Para-typhoid Disease/ Salmonellosis Paratyphoid Dr. Latif Ahmad-PhD, Assistant Professor

Salmonellosis Paratyphoid Numerous motile members of bact. genus Salmonella are often referred to collectively as paratyphoid (PT) salmonellae. Salmonellosis PT is world-wide problem in integrated (combined) com.-egg & broiler operations & also on small-scale farms. PT salmonellae have additionally been identified as important agents of foodborne human dis.

Etiology Salm. spp except S. pullorum & S. gallinarum. Gen. paratyphoid (PT) salm. spp. will result in up to 3% losses during the first 14 days. PT salm. spp (e.g., S. enteritidis, phage type 4), may cause high mortality resembling S. pullorum inf. PT Salm. spp. are resp. for food-borne inf. in: Consumers of eggs (S. Enteritidis) & Consumers of poultry meat (S. typhimurium, S. agona, S. heidelberg & perhaps 50 other freq. serotypes).

Host Range PT salmonellosis can infect a very wide variety of hosts (including invertebrate & vertebrate wildlife, domestic animals, and humans) to yield either asymptomatic intestinal carriage or cl. dis. First reported in avian spp. in 1895 in an outbreak of inf. enteritis in pigeons, PT infections have long been known to cause signif. dis. losses in young poultry.

Transmission S. enteritidis transmitted vertically by trans-ovarial & trans-oviductal routes. Other PT spp be transmitted mech. By fecal contamination of egg shells mostly & By transovarial route, infreq. (immuno-suppressed flocks) Rodents & litter beetles serve as reservoirs of inf. PT salm. & introduced by contam. equip., personnel & wild birds. Feed containing contaminated ingredients of animal-origin is often resp. for introduction of PT salm. into integrations or entire countries. Condition can be perpetuated by recycling contaminated by-product meal from inf. broilers & com. laying flocks.

Clinical Signs Elevated chick mortality and unevenness in brooding flocks No sp. signs are linked with PT inf. in mature flocks Vertically transmitted S. enteritidis for inf. resembles PD in chicks.

Pathology Acute cases show enlargement of the spleen and liver and occasionally enteritis and peritonitis. Chicks may show omphalitis.

Diagnosis Confirmation is based on isolation & identification of salm. spp. from liver, spleen, intestine, or heart blood. Routine microb. screening of liver/spleen/ intestinal pools from post mortem submissions to labs. is strongly recommended. Specific ELISA-based test kits are available for assaying for S. enteritidis abs.

ELISalmonella E ELISA kit is used for quantitative detection of antibodies against Salmonella enteritidis in chicken serum and egg yolk.

Prevention Reduction in prevalence in breeding flocks is possible (absolute elimination of S. enteritidis & progressively S. typhimurium carriers) by: Implementing intensive programs of microb. screening together with Appropriate biosecurity procedures. S. enteritidisis controlled in com. level stock by: Live, modified S. typhimurium vaccines alone OR Live, modified S. typhimurium vaccines along with inactivated S. enteritidis emulsion boosters at point of lay

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