It has always amazed me how some people eat contaminated food and are hardly affected, while others end up dying. Death is clearly NOT caused by the common denominator, the biological contaminant.
I have attributed death to deficiencies in stomach acid (poor acid production, the taking of antacids, or direct or indirect acid blockers), to a meal with low fat, to immunosuppression, to under-developed immunity (in the very young), poor competition by limited or unbalanced intestinal flora (often due in part to a chronic course of antibiotics), generally poor health, etc.
But another thought, another deficiency, self-inflicted: poor hygiene. Those who end up dying may have re-ingested excreted bacteria and toxins. Perhaps this bio-amplification is almost a necessary precondition for fatality.
When the very young die following (not because of) bacterial infection, it is almost always blamed on under-developed immunity. How about an additional factor of bio-amplification in this group? Is there a well-defined group with poorer hygiene in general than the very young? Another factor: this group puts its contaminated hands in its mouth more than any other.