Question

Part V – Environmental studies and food investigation

Pastel de Carne is a traditional Uraguayan dish prepared from chopped meat, mashed potato, green peppers, olives, and eggs. In a traceback of the implicated Pastel de Carne, the MOH discovered that it originated from a small scale producer located not far from the terminal stop of the bus route. The Pastel de Carne was purchased at a local market on January 3 by the owners of the home that served the Pastel de Carne. The MOH initiated an environmental health assessment of the Pastel de Carne to identify production factors that could have contributed to the occurrence of botulism.

A complete environmental health assessment is not a cursory inspection of operations and sanitary conditions as is performed for the licensing of a food establishment, but focuses on the suspect food or meal and follows it from its raw ingredients to consumption by the customer. The objective of the environmental health assessment is to identify critical points where the implicated food could have become contaminated or microbial survival and growth in the food could have occurred, determine why these conditions existed, and identify appropriate interventions. The factors in Table 3, often found in these assessments, have been associated with an increased risk of foodborne disease.

Table 3. Factors that commonly contribute to outbreaks of foodborne diseases, from Bryan et al., 1987. Contamination Survival Growth o raw foods that are inadequate cooking inadequate reheating inadequate acidificationinadequate hot-holding . inadequate refrigeration contaminated o infected foodhandler » unclean equipment » cross-contamination » contaminated foods eaten » raw or lightly cooked improper cooling * preparation too far in advance of serving o use of leftover foods * inadequate acidification * high water content . inadequate curing salt . environment that provides inappropriate container for food » unsafe sources » added poisonous chemicals favorable conditions for pathogen (e.g., anaerobic packaging,) natural toxicant * poor dry-storage practices

Clostridium botulinum is a spore-forming obligate anaerobic bacterium (i.e., it cannot grow in the presence of oxygen). The spores are widespread in soil and dust worldwide. The toxin is produced in improperly canned, low-acid or alkaline foods and in pasteurized and lightly cured foods held without adequate refrigeration, especially in airtight containers. The toxin is destroyed by boiling; inactivation of spores requires much higher temperatures.

Food safety inspectors from the local health department initiated the environmental health assessment on January 20. The home at the terminal stop of the bus route was not formally licensed or equipped as a restaurant. Perishable foods, such as the Pastel de Carne, were kept in two large refrigerators inside the home. Although the refrigerators were set at the coldest possible setting, temperatures measured inside the refrigerators were 90C and 100C (480F and 500F, respectively).

The home owner reported the Pastel de Carne was served in sandwiches, usually with a spicy sauce; no other condiment or ingredient was added to the sandwiches. No Pastel de Carne was available for testing.

The implicated Pastel de Carne was bought at a local market where it had been stored in a refrigerator. The market had no temperature records or sales receipts; however, some customers reported that the Pastel de Carne had recently been sold at reduced prices because of power outages.

The market purchased Pastel de Carne from a small scale commercial producer who made Pastel de Carne and processed hams in his home. To make Pastel de Carne, the producer placed a slab of raw beef (1- to 3-cm thick) on a stainless steel table. Ingredients included raw sliced carrots, hard-boiled eggs, salt, red pepper flakes, dried oregano, and commercial potato flour. The meat was rolled up around the vegetables and eggs to make an approximately 10 x 30 cm cylinder. The meat roll was placed into a rectangular stainless steel pan to keep ingredients in side during cooking. Between 10 and 15 Pastel de Carne in individual steel pans were immersed together in water heated to 70 to 800C (158 to 1760F) and cooked approximately 4 hours. The Pastel de Carne was never brought to a boil. After cooking, the water was drained and the temperature was checked to ensure an internal temperature of about 680C (1540F). The producer placed each warm Pastel de Carne in plastic wrap, squeezed out the air, and sealed the plastic with heat. The plastic wrapped Pastel de Carne were allowed to cool, placed in a walk-in refrigerator, and were stored for up to 2 weeks before being sold to either supermarkets or directly to consumers.

The producer reported making Pastel de Carne every 2 weeks in batches of 15-20 each time. The last batch produced before the outbreak was made in early December. No Pastel de Carne were available from that batch.

Question: What control measures would you initiate at this time? What difficulties might you encounter?

Answer 1

Control measures to be taken:

• The product and raw material should be refrigerated properly with specific cold temperature.
• Proper power backup is necessary so that food products are refrigerated continuously without gap.
• Canning of product should be through.
• proper boiling of product is a must.
• The surface, utensils, while making the products should be clean. Raw materials should be washed thoroughly before use.

Difficultes faced:

• Power cutoffs.
• less manpower to carry each step properly
• Refrigirator settings being changed according to the product.
• Contaminated raw material.