Description
Tetanus, an acute disease caused by Clostridium tetani, is characterized by muscle rigidity and painful spasms, often starting in the muscles of the jaw and neck. Severe tetanus can lead to respiratory failure and death. The disease is caused by a neurotoxin produced by anaerobic tetanus bacilli growing in contaminated wounds (1,2). Lesions that are considered “tetanus prone” are wounds contaminated with dirt, feces or saliva, deep wounds, burns, crush injuries, or those with necrotic tissue. However, tetanus has also been associated with apparently clean superficial wounds, surgical procedures, insect bites, dental infections, chronic sores and infections, and intravenous drug use. In 10% of reported cases in the United States, no antecedent wound was identified (3).
Clinical Presentation
Three clinical syndromes are associated with tetanus infection: generalized, localized, and cephalic. Generalized tetanus is the most common form, accounting for more than 80% of cases (3). In generalized tetanus, the average incubation period between injury and symptom onset is 7-8 days (range 3 days-3 weeks). The most common initial sign is trismus (spasm of the muscles of mastication or “lockjaw”). Trismus may be followed by painful spasms in other muscle groups in the neck, trunk, and extremities and by generalized tonic tetanic seizure-like activity or frank convulsions in severe cases. Generalized tetanus can be accompanied by autonomic nervous system abnormalities, as well as a variety of complications related to severe spasm and prolonged hospitalization. Neonatal tetanus is generalized tetanus occurring in neonates, usually due to umbilical stump infections. The clinical course of generalized tetanus is variable and depends on the degree of prior immunity, the amount of toxin present, and the age and general health of the patient (5). Even with modern intensive care, generalized tetanus is associated with mortality rates of 10%-20% (3).
Localized tetanus is an unusual form of the disease, consisting of spasm of muscles in a confined area close to the site of the injury. Although localized tetanus often occurs in persons with partial immunity and is usually mild, progression to generalized tetanus can occur. Cephalic tetanus, the rarest form, is associated with lesions of the head or face, and also has been described in association with ear infections (i.e., otitis media). The incubation period is short, usually 1-2 days. Unlike generalized and localized tetanus, cephalic tetanus results in flaccid cranial nerve palsies rather than spasm. Trismus may also be present. Like localized tetanus, cephalic tetanus can progress to the generalized form.
Prevention
WOUND CARE
Travelers should be advised that any tetanus-prone wound should receive prompt local treatment by thorough cleansing and débridement of the wound if necrotic tissue or dirt is present. In addition, those travelers who received their most recent tetanus toxoid-containing vaccine more than 5 years ago or who have not received at least three doses of tetanus toxoid-containing vaccines may require a dose of tetanus toxoid-containing vaccine (Tdap,Td or DTaP), according to the guidelines in Table 4-19. Human tetanus immune globulin (TIG) is indicated in travelers with tetanus-prone wounds who have an unknown or incomplete history of primary tetanus vaccination.
VACCINE
Immunizations for Infants and Children Younger than 7 Years of Age
Immunization with tetanus toxoid in combination with diphtheria toxoid and acellular pertussis vaccine (DTaP) during infancy is recommended (see Chapter 8). DTaP is not licensed for persons older than 7 years of age. Diphtheria and tetanus toxoid with whole-cell pertussis antigens (DTwP) is no longer available in the United States, but is used in other countries. Immunization for infants and children up to the seventh birthday consists of five doses of DTaP vaccine. The first three doses are usually given at ages 2, 4 and 6 months, the fourth dose at age 15-18 months, and the fifth dose at age 4-6 years. The fifth dose is not necessary if the fourth dose was given after the child’s fourth birthday (6).
At least three doses of DTaP are necessary for protection against tetanus (1). Children should complete as many doses as possible of the three-dose primary series before traveling. If an accelerated schedule is required to complete the series of DTaP vaccine, the schedule may be started as soon as the infant is 6 weeks of age, with the second and third doses given 4 weeks after each preceding dose (see Chapter 8). The fourth dose should not be given before the child is age 12 months and should be separated from the third dose by at least 6 months. The fifth dose should not be given before the child is age 4 years. Interruption of the recommended schedule or delay in doses does not lead to a reduction in the level of immunity reached on completion of the primary series. There is no need to restart a series regardless of the time that has elapsed between doses. For infants and children younger than 7 years who have a contraindication to the pertussis component of DTaP, diphtheria-tetanus (DT) should be used (6).
