Tetanus
(Lockjaw)
1.Identification: an acute disease induced by an
exotoxin of the tetanus bacillus, which grows
anerobically at the site of an injury. It is
characterized by painful muscular contractions,
primarily of the masseter and neck muscles,
secondarily of trunk muscles. A common first sign
suggestive of tetanus in older children and adults
is abdominal rigidity, though rigidity is sometimes
confined to the region of injury. Generalized
spasms occur, frequently induced by sensory
stimuli.
Typical features of tetanic spasm are the position of
opisthotonos and the facial expression known as
“risus sardonicus”.
History of an injury or apparent portal of entry may
be lacking. Case – fatality rate ranges from 10% to
over 80% depending on age and quality of care
available, is highest in infants and the elderly, and
varies inversely with the length of the incubation
period and the availability of experienced
intensive care unit personnel and resources.
Infectious agent: Clostridium tetani, the tetanus
bacillus.
Occurrence: worldwide, the disease is more
common in agricultural regions and in areas
where contact with animal excreta is more likely
and immunization is inadequate. Parenteral use
of drugs by addicts, intramuscular or
subcutaneous use, can result in individual cases
and occasional circumscribed outbreaks.
4.Reservoir : intestines of horses and other animals, humans in which
the organism is a harmless normal inhabitant. Soil or fomites
contaminated with animal and human feces. Tetanus spores,
ubiquitous in the environment, can contaminate wounds of all
types.
5.Mode of transmission : tetanus spores are usually introduced into
the body through a puncture wound contaminated with soil, street
dust or animal or human feces; through lacerations, burns and
trivial or unnoticed wounds; or by injected contaminated drugs (e.g.
street drugs).
Tetanus occasionally follows surgical procedures, which include
circumcision and abortions performed under unhygienic conditions.
The presence of necrotic tissue and/or foreign bodies favors growth
of the anerobic pathogen.
6.Incubation period: usually 3 – 21 days, although it may range from 1
day to several months, depending on the character, extent, and
location of the wound; average 10 days. Most cases occur within 14
days. In general, shorter incubation periods are associated with
more heavily contaminated wounds, more sever disease, and a
worse prognosis.
7.Period of communicability: no direct person to person transmission.
8.Susceptibility and resistance: susceptibility is general. Active
immunity is induced by tetanus toxoid and persists for at least 10
years after full immunization ; transient passive immunity follows
injection of tetanus immune globulin (TIG) or tetanus antitoxin
(equine origin). Infants of actively immunized mothers acquire
passive immunity that protects them from neonatal tetanus.
Recovery from tetanus may not result in immunity; second attacks
can occur and primary immunization is indicated after recovery.
9.Methods of control:
A. Preventive measures:
1.Educate the public on the necessity for complete immunization with
tetanus toxoid, the hazards of puncture wounds and closed injuries
that are particularly liable to be complicated by tetanus, and the
potential need after injury for active and / or passive prophylaxis.
2.Active immunization withadsorbed tetanus toxoid (TT) which gives
durable protection for at least 10 years; after the initial basic series
has been completed, single booster doses elicit high levels of
immunity. In children under 7 , the toxoid is generally administered
together with diphtheria toxoid and pertussis vaccine as atriple
(DTP) antigen or as (DT) antigen.Tetanus and diphtheria (Td) vaccine
is used for children older than 7 years .
In countries with incomplete immunization programs for
children , all pregnant women should receive 2 doses
of tetanus toxoid in the first pregnancy , with an
interval of at least 1 month , and with the second dose
at least 2 weeks prior to child birth , in order to prevent
maternal and neonatal tetanus . Booster doses may be
necessary to ensure ongoing protection.
Minor local reactions following tetanus toxoid injections
are relatively frequent ; sever local and systemic
reactions are infrequent but do occur , particularly
after excessive numbers of prior doses have been
given.
a) The schedule recommended for tetanus immunization in
childhood is the same as for diphtheria.
b) While tetanus toxoid is recommended for universal use
regardless of age , it is especially important for workers in
contact with soil , sewage and domestic animals;members
of military forces; policemen and others with greater than
usual risk of traumatic injury; adults with diabetes mellitus ;
older adults who are currently at highest risk for tetanus
and tetanus related mortality; and women of reproductive
age and newborns.Vaccine – induced maternal immunity is
important in preventing maternal and neonatal tetanus.
c) Active protection should be maintained by administrating
booster doses of Td every 10 years.
d) For children and adults who are severely
immunocompromized or infected with HIV, tetanus
toxoid is indicated in the same schedule and dose for
immunocompetent persons, even though the immune
response may be suboptimal.
