Source of food samples. Of the surveyed vegetables, fish, and meat products, 70% were bought from
stall-owners at the Mercato market, Addis Ababa. The
history of these foods before purchase was unknown.
The remainder of the food samples were purchased
from city hawkers from March through December
1977. Individual food products were transported and
stored in separate plastic bags, and the samples were
cultured within 2 h of purchase.