Dictionary

Parvovirus B19 The virus responsible for the disease known as fifth disease. See also fifth disease.

passive immunity Immunity produced by the transfer to one person of antibodies that were produced by another person. Protection from passive immunity diminishes in a relatively short time, usually a few weeks or months. For example, antibodies passed from the mother to the baby before birth confer passive immunity to the baby for the first…

passive smoking Inhalation of smoke that comes from someone else smoking. Passive smoking is associated with the same array of diseases as actual smoking, with an elevated risk of lung cancer and other diseases.

Pasteur, Louis A French chemist and biologist who invented pasteurization, developed the germ theory, founded the field of bacteriology, and created the first vaccines against anthrax and rabies.

pasteurization A method of treating food by heating it to a certain point to kill disease-causing organisms but keep the flavor or quality of the food intact. Pasteurization is used with beer, milk, fruit juice, cheese, and egg products.

paralysis, stomach See gastroparesis.

paralysis agitans See Parkinson’s disease.

paramyxovirus One of a group of RNA viruses that are predominantly responsible for acute respiratory diseases and are usually transmitted by airborne droplets. The paramyxoviruses include the agents of mumps, measles (rubeola), RSV (respiratory syncytial virus), Newcastle disease, and parainfluenza.

paraneoplastic syndrome A group of signs and symptoms caused by a substance that is produced by a tumor or in reaction to a tumor. Paraneoplastic syndrome can be due to a number of causes, including hormones or other biologically active products made by the tumor, blockade of the effect of a normal hormone, autoimmunity, immune-complex…

paraphilia One of several complex psychiatric disorders that are manifested as deviant sexual behavior. For example, in men, the most common forms are pedophilia (sexual behavior or attraction toward children) and exhibitionism (exposing one’s body in a public setting). Other paraphilias include compulsive sexual behavior (nymphomania), sadism, masochism, fetishism, bestiality (zoophilia), and necrophilia. Treatment may…

paraphimosis An emergency condition in which the foreskin of the penis, once retracted, cannot return to its original location. The foreskin remains trapped behind the groove of the coronal sulcus, between the shaft and the glans. This causes blood to pool in the veins behind the entrapment, leading to swelling and severe pain. Treatment involves…

paraplegia Paralysis of the lower part of the body, including the legs.