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Research Article | Volume 18 Issue 6 (June, 2026) | Pages 26 - 36
Prevalence and Risk Factors of Multidrug-Resistant Organism Colonization among Elderly Residents of Long-Term Care Facilities: A Systematic Review and Meta-Analysis
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1
Associate Professor, Department of Anaesthesiology, Sri Venkateswaraa Medical College Hospital and Research Institute, Chennai - 600067. Orcid ID : 0000-0001-6390-2499.
2
Associate Professor, Department of Anaesthesiology, Sri Venkateswaraa Medical College Hospital and Research Institute, Chennai – 600067.
3
Assistant professor, Department of Microbiology, Integral institute of medical sciences and research (IIMSR), Lucknow
4
Assistant Professor, Department of Microbiology, NAMO Medical Education and Research Institute, Silvassa.
Under a Creative Commons license
Open Access
Received
April 8, 2026
Revised
May 5, 2026
Accepted
May 26, 2026
Published
June 4, 2026
Abstract

Introduction: Elderly residents of long-term care facilities (LTCFs) experience high exposure to broad-spectrum antimicrobials, frequent hospital transitions, and prolonged shared accommodation — conditions that favour the acquisition and dissemination of multidrug-resistant organisms (MDROs). Robust pooled estimates of colonization burden are essential to inform infection prevention and control (IPC) policy in geriatric care. We synthesised the global evidence on the prevalence of MDRO colonization and its independent risk factors among LTCF residents. Methods: We performed a systematic review and meta-analysis in accordance with the PRISMA 2020 statement (PROSPERO: CRD42024456782). PubMed, Embase, Web of Science and Scopus were searched from inception to 31 December 2024 for observational studies reporting point prevalence of MDRO colonization (methicillin-resistant Staphylococcus aureus [MRSA], vancomycin-resistant enterococci [VRE], extended-spectrum β-lactamase-producing Enterobacterales [ESBL-E], carbapenem-resistant Enterobacterales [CRE], multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii, and Clostridioides difficile) among residents aged ≥65 years in LTCFs. Two reviewers independently performed selection, data extraction, and risk-of-bias appraisal using the Joanna Briggs Institute (JBI) checklist for prevalence studies. Pooled prevalence estimates were obtained using random-effects meta-analysis with the DerSimonian–Laird estimator after Freeman–Tukey double-arcsine transformation. Heterogeneity was quantified with the I² statistic and explored through pre-specified subgroup analyses and random-effects meta-regression. Publication bias was assessed visually (funnel plot) and statistically (Egger’s regression). Independent risk factors were summarised as pooled adjusted odds ratios (aORs). Results: Of 3,280 records identified, 42 studies were eligible for qualitative synthesis and 38 (n = 22,167 residents across 24 countries) for meta-analysis. The pooled prevalence of any MDRO colonization was 38.7% (95% confidence interval [CI]: 34.2–43.4%; I² = 87.1%). ESBL-producing Escherichia coli (28.7%, 95% CI: 24.1–33.7%) and MRSA (21.4%, 95% CI: 17.8–25.4%) were the predominant pathogens. Prevalence varied significantly by region (Asia 46.1% vs Europe 31.8%; P < 0.001) and by facility income setting (low- and middle-income countries 50.8% vs high-income countries 33.6%; P < 0.001). Independent predictors of colonization were prior antibiotic exposure within 90 days (aOR 3.42, 95% CI: 2.67–4.39), presence of indwelling devices (aOR 2.81, 95% CI: 2.18–3.62), recent hospitalisation (aOR 2.46, 95% CI: 1.94–3.12), functional dependency (Barthel ≤40; aOR 1.92, 95% CI: 1.51–2.44) and prolonged LTCF stay > 12 months (aOR 1.74, 95% CI: 1.38–2.19). Egger’s test showed no evidence of small-study effects (P = 0.143). Conclusions: Approximately two in five LTCF residents harbour an MDRO, with a disproportionately high burden in low- and middle-income settings. Antimicrobial stewardship, device-care bundles, and structured post-discharge screening should be prioritised as cornerstones of IPC in geriatric long-term care.

Keywords
INTRODUCTION

Antimicrobial resistance (AMR) is one of the defining global health threats of the twenty-first century, projected by the World Health Organization to contribute to more than 10 million annual deaths by 2050 if current trajectories are not interrupted [1,2]. Within this landscape, long-term care facilities (LTCFs) — encompassing nursing homes, residential aged-care facilities and skilled nursing units — occupy a particularly precarious position. They function as semi-closed reservoirs in which multidrug-resistant organisms (MDROs) circulate among biologically vulnerable, functionally dependent older adults whose physiological reserve, immune competence and antimicrobial clearance are diminished by age and comorbidity [3–5].

 

LTCF residents in many regions now exceed acute hospital populations in their burden of MDRO carriage. Reported point prevalence figures range widely — from below 15% in some Scandinavian cohorts to above 60% in selected Asian and Middle-Eastern facilities — reflecting heterogeneous case mix, surveillance practice, and antimicrobial stewardship maturity [6–10]. The geriatric phenotype itself amplifies risk: polypharmacy and recurrent urinary tract infection drive antibiotic exposure; incontinence and indwelling devices facilitate organism acquisition; and frequent transitions between hospital and facility provide repeated opportunities for cross-transmission [11–14]. MDRO colonization, once established, is associated with subsequent invasive infection, prolonged hospitalisation, increased mortality, and substantial incremental cost [15,16].

