However, it can cause life-threatening illness in infants, HIV patients, transplant recipients, and those with weak immune systems.

When ingested, Listeria bacteria can cause illness and death among the elderly, pregnant women, newborns and those with weakened immune systems.

Lactobacillus in yogurt has caused disease, but rarely, in people with weakened immune systems.

Some types of E-coli have caused outbreaks of severe illness and even death, particularly among young children, the elderly and others with limited immune systems.

Listeria monocytogenes is an organism, which ca cause serious and sometimes fatal infections in young children, frail or elderly people, and others with weakened immune systems.

Salmonella can cause serious and sometimes fatal infections in young children, frail or elderly people, and others with weakened immune systems.

Recently however, research indicates that Bordetella bronchiseptica may cause disease in some humans, primarily those with compromised immune systems.

Listeriosis can cause lethal or disabling encephalitis and meningitis, usually in older people or those with weakened immune systems.

It can cause death or injury in susceptible people, particularly people with weakened immune systems.

While these two causes have not been proven they're likely suspects as they cause issues with both the blood flow and nervous systems.