, World population projected to reach 9.8 billion in 2050, and 11.2 billion in 2100

U. N. Desa-|, United Nations Department of Economic and Social Affairs, 2017.

D. Sur,

P. Chassagne, M. B. Perol, J. Doucet, C. Trivalle, J. F. Ménard et al., Is presentation of bacteremia in the elderly the same as in younger patients?, Am J Med. janv, vol.100, issue.1, pp.65-70, 1996.

T. D. Girard, S. M. Opal, and E. W. Ely, Insights into severe sepsis in older patients: from epidemiology to evidence-based management, Clin Infect Dis Off Publ Infect Dis Soc Am. 1 mars, vol.40, issue.5, pp.719-746, 2005.

C. Hernández, C. Fehér, A. Soriano, F. Marco, M. Almela et al., Clinical characteristics and outcome of elderly patients with community-onset bacteremia, J Infect. févr, vol.70, issue.2, pp.135-178, 2015.

B. M. Greenberg, R. L. Atmar, C. E. Stager, and S. B. Greenberg, Bacteraemia in the elderly: predictors of outcome in an urban teaching hospital, J Infect. 1 mai, vol.50, issue.4, pp.288-95, 2005.

H. Chou, S. Han, C. Yeh, I. Tzeng, T. Hsieh et al., Systemic inflammatory response syndrome is more associated with bacteremia in elderly patients with suspected sepsis in emergency departments, Medicine (Baltimore). déc, vol.95, issue.49, p.5634, 2016.

L. Leibovici, I. Shraga, M. Drucker, H. Konigsberger, Z. Samra et al., The benefit of appropriate empirical antibiotic treatment in patients with bloodstream infection, J Intern Med. nov, vol.244, issue.5, pp.379-86, 1998.

C. Lee, C. Chang, M. Hong, H. Hsu, and W. Ko, Different impact of the appropriateness of empirical antibiotics for bacteremia among younger adults and the elderly in the ED, Am J Emerg Med. févr, vol.31, issue.2, pp.282-90, 2013.

M. H. Kollef, G. Sherman, S. Ward, and V. J. Fraser, Inadequate antimicrobial treatment of infections: a risk factor for hospital mortality among critically ill patients, Chest. févr, vol.115, issue.2, pp.462-74, 1999.

D. F. Gaieski, M. E. Mikkelsen, R. A. Band, J. M. Pines, R. Massone et al., Impact of time to antibiotics on survival in patients with severe sepsis or septic shock in whom early goal-directed therapy was initiated in the emergency department, Crit Care Med. avr, vol.38, issue.4, pp.1045-53, 2010.

L. Leibovici, S. D. Pitlik, H. Konisberger, and M. Drucker, Bloodstream infections in patients older than eighty years, Age Ageing. nov, vol.22, issue.6, pp.431-473, 1993.

P. B. Fontanarosa, F. J. Kaeberlein, L. W. Gerson, and R. B. Thomson, Difficulty in predicting bacteremia in elderly emergency patients, Ann Emerg Med. juill, vol.21, issue.7, pp.842-850, 1992.

J. E. Green, Y. Ariathianto, S. M. Wong, C. Aboltins, and K. Lim, Clinical and inflammatory response to bloodstream infections in octogenarians, BMC Geriatr. 23 avr, vol.14, p.55, 2014.

T. Taniguchi, S. Tsuha, Y. Takayama, and S. Shiiki, Shaking chills and high body temperature predict bacteremia especially among elderly patients, SpringerPlus, vol.2, p.624, 2013.

A. L. Wester, O. Dunlop, K. K. Melby, U. R. Dahle, and T. B. Wyller, Age-related differences in symptoms, diagnosis and prognosis of bacteremia, BMC Infect Dis. 24 juill, vol.13, p.346, 2013.

C. Lee, S. Chen, C. Chen, S. Wu, and S. , Comparison of clinical manifestations and outcome of community-acquired bloodstream infections among the oldest old, elderly, and adult patients, Medicine (Baltimore). mai, vol.86, issue.3, pp.138-182, 2007.

K. B. Laupland, L. W. Svenson, D. B. Gregson, and D. L. Church, Long-term mortality associated with community-onset bloodstream infection. Infection, vol.39, pp.405-415, 2011.

L. Leibovici, Bacteraemia in the very old. Features and treatment, Drugs Aging. juin, vol.6, issue.6, pp.456-64, 1995.

G. Gavazzi, M. Mallaret, P. Couturier, A. Iffenecker, and A. Franco, Bloodstream Infection: Differences Between Young-Old, Old, and Old-Old Patients, J Am Geriatr Soc, vol.50, issue.10, pp.1667-73, 2002.

