Trends in the prevalence of hospital-associated infections caused by high-priority pathogens

By Bhavana KunkalikarReviewed by Danielle Ellis, B.Sc.Jun 19 2023

In a recent study published in PLOS Medicine, researchers explored the prevalence of antibiotic-resistant hospital-associated infections worldwide.

Background

Hospitals in low- and middle-income settings (LMICs) with inadequate antimicrobial stewardship and restricted microbiology diagnostic capabilities are significantly impacted by hospital-associated drug-resistant infections (HARIs). Healthcare-associated infections (HAIs) significantly contribute to illness and death globally. The global understanding of the global prevalence of HARIs remains unclear despite many HAIs being caused by drug-resistant bacterial pathogens. The present study estimated the prevalence trends of high-priority pathogen-induced HARIs in 195 countries.

About the study

The authors searched Google Scholar and Pubmed for articles published from January 2010 to December 2020. The search focused on the prevalence of drug-resistant and drug-sensitive infections for common bacterial pathogens, including Escherichia coli, Klebsiella spp., Acinetobacter spp., Enterobacter spp., Staphylococcus aureus, and Pseudomonas spp.

Prevalences of antibiotic resistance were reported for 122 antimicrobials. Thirteen categories were identified, including tetracyclines, sulfonamides, penicillins, monobactams, macrolides, quinolones, aminoglycosides, amphenicols, cephalosporins, polymyxins, carbapenems, glycopeptides, and a miscellaneous group referred to as "others."

The survey data included the digital object identifier (DOI), first author's last name, publication date, country ISO3 code, latitude-longitude decimal coordinates of the survey location, survey start and end dates, and the number of hospital beds in the survey location. The study included details about the pathogen-causing infections such as the pathogen strain, infection type, number of reported infections, sample type, the prevalence of resistance for each antibiotic-pathogen combination assessed, antibiotic compounds examined, and the related anatomical therapeutic chemical classification system (ATCCS) code.

Hospitalization rates per capita were estimated using country-level indicators, which represent the number of hospitalizations per population per year. The study also estimated the annual number of HARIs in different countries by multiplying the population size, the proportion of hospitalized individuals, and the probability of a patient being hospitalized due to an antimicrobial-resistant infection.

Results

A total of 474 publications from 99 countries reported on antibiotic resistance proportions for hospital-associated infections. Approximately 15,723 resistance proportions were obtained from six groups of pathogens, including 4,014 of E. coli, 3,524 of Klebsiella spp., 2,979 of Staphylococcus spp., 2,296 of Acinetobacter spp., 1,791of Pseudomonas spp., and 1,119 of Enterobacter spp.

Sri Lanka, Russia, the Czech Republic, Germany, and Slovakia had the highest hospitalization rates. The average hospitalization rates varied across different income countries, with the average rate being 3% in low-income countries, 6% in middle-income countries, and 11% in high-income countries. Russia, China, Serbia, Bosnia, Madagascar, and Benin had the highest HARIs per year among countries where a minimum of two surveys were performed on hospital-associated drug resistance.

The estimated global number of HARIs per year was 136 million, based on the imputation of resistance rates for each hospital visit as per income group. In absolute terms, China had the highest number of HARIs per year with 52 million, followed by Pakistan with 10 million, India with nine million, Russia with seven million, Brazil with four million, Ukraine with three million, the United States with three million, and Nigeria with two million. The United States had the highest number of HARIs per year among high-income countries.

HARIs per year were more prevalent in middle-income countries, with a total of 119 million cases, compared to low-income countries, with two million cases, and high-income countries, with 15 million cases. Acinetobacter spp., E. coli, and Staphylococcus spp. were the dominant contributors to the HARI burden in low-income countries, while Klebsiella spp. and Enterobacter spp. had a low burden. Also, E. coli and Acinetobacter spp. were primary contributors to the burden in middle-income countries, with a rise in Klebsiella spp. Furthermore, high-income countries had a significant burden of HARI caused by E. coli, Acinetobacter spp., and Klebsiella spp, while Staphylococcus spp. infection burden was lower in comparison.

Conclusion

The study has identified an urgent need to estimate the impact of HARIs caused by high-priority pathogens such as E. coli, Acinetobacter spp., Klebsiella spp., Staphylococcus spp, Pseudomonas spp., and Enterobacter spp. in low-, middle-, and high-income countries. The study presents an overview of the significant burden of HARIs and identifies countries and income groups with a particularly high risk. Globally, the annual HARI burden is similar to that of malaria with respect to the number of infections and hence requires immediate attention and intervention from public health stakeholders.