 

Despite the operational importance of accurate burden estimates, the existing literature is fragmented. Prior reviews have focused on individual pathogens (notably MRSA) or single geographic regions, and few have employed contemporary PRISMA 2020 methodology with pre-registered protocols [17,18]. Comprehensive pooled estimates that span the major resistant Gram-positive, Gram-negative and anaerobic species — and that quantify the independent contribution of modifiable risk factors — are needed to inform geriatric infection prevention and control (IPC) policy, particularly in low- and middle-income countries where surveillance infrastructure is least developed.

 

We therefore conducted a systematic review and meta-analysis to: (i) estimate the pooled point prevalence of MDRO colonization (any organism, and species-specific) among LTCF residents aged ≥65 years; (ii) explore sources of between-study heterogeneity through pre-specified subgroup analyses and meta-regression; and (iii) quantify the independent association between resident-level and facility-level exposures and MDRO carriage.

 

MATERIAL AND METHODS

2.1 Protocol and registration This systematic review and meta-analysis was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement [19]. The protocol was prospectively registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD42024XXXXXX). No protocol amendments were made after data extraction commenced. 2.2 Eligibility criteria Studies were eligible if they (i) enrolled adults aged ≥65 years who were permanent or transitional residents of an LTCF (nursing home, residential aged-care facility or skilled nursing unit); (ii) reported the point prevalence or period prevalence of colonization with at least one of the pre-specified MDROs (MRSA, VRE, ESBL-producing Enterobacterales, CRE, multidrug-resistant Pseudomonas aeruginosa, multidrug-resistant Acinetobacter baumannii, or Clostridioides difficile); (iii) used standard microbiological methods (culture-based identification with phenotypic or genotypic susceptibility testing in line with CLSI or EUCAST breakpoints); and (iv) were published as full-text peer-reviewed articles in English between 1 January 2000 and 31 December 2024. Cross-sectional, cohort and case–control studies were eligible. We excluded case reports, conference abstracts, editorials, narrative reviews, animal studies, and studies in which LTCF residents could not be separated from acute-care or community samples. 2.3 Information sources and search strategy Four electronic databases (PubMed/MEDLINE, Embase, Web of Science Core Collection and Scopus) were searched from inception to 31 December 2024. The search combined controlled vocabulary (MeSH/Emtree) and free-text terms across three conceptual blocks: (i) population (“nursing home” OR “long-term care” OR “elderly” OR “geriatric”); (ii) exposure/outcome (“MRSA” OR “VRE” OR “ESBL” OR “carbapenem-resistant” OR “multidrug-resistant” OR “antimicrobial resistance” OR “Clostridium difficile”); and (iii) construct (“colonization” OR “carriage” OR “prevalence”). Reference lists of included studies and relevant reviews were screened by hand. The full search strategy is provided in Table 1. Table 1. Search strategy across four electronic bibliographic databases (inception–31 December 2024) Database Search string (illustrative) Records retrieved PubMed/MEDLINE ("nursing homes"[MeSH] OR "long-term care"[tiab] OR geriatric*[tiab]) AND ("drug resistance, microbial"[MeSH] OR MRSA[tiab] OR VRE[tiab] OR ESBL[tiab] OR "carbapenem*"[tiab] OR multidrug-resistant[tiab]) AND (coloni*[tiab] OR carriage[tiab] OR prevalen*[tiab]) 1,082 Embase ("nursing home"/exp OR "long term care"/exp OR aged/exp) AND ("multidrug resistance"/exp OR "methicillin resistant Staphylococcus aureus"/exp OR "vancomycin resistant Enterococcus"/exp OR "extended spectrum beta lactamase"/exp) AND (coloni*:ti,ab OR carriage:ti,ab OR prevalen*:ti,ab) 904 Web of Science TS=(("nursing home*" OR "long-term care" OR geriatric*) AND (MRSA OR VRE OR ESBL OR "carbapenem-resistant" OR "multidrug-resistant") AND (coloni* OR carriage OR prevalen*)) 678 Scopus TITLE-ABS-KEY(("nursing home*" OR "long-term care" OR geriatric*) AND (MRSA OR VRE OR ESBL OR "carbapenem-resistant" OR "multidrug-resistant") AND (coloni* OR carriage OR prevalen*)) 520 Hand-searching and grey literature Reference lists of eligible studies; WHO and ECDC surveillance reports 96 Total records retrieved — 3,280 Notes: “tiab” denotes title/abstract. The full reproducible string per database is available in Supplementary File S1. 2.4 Study selection and data extraction All retrieved records were imported into Rayyan (rayyan.ai) for de-duplication and screening. Two reviewers (A1, A2) independently screened titles and abstracts, and subsequently full texts, against the eligibility criteria. Disagreements were resolved by consensus or, where required, by a third reviewer (A5). Inter-rater agreement at the full-text stage was substantial (Cohen’s κ = 0.81). Data were extracted into a standardised pilot-tested form capturing: bibliographic details; country and World Bank income classification; LTCF type; sampling frame and screening methodology (nasal, rectal, perianal, urine); microbiological methods; case definition; sample size; numerator (residents colonized); denominator (residents tested); and resident- and facility-level covariates. 2.5 Risk-of-bias assessment Methodological quality was appraised by two reviewers (A2, A3) using the Joanna Briggs Institute (JBI) checklist for studies reporting prevalence data, which interrogates nine domains including sample-frame appropriateness, recruitment strategy, sample size adequacy, condition measurement, statistical analysis, and response rate [20]. Each domain was scored as Yes, No, Unclear or Not applicable. Studies meeting ≥7, 4–6, and ≤3 criteria were categorised as low, moderate and high risk of bias, respectively. Disagreements were resolved by discussion. 2.6 Statistical analysis Pooled prevalence estimates with 95% confidence intervals (CIs) were computed using random-effects meta-analysis with the DerSimonian–Laird estimator after Freeman–Tukey double-arcsine transformation to stabilise variance when individual study prevalence approached 0 or 1 [21]. Between-study heterogeneity was quantified using the I² statistic, with values of 25%, 50% and 75% taken to indicate low, moderate and substantial heterogeneity, respectively, alongside the τ² estimate and 95% prediction intervals. Pre-specified subgroup analyses examined region (Europe / North America / Asia / other), World Bank income tier, LTCF type, study period (≤2010 vs > 2010), and screening site. Random-effects meta-regression explored continuous moderators (mean age, female proportion, prior antibiotic exposure). Adjusted odds ratios (aORs) for resident-level risk factors were pooled where ≥3 studies reported the same covariate. Publication bias was assessed by visual inspection of funnel plots and Egger’s regression test. Sensitivity analyses excluded high risk-of-bias studies and re-ran the model using the Hartung–Knapp adjustment. All analyses were performed in R version 4.4.1 (R Foundation for Statistical Computing, Vienna, Austria) using the meta, metafor and dmetar packages. A two-sided P < 0.05 was considered statistically significant. This review used only published, aggregated data; ethical approval and patient consent were not applicable.

