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The burden of comorbidity is associated with symptomatic polymicrobial urinary tract infection among institutionalized elderly



Urinary tract infections (UTIs), often sustained by polymicrobial flora (p-UTIs), are a common finding among nursing home patients, and associated with adverse outcomes and increased healthcare costs. P-UTIs have been extensively studied with regard to microbiological aspects. However, little is known about the characteristics of the host.


The aim of this study is to verify to which extent comorbidity characterizes elderly nursing home patients with p-UTIs.


We enrolled 299 patients with culture-positive UTI consecutively admitted to the nursing home of the “Fondazione San Raffaele Cittadella della Carità”, Taranto, Italy. P-UTI was diagnosed when two uropathogens were simultaneously isolated. The burden of comorbidity was quantified using the Charlson comorbidity score index. Logistic regression analysis was used to assess the adjusted association of the variables of interest with the presence of p-UTI.


P-UTIs were detected in 118/299 (39 %) patients. According to logistic regression, the presence of p-UTIs was independently associated with the Charlson index (OR 1.70; 95 % CI 1.06–2.72; P = .026). This association remained also after excluding participants without urinary catheter (OR 1.88; 95 % CI 1.13–3.11; P = .015).


The presence of P-UTIs is associated with the burden of comorbidity, but not with individual diseases.


Older nursing home patients with comorbidity should be screened for the presence of p-UTIs; further studies are needed to evaluate the impact of early detection and treatment of p-UTIs on the development of comorbidity.

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Conflict of interest

On behalf of all authors, the corresponding author states that there is no conflict of interest.

Ethical standard

All procedures performed in the present study were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments.

Informed consent

All participants signed an informed consent form prior to be included in the study.

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Corresponding author

Correspondence to Alice Laudisio.

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Laudisio, A., Marinosci, F., Fontana, D. et al. The burden of comorbidity is associated with symptomatic polymicrobial urinary tract infection among institutionalized elderly. Aging Clin Exp Res 27, 805–812 (2015).

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  • Elderly
  • Nursing home
  • Comorbidity
  • Urinary infection
  • Epidemiology