Canadian Perspectives on Verocytotoxin-Producing Escherichia coli Infection ^†.

Area of Science:

• Veterinary epidemiology
• Infectious disease control
• Food safety

Background:

• Verocytotoxin-producing Escherichia coli (VTEC) infections became nationally reportable in 1990.
• Incidence ranged from 3 to 5.3 per 100,000 inhabitants between 1990-1994.
• E. coli O157:H7 is the most common cause, with risk factors including undercooked beef, cattle contact, and rural environments.

Purpose of the Study:

• To investigate the epidemiology of VTEC infections.
• To identify risk factors and transmission routes.
• To explore control strategies at the farm level.

Main Methods:

• Analysis of national incidence data (1990-1994).
• Review of case-control studies.
• Longitudinal studies on dairy farms to assess E. coli O157:H7 carriage in cattle and farm environments.

Main Results:

• Person-to-person spread is increasingly emphasized in VTEC epidemiology.
• Cattle are the primary reservoir for E. coli O157:H7 on dairy farms, with carriage being transient.
• Small herds with traditional management practices show the highest risk for VTEC infection.

Conclusions:

• Controlling VTEC at the farm level can significantly reduce foodborne infections.
• Targeting cattle as the reservoir is crucial for effective VTEC control strategies.
• Further research will likely yield effective farm-level VTEC control methods.