3.Prophylaxis in wound management : tetanus
prophylaxis in patients with wounds is based on careful
assessment of whether the wound is clean or
contaminated, the immunization status of the patient ,
proper use of tetanus toxoid and / or TIG, wound
cleaning , and – where required – surgical debridement
and the proper use of antibiotics.
a)Those who have been completely immunized and who sustain minor
and uncontaminated wounds require a booster dose of toxoid only
if more than 10 years have elapsed since the last dose was given.
For major and / or contaminated wounds , a single booster injection
of tetanus toxoid should be administered promptly on the day of
injury if the patient has not received tetanus toxoid withen the
preceding 5 years.
b) Persons who have not completed a full primary series of tetanus
toxoid require a dose of toxoid as soon as possible following the
wound , and may require passive immunization with human TIG if
the wound is a major one and / or if it contaminated with soil
containing animal excreta. DTP,DT or Td, as determined by the age
of the patient and previous immunization history, should be used at
the time of the wound ,and ultimately to complete the primary
series.
Passive immunization with at least 250 IU of
human – derived TIG IM (or 1500 to 5000 IU
of antitoxin of animal origin if globulin is not
available), regardless of the age of the patient,
is indicated for patients with other than clean
, minor wounds and a history of no, unknown
or fewer than 3 previous tetanus toxoid doses.
When tetanus toxoid and TIG or antitoxin are
given concurrently, separate syringes and
separate sites must be used.
Antibiotics may theoretically prevent the multiplication of C.
tetani in the wound and thus reduce the production of
toxin , but this does not obviate the need for prompt
treatment of the wound together with appropriate
immunization .
B. Control of patient , contacts and the immediate
environment :
1) Report to local health authority
2) Isolation : not applicable
3) Concurrent disinfection : not applicable
4) Quarantine : not applicable
5) Immunization of contacts : not applicable
6)Investigation of contacts and source of infection : case investigation
to determine circumstances of injury
7)Specific treatment : TIG IM in doses of 3000- 6000 IU. If tetanus IG is
not available, tetanus antitoxin (equine origin) in a single large dose
should be given IV following testing for hypersensitivity.
Metronidazole, the most appropriate antibiotic in terms of recovery
time and case – fatality , should be given for 7 – 14 days in large
doses ; this also allows for a reduction in the amount of muscle
relaxant and sedative required . The wound should be debrided
widely if possible. Wide debridement of the umbilical stump in
neonates is not indicated . Maintain an adequate airway and
employ sedation as indicated ; muscle relaxant drugs , together
with tracheostomy or nasotracheal intubation and mechanically
assisted respiration , may be life saving .Active immunization should
be initiated concurrently with treatment.
C.Epidemic measures : In the rare outbreak, search
for contaminated street drugs or other common –
use injections.
D.Disaster implications: military conflicts and
natural disasters (floods, earthquakes) that can
cause many traumatic injuries in non- immunized
populations will result in an increased need for
TIG or tetanus antitoxin and toxoid for injured
patients.
E.International measures: Up-to-date immunization
against tetanus is advised for injured patients.
Tetanus Neonatorum
It is a serious health problem in many developing
countries where maternity care services are
limited and immunization against tetanus is
inadequate .In the past 10 years the incidence of
tetanus neonatorum has declined considerably in
many developing countries, thanks to improved
training of birth attendants and immunization
with tetanus toxoid for women of childbearing
age.
Despite this decline, WHO estimated in 2006 that tetanus
neonatorum still caused about 257000 deaths , mainly
in the developing world. Most newborn infants with
tetanus are born to non-immunized mothers delivered
by an untrained birth attendant outside a hospital.
The disease usually occurs through introduction of
tetanus spores via the umbilical cord, during delivery
through the use of an unclean instrument to cut the
cord , or after delivery by dressing the umbilical stump
with substances heavily contaminated with tetanus
spores.
Tetanus neonatorum is typified by a newborn infant who
sucks and cries well for the first few days after birth but
subsequently develops progressive difficulty and then
inability to feed because of trismus , generalized
stiffness with spasms or convulsions and opisthotonos.
The average incubation period is about 6 days , with a
range from 3 to 28 days. Overall, case – fatality rates
for neonatal tetanus are very high, exceeding 80%
among cases with short incubation periods.
Neurological sequelae including mild retardation occur
in 5% to over 20% of those children who survive .
Prevention :
1.Improving maternity care , with emphasis on
increasing the tetanus toxoid immunization
coverage of women of childbearing age
(especially pregnant women) and clean
deliveries.
2.Increasing the proportion of deliveries
attended by trained attendants.
Non – immunized pregnant women should
receive at least 2 doses of tetanus toxoid ,
preferably as Td, according to the following
schedule: the first dose at initial contact or as
early as possible during pregnancy ; the
second dose 4 weeks after the first and
preferably at least 2 weeks before delivery. A
third dose could be given 6-12 months after
the second .An additional 2 doses should be
given at annual intervals.