I know I am going to the extreme, but when you've been taken to the extreme, pushed over the edge and pulled back up, it's easier to revist.
First, I'm glad she's okay. She is, right?
The temps are
outdated as Greg suggests, but they are still commonly quoted--it's the cover-your-ass approach to cooking meat that is still advocated by those who want to be sure they're not blamed if something
Moving on: Trichina in pigs (and hence trichinosis in humans) is extremely rare in the US and other developed countries and has been for some time. Regardless, trichina are killed at 137. Because of the MRI results and their subsequent questions, it is likely the doctors suspected neurocysticercosis (although I'm not sure why they'd go there first). Neurocysticercosis is a form of cysticercosis which manifests in the brain or in the central nervous system (cysticercosis manifests outside the intestinal tract) and is caused by a tapeworm from the genus taenia found in pork and beef (the infection, if it manifests in the intestinal tract is called taeniasis). It, like trichinosis, is quite rare in developed countries but, unfortunately, is not rare in undeveloped and developing countries. Poor sanitation, poor waste disposal, poor animal husbandry, etc., keeps it more common elsewhere. Larval cysts in pork and beef that cause these infections are killed by temps of 150 or if frozen for at least 12 hours.
Bacteria are another issue. Bacteria do not
reside inside meat, they can grow on the surface at prolonged temps of 40-140 degrees. It is the surface
temp of the meat that is the concern when it comes to bacterial issues and bacteria can multiply if the meat is held too long between these temps. The bacteria produce toxins. Though the bacteria will be killed with a subsequent temp rise above 140 the toxins will not be neutralized--even at temps higher than 500.
Caveat: Though this applies to surface conditions it can apply to meat where the interior was formerly the exterior, as in ground beef or other ground meats. It can also apply to where the surface might be pushed into the interior, such as with injecting or cutting slits in a roast to insert herbs or garlic. Proper food handling and procedures (using a cold injection mix, for example) can prevent problems from arising.
I cook steaks to rare--120; lean pork to med-well--147-150, lamb to 126-135 depending on the cut; most fowl 160 breast, 175 thigh.
When I travel in developing countries it's a whole nother thing.[/i]