Length of hospital stay and associated treatment costs for patients with susceptible and antibiotic-resistant Salmonella infections: a systematic review and meta-analysis

Abstract

Objectives: The global disease burden of Salmonella infections in 2017 included 135 900 deaths caused by Salmonella Typhi and Paratyphi and 77 500 deaths caused by invasive non-typhoidal Salmonella, with increasing antimicrobial resistance (AMR) exacerbating morbidity, mortality and costs. The aim of our systematic review and meta-analysis is to estimate the length of hospital stay and associated treatment costs for patients with susceptible and antibiotic-resistant Salmonella Typhi, Paratyphi and non-typhoidal Salmonella infections.

Design: Systematic review and meta-analysis.

Data sources: We searched EMBASE, Medline/PubMed, Scopus, Hinari and LILACS databases for studies published between 1 January 2005 and 15 May 2024, with no language restrictions.

Eligibility criteria: We included 30 studies that reported the length of hospital stay or treatment costs for patients with susceptible or antibiotic-resistant Salmonella Typhi, Paratyphi and non-typhoidal Salmonella infections. We excluded studies with sample sizes of less than 30 patients, those focused on non-human subjects and those not reporting our outcomes of interest.

Data extraction and synthesis: Two reviewers independently screened studies and extracted data on the length of hospital stay and associated costs, with monetary values converted to 2019 USD. We aggregated data according to GDP per capita quantiles using a random-effects meta-analysis. We conducted a quality assessment using an adapted Joanna Briggs Institute tool.

Results: Patients with drug-resistant Salmonella infections had longer hospital stays, with an additional 0.5-2.2 days compared with drug-susceptible Salmonella infections. Based on our meta-analysis, the mean hospital stay for typhoidal Salmonella infections was 6.4 days (95% CI 4.9 to 7.8) for drug-susceptible cases and 8.4 days (95% CI 5.1 to 11.7) for resistant cases in the lowest income quartiles. While there were insufficient data to perform a pooled analysis, individual studies inferred that treatment costs for resistant typhoidal Salmonella infections were higher than for susceptible infections, and resistant non-typhoidal Salmonella infections had longer hospital stays and higher costs compared with susceptible infections. Data were scarce from high-Salmonella-burden countries, particularly in sub-Saharan Africa and parts of Asia.

Conclusions: Patients with antibiotic-resistant Salmonella infections experience a greater healthcare burden in terms of hospitalisation length and direct costs compared with those with susceptible infections. We highlight the economic burden of AMR in Salmonella infections and emphasise the need for preventive measures.

Keywords: Economics; INFECTIOUS DISEASES; Public health.

Figure 1. Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram. After removing duplicates from the 4993 studies identified, 3741 studies published between 1 January 2005 and 15 May 2024 were identified. After screening titles and abstracts, 113 studies proceeded to full-text review. After full-text screening, 83 studies were excluded due to different outcomes, different pathogens, small sample sizes and other reasons. 30 publications were ultimately included in the review. S. non-Typhi, non-typhoidal Salmonella; S. Paratyphi, Salmonella Paratyphi; S. Typhi, Salmonella Typhi.

Figure 2. Length of hospital stay for drug-susceptible and drug-resistant Salmonella Typhi, Paratyphi and non-typhoidal Salmonella infections. The length of hospital stays for drug-susceptible and drug-resistant Salmonella Typhi, Paratyphi and nontyphoidal Salmonella infections was classified by GDP per capita quantile level and estimated from the meta-analysis. (A) Length of hospital stays of susceptible Salmonella Typhi and/or Paratyphi infection. (B) Length of hospital stays of resistant Salmonella Typhi and/or Paratyphi infection. (C) Length of hospital stays of susceptible Salmonella non-Typhi infection (D) Length of hospital stays of resistant Salmonella non-typhi infection. GDP, gross domestic product; MDR, multidrug-resistant; S. non-Typhi, non-typhoidal Salmonella; S. Paratyphi, Salmonella Paratyphi; S. Typhi, Salmonella Typhi; XDR, extensively drug-resistant.

Figure 3. Length of illness for drug-susceptible and drug-resistant Salmonella Typhi and Paratyphi. The length of hospital stays for drug-susceptible and drug-resistant Salmonella Typhi and Paratyphi infections was classified by GDP per capita quantile level and estimated from the meta-analysis. (A) Length of illness (fever) of susceptible Salmonella Typhi and/or Paratyphi infection (B) Length of illness (fever) of resistant Salmonella Typhi and/or Paratyphi infection. GDP, gross domestic product; MDR, multidrug-resistant; S. non-Typhi, non-typhoidal Salmonella; S. Paratyphi, Salmonella Paratyphi; S. Typhi, Salmonella Typhi; XDR, extensively drug-resistant.