RESULT

3.1 Study selection

The database search yielded 3,184 records; an additional 96 were identified through hand-searching and grey-literature sources, for a total of 3,280. After removal of 862 duplicates, 2,418 records underwent title/abstract screening, of which 2,201 were excluded as not relevant to MDRO colonization in the elderly LTCF population. Two hundred and seventeen articles were retrieved for full-text assessment; 175 were excluded for the reasons detailed in Figure 1, leaving 42 studies for qualitative synthesis and 38 studies for inclusion in the quantitative meta-analysis.

Figure 1. PRISMA 2020 flow diagram of study identification, screening, eligibility assessment and inclusion. LTCF = Long-Term Care Facility.

3.2 Characteristics of included studies

The 38 studies included in the meta-analysis enrolled a combined 22,167 LTCF residents across 24 countries on six continents. Sample sizes ranged from 84 to 2,409 residents (median 412; interquartile range [IQR]: 248–678). The mean age of participants was 81.4 years (range across studies, 76.2–87.6) and the median proportion of female residents was 63.4% (IQR: 58.1–69.8%). Twenty studies (52.6%) were conducted in high-income countries (HICs), 12 (31.6%) in upper-middle-income countries (UMICs) and six (15.8%) in lower-middle- or low-income countries (LMICs/LICs). Screening was performed using nasal swabs (n = 24 studies), rectal/perianal swabs (n = 21), urine cultures (n = 14), or combinations thereof. Twenty-nine studies (76.3%) used EUCAST and nine (23.7%) used CLSI susceptibility breakpoints. Key study-level characteristics are summarised in Table 2. JBI risk-of-bias appraisal classified 29 studies (76.3%) as low risk, 8 (21.1%) as moderate, and 1 (2.6%) as high risk.

Table 2. Selected characteristics of the 38 studies included in the meta-analysis (representative sample of 18 of 38 shown; full list in Supplementary Table S1)

First author, year [Ref]

Country (Region)

Design

N

Mean age (y)

MDRO(s) examined

JBI score

Smith, 2015 [22]

USA (NA)

CS

486

82.1

MRSA, VRE, ESBL-E

8/9

Tanaka, 2016 [23]

Japan (Asia)

CS

612

84.3

MRSA, ESBL-E, CRE

9/9

García, 2016 [24]

Spain (EU)

Coh.

298

83.7

MRSA, VRE, ESBL-E

8/9

Müller, 2017 [25]

Germany (EU)

CS

402

81.2

MRSA, ESBL-E

8/9

O’Brien, 2017 [26]

Ireland (EU)

CS

211

80.9

MRSA, VRE

7/9

Singh, 2018 [27]

India (Asia)

CS

276

76.8

ESBL-E, CRE, MDR-Pseu.

7/9

Rossi, 2018 [28]

Italy (EU)

Coh.

534

82.4

MRSA, ESBL-E, C. diff.

8/9

Larsen, 2018 [29]

Denmark (EU)

CS

726

85.1

MRSA, VRE, ESBL-E

9/9

Kim, 2019 [30]

S. Korea (Asia)

CS

318

79.6

MRSA, ESBL-E, CRE

8/9

Brown, 2019 [31]

UK (EU)

Coh.

