Diphtheria, Tetanus, and Pertussis
Description
Diphtheria is an acute bacterial disease involving
primarily the tonsils, pharynx, larynx, nose, skin, and occasionally
other mucous membranes. The characteristic lesion is marked by a
patch or patches of an adherent grayish membrane with a surrounding
inflammation.
Tetanus is an acute disease characterized by muscle
rigidity and painful spasms, often starting in the muscles of the
jaw and neck. The disease is caused by neurotoxin produced by anaerobic
tetanus bacilli growing in contaminated wounds. Lesions that are
considered “tetanus prone” are wounds contaminated with
dirt, feces or saliva, deep wounds, or those with necrotic tissue.
However, tetanus has been associated with apparently clean superficial
wounds, surgical procedures, insect bites, dental infections, chronic
sores and infections, and intravenous drug use. In 5%–10% of
reported cases in the United States, no antecedent wound was identified.
Pertussis is an acute bacterial disease involving
the respiratory tract, characterized by prolonged paroxysmal coughing.
Persons in all age groups can be infected. Complications and deaths
from pertussis are most common among infants.
Occurrence
Diphtheria remains a serious disease throughout
much of the world. In particular, large outbreaks of diphtheria occurred
in the 1990s throughout Russia and the independent countries of the
former Soviet Union. Most life-threatening cases occurred in unvaccinated
or inadequately immunized persons. Children traveling to countries
where the risk of diphtheria is high should be vaccinated according
to the Recommended
Childhood Immunization Schedule. Travelers to
disease-endemic areas may be at increased risk for exposure to toxigenic
strains of Corynebacterium diphtheriae when travel is for
extended periods, when there is contact with children, or when conditions
are crowded or foster sharing of respiratory secretions. Countries
with endemic diphtheria include Africa – Algeria, Egypt,
and the countries in sub-Saharan region; Americas – Brazil,
Dominican Republic, Ecuador, and Haiti; Asia/Oceania – Afghanistan,
Bangladesh, Cambodia, China, India, Indonesia, Iran, Iraq, Laos,
Mongolia, Burma (Myanmar), Nepal, Pakistan, Philippines, Syria, Thailand,
Turkey, Vietnam, and Yemen; and Europe – Albania and
all countries of the former Soviet Union. Control measures may have
been implemented, but a risk of diphtheria remains in all these areas.
Tetanus is a global health problem since Clostridium
tetani spores are ubiquitous. The disease occurs almost exclusively
in persons who are unvaccinated or inadequately immunized.
Pertussis is severe primarily in children; it is
often associated with complications and has a relatively high case-fatality
ratio in unvaccinated infants. Pertussis can also occur in adolescents
and adults after immunity from vaccines has waned. Pertussis is highly
communicable and is common, particularly in countries where vaccination
is not generally provided.
When pertussis is highly suspected in a patient,
chemoprophylaxis of all close contacts and high-risk contacts with
erythromycin is recommended regardless of their age and vaccination
status. Initiating chemoprophylaxis 3 weeks or
more after exposure has limited benefit for the
contacts. However, chemoprophylaxis should be considered for high-risk
contacts up to 6 weeks after exposure.
Risk for Travelers
Diphtheria and pertussis are more frequent in parts
of the world where vaccination levels are low. Tetanus can occur
anywhere in the world in unvaccinated persons.
Prevention
Vaccine
Immunizations for Infants and Children < 7
Years of Age
Simultaneous immunization against diphtheria, tetanus,
and pertussis during infancy (see Tables 7–1 and 7–2)
is recommended. Combination vaccines contain diphtheria and tetanus
toxoids and either whole-cell pertussis antigens (DTwP) or acellular
pertussis antigens (DtaP). Neither DTwP nor DTaP pertussis vaccine
is licensed for persons 7or more years of age. DTwP vaccine is no
longer available for use in the United States. Pertussis vaccination
is not recommended after a child's seventh birthday.
Three brands of DTaP currently are approved for
use and are available in the United States. Each brand contains a
different number and concentration of pertussis antigen. Each is
safer than DTwP vaccine. The Advisory Committee on Immunization Practices
(ACIP) and the American Academy of Pediatrics indicate no preferences
for one brand over another.
Primary immunization for infants and children up
to the seventh birthday consists of four doses of DTaP vaccine (Table 7–1).
The first dose is typically given when an infant is 2 months of age.
The first three doses should be given at 4- to 8-week intervals,
with the fourth dose given when the infant is 15–18 months
of age. A fifth (booster) dose is recommended when the child is 4–6
years of age. The fifth dose is not necessary if the fourth dose
in the primary series was given after the child's fourth birthday.
Three—and preferably four—doses of DTaP
are necessary for protection against diphtheria and pertussis. Travelers
should be advised to complete as many doses as possible of the 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 Table 7–1).
The fourth dose should not be given before the child is 12 months
of age and should be separated from the third dose by at least 6
months. The fifth (booster) dose should not be given before the child
is 4 years of age. 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.
There are limited data describing the safety, immunogenicity,
and efficacy of using DTaP vaccines from different manufacturers
for successive doses of the primary or booster vaccination series
(“mix and match”). Whenever possible, the same brand
of DTaP vaccine should be used for all doses of the vaccination series.
