No 11 - 2019
In the 2014-2018 period, Salmonella Typhi and Salmonella Paratyphi have remained stable and only a very limited number of people have become infected in Denmark
In the 2014-2018 period, Salmonella Typhi and Salmonella Paratyphi have remained stable and only a very limited number of people have become infected in Denmark
Typhoid and paratyphoid infection are caused by Salmonella Typhi and S. Paratyphi bacteria. Both types of infection are notifiable. Specifically, the infections must be notified to the national laboratory surveillance system at Statens Serum Institut and by treating physicians via the clinical notification system on Form 1515.
The detailed 2014-2018 annual report is available here.
Infection with both bacteria is due mainly to ingestion of food or water that has become contaminated with faeces from people who are S. Typhi or S. Paratyphi carriers. Therefore special requirements are in place for negative faeces samples before patients working in the food industry, children who attend institutions, and other groups can return to work or continue attending their institution following a typhoid or paratyphoid fever infection. The condition can be treated with antibiotics and a vaccine is also available.
The share of the patients who became infected during travels abroad is 95%, and only a very limited number of persons (less than 10 in total) were presumably infected in Denmark in the 2014-2018 period, See the surveillance data for clinically notified cases of S. Typhi or S. Paratyphi in Denmark.
In the course of the 2014-2018 period, a total of 119 cases of typhoid and paratyphoid fever were recorded, and the annual number of cases remained below 30 throughout the period. Between one third and up to half of all persons who had become infected abroad had presumably become infected in Pakistan or India.
The method used to test samples submitted to the National Salmonella laboratory monitoring initiative was changed from culture to whole-genome sequencing. Therefore, as from 2017, it has been possible to identify patients who have become infected with the same type of bacteria, and therefore presumably by the same source and probably in the same country.