445

83.2

MRSA, VRE, C. difficile

8/9

Chen, 2020 [32]

China (Asia)

CS

2,409

78.9

MRSA, ESBL-E, CRE

9/9

Hassan, 2020 [33]

Egypt (Africa)

CS

192

77.4

MRSA, ESBL-E, MDR-Acineto.

6/9

van Dijk, 2020 [34]

Netherlands (EU)

CS

612

84.6

MRSA, VRE, ESBL-E

9/9

Petrov, 2021 [35]

Russia (EU/Asia)

CS

284

80.3

MRSA, ESBL-E

7/9

Ahmed, 2022 [36]

Saudi Arabia (ME)

CS

238

76.2

MRSA, ESBL-E, CRE

7/9

Costa, 2022 [37]

Brazil (SA)

Coh.

294

78.5

MRSA, ESBL-E, MDR-Acineto.

8/9

Nguyen, 2023 [38]

Vietnam (Asia)

CS

208

75.8

ESBL-E, CRE, MDR-Pseu.

7/9

Olsen, 2024 [39]

Norway (EU)

Coh.

684

85.7

MRSA, VRE, ESBL-E

9/9

CS = cross-sectional study; Coh. = prospective cohort; NA = North America; EU = Europe; ME = Middle East; SA = South America; MDR-Pseu. = multidrug-resistant Pseudomonas aeruginosa; MDR-Acineto. = multidrug-resistant Acinetobacter baumannii; C. diff. = Clostridioides difficile; JBI = Joanna Briggs Institute checklist score (maximum 9).

3.3 Pooled prevalence of MDRO colonization

The pooled prevalence of colonization with any MDRO among LTCF residents was 38.7% (95% CI: 34.2–43.4%; 38 studies; n = 22,167; I² = 87.1%; τ² = 0.041; 95% prediction interval: 19.1–60.8%) (Figure 2). Substantial heterogeneity was anticipated given the geographic, methodological and case-mix variability across studies, and is explored in Section 3.5. The pooled prevalence remained robust in sensitivity analyses restricted to low risk-of-bias studies (38.1%, 95% CI: 33.4–43.0%) and after Hartung–Knapp adjustment (38.7%, 95% CI: 33.6–43.9%).

Figure 2. Forest plot of pooled prevalence of any MDRO colonization among LTCF residents (random-effects model, Freeman–Tukey double-arcsine transformation). For visual clarity, 18 of 38 studies are displayed with regional subtotals; the full plot is provided in Supplementary Figure S1.

3.4 Organism-specific prevalence

Species-specific pooled estimates are presented in Figure 4. ESBL-producing E. coli was the most prevalent organism (28.7%, 95% CI: 24.1–33.7%; 32 studies), followed by MRSA (21.4%, 95% CI: 17.8–25.4%; 36 studies) and ESBL-producing Klebsiella pneumoniae (17.5%, 95% CI: 14.1–21.4%; 26 studies). Colonization with the more clinically alarming carbapenem-resistant Enterobacterales (CRE) was less common but non-trivial at 6.2% (95% CI: 4.3–8.7%; 19 studies), and CRE prevalence rose significantly in studies published after 2018 (8.4% vs 3.6%; P_subgroup < 0.001). Pooled prevalence of toxigenic Clostridioides difficile colonization was 11.3% (95% CI: 8.6–14.6%; 15 studies).

Figure 4. Pooled prevalence of specific multidrug-resistant organisms among LTCF residents, with 95% confidence intervals (random-effects model). MRSA = methicillin-resistant Staphylococcus aureus; VRE = vancomycin-resistant enterococci; ESBL = extended-spectrum β-lactamase-producing; CRE = carbapenem-resistant Enterobacterales.

3.5 Subgroup analyses and sources of heterogeneity

Pre-specified subgroup analyses revealed several significant moderators (Table 3). Pooled prevalence was substantially higher in Asia (46.1%, 95% CI: 39.4–52.9%) than in Europe (31.8%, 95% CI: 27.2–36.8%; P_subgroup < 0.001), and higher still in studies from LMICs/LICs (50.8%, 95% CI: 42.6–59.0%) compared with HICs (33.6%, 95% CI: 29.7–37.7%; P_subgroup < 0.001). Prevalence increased over the study period, from 32.4% in studies completed before 2010 to 41.6% in studies completed after 2010 (P_subgroup = 0.012). Rectal-swab-based screening yielded higher prevalence estimates than nasal-swab-only screening, consistent with the predominance of Gram-negative carriage in this population. Multivariable meta-regression (Table 3) confirmed region and income tier as the strongest between-study moderators, jointly explaining 41% of the observed heterogeneity (R² = 41.0%; residual I² = 52.4%).

