Turns out about 75% of the country's spinach comes from California, and the company whose spinach has been linked to the outbreak (Natural Selection) is from San Juan Batista on the central coast (...which we've decided is close enough to us and far enough away from LA that it falls within the SFist bailiwick).
So here's the latest: Natural Selections has released a statement that the only non-organic bagged fresh spinach has been ID'ed as infected. However, the FDA says not to eat the organic stuff either, and further, you should refrain from eating not only bagged spinach but all fresh spinach in general, because you can't be sure if someone took the "fresh" spinach you see out of a bag to start out with. Frozen and canned spinach is fine to eat (for health reasons, anyways -- we express no opinion about its taste quality).
Tampering is not suspected, but the FDA is still looking into whether the spinach was contaminated on the field or in processing.
Info on the brands to throw out after the jump.