Same R 0 , Different Risk: Colonization-Age Timing and Heterogeneity Drive ICU MRSA Establishment and Burden.

@article{faniran2026same,
  title = {{Same R 0 , Different Risk: Colonization-Age Timing and Heterogeneity Drive ICU MRSA Establishment and Burden.}},
  author = {Taye Samuel Faniran},
  journal = {Bulletin of mathematical biology},
  year = {2026},
  month = oct,
  doi = {10.1007/s11538-026-01770-9},
  url = {https://europepmc.org/article/MED/42955490},
  note = {CC BY},
}

TY  - JOUR
TI  - Same R 0 , Different Risk: Colonization-Age Timing and Heterogeneity Drive ICU MRSA Establishment and Burden.
AU  - Taye Samuel Faniran
PY  - 2026
DA  - 2026/10/28
JO  - Bulletin of mathematical biology
DO  - 10.1007/s11538-026-01770-9
UR  - https://europepmc.org/article/MED/42955490
AB  - Intensive care unit (ICU) control of methicillin-resistant Staphylococcus aureus (MRSA) occurs over short horizons, whereas \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}R_0\end{document}R0 summarizes average transmission at the importation-free disease-free state without encoding timing. We couple within-host bacterial and immune dynamics to an ICU model structured by colonization age, generating transmission and progression kernels that vary with colonization age. A two-stage framework uses a branching process to quantify finite-threshold crossing and a deterministic ward model to quantify conditional burden after the threshold is reached. Calibration fixes η =0.10η=0.10 and distributes colonized admissions across pre-admission colonization ages. Of 1, 000, 000 parameter sets, 45, 250 satisfy cumulative \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}R^2≥ 0.90\end{document}R2≥0.90. The representative calculation is subcritical, with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}R_0=0.907957\end{document}R0=0.907957; across accepted sets, the median and 95% behavioral range are 0.917464 and [0.814593, 1.032975][0.814593,1.032975], with 92.460%92.460% below one. At \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}Z_crit=5\end{document}Zcrit=5, exact threshold-reaching probabilities are 0.114659 for age-dependent transmission and 0.117074 for matched constant transmission. Their accepted-set difference range crosses zero, so this contrast has no robust direction. By contrast, age-dependent transmission reaches 50% of reproductive potential earlier in 98.378%98.378% of accepted sets. In 200-day conditional simulations, delaying \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}τ _crit\end{document}τcrit from 5 to 15 days increases the age-dependent peak total MRSA burden from 5.629 to 7.298 patients and cumulative total burden from 683.8 to 1398.0 patient-days. At the 9-day baseline and equal \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}R_0\end{document}R0, age dependence gives a 7.372%7.372% higher peak but a 9.304%9.304% lower cumulative burden than constant transmission. Increasing \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}κ _max \end{document}κmax from 0.6 to 1.4 times baseline reduces \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}R_0\end{document}R0 by 4.133%4.133%. Thus, matching \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}R_0\end{document}R0 does not preserve timing-sensitive outcomes, but their magnitude and direction depend on the endpoint; over the examined ranges, clearance timing has greater leverage than immune-strength intensification.
SN  - 0092-8240
SN  - 1522-9602
ER  -