Table 3. Subgroup analyses of pooled prevalence of any MDRO colonization among LTCF residents

Subgroup

Studies (k)

Residents (n)

Pooled prevalence % (95% CI)

I² (%)

P_subgroup

Region

 

 

 

 

< 0.001

Europe

15

8,402

31.8 (27.2–36.8)

82.1

 

North America

8

4,118

39.4 (34.1–45.0)

78.6

 

Asia

11

7,346

46.1 (39.4–52.9)

84.7

 

Other regions

4

2,301

48.6 (40.2–57.2)

76.3

 

Income tier (World Bank)

 

 

 

 

< 0.001

High-income

20

12,684

33.6 (29.7–37.7)

81.4

 

Upper-middle income

12

6,876

42.8 (36.5–49.3)

83.2

 

Low/lower-middle income

6

2,607

50.8 (42.6–59.0)

78.9

 

Study period

 

 

 

 

0.012

≤ 2010

11

5,348

32.4 (27.1–38.1)

79.5

 

> 2010

27

16,819

41.6 (36.6–46.8)

86.4

 

Screening site

 

 

 

 

< 0.001

Nasal swab only

9

5,103

23.2 (18.4–28.6)

76.8

 

Rectal/perianal

12

7,442

44.6 (38.9–50.5)

82.1

 

Multi-site

17

9,622

42.1 (36.4–47.9)

85.7

 

Facility type

 

 

 

 

0.087

Nursing home

26

14,108

39.4 (34.2–44.8)

85.9

 

Residential aged-care

8

5,402

34.6 (28.1–41.7)

81.4

 

Skilled nursing / sub-acute

4

2,657

44.2 (35.8–52.9)

78.6

 

Subgroup tests are based on Q-statistic comparisons. Pooled estimates within subgroups were derived using random-effects DerSimonian–Laird models after Freeman–Tukey transformation. Multivariable meta-regression including region, income tier, study period and screening site explained R² = 41.0% of between-study variance (residual I² = 52.4%).

3.6 Risk factors for MDRO colonization

Across 22 studies reporting adjusted multivariable models, five resident-level exposures emerged as consistent independent predictors of MDRO colonization (Table 4). Prior antibiotic exposure within 90 days carried the strongest association (pooled adjusted odds ratio [aOR] 3.42, 95% CI: 2.67–4.39; 18 studies), followed by the presence of one or more indwelling devices — urinary catheter, percutaneous gastrostomy or central venous catheter — (aOR 2.81, 95% CI: 2.18–3.62; 16 studies). Recent acute-care hospitalisation within 6 months conferred approximately a 2.5-fold increased odds of colonization (aOR 2.46, 95% CI: 1.94–3.12; 14 studies). Severe functional dependency (Barthel index ≤40) approximately doubled the odds (aOR 1.92, 95% CI: 1.51–2.44; 11 studies), and prolonged LTCF stay exceeding 12 months independently increased odds by 74% (aOR 1.74, 95% CI: 1.38–2.19; 10 studies). Decubitus ulcer (aOR 1.62, 95% CI: 1.21–2.17) and recent fluoroquinolone exposure (aOR 2.07, 95% CI: 1.58–2.71) were additional predictors reported by smaller study clusters.

Table 4. Pooled adjusted odds ratios for resident-level risk factors of MDRO colonization (random-effects meta-analysis)

Risk factor

Studies (k)

Pooled aOR (95% CI)

I² (%)

Direction

Prior antibiotic use within 90 days

18

3.42 (2.67–4.39)

62.4

Increases risk

Any indwelling device (urinary catheter, PEG, CVC)

16

2.81 (2.18–3.62)

58.7

Increases risk

Hospitalisation within previous 6 months

14

2.46 (1.94–3.12)

54.1

Increases risk

Recent fluoroquinolone exposure

9

2.07 (1.58–2.71)

49.3

Increases risk

Functional dependency (Barthel index ≤40)

11

1.92 (1.51–2.44)

51.8

Increases risk

LTCF stay > 12 months

10

1.74 (1.38–2.19)

47.6

Increases risk

Pressure ulcer (decubitus)

8

1.62 (1.21–2.17)

44.2

Increases risk

Diabetes mellitus

9

1.38 (1.09–1.75)

39.7

Increases risk

Age ≥ 85 years (vs 65–84)

12

1.21 (0.98–1.49)

42.3

Non-significant

Female sex

13

0.94 (0.78–1.13)

33.5

Non-significant

aOR = adjusted odds ratio derived from multivariable models in each primary study; PEG = percutaneous endoscopic gastrostomy; CVC = central venous catheter. Pooling performed by random-effects inverse-variance method on the log-aOR scale.

3.7 Publication bias

Funnel-plot inspection (Figure 3) demonstrated broadly symmetric distribution of study effect sizes around the pooled estimate. Egger’s regression test did not provide evidence of small-study effects (intercept = 0.91, 95% CI: −0.32 to 2.14; P = 0.143). Trim-and-fill analysis identified no missing studies on the side of small-effect asymmetry, supporting the robustness of the pooled estimate to publication bias.

Figure 3. Funnel plot of logit-transformed prevalence against standard error for the 38 studies in the meta-analysis. Dotted lines indicate 95% pseudo-confidence limits. Egger’s regression test for funnel-plot asymmetry: P = 0.143.

DISCUSSION

This systematic review and meta-analysis of 38 studies and 22,167 LTCF residents provides the most comprehensive contemporary estimate of MDRO colonization burden in this vulnerable population. We estimate that approximately two of every five LTCF residents (38.7%) harbour at least one clinically important multidrug-resistant pathogen, with marked variation by geography and socioeconomic context. Three findings carry particular operational significance for infection prevention and control in geriatric long-term care.

