Salmonella infections in Stockholm. A 10-year review

During the 10-year period 1963-1972 the total number of cases of salmonella infection reported to the Public Health Administration in Stockholm was 3012. The annual incidence varied between 72 (1966) and 23 (1972) per 100000 population. Peak frequencies appeared in the age groups 15-25 and 45-64 years. 101 different serotypes were diagnosed with S. typhi murium being the most common type (37%). 63% of the cases were infected during travel to foreign countries and in 19% food-borne transmission occurred. During the 6-year period 1963-1968 85% of all cases were treated in hospitals. In 1969 a new law governing infectious diseases came into force making it easier to reduce the strict measures imposed by the previous law of 1919. During the 4-year period 1969-1972 53% of the cases were hospitalized. In spite of this reduction no change in the annual pattern of secondary cases has been observed.