The pattern of mortality across age groups conformed to a standard epidemiological phenomenon known as "depletion of susceptible individuals over time" - or in other words, those who are likely to get a disease do so and suffer its effects, such as death. As time passes, fewer susceptible individuals remain and the number of new cases and deaths begin to decrease.

"What seems to be happening is that teachers who are susceptible to auto-immune diseases start their careers and, very shortly afterwards, encounter one or more triggers, perhaps in the school setting, that initiate an autoimmune disease," he says. "For some of these individuals it leads to death."

What could that trigger be?

Scientists know that rheumatic fever, also an autoimmune disease, is triggered by streptococcal bacteria - the bacteria that cause strep throat. Rheumatic fever was one of the diseases that teachers in the 35-44 year age group were dying from more often than expected. This led Walsh to think that the other autoimmune diseases among teachers might also be triggered by infectious agents.

Four other autoimmune diseases were significantly more common among teachers - lupus, rheumatoid arthritis, Sjogren's disease, and multiple sclerosis. For each of these diseases there's evidence to suggest that Epstein-Barr virus is the environmental trigger. Epstein-Barr is the cause of infectious mononucleosis, a disease common among American high school students. Coincidentally, Walsh's findings showed that high school teachers were significantly more likely to die from an autoimmune disease than elementary school teachers.

In looking at them, we see evidence that's consistent with the possibility that infectious diseases provide an environmental trigger for the most common autoimmune diseases.

CIDPUSA recommends that school teachers use Vitamin-D, regularly and follow the diet guidelines with hand washing regularly and read the electronic section for disease prevention. Must read the H202 page for change in lifestyle.

Pat keele