A young traveller presenting with typhoid fever after oral vaccination: a case report

INTRODUCTION: Typhoid fever is one of the most common vaccine-preventable diseases in travellers returning from tropical destinations. However, immunity and the immune response to infection are barely understood. CASE PRESENTATION: We report a case of tyhoid fever in a 29-year-old Caucasian, previously healthy woman who did not develop protective immunity or seroconversion of H or O antibodies neither after vaccination with the oral Ty21 vaccine, nor after infection with Salmonella typhi. CONCLUSIONS: This case highlights the insufficiencies of the current vaccination and the lack of a reliable, rapid serologic diagnostic tool for typhoid fever. With this case report, we aim to sensitize the reader that typhoid fever has to be taken into account as a differential diagnosis in patients even after vaccination and with negative serological test results.