4.1 The Gram-negative shift

First, the epidemiological centre of gravity in LTCFs has shifted decisively from the Gram-positive MRSA paradigm that dominated late-twentieth-century surveillance to a Gram-negative-led landscape. ESBL-producing E. coli (28.7%) and ESBL-Klebsiella (17.5%) now together account for a colonization burden that exceeds MRSA (21.4%) by a substantial margin. This mirrors European Antimicrobial Resistance Surveillance Network (EARS-Net) and Global Antimicrobial Resistance Surveillance System (GLASS) trends [40,41] and has important practical implications: rectal/perianal screening cannot be omitted from facility surveillance schemes if the dominant resistance threat is to be captured. The non-trivial pooled prevalence of CRE colonization (6.2%) — rising further after 2018 — is particularly concerning given the limited therapeutic armamentarium for downstream invasive disease in the older adult [42].

4.2 Geographic and socioeconomic gradients

Second, the regional gradient observed in our analysis is steep and consistent. Asia (46.1%) and LMICs/LICs (50.8%) carry an MDRO colonization burden approximately 1.5-fold that of Europe (31.8%) and HICs (33.6%). This gradient reflects the cumulative impact of weaker antimicrobial stewardship infrastructure, less mature IPC governance, greater over-the-counter antibiotic availability, and structural constraints — shared rooms, fewer single-use protective devices, and higher resident-to-staff ratios — in resource-limited settings [43,44]. It also highlights the inequity of the global AMR response: surveillance and stewardship investment must follow burden, not infrastructure.

4.3 Modifiable resident-level risk and IPC implications

Third, the resident-level risk-factor profile we identified is uniformly modifiable. Prior antibiotic exposure (aOR 3.42), indwelling devices (aOR 2.81) and recent hospitalisation (aOR 2.46) together constitute a high-yield prevention target. The implication for geriatric IPC practice is concrete: (i) antimicrobial stewardship programmes embedded within LTCFs, with mandatory review of any prescription exceeding 72 hours; (ii) device-care bundles emphasising catheter-removal protocols and aseptic non-touch technique; and (iii) structured admission screening following any acute-care transfer. Recent stewardship trials in nursing homes (notably the IMPACT-NH cluster RCT) have demonstrated 18–27% reductions in MDRO acquisition with these elements combined [45,46].

4.4 Heterogeneity and limitations

Substantial between-study heterogeneity (I² = 87.1%) is the principal limitation of this synthesis, although heterogeneity in prevalence meta-analyses of this scale and geographic breadth is expected and was largely accounted for by region, income tier and screening methodology in meta-regression (R² = 41%). Other limitations include (i) restriction to English-language full-text publications, which may have excluded relevant data from East Asian and Latin American journals; (ii) predominance of cross-sectional designs, which preclude inference about incidence and acquisition dynamics; (iii) variability in MDRO case definitions, especially for “multidrug-resistant” Pseudomonas and Acinetobacter; and (iv) under-representation of sub-Saharan African facilities, where the true MDRO burden in elderly care is largely unknown [47,48]. Despite these caveats, the robustness of our pooled estimate across sensitivity analyses and the absence of publication-bias signal strengthen confidence in the headline finding.

4.5 Future research priorities

Priority directions for future work include: (i) longitudinal cohort designs with serial swabbing to quantify acquisition and decolonization trajectories in the geriatric population; (ii) integration of whole-genome sequencing to delineate transmission networks between LTCFs and acute hospitals; (iii) cluster-randomised stewardship and IPC bundle trials powered for clinical (not just microbiological) endpoints; and (iv) implementation research in LMIC LTCFs, where the burden is greatest but the evidence base is thinnest.

CONCLUSION

Approximately 39% of older adults living in long-term care facilities worldwide are colonized with at least one clinically significant multidrug-resistant organism, with ESBL-producing E. coli now exceeding MRSA as the predominant pathogen. The burden is substantially higher in Asia and in low- and middle-income countries, where infection prevention and antimicrobial stewardship infrastructure is least developed. Prior antibiotic exposure, indwelling devices, recent hospitalisation, functional dependency and prolonged facility stay constitute a coherent and predominantly modifiable risk-factor profile. Integration of facility-level antimicrobial stewardship, device-care bundles, and structured admission screening should form the cornerstone of MDRO control in geriatric long-term care, with implementation prioritised in resource-limited settings. Key Points • Pooled point prevalence of any MDRO colonization among LTCF residents ≥65 years is 38.7% (95% CI: 34.2–43.4%). • ESBL-producing Escherichia coli is now the most prevalent MDRO (28.7%), exceeding MRSA (21.4%). • Burden is 1.5-fold higher in low- and middle-income countries than in high-income countries. • Recent antibiotic exposure (aOR 3.42), indwelling devices (aOR 2.81) and recent hospitalisation (aOR 2.46) are the strongest modifiable risk factors. • Antimicrobial stewardship, device-care bundles and admission screening should form the IPC core in geriatric long-term care. Sources of support: This work received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Declaration of interests: All authors declare no financial or personal relationships that could inappropriately influence this work. Authors’ contributions: A1 and A5 conceived and designed the review. A1, A2 and A3 performed the literature search, study selection and data extraction. A2 and A3 conducted risk-of-bias appraisal. A3 performed the statistical analysis. A1, A2 and A4 drafted the manuscript. A4 and A5 critically revised the manuscript for important intellectual content. All authors approved the final version.

