Milkborne campylobacter infection in Hungary

Area of Science:

• Foodborne illness epidemiology
• Microbial source tracking
• Public health microbiology

Background:

• An outbreak of inflammatory enteritis occurred following an animal farm sale in Hódmezóvásárhely in April 1998.
• The outbreak affected 52 individuals, with Campylobacter positivity in 34 cases (30 Campylobacter jejuni, 4 Campylobacter coli).

Purpose of the Study:

• To identify the source of the Campylobacter outbreak.
• To investigate the genetic relatedness of human and animal Campylobacter isolates.
• To determine antibiotic resistance and endotoxin production of the causative agents.

Main Methods:

• Epidemiological investigation of human cases.
• Environmental sampling of suspected sources (raw milk, cow swabs).
• Randomly amplified polymorphic DNA (RAPD) analysis for isolate typing.
• Antibiotic susceptibility testing (disk diffusion, E test).
• Vero cell line assay for endotoxin production.

Main Results:

• Two rectal swabs from cows tested positive for C. jejuni.
• RAPD analysis confirmed fecally contaminated milk as the outbreak source, with identical DNA patterns in 19 human and 1 animal C. jejuni isolates.
• Tetracycline resistance was observed in a small number of isolates (6 human C. jejuni, 1 human C. coli, 1 animal C. jejuni) without plasmid detection.
• Endotoxin production varied among isolates, with two human C. jejuni isolates showing high positivity, associated with severe cases requiring hospitalization.

Conclusions:

• Unpasteurized, fecally contaminated milk was the definitive source of the Campylobacter outbreak.
• The outbreak highlights the risk associated with consuming raw milk from animal sales.
• Understanding Campylobacter virulence factors like endotoxin is crucial for managing severe cases.