ABSTRACT
Data which accurately enumerate the economic costs of antimicrobial resistance (AMR) in low- and middle- income countries are essential. This study aimed to quantify the impact of third-generation cephalosporin resistant (3GC-R) bloodstream infection (BSI) on economic and health related quality of life outcomes for adult patients in Blantyre, Malawi. Participants were recruited from a prospective, longitudinal cohort study of hospitalised patients with bloodstream infection caused by Enterobacterales at Queen Elizabeth Central Hospital (QECH). Primary costing studies were used to estimate the direct medical costs associated with the inpatient stay. Recruited participants were asked about direct non-medical and indirect costs associated with their admission and their health-related quality of life was measured using the EuroQol EQ-5D questionnaire. Multiple imputation was undertaken to account for missing data. Costs were adjusted to 2019 US Dollars. Cost and microbiology surveillance data from QECH, Blantyre was used to model the annual cost of, and quality-adjusted life years lost to, 3GC-R and 3GC-Susceptible BSI from 1998 to 2030 in Malawi. The mean health provider cost per participant with 3GC-R BSI was US$110.27 (95%CR; 22.60-197.95), higher than for those with 3GC-S infection. Patients with resistant BSI incurred an additional indirect cost of US$155.48 (95%CR; -67.80, 378.78) and an additional direct non-medical cost of US$20.98 (95%CR; -36.47, 78.42). Health related quality of life outcomes were poor for all participants, but participants with resistant infections had an EQ-5D utility score that was 0.167 (95% CR: -0.035, 0.300) lower than those with sensitive infections. Population level burden estimates suggest that in 2016, 3GC-R accounted for 84% of annual societal costs from admission with bloodstream infection and 82% of QALYs lost. 3GC-R bloodstream infection was associated with higher health provider and patient level costs than 3GC-S infection, as well as poorer HRQoL outcomes. We demonstrate a substantial current and future economic burden to society as a result of 3GC-R E. coli and Klebsiella spp. BSI, data urgently needed by policy makers to provide impetus for implementing strategies to reduce AMR.
ABSTRACT
BACKGROUND: The burden of antimicrobial resistance is a major threat to global health; however, prospective clinical outcome data from Africa are scarce. In Malawi, third-generation cephalosporins are the antibiotics of choice in patients admitted to hospital despite a rapid proliferation of resistance to these drugs. We aimed to quantify the effect of resistance to third-generation cephalosporins on mortality and length of hospital stay among patients with bloodstream infections. METHODS: We did a prospective cohort study of patients admitted to Queen Elizabeth Central Hospital in Blantyre, Malawi. Patients of all ages who had positive blood cultures for Enterobacterales were included, with the exception of those from the genus Salmonella, and were followed up for 180 days. We characterised blood culture isolates using whole-genome sequencing and used Cox regression models to estimate the effect of resistance to third-generation cephalosporins on length of hospital stay, in-hospital mortality, and survival. FINDINGS: Between Jan 31, 2018, and Jan 13, 2020, we recruited 326 patients, from whom 220 (68%) of 326 isolates were resistant to third-generation cephalosporins. The case fatality proportion was 45% (99 of 220) in patients with bloodstream infections that were resistant to third-generation cephalosporins, and 34% (36 of 106) in patients with bloodstream infections that were sensitive to third-generation cephalosporins. Resistance to third-generation cephalosporins was associated with an increased probability of in-hospital mortality (hazard ratio [HR] 1·44, 95% CI 1·02-2·04), longer hospital stays (1·5 days, 1·0-2·0) and decreased probability of discharge alive (HR 0·31, 0·22-0·45). Whole-genome sequencing showed a high diversity of sequence types of both Escherichia coli and Klebsiella pneumoniae. Although isolates associated with death were distributed across clades, we identified three Eâcoli clades (ST410, ST617, and ST648) that were isolated from 14 patients who all died. INTERPRETATION: Resistance to third-generation cephalosporins is associated with increased mortality and longer hospital stays in patients with bloodstream infections in Malawi. These data show the urgent need for allocation of resources towards antimicrobial resistance mitigation strategies in Africa. FUNDING: Wellcome Trust and Wellcome Asia and Africa Programme.
