A viral disease of chickens, turkeys (see separate summary), guinea fowl and possibly pheasants seen in Europe, Africa, South America and North America. It is caused by a pneumovirus of the Paramyxoviridae family, first isolated from poults in South Africa in 1978. Two subgroups have been identified on the basis of the G-protein sequence: A (original UK isolates) and B (original southern Europe isolates). There is rapid lateral transmission with infection by aerosol through the respiratory route; vertical transmission is uncertain. As for many infections, fomites can be important in moving infection between farms. The incubation period is 5-7 days, morbidity is 10-100% and mortality can be 1-10%.

Signs

Decreased appetite,

weight gain and feed efficiency.

Facial and head swelling (though this can occur in other conditions).

Loss of voice.

Ocular and nasal discharge.

Conjunctivitis.

Snick.

Dyspnoea.

Sinusitis.

Prevention

All-in/all-out production, vaccination (degree of cross protection between A and B types remains to be established). Live vaccines can reduce clinical signs and adverse effects, inactivated vaccines may be used in breeders prior to lay.

Information taken from the poultrysite.