Webster's New World Medical Dictionary

DTaP immunization
Diphtheria-tetanus-acellu-
lar-pertussis immunization, a vaccine that, like DTP,
protects against diphtheria, pertussis (whooping
cough), and tetanus. DTaP is the same as DTP,
except that it contains only acellular pertussis vac-
cine, which is thought to cause fewer of the minor
reactions associated with immunization. Acellular
pertussis vaccine is also probably less likely than
regular pertussis vaccine to cause the more severe
reactions occasionally seen following pertussis vac-
cination. It is currently recommended that DTaP be
given at 18 months and at 4 to 6 years of age. See
also 
diphtheria; pertussis; tetanus.
DTP immunization
Diphtheria, tetanus, and per-
tussis (whooping cough) immunization, a vaccine
that is given in a series of five shots at 2, 4, 6, and 18
months of age and again at 4 to 6 years of age. Due to
vaccination programs, diphtheria, tetanus, and per-
tussis have become less common than they were in
the past. However, there are still unvaccinated indi-
viduals who are capable of carrying and passing
diphtheria and pertussis to others who are not vacci-
nated. Tetanus bacteria are prevalent in natural sur-
roundings, such as contaminated soil. Children with
compromised immune systems or known neurologi-
cal disorders generally should not receive the DTP
immunization, particularly during infancy. See also
DTaP immunization.
DTs
See 
delirium tremens.
dual diagnosis
A diagnosis of both a mental ill-
ness and a substance abuse disorder.
Duchenne muscular dystrophy
See 
DMD.
duct
A walled passageway, such as a lymph duct,
that carries fluid from one place to another. Also
known as a ductus.
duct, thoracic
See 
thoracic duct.