BBB - Infective Dose Information
Bad Bug Book:
Foodborne Pathogenic Microorganisms and Natural Toxins Handbook
Infective Dose Information
Most chapters include a statement on infectious dose. These numbers should be viewed with caution for any of the following reasons:
- Often they were extrapolated from epidemiologic investigations.
- They were obtained by human feeding studies on healthy, young adult volunteers.
- They are best estimates based on a limited data base from outbreaks.
- They are worst case estimates.
- Because of the following variables they cannot be directly used to assess risk:
Variables of the Parasite or Microorganism
- Variability of gene expression of multiple pathogenic mechanism(s)
- Potential for damage or stress of the microorganism.
- Interaction of organism with food menstruum and environment
- pH susceptibility of organism
- Immunologic "uniqueness" of the organism
- Interactions with other organisms
Variables of the Host
- General health
- Medications--OTC or prescription
- Metabolic disorders
- Alcoholism, cirrhosis, hemochromatosis
- Amount of food consumed
- Gastric acidity variation: antacids, natural variation, achlorhydria
- Genetic disturbances
- Nutritional status
- Immune competence
- Surgical history
Because of the complexity of factors involved in making risk decisions, the multidisciplinary Health Hazard Evaluation Board judges each situation on all available facts.