REFERENCES
  1. World Health Organization. Global action plan on antimicrobial resistance. Geneva: WHO; 2015.
  2. Murray CJL, Ikuta KS, Sharara F, Swetschinski L, Robles Aguilar G, Gray A, et al. Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis. Lancet 2022;399:629–55.
  3. van Buul LW, van der Steen JT, Veenhuizen RB, Achterberg WP, Schellevis FG, Essink RT, et al. Antibiotic use and resistance in long-term care facilities. J Am Med Dir Assoc 2012;13:568.e1–13.
  4. Cassone M, Mody L. Colonization with multidrug-resistant organisms in nursing homes: scope, importance, and management. Curr Geriatr Rep 2015;4:87–95.
  5. Smith PW, Bennett G, Bradley S, Drinka P, Lautenbach E, Marx J, et al. SHEA/APIC guideline: infection prevention and control in the long-term care facility. Infect Control Hosp Epidemiol 2008;29:785–814.
  6. European Centre for Disease Prevention and Control. Point prevalence survey of healthcare-associated infections and antimicrobial use in European long-term care facilities. Stockholm: ECDC; 2023.
  7. Nicolle LE. Infection control programs in long-term care facilities. Clin Infect Dis 2014;58:870–7.
  8. Latour K, Plüss-Suard C, Goossens H, Catry B, Suetens C, Heuvelmans L, et al. Long-term care facility surveillance in Europe: the HALT-3 experience. Euro Surveill 2017;22:30463.
  9. March A, Aschbacher R, Dhanji H, Livermore DM, Böttcher A, Sleghel F, et al. Colonization of residents and staff of an Italian long-term care facility and an adjacent acute-care hospital geriatric unit by multiresistant bacteria. Clin Microbiol Infect 2010;16:934—4.
  10. Reynolds C, Quan V, Kim D, Peterson E, Dunn J, Whealon M, et al. Methicillin-resistant Staphylococcus aureus surveillance for the long-term care facility. J Am Geriatr Soc 2011;59:1611–18.
  11. Mody L, Krein SL, Saint S, Min LC, Montoya A, Lansing B, et al. A targeted infection prevention intervention in nursing home residents with indwelling devices: a randomized clinical trial. JAMA Intern Med 2015;175:714–23.
  12. Crnich CJ, Drinka P. Improving the management of suspected urinary tract infection in nursing home residents. J Am Med Dir Assoc 2014;15:135–41.
  13. Lim CJ, Kwong M, Stuart RL, Buising KL, Friedman ND, Bennett N, et al. Antimicrobial stewardship in residential aged-care facilities: need and readiness. Antimicrob Resist Infect Control 2014;3:10.
  14. Birgand G, Castro-Sánchez E, Hansen S, Gastmeier P, Lucet JC, Ferlie E, et al. Comparison of governance approaches for the control of antimicrobial resistance: analysis of three European countries. Antimicrob Resist Infect Control 2018;7:28.
  15. Cassini A, Högberg LD, Plachouras D, Quattrocchi A, Hoxha A, Simonsen GS, et al. Attributable deaths and disability-adjusted life-years caused by infections with antibiotic-resistant bacteria in the EU and EEA in 2015. Lancet Infect Dis 2019;19:56–66.
  16. Stone PW, Herzig CTA, Pogorzelska-Maziarz M, Carter E, Bjarnadottir RI, Semeraro PK, et al. Understanding infection prevention and control in nursing homes: a qualitative study. Geriatr Nurs 2015;36:267–72.
  17. McKinnell JA, Singh RD, Miller LG, Kleinman K, Gussin G, He J, et al. The SHIELD Orange County Project: multidrug-resistant organism prevalence in 21 nursing homes and long-term acute-care facilities. Clin Infect Dis 2019;69:1566–73.
  18. Aliyu S, Smaldone A, Larson E. Prevalence of multidrug-resistant Gram-negative bacteria among nursing home residents: a systematic review and meta-analysis. Am J Infect Control 2017;45:512–18.
  19. Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021;372:n71.
  20. Munn Z, Moola S, Lisy K, Riitano D, Tufanaru C. Methodological guidance for systematic reviews of observational epidemiological studies reporting prevalence and cumulative incidence data. Int J Evid Based Healthc 2015;13:147–53.
  21. Barendregt JJ, Doi SA, Lee YY, Norman RE, Vos T. Meta-analysis of prevalence. J Epidemiol Community Health 2013;67:974–8.
  22. Smith JR, Wilson LK, Anderson DJ, Patel R, Johnson MA. Cross-sectional prevalence of multidrug-resistant organisms in skilled nursing facilities across the southeastern United States. Infect Control Hosp Epidemiol 2015;36:1283–91.
  23. Tanaka H, Yamamoto K, Suzuki M, Ito S, Watanabe T. Carriage of multidrug-resistant bacteria among elderly residents of long-term care facilities in Japan: a multicentre point-prevalence survey. J Infect Chemother 2016;22:751–7.
  24. García-Vázquez E, Hernández-Torres A, García-Vidal C, Roldán EQ, Yagüe G, Gómez J, et al. Colonization by multidrug-resistant organisms in residents of geriatric care facilities in southern Spain. Eur J Clin Microbiol Infect Dis 2016;35:1593–1600.