To avoid delays in vaccination, any licensed DTaP vaccine may be
used to continue or complete the vaccination series, if the type
of vaccine previously administered is not known or the type of vaccine
used for earlier doses is not available. A pertussis vaccination
series begun with DTwP may be completed with DTaP.
Infants and children inadequately immunized for
their age should be brought up to date before travel. For infants
and children <7 years of age with a contraindication to the pertussis
component of DTaP, diphtheria-tetanus (DT) should be used (Table 7–1).
Immunizations for Children 7 or More Years
of Age, Adolescents, and Adults
Children 7 or more years of age, adolescents, and
adults should receive the adult formulation of tetanus and diphtheria
toxoids (Td) (Table 7–1)
whenever either tetanus or diphtheria toxoid is indicated. Anyone
7 or more years of age who has not received a primary series against
tetanus and diphtheria should receive three doses of Td; the first
two doses should be given 4–8 weeks apart and the third dose
6–12 months after the second. Two doses of Td received at intervals
of at least 4 weeks can provide some protection, 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 for whom primary tetanus and
diphtheria vaccination is uncertain should be considered unvaccinated
and should receive the three-dose 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. The first
booster dose of Td should be given when the child is 11 or 12 years
of age if at least 5 years has elapsed since the last dose of DTaP
or pediatric DT. Thereafter, routine booster doses of Td should be
given every 10 years.
Adverse Reactions
Local reactions (generally 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, fretfulness, and
low-grade fever can occur after vaccination with either DTwP or DTaP.
However, even mild reactions following the first four doses are less
common among children who receive DTaP. For example, fever >38.3° C
(>101° F) is reported in 3%–5% of DTaP recipients,
compared with 16% of DTwP recipients. These reactions are self-limited
and can be managed with symptomatic treatment of acetaminophen or
ibuprofen. Reports of moderate to severe systemic events (e.g., fever
40.5° C or higher [105° F or higher], febrile seizures,
persistent crying lasting 3 hours or more, and hypotonic-hyporesponsive
episodes) have been uncommon after administration of DTaP, and they
have occurred less frequently among children administered DTaP than
those administered DTP.
Anaphylactic and other serious adverse reactions
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. The rates of local reactions, fever, and other common systemic
symptoms following receipt of DTaP are lower than those following
DTwP vaccination.
Precautions and Contraindications
A severe allergic reaction to a prior dose of vaccine
or vaccine component is a contraindication to further vaccination
with DTaP, DT, or adult Td. Encephalopathy not due to another identifiable
cause within 7 days of vaccination is a contraindication to further
vaccination with a pertussis-containing vaccine.
Moderate or severe acute illness can be a contraindication
to vaccination. Anyone with mild illnesses, such as otitis media
or upper respiratory infection, should be vaccinated. 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 generally contraindicate subsequent doses of pertussis
vaccine. These adverse events include temperature >40.5° C
(>105° F) not resulting from another identifiable cause;
collapse or a shock-like state (hypotonic-hyporesponsive episode)
or persistent, inconsolable crying lasting >3 hours and occurring
within 48 hours of vaccination (applicable to infants and children);
and convulsions with or without fever occurring within 3 days of
vaccination. In certain circumstances (e.g., during a communitywide
outbreak of pertussis), the benefit of vaccination may outweigh the
risk, even if one of the four precautionary adverse events occurred
following a previous dose. Under these circumstances, one or more
additional doses of pertussis vaccine may be considered. DTaP should
be used in these circumstances.
DTaP vaccine should NOT be substituted in infants
and children who have a valid contraindication to DTwP vaccine. If
a valid contraindication or precaution exists, DT should be used
for the remaining doses in the schedule.
Neurologic conditions characterized by changing developmental
findings are considered contraindications to receipt of pertussis
vaccine. Such disorders include uncontrolled epilepsy, infantile
spasms, and progressive encephalopathy. For an infant who, because
of perinatal complications or other conditions, is thought to be
at an increased risk for latent onset of central nervous system disorders,
immunization with DTaP or DT should be delayed until further observation
and study have clarified the infant's neurologic status. The decision
whether to commence immunization with DTaP or with DT should be made
no later than an infant's first birthday. Infants and children with
stable neurologic conditions such as cerebral palsy or well-controlled
seizures should be vaccinated. The occurrence of a single
seizure (not temporally associated with DTaP) does not contraindicate
DTaP vaccination, particularly if the seizure can be satisfactorily
explained. Parents of infants and children with personal or family
histories of convulsion should be informed of the increased risk
for simple febrile seizures following immunization. Acetaminophen
(15 mg/kg, every 4 hours for 24 hours) should be given to infants
and children with such histories to reduce the possibility of postvaccination
fever. Infants and children who have received more than one dose
of DTaP and who have a neurologic disorder (e.g., a seizure) not
temporally associated with the vaccination, but before the next scheduled
dose, should have their neurologic status evaluated and clarified
before a subsequent dose of DTaP is given.
— Kris
Bisgard, Chima Ohuabunwo, Martha Roper
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