Immunizations for Children 7-10 Years of Age
Children 7-9 years of age should receive the adult formulation of tetanus and reduced diphtheria toxoids (Td) whenever tetanus toxoid is indicated, because no pertussis-containing vaccine is licensed for use in this age group (6,7). If a child is 10 years old, a single dose of BOOSTRIX may be substituted for one of the Td doses.
Immunizations for Adolescents and Adults
In 2005, two tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine products were licensed for use by the FDA. BOOSTRIX (GlaxoSmithKline Biologicals) and ADACEL (Sanofi Pasteur) are licensed for use in persons aged 10-18 years and 11-64 years, respectively.
Adolescents aged 11-18 years who have completed their childhood vaccination series with DT, DTaP and/or DTwP should receive a single dose of Tdap instead of Td for booster immunization against tetanus as well as diphtheria and pertussis (7). Adults aged 19-64 years who have not previously received Tdap should receive a single dose of Tdap if their last dose of tetanus toxoid-containing vaccine was administered more than 10 years prior (8,9). Tdap is not licensed or recommended for adults older than 65 years, who should receive Td instead.
Adolescents or adults who have never been immunized against tetanus, or whose immunization history is uncertain, should receive a three-dose series of vaccinations. The preferred schedule is a single Tdap dose, followed by a dose of Td 4-8 weeks after the Tdap dose, and a second dose of Td 6-12 months after the first Td dose; however, a single dose of Tdap can be substituted for any one of the three doses in the series (7,8). Two doses of Tdap/Td received at intervals of at least 4 weeks can provide some protection against tetanus, but a single dose is of little benefit. In the rare instance when administration of the third dose following a 6- to 12-month interval cannot be ensured, the third Td dose can be given 4-8 weeks after the second dose to complete the primary series.
Anyone who has received only one or two prior doses of tetanus and diphtheria toxoids should receive additional doses to complete the three-dose series. A single dose of Tdap can be substituted for any of the Td doses.
Adverse Reactions
Local reactions (erythema and induration with or without tenderness) are common after the administration of vaccines containing diphtheria, tetanus, and pertussis antigens. Mild systemic reactions, such as fever, drowsiness, and fretfulness, can occur after vaccination with DTaP. These reactions are generally self-limited and can be managed with symptomatic treatment of acetaminophen or ibuprofen (9). Swelling involving the entire thigh or upper arm has occurred after the fourth and fifth doses of DTaP; these reactions are also self limited. Prelicensure studies support the safety of Tdap, with an overall safety profile of local and systemic events comparable to Td.
Anaphylactic and other serious adverse events are rare after receipt of preparations containing diphtheria, tetanus or pertussis components, or a combination of these. Arthus-type hypersensitivity reactions, characterized by severe local reactions, have been reported in adults who received frequent boosters of tetanus or diphtheria toxoids. In 1994, the Institute of Medicine published a report concluding that evidence favors acceptance of a causal relationship between receipt of tetanus toxoid-containing vaccines and both brachial neuritis and Guillain-Barré syndrome (10). The size of prelicensure studies for Tdap was insufficient to detect rare adverse events.
Precautions and Contraindications
An immediate anaphylactic reaction to a prior dose of vaccine or vaccine component is a contraindication to further vaccination with DTaP, DT, or adult Td or Tdap. Encephalopathy not due to another identifiable cause within 7 days of vaccination is a contraindication to further vaccination with a pertussis-containing vaccine. DT or Td may be substituted for DTaP or Tdap, respectively.
Moderate or severe acute illness is a precaution to vaccination. Mild illnesses, such as otitis media or upper respiratory infection, are not contraindications (9). Anyone for whom vaccination is deferred because of moderate or severe acute illness should be vaccinated when the condition improves.
Certain infrequent adverse events following pertussis vaccination are considered precautions (not contraindications) to additional doses of DTaP, but not to Tdap: a seizure, with or without fever, occurring within 3 days of immunization; temperature higher than 40.5° C (105° F) not resulting from another identifiable cause within 48 hours of immunization; collapse or a shock-like state (hypotonic-hyporesponsive episode) within 48 hours of immunization, or persistent, inconsolable crying lasting longer than 3 hours and occurring within 48 hours of immunization. These events have not been proven to cause permanent sequelae. Development of Guillain-Barré 6 weeks or less after a previous dose of a tetanus toxoid-containing vaccine is considered a precaution.
Progressive neurologic conditions characterized by changing developmental findings are considered contraindications to receipt of pertussis vaccine. Such disorders include infantile spasms and other epilepsies beginning in infancy (10). Adult and pediatric patients of all ages with stable neurologic conditions such as cerebral palsy, controlled seizures, or progressive dementia may be vaccinated with pertussis vaccines.
