.g. contaminated with stable manure, human tetanus immunoglobulin will give immediate additional protection.

Because of the widespread use of the tetanus toxoid the number of cases of tetanus in the UK is low, with an average of only six cases each year. It remains however, a significant problem world-wide, particularly the neonatal form, where there are more than 300,000 cases annually. Clearly there is still work to be done to eradicate this disease.