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| TETANUS |
Disease
Tetanus is acquired through environmental exposure to the spores of Clostridium
tetani, which are present in soil worldwide. The disease is caused by the action of
a potent neurotoxin produced by the bacterium in dead tissue (e.g. dirty wounds).
Clinical symptoms of tetanus are muscle spasms, initially of the muscles of
mastication causing trismus or “lockjaw”, which results in a characteristic facial
expression – risus sardonicus. Trismus can be followed by sustained spasm of
the back muscles (opisthotonus) and by spasms of other muscles. Finally, mild
external stimuli may trigger generalized, tetanic seizures, which contribute to the
serious complications of tetanus (dysphagia, aspiration pneumonia) and lead to
death unless intense supportive treatment is rapidly initiated.
Occurrence
Dirty wounds can become infected with the spores of Clostridium tetani anywhere
in the world.
Risk for travellers
Every traveller should be fully protected against tetanus. Almost any form of
injury, from a simple laceration to a motor-vehicle accident, can expose the individual to the spores.
Vaccine
Tetanus vaccines stimulate production of a protective antitoxin. In general, adsorption on aluminum hydroxide or aluminum phosphate improves antigenicity.
Tetanus toxoid is available as single toxoid (TT), combined with diphtheria toxoid (DT), or low dose dephtheria toxoid (Td), or combined with diphtheria and pertussis vaccine (whole pertussis – wP or acellular pertussis – aP).
Vaccine combinations containing diphtheria toxoid (D or d) and tetanus toxoid, rather than tetanus toxoid alone, are being used now when immunization against tetanus is indicated.
Primary immunization for children under 10 years consists of 3 doses of a combined preparation containing adsorbed tetanus vaccine, with an interval of 1 month between doses. The recommended schedule of tetanus vaccination not only gives protection against tetanus in childhood but also gives the basic immunity for subsequent booster doses.
For primary immunization of adults and children over 10 years previously unimmunised against tetanus, 3 doses of adsorbed diphtheria [low dose] and tetanus vaccine are given with an interval of 1 months between doses.
Following routine childhood vaccination, 2 booster doses of a preparation containing adsorbed tetanus vaccine are recommended, the first before school entry and the second before leaving school.
Wounds are considered to be tetanus prone if they are sustained more than 6 hours before surgical treatment or at any interval after injury and are puncture type (particularly if contaminated with soil or manure) or show much devitalized tissue or are septic or are compound fractures or contain foreign bodies. All wounds should receive thorough cleansing.
The type of tetanus prophylaxis that is required following injury depends on the nature of the lesion and the history of previous immunizations. However, no booster is needed if the last dose of tetanus vaccine was given less than 5 (for dirty wounds) to 10 years (for clean wounds) previously.
Individuals whose primary immunization is incomplete or whose boosters are not up to date require a reinforcing dose of a tetanus containing vaccine (followed by further doses as required to complete the schedule); non-immunized individuals (or whose immunization status is not known or who have been fully immunized but are now immuno compromised) should be given a dose of the appropriate tetanus containing vaccine immediately followed by completion of the full course of the vaccine.
For tetanus prone wounds, management is as for clean wounds with the addition of a dose of tetanus immunoglobulin given at a different site in fully immunized individuals the immunoglobulin is needed only if the risk of infection is especially very high. Systemic as well as local tetanus immunoglobulin is given in individuals with tetanus prone wounds where no immunization or incomplete immunization has taken place.
Very rarely, tetanus has developed after abdominal surgery; patients awaiting elective surgery should be asked about tetanus immunization and immunized if necessary. Parenteral drug abuse is also associated with tetanus; those abusing drugs by injection should be vaccinated if unimmunised. Booster doses should be given if there is any doubt about the immunization status. All laboratory staff should be offered a primary course if unimmunised.
All travellers should be up to date with the vaccine before departure. |
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