infectious

(ĭn-fĕk'shəs)
adj.

1. Capable of causing infection.
2. Caused by or capable of being transmitted by infection.
3. Caused by a pathogenic microorganism or agent.
4. Easily or readily communicated: an infectious laugh.

infectiously in·fec'tious·ly adv.
infectiousness in·fec'tious·ness n.

View more Health videos

adjective

Capable of transmission by infection: catching, communicable, contagious, taking. See move/halt.

adj

Definition: catching, spreading
Antonyms: antiseptic, germless, harmless, incommunicable, non-infectious, uncontagious

IN BRIEF: Spreading rapidly to others.

A bad attitude is the worst thing that can happen to a group of people. It’s infectious. — Roger Allan Raby

LearnThatWord.com is a free vocabulary and spelling program where you only pay for results!

1. (of a disease) caused by pathogenic (micro)organisms.
2. causing or transmitting infection.
3. (of a disease) capable of being transmitted to another organism.

—infectiously adv.; infectious-ness n.

Previous:	infection, infect, infantile sialic acid storage disease
Next:	infectious viral nucleic acid, infective, infinite

Caused by or capable of being communicated by infection.

• i. avian nephritis — caused by a picornavirus this disease of young chickens causes a transient unremarkable disease with lesions appearing in the kidney.
• i. bovine cervicovaginitis — thought to be due to a herpesvirus-4 infection, transmitted by coitus, causing sterility in a high percentage of cows and some bulls. Recorded only in South Africa. Called also epivag.
• i. bovine keratoconjunctivitis — the common infectious keratitis of cattle caused by Moraxella bovis with solar radiation, dust and face flies as contributing factors.. It occurs as outbreaks, characterized by ocular discharge, blepharospasm and pain. Underrunning of the conjunctiva leads to complications in a few cases. Called also pinkeye, blight, New Forest disease.
• i. bovine meningoencephalomyelitis — see hemophilosis.
• i. bovine rhinotracheitis (IBR) — a highly infectious disease of cattle, particularly when crowded together as in feedlots, caused by bovine herpesvirus 1 and characterized by nasal discharge, rhinitis, tracheitis, conjunctivitis, fever and a short course unless complicated by other infections, particularly those leading to pneumonia. Less common forms of the disease include encephalitis in calves and a systemic infection in neonates, manifested by oral erosions and diarrhea. Infectious pustular vulvovaginitis is also caused by this virus. Called also rednose.
• i. bulbar paralysis — see aujeszky's disease.
• i. caprine keratoconjunctivitis — contagious ophthalmia caused by Mycoplasma conjunctivae.
• i. coryza — see fowl coryza.
• i. equine anemia — see equine infectious anemia.
• i. equine bronchitis — see equine influenza.
• i. equine cough — see equine influenza.
• i. equine encephalomyelitis — see equine viral encephalomyelitis.
• i. hematopoietic necrosis of fish — important rhabdoviral infection of Onchorhyncus spp. especially steelhead (anadromous rainbow trout).
• i. hypodermal and hemopoietic necrosis — parvovirus infection causing high mortalities in juvenile Penaeus stylirostris and runt deformity syndrome in P. vanname.
• i. labial dermatitis — see contagious ecthyma.
• i. laryngotracheitis (ILT) — a highly infectious disease of birds of all ages caused by avian herpesvirus 1 and characterized by a very rapid spread of respiratory distress, the signs including gasping, respiratory gurgling and rattling, and death often from asphyxiation because of massive pseudomembrane formation in the trachea. The mortality rate may be as high as 70%.
• i. necrotic hepatitis — an acute toxemia of cattle, sheep and pigs caused by Clostridium novyi which elaborates a toxin in necrotic infarcts in the liver. These infarcts are caused usually by larvae of Fasciola hepatica. Many affected animals are found dead. Clinical findings include severe depression, hypothermia and muffling of heart sounds. Called also black disease.
• i. pancreatic necrosis of fish — a disease of salmonids caused by a group of related birnaviruses. It is characterized by hemorrhages and anemia, and spiral swimming and abdominal distention in fry.
• i. porcine dermatitis — see contagious porcine pyoderma.
• i. porcine polyarthritis — see glässer's disease.
• i. pustular vulvovaginitis — see infectious pustular vulvovaginitis.
• i. salmon anemia — severe disease of Atlantic salmon, reported only, to date, from Norway; characterized by liver necrosis caused by an unidentified virus.
• i. serositis — a septicemic disease of young ducks caused by Riemerella anatipestifer and characterized by torticollis, head tremor, loss of balance and a high mortality rate.
• i. sinusitis — a contagious disease of turkeys caused by Mycoplasma gallisepticum. The same infection also causes chronic respiratory disease of chickens. The disease in turkeys is characterized by swelling of the infraorbital sinuses, which are filled with thick exudate. The course is chronic and the death rate low but there is severe loss of condition and damage to the respiratory tract.
• i. stunting syndrome — caused by an enterolike virus this disease causes serious losses in the broiler industry; it is characterized by severe growth depression commencing at 1 week of age or earlier. Called also helicopter disease.
• i. synovitis — see infectious avian synovitis.

adj

Contagious; communicable; capable of causing infection.

For a list of words related to infectious, see:

• Diagnostic Terminology - infectious: (adj) designating a communicable disease, esp. one caused by invasion of harmful organisms such as bacterium, fungus, protozoan, or virus into body
• Happy, Playful, Optimistic, or Elated

---

See words rhyming with "infectious."

Common misspelling(s) of infectious

• infectuous

Dansk (Danish)
adj. - smitsom, smittende

Nederlands (Dutch)
besmettelijk, aanstekelijk

Français (French)
adj. - (Méd) infectieux, contagieux, communicatif, qui s'attrape facilement (un accent)

Deutsch (German)
adj. - ansteckend, infektiös

Ελληνική (Greek)
adj. - (παθολ., μτφ.) μολυσματικός, κολλητικός, λοιμώδης, μεταδοτικός

Italiano (Italian)
infetto, contagioso

Português (Portuguese)
adj. - infeccioso, infectante

Русский (Russian)
инфекционный, заразительный

Español (Spanish)
adj. - infeccioso, contagioso

Svenska (Swedish)
adj. - smitt (o)sam, infektiös, smittande (bildl.)

中文（简体）(Chinese (Simplified))
有传染性的, 有感染力的, 易传染的

中文（繁體）(Chinese (Traditional))
adj. - 有傳染性的, 有感染力的, 易傳染的

한국어 (Korean)
adj. - 전염하는, 전염되기 쉬운

日本語 (Japanese)
adj. - 伝染する, 伝染性の, 人にうつる, 伝わりやすい

idioms:

• infectious mononucleosis    伝染性単核細胞症

العربيه (Arabic)
‏(صفه) معد, ناقل للمرض‏

עברית (Hebrew)
adj. - ‮מידבק (מחלה, צחוק), מנגע‬

If you are unable to view some languages clearly, click here.

To select your translation preferences click here.