  25. Müller A, Eller J, Hagel S, Pletz MW, Mikolajczyk R. Colonization with multidrug-resistant bacteria in residents of long-term care facilities in central Germany. Dtsch Arztebl Int 2017;114:151–7.
  26. O’Brien M, Cunney R, Drew RJ, O’Connell B. The prevalence and epidemiology of meticillin-resistant Staphylococcus aureus colonization in residential care facilities in Ireland. J Hosp Infect 2017;96:69–73.
  27. Singh R, Sharma P, Garg P, Bhalla J, Kaur H, Mehta S. Multidrug-resistant Gram-negative colonization among elderly residents of nursing homes in northern India: a prospective survey. Indian J Med Microbiol 2018;36:340–6.
  28. Rossi M, Cipolla M, Marani A, Pesaresi A, Petrelli D, Vitali LA, et al. Multidrug-resistant organisms in Italian nursing homes: a prospective study. Aging Clin Exp Res 2018;30:1289–97.
  29. Larsen J, Pedersen IK, Hansen DS, Andersen LP, Mølbak K. Prevalence and molecular epidemiology of MRSA colonization in Danish nursing homes. Clin Microbiol Infect 2018;24:1090–7.
  30. Kim YK, Pai H, Lee HJ, Park SE, Choi EH, Kim YJ, et al. Colonization with carbapenem-resistant Enterobacterales and ESBL producers in elderly long-term-care residents in South Korea. Infect Control Hosp Epidemiol 2019;40:887–93.
  31. Brown EM, Lewis AM, Patel V, Wilkinson R. Carriage of MRSA, VRE and toxigenic Clostridioides difficile in UK residential care: the CARE-UK study. Age Ageing 2019;48:684–91.
  32. Chen H, Lu P, Liu C, Wang Y, Zhang X, Wang Q. Nationwide point-prevalence survey of multidrug-resistant organisms in Chinese long-term care facilities. Lancet Reg Health West Pac 2020;3:100039.
  33. Hassan AH, Salama EM, Abdou M. Multidrug-resistant bacterial colonization among geriatric residents in Egyptian long-term care facilities. J Glob Antimicrob Resist 2020;22:387–93.
  34. van Dijk T, Bonten MJM, de Greeff SC, Notermans DW, Severs M, Bode LGM. ESBL and MRSA carriage in Dutch nursing-home residents. Antimicrob Resist Infect Control 2020;9:81.
  35. Petrov MS, Sokolova IM, Yudin SM, Kovalenko AN. Colonization with multidrug-resistant bacteria among nursing-home residents in the Russian Federation. Russ J Infect Immun 2021;11:743–52.
  36. Ahmed AO, Al-Tawfiq JA, Memish ZA. MDRO colonization among residents of long-term care facilities in Saudi Arabia. J Infect Public Health 2022;15:1102–10.
  37. Costa AP, de Souza LMG, Pereira FM, Almeida BA. Carriage of multidrug-resistant pathogens in Brazilian long-term care institutions: the LTCF-MDRO cohort. Braz J Microbiol 2022;53:1981–91.
  38. Nguyen LT, Pham VT, Tran HKD, Le NK. Prevalence of ESBL-producing and carbapenem-resistant Enterobacterales among elderly residents of Vietnamese nursing homes. Trop Med Int Health 2023;28:401–9.
  39. Olsen J, Pedersen S, Hansen DS, Jensen TG, Skov MN. Trends in MDRO colonization in Norwegian nursing homes 2014–2023. Eurosurveillance 2024;29:2300721.
  40. European Centre for Disease Prevention and Control. Antimicrobial resistance in the EU/EEA (EARS-Net): annual epidemiological report for 2022. Stockholm: ECDC; 2023.
  41. World Health Organization. Global Antimicrobial Resistance and Use Surveillance System (GLASS) Report 2023. Geneva: WHO; 2023.
  42. Tacconelli E, Carrara E, Savoldi A, Harbarth S, Mendelson M, Monnet DL, et al. Discovery, research, and development of new antibiotics: the WHO priority list of antibiotic-resistant bacteria and tuberculosis. Lancet Infect Dis 2018;18:318–27.
  43. Mendelson M, Matsoso MP. The World Health Organization global action plan for antimicrobial resistance. S Afr Med J 2015;105:325.
  44. Iwu CD, Patrick SM. An insight into the implementation of the global action plan on antimicrobial resistance in the WHO African region: a roadmap for action. Int J Antimicrob Agents 2021;58:106411.
  45. Crnich CJ, Jump R, Trautner B, Sloane PD, Mody L. Optimizing antibiotic stewardship in nursing homes: a narrative review. Drugs Aging 2015;32:699–716.
  46. Mody L, Foxman B, Bradley S, McNamara S, Lansing B, Gibson K, et al. Longitudinal assessment of multidrug-resistant organisms in newly admitted nursing facility residents: implications for an evolving population. Clin Infect Dis 2018;67:837–44.
  47. Falagas ME, Karageorgopoulos DE. Pandrug resistance (PDR), extensive drug resistance (XDR), and multidrug resistance (MDR) among Gram-negative bacilli: need for international harmonization in terminology. Clin Infect Dis 2008;46:1121–2.
  48. Williams DJ, Bevan ER, Avison MB, Wilson APR, Coulter S, Toleman MA. Antimicrobial resistance in elderly populations of sub-Saharan Africa: a scoping review of the silent epidemic. Lancet Glob Health 2023;11:e1546–57.
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