A recent Mexican study revealed that 10 percent of foods from markets are contaminated by a bacterium responsible for Listeriosis. These may include meats, sausages and other meat products that can be bought from these places. Contamination with the bacteria, Listeria monocytogenes is responsible for the infection in humans. The infection usually can be passed orally and through wastes and excreta from the infected person.

Ernesto Liebana, a scientist working for the European food safety authority discussed that the food from markets which might harbor Listeria are smoked salmon, cold meats and cheeses. Although Listeriosis is relatively rare, it is often severe upon hospitalization. There have been 1,300 cases of Listeriosis with a mortality of 13 percent. Consumption of contaminated food is the main source of contamination for humans and infection can also occur through contact with infected animals and person. Liebana discussed that once foods from markets have been contaminated and are consumed, a person may develop flu-like symptoms and may progress to serious infection such as meningitis and other potentially life-threatening infection.

Since the bacteria can be found on plants, soil and water, careful cleaning and inspection of meat and food products is crucial. Meanwhile, a European-based sea food corporation has issued a recall for their packs of smoked salmon and mackerel for fear that they might have been contaminated by Listeria. The Food Safety Agency in UK explained that products that are not advised to be consumed might affect pregnant women and their unborn child. Another report claimed that 24 cases of Listeriosis have been detected in Denmark on Monday August 18. The State Serum Institute reported that a sausage distributed by a company in Hedehusene is responsible. Institutes for food safety suggest that to ensure public health safety, buying foods from markets should be done with utmost caution.