Related Experiment Videos
Epidemiology of an unusually prolonged outbreak of typhoid fever in Terrassa, Spain
M Xercavins1, T Llovet, F Navarro
1Servei de Microbiologia and Servei de Medicina Interna, Hospital Mutua de Terrassa, Spain.
Abstract:
An unusually prolonged outbreak of typhoid fever, from 1988 to 1994, in Terrassa (Barcelona, Spain), was caused by a casual food handler who was a carrier. The pattern of this outbreak suggested intermittent low-level exposure to Salmonella typhi. We found 70 patients with S. typhi infections, 52 of whom were available for study. Medical records were reviewed and patients were interviewed with use of a standard questionnaire. Phage typing and pulsed-field gel electrophoresis (PFGE) for strain subtyping were used to confirm the epidemiological data. The 27 outbreak strains shared the same phage type and the same PFGE pattern. Four sporadic strains shared the same phage type as the outbreak strain. PFGE was found to be useful for differentiating strains for epidemiological purposes.
Insights
A prolonged typhoid fever outbreak in Spain was traced to a food handler. Molecular subtyping confirmed the source and helped differentiate outbreak strains from sporadic cases.
Area of Science:
- Epidemiology
- Infectious Diseases
- Microbiology
Background:
- Typhoid fever outbreaks pose significant public health challenges.
- Identifying the source and transmission patterns of Salmonella typhi is crucial for control.
Observation:
- An extended typhoid fever outbreak occurred in Terrassa, Spain, between 1988 and 1994.
- The outbreak's pattern suggested intermittent, low-level exposure to Salmonella typhi.
- A single food handler was identified as the likely source of the outbreak.
Findings:
- Seventy patients were identified with S. typhi infections; 52 participated in the study.
- Phage typing and pulsed-field gel electrophoresis (PFGE) confirmed 27 outbreak strains shared identical profiles.
- Four sporadic strains shared the outbreak's phage type, highlighting the utility of PFGE for strain differentiation.
Implications:
- This case underscores the importance of carrier identification in prolonged foodborne outbreaks.
- Molecular subtyping techniques like PFGE are essential tools for epidemiological investigations.
- Effective control measures require understanding transmission dynamics and identifying asymptomatic carriers.