Laboratory methods
acute febrile illness
ENTERIC FEVER
All healthcare facilities partnered with the study will be encouraged to conduct a blood culture in case a patient has an acute febrile illness that lasts more than 2 days, has a temperature of ≥ 38 °C documented at the facility, or if the physician intends to begin antimicrobial therapy. The physician may defer the blood culture in case no antimicrobials are being initiated, if there is a confirmed alternate aetiology that excludes enteric fever, or if the patient has a documented negative blood culture report within the past 7 days.All blood cultures will be collected under aseptic conditions and as per study SOPs. The blood volumes to be collected and inoculated into blood culture bottles (BacT/Alert) will be 5 mL for children between 1 and 15 years of age, and 8–10 mL for those ≥ 15 years. In case the study physician requires additional blood for investigations, it will be drawn during the same phlebotomy procedure. The weights of culture bottles before and after sample collection will be documented, along with the dates/times of loading into the BacT/Alert machine and of positivity. Any blood or bone-marrow cultures that are positive for Any additional serum samples collected from participants will also be stored at − 80 °C and tested for IgA HLyE antibodies, and other assays as indicated during their routine diagnosis.