With this study the researchers aim to provide observational data on the treatment efficacy of currently used antibiotic treatment regimens for NTS BSI in hospital-admitted children. The study is an observational cohort study where the antibiotic treatments used and treatment outcomes in the St. Luc general referral hospital in Kisantu health zone (Province Kongo Central, DR Congo) will be described.

In sub-Saharan Africa, non-typhoidal Salmonella (NTS) are a frequent cause of bloodstream infection (BSI) in young children, display high levels of antibiotic resistance and have a high case fatality rate (15%). In Kisantu hospital in the Democratic Republic of Congo (DR Congo), NTS account for 75% of blood culture pathogens in young children.

Currently, NTS BSI are mostly treated with third generation cephalosporins or fluoroquinolones. However, resistance to these antibiotics is emerging in NTS BSI. Third generation cephalosporine and fluoroquinolone resistant Salmonella are identified as critical priority pathogens by the World Health Organization (WHO). To combat the developing antimicrobial resistance, rational and evidence-based antibiotic treatment of NTS BSI is crucial.

So far, there are no guidelines to treat NTS BSI in a low-resource setting. The currently used antibiotic regimens are experience-based or extrapolated from typhoid fever. The absence of dedicated studies addressing antibiotic treatment efficacy in NTS BSI in sub-Saharan African children hampers the development of evidence-based antibiotic treatment guidelines and antibiotic stewardship.

Clinical practice guidelines established for high- and middle-income countries recommend 7 - 14 days of parenteral antibiotic treatment for NTS BSI. In sub-Saharan Africa however, financial, logistic and nursing care barriers preclude such long parenteral treatment regimens.

To decrease the case fatality and combat antibiotic resistance of NTS BSI in its most affected population (i.e. children in sub-Saharan Africa), data that support appropriate antibiotic treatment (i.e. antibiotic class, dose, route and duration) are urgently needed.

The researchers aim to provide observational data on the treatment efficacy of currently used antibiotic treatment regimens for NTS BSI in hospital-admitted children.

They hypothesize that, in terms of treatment efficacy in hospital admitted children with NTS BSI, a short course of parenteral antibiotics (<7 days) with switch to oral antibiotics is not inferior to a full parenteral antibiotic course (≥7 days).

This study is designed as a prospective, single-center, hospital-based observational study on the efficacy of antibiotic treatment of a cohort of young children (1 month to 5 years old) with NTS BSI. Data will be collected from the enrolled children during three different study phases, i.e., upon admission, daily in-hospital follow-up and post-discharge follow-up.

Inclusion Criteria:

• Be a child > 28 days and < 5 years old
• Be admitted to Kisantu Hospital
• Have a blood culture sampled upon hospital admission
• Having a caregiver willing and able to provide written informed consent, which will be requested as soon as possible after screening of the other three eligibility criteria. By consenting with study participation of the child, the caregiver agrees to that the child participates in the study procedures at presentation in the hospital, during hospital admission and during 1 month after discharge.

Exclusion Criteria:

• Child died and caregiver left the hospital before enrollment
• Child and caregiver left the hospital before enrollment

Children between 28 days and 5 years that are admitted to the Kisantu hospital with a need for a blood sample culture (suspicion of a blood-stream infection).

The data sharing procedure for the study will comply with the Institute of Tropical Medicine's data sharing policy on open access to research data. After publishing the manuscript, participant level study data may be shared with other interested users under restricted conditions or made available through an open data repository. These study data will only be shared if the enrolled child are anonymized so that their identity cannot be determined, neither directly nor indirectly. Any subsequent sharing of participant level data will require approval from Institut National de Recherche Biomédicale (INRB) and Institute of Tropical Medicine (ITM).