Bacillus cereus

Epidemiology of Infectious Diseases: Bacillus cereus

Causal agent
Bacillus cereus food poisoning is a gastrointestinal intoxication caused by toxins produced by the Bacillus cereus bacterium.

Two enterotoxins have been identified1.

    1.Diarrhoeal (heat labile - causes diarrhoea).
    2.Emetic (heat stable - causes vomiting).

Common clinical features
Characterised by sudden onset of nausea, abdominal pain and vomiting or by colic and diarrhoea2.

Illness in either form commonly lasts between 12-24 hours.

Epidemiology
Occurs worldwide.
Outbreaks have been linked to fried rice. Other sources of infection identified include pasta dishes, vanilla sauce, cream, meatballs barbecue chicken and turkey loaf1.

Reservoir
B. cereus is ubiquitous in the environment and is found at low levels in many raw, dried or processed foods1,2.

Mode of transmission
Ingestion of contaminated food.

Incubation period
Vomiting illness: 2-3 hours, range 1-6 hours.
Diarrhoeal illness: 8-12 hours, range 6-24 hours.

Period of Communicability
No person to person spread.

Treatment
No specific treatment is indicated except fluid replacement.

Prevention and control
Keep cooked hot food above 60ºC if not served immediately.
Rapid cooling of cooked food.
Store cold foods below 4ºC
Reheat foods 75ºC or until piping hot.

References

Hawker J, Begg N, Blair I, Reintjes R, Weinberg J. Communicable Disease Control Handbook, Blackwell, 2005.
Heymann D L, editor, Control of Communicable Disease Manual. 18th ed. American Public Health Association; 2004.

© CM Kirwan 2006