Salmonella enterica serotype Typhi infections in a Canadian pediatric hospital: a retrospective case series

Typhoid fever is a systemic febrile illness caused by the bacterium Salmonella enterica serotype Typhi that infects about 26.9 million people annually and is responsible for more than 200 000 deaths each year worldwide. Overcrowded populations and poor hygienic conditions predispose developing countries to being endemic for typhoid fever, with the highest incidence found in the Indian subcontinent and Southeast Asia. The introduction of effective antibiotic treatment has substantially reversed this lifethreatening disease into a readily treatable condition. However, the emergence of multidrug-resistant strains of the bacterium in recent years, the lack of rapid diagnostic tests and increasing globalization have led to new challenges in the management of typhoid fever as a serious global public health concern. Early studies showed that children and young adults between the ages of 5 and 25 years were the most likely group to be admitted to hospital for typhoid fever; thus, it was thought to be a disease predominantly affecting school-aged and adolescent children. In 1999, however, a large cohort study including more than 8000 people in Kalkaji, Delhi, India, showed that 44% of culture-positive cases of typhoid fever occurred in children less than 5 years of age. More recently, an Indian study profiling children in hospital in Chennai, India, showed that almost 50% of patients in hospital with typhoid fever were 5 years old or younger. In developed countries, this infection is generally seen in travellers or recent immigrants from endemic areas. Considering the population served by our hospital, the objective of our study was to describe the epidemiology of S. enterica ser. Typhi Salmonella enterica serotype Typhi infections in a Canadian pediatric hospital: a retrospective case series