Abstract

Chile has experienced a dramatic epidemiologic change in the last decade with a progressive decline in typhoid fever, -a disease mainly associated to Salmonella typhi- and the parallel emergence of Salmonella enteritidis. This pathogen causes diarrhea by the ingestion of contaminated avian products, and differs from S. typhi because it does not have an effective antibiotic treatment. Typhoid fever rates have declined due to global human development in Chile that has reached a high coverage in tap water provision, higher educational rates, and feces and solid waste disposal. These factors limit the spread of S. typhi in the environment or the adquisition of this pathogen by susceptible hosts. Despite this remarkable achievement, another Salmonella serotype has irrupted and has taken advantage of the new scenario where thousand of lay hens share closed spaces facilitating the horizontal transfer of S. enteritidis. Intermitent inoculation of eggs either by a transovaric route or by simple superficial contamination allow that this agent reaches human hosts in an sporadic but persistent way. The new epidemiological condition requires adoption of different preventive strategies that should involve health authorities, producers, retail-market distributors and consumers of the avian food industry