Tetanus: Are you Immunized?

Tetanus is an acute disease caused by exo-toxin produced Clostridium tetani. It is characterized by painful muscular rigidity which persists throughout illness. The painful spasms of the muscles specially the Masseters resulting in Trismus or lock-jaw; muscle of the face resulting Risus Sardonicus; muscle of neck, back, abdomen and lower limbs resulting Opisthotomus. Case fatality rate is quite high; varying from 30 to 90%.

Agent Factors:
Agent Clostridium Tetani is a Gram-positive anaerobic, spore-bearing organism. The spores are terminal and give the organism a drum-stick appearance. The spores are highly resistant to a number of injurious agents; including boiling, phenol, cresol etc. It is destroyed by autoclaving for 20 minutes at 120°C & by irradiation. They germinate under anaerobic conditions & produce a potent exotoxin. It is one of the important causes of infant mortality. It produces potent neurotoxin which acts on nervous system. The spores remain viable for months in warm moist soil.

Period of communicability:
Not transmitted from person to person.

Reservoir of infection:
The natural habitat is many herbivorous animals e.g. cattle, sheep, horses, goats etc. They excrete it through their feces. The spores can survive for years in nature. The spores are blown through air with dust.

Host Factors:
The disease affects all ages and both sexes equally. The tetanus occurring in the new-born is known as “Tetanus Neonatum”.
The neonate typically contact with the disease at birth; because most of the delivery occurs or taken place in non-specific conditions i.e. unclean/ unsterilized space, untrained TBA, and specially when the umbilical cord is cut with unsterilized instruments or when the umbilical cord is stumped or dressed with ashes, soil or cow dung.

Sex:
Both sexes are affected. The males are more affected then the female. The males are more exposed to their occupation. Tetanus is common among agricultural workers, in neonate and in female during puerperal tetanus.

Immunity:
No age group is immune if not immunized by vaccination or immunoglobulin. The immunity resulting from two doses of injections of Tetanus Toxoid is highly effective and lasts for several years. After recovery from tetanus, one should be actively immunized, because the amount of toxin that causes Tetanus is not enough to stimulate protective immunity in side the human body. This is a disease in which Herd Immunity does not protect the individual.

Environmental and Social Factor:
It is one of the environmental hazards. Its occurrence depends upon human’s physical & ecological surroundings; the soil, agriculture, animal and not on the presence or absence of infection in the population. Environmental factors are accompanied by social factor; such as unhygienic customs and habits, application of cow dung in wounds; unhygienic delivery practices; using of unsterilized instruments for cutting of umbilical cord. Ignorance is one of the most important causes in case of infection and lack of Primary Health Care services.
In UK, USA and Germany the incidence is reduced.

Mode of Transmission:
Infection is acquired by contamination of wounds with tetanus spores. The range of injuries and accidents which may lead to tetanus comprises a trivial pin prick, skin abrasion, puncture wounds, burns, human bite, animal bite, unsterile surgery, intrauterine death, bowel surgery, dental extracting, injections, unsterile division of umbilical cord, compound fracture, otitis media, chronic skin ulcers, eye infections, gangrenous limbs etc.

Incubation Period:
The incubation period is usually 6 to 10 days. It may be short like one day or as long as several months.

Types of Tetanus:
(1) Traumatic
(2) Puerperal
(3) Otogenic
(4) Idiopathic
(5) Tetanus Neonatum

Prevention:
(1) Active immunization in EPI: Scheduled administration of Tetanus Toxoid. All persons should be immunized regardless of age.
(2) Passive Immunization: By Anti-tetanus Serum (ATS)

Prevention of Tetanus after injury:
All wounds must be thoroughly cleaned soon after injury, removal of foreign body, soil, dust, necrotic tissue. In this way anaerobic condition is abolished.
ATS is given in divided doses.