Changes

*Young and debilitated animals susceptible

*Young and debilitated animals susceptible

*''Salmonella'' serotypes:

*''Salmonella'' serotypes:

**''S.'' Tymphimurium infects many species; causes severe diarrhoea; non-invasive; causes of food poisoning in humans, e.g. from infected poultry

**''S.'' Typhimurium infects many species; causes severe diarrhoea; non-invasive; causes of food poisoning in humans, e.g. from infected poultry

**''S. enteritidis'': non species-specific; losses in young birds; causes food poisoning in humans

**''S. enteritidis'': non species-specific; losses in young birds; causes food poisoning in humans

**''S.'' Dublin: invasive serovar; infects cattle

**''S.'' Dublin: invasive serovar; infects cattle