Paediatric enteric fever in Brussels: a case series over 16 years

Enteric fever (EF) is a major public health problem and a witness of the global health disparities. It is caused by Salmonella enterica serovar Typhi (Salmonella ser. Typhi) and Salmonella enterica serovar Paratyphi A, B, C (Salmonella ser. Paratyphi) and is estimated to infect 12-26 million persons yearly. Paediatric data on enteric fever in Europe are scarce. A case series of EF was analysed to describe the clinical presentation, laboratory characteristics and diagnostic challenges identified in a paediatric population in Brussels. We performed a retrospective study of all lab-confirmed cases of enteric fever in children aged 0-15 years at two Brussels teaching hospitals, between January 2005 and December 2020. We reviewed age, gender, travel history, consultations before diagnosis, hospitalisation duration, clinical symptoms and laboratory findings. There were 34 positive isolates of S. typhi and S. paratyphi: 31 patients had positive blood culture, 1 patient had positive bone aspirate and 2 patients had positive stool culture (one was excluded for missing data). There were 20 girls (60%). Median age was 3.5 years (range 5 months to 14 years). Travel to EF endemic areas was present in 55% of patients. Diagnosis was delayed in 80% of children. Eosinopenia was present in 93% of the cohort. The patients had not received any preventive travel education or vaccination.  Conlusion: Enteric fever poses diagnostic challenges to clinicians. Eosinopenia in a febrile patient coming from the tropics should raise suspicion of EF. Travellers to endemic areas should be better educated about EF risks, and typhoid fever vaccination must be promoted. What is Known: • Enteric fever is a global public health problem and includes typhoid and paratyphoid fever. • Typhoid fever is vaccine preventable disease. Paratyphoid fever is not vaccine preventable. What is New: • Enteric fever diagnosis is very challenging in non-endemic settings, and a large proportion of patients may develop serious complications if they receive delayed management. Occurrence of small family clusters is possible and mandates education and monitoring of the families of enteric fever affected children. • We report that the widest majority of our enteric fever affected patients (69%) had aneosinophilia (zero eosinophil count), and almost all patients (93%) had eosinopaenia (less than 50 eosinophil count) during their bacteriaemic phase.