Paratyphoid

Occurrence: Worldwide.
Species affected: All.
Age affected: All, usually young.
Causes: Salmonella typhimurium is a facultative anaerobe, with motile flagella, which produces endotoxins. There are many routes of transmission. It is difficult to eradicate as it can be transmitted by many wild biological vectors.
Effects: Young birds tremble (cry), whereas birds older than 1 month usually show subclinical disease. Young birds act cold, gasp and are anorectic. Watery diarrhoea, blindness, conjunctivitis, weakness and lameness can occur. There are often carriers without symptoms and there are risks for human health.

GO TO:
 



Causes

Turkeys of all ages, usually the young and many higher forms of animals are susceptible to this acute to chronic disease. The agents involved in the aetiology of this disease are Salmonella typhimurium and other species; at least 33 Salmonella shown to infect birds. All are serologically related. It is a facultative anaerobe, with motile flagella, and it produces endotoxins.

Mode of transmission

Faecal contamination of eggs is the most common mode of transmission. Transovarian transmission is rare. Contaminated feed and water spreads the organism. Biological vectors include mice, insects, dogs, cats and birds. Fomites include trucks, litter, dust, etc. It is not species-specific and therefore it is difficult to eradicate because of many natural, wild biological vectors, which cannot be eliminated.

Clinical signs

Young birds tremble (cry), whereas birds older than 1 month are usually subclinical. Young birds act cold, gasp and are anorexic (do not eat). Watery diarrhoea, blindness, conjunctivitis, weakness and lameness can occur.

Prevention

Recombinant S. typhimurium vaccine in use for day of age in broilers by coarse spray in the hatchery. Killed vaccine can be used to prevent S. enteritis in pullets. Pro and prebiotics for young poultry by drinking water, spray, or feed to competively exclude colonization of Salmonella from the gut. Control rodents.

Special note

It has a public health significance and is a common zoonosis (disease transmitted from animals to humans). S. enteritidis infects eggs and S. typhimurium- may contaminate broiler meat anywhere in the world. It is most commonly salmonella infection in poultry. Commonly infects dogs, cats and livestock. One in 250 eggs in the U.S. are contaminated with S. enteritidis. USDA requires testing of all layer flocks for S. enteritidis-. U.S. strain of S. enteritidis is nonpathogenic in avians. European isolate has a plasmid for virulence and may produce significant morbidity and mortality in poultry. The US government has legislated the MEGA REG regulations. HACCP is under these guidelines and its aim is to eliminate or reduce critical points in the field and processing plant, where pathogenic organisms can contaminate poultry meat and eggs.