TETANUS

                                           Tetanus is an acute, fatal disease caused by exotoxin producing bacteria clostridium tetani. It is characterized by generalized rigidity & convulsions of skeletal muscles.

CLOSTRIDIUM TETANI:

1.      It is a gram positive, anaerobic, sporeforming, drumstick shaped bacilli.

2.      It is sensitive to heat, oxygen,the spores are resistant to heat, antiseptics, autoclaving, phenol and other chemicals.

3.      The spores are distributed in soil, intestine &faeces of animals.

4.      It produces two exotoxins:      

a. Tetanolysin-function not known.

b.Tetanospasmin-a neurotoxin

PATHOGENESIS:

1.      Clostridium tetani usually enters the body through wound.

2.       Anaerobic conditions allow germination of spores and production of toxins.

3.      Toxin binds in central nervous system.

4.      Toxin interferes with neurotransmitter release to block inhibitory impulses.

5.      This leads to unopposed muscle contraction and spasm.

CLINICAL FEATURES:

                 Incubation period ranges from 3 to 21 days .Three clinical forms are recognized;

                       Local Tetanus, in which there is contraction of muscles in the same anatomic area of injury; Cephalic tetanus occurring following the otitis media, head injuries.

                       Generalised tetanus, which presents in a descending order, trismus, stiffness of neck, difficulty in swallowing, rigidity of abdominal muscles, temperature elevation, sweating, rise in BP.

                       Spasms may continue for 3 to 4 months.

                       Neonatal Tetanus,occurs in infants born without passive immunity,occurs as generalized tetanus.

COMPLICATIONS:

·        Laryngospasm

·        Fractures

·        Hypertension

·        Nosocomial infections

·        Pulmonary embolism

·        Aspiration

·        Death

LABORATORY DIAGNOSIS:

                   The diagnosis is entirely clinical and doesnot depend on bacteriological confirmation.

MEDICAL MANAGEMENT

                         All wounds should be cleaned with removal of necrotic tissue &foreign material.If tetanic spasms are occurring ,supportive theraphy &maintenance of adequate airway are essential.

                         A single intramuscular dose of 3000 to 5000 units is generally recommended for children &adults with tetanus.Intravenous immunoglobulin containing tetanus antitoxin is also useful.

WOUND MANAGEMENT:

                         Persons with wounds that are neither clean nor minor, and who have had 0-2 prior doses or have an uncertain history of prior doses, need tetanus immune globulin as well as tetanus toxoids.

TETANUS EPIDEMIOLOGY:

                  Reservoir: Soil and intestine of animals and humans.

                  Transmission: Contaminated wounds &tissue injury

                  Temporal pattern: Peak in summer or wet season.

                  Communicability: Not contagious

TETANUS TOXOID:

                        Tetanus toxoid consists of a formaldehyde treated toxin. There are two types of toxoids available –adsorbed (aluminium salt precipitated) and fluid toxoids. Adsorbed toxoid is preferred because the antitoxin response reaches high titers and long lasting.

                        Tetanus toxoid is available as a single antigen preparation, combined with diphtheria as paediatric DT or adult Td and with both diphtheria toxoid and acellular pertussis vaccine as DtaP.Children younger than 7 years of age should receive either DtaP or paediatric DT.Persons 7 years of age or older should receive the adult formulation.

IMMUNOGENICITY&VACCINE EFFICACY:

                         A primary series of three properly spaced doses of tetanus toxoid in persons Ê7 years of age and four doses in children <7years is recommended. Routine boosters are recommended every 10 years.

VACCINATION SCHEDULE&USE:                

Routine DtaP primary vaccination schedule

Children Who receive DT

                      The number of doses of DT needed to complete the series depends on the child’s age at the first dose. If first dose given at <12 months of age 4 doses are needed. If first dose given at >12months 3 doses are needed.

Routine DtaP schedule children <7 years of age

     Booster doses

            4-6 years, before entering school

            11-12 years of age if 5 years since last dose

            Every 10 years thereafter

Routine DT schedule unvaccinated persons >7 years of age

Diphtheria and Tetanus Toxoids Adverse reactions

          -         Local reactions (erythema, induration)

          -         Exaggerated local reactions (Arthus type)

          -         Fever and systemic symptoms not common

          -         Severe systemic reactions rare

Diphtheria and Tetanus Toxoids Contraindications and Precautions

         -         Severe allergic reactions to vaccine components or following prior dose

         -         Moderate or severe acute illness.

Vaccine storage and handling:

         Vaccines should be stored continuously at 2°-8°c. Freezing reduces the potency.

  Submitted by :

Dr.Chandramouli