M. Søgaard, H. C. Schønheyder, A. Riis, H. T. Sørensen, and M. Nørgaard, Short-term mortality in relation to age and comorbidity in older adults with community-acquired bacteremia: a population-based cohort study, J Am Geriatr Soc. sept, vol.56, issue.9, pp.1593-600, 2008.

C. Lai, S. Chen, C. Wang, J. Wang, C. Su et al., Diagnostic Value of Procalcitonin for Bacterial Infection in Elderly Patients in the Emergency Department, J Am Geriatr Soc. 1 mars, vol.58, issue.3, pp.518-540, 2010.

D. A. Whitelaw, B. L. Rayner, and P. A. Willcox, Community-acquired bacteremia in the elderly: a prospective study of 121 cases, J Am Geriatr Soc. oct, vol.40, issue.10, pp.996-1000, 1992.

J. Garnacho-montero, M. J. Huici-moreno, A. Gutiérrez-pizarraya, I. López, J. A. Márquez-vácaro et al., Prognostic and diagnostic value of eosinopenia, C-reactive protein, procalcitonin, and circulating cell-free DNA in critically ill patients admitted with suspicion of sepsis, Crit Care Lond Engl. 5 juin, vol.18, issue.3, p.116, 2014.

B. A. Wibrow, K. M. Ho, J. P. Flexman, A. D. Keil, and D. L. Kohrs, Eosinopenia as a diagnostic marker of bloodstream infection in hospitalised paediatric and adult patients: a case-control study, Anaesth Intensive Care. mars, vol.39, issue.2, pp.224-254, 2011.

K. M. Ho and S. C. Towler, A comparison of eosinopenia and C-reactive protein as a marker of bloodstream infections in critically ill patients: a case control study, Anaesth Intensive Care. mai, vol.37, issue.3, pp.450-456, 2009.

D. Anand, S. Ray, S. Bhargava, L. M. Srivastava, A. Garg et al., Exploration of eosinopenia as a diagnostic parameter to differentiate sepsis from systemic inflammatory response syndrome: Results from an observational study, Indian J Crit Care Med Peer-Rev Off Publ Indian Soc Crit Care Med. mai, vol.20, issue.5, pp.285-90, 2016.

A. Darowski, Z. Najim, J. Weinberg, and A. Guz, The febrile response to mild infections in elderly hospital inpatients, Age Ageing. mai, vol.20, issue.3, pp.193-201, 1991.

N. H. Ismail, P. K. Lieu, C. T. Lien, and M. L. Ling, Bacteraemia in the elderly, Ann Acad Med Singapore. sept, vol.26, issue.5, pp.593-601, 1997.

S. Tal, V. Guller, S. Levi, R. Bardenstein, D. Berger et al., Profile and prognosis of febrile elderly patients with bacteremic urinary tract infection, J Infect. 1 mai, vol.50, issue.4, pp.296-305, 2005.

A. Burlaud, D. Mathieu, B. Falissard, and C. Trivalle, Mortality and bloodstream infections in geriatrics units, Arch Gerontol Geriatr. déc, vol.51, issue.3, pp.106-109, 2010.

, Bibliographie 1. World population projected to reach 9, p.2100

U. N. Desa-|, United Nations Department of Economic and Social Affairs, 2017.

P. Chassagne, M. B. Perol, J. Doucet, C. Trivalle, J. F. Ménard et al., Is presentation of bacteremia in the elderly the same as in younger patients?, Am J Med. janv, vol.100, issue.1, pp.65-70, 1996.

T. D. Girard, S. M. Opal, and E. W. Ely, Insights into severe sepsis in older patients: from epidemiology to evidence-based management, Clin Infect Dis Off Publ Infect Dis Soc Am. 1 mars, vol.40, issue.5, pp.719-746, 2005.

C. Hernández, C. Fehér, A. Soriano, F. Marco, M. Almela et al., Clinical characteristics and outcome of elderly patients with community-onset bacteremia, J Infect. févr, vol.70, issue.2, pp.135-178, 2015.

B. M. Greenberg, R. L. Atmar, C. E. Stager, and S. B. Greenberg, Bacteraemia in the elderly: predictors of outcome in an urban teaching hospital, J Infect. 1 mai, vol.50, issue.4, pp.288-95, 2005.

H. Chou, S. Han, C. Yeh, I. Tzeng, T. Hsieh et al., Systemic inflammatory response syndrome is more associated with bacteremia in elderly patients with suspected sepsis in emergency departments, Medicine (Baltimore). déc, vol.95, issue.49, p.5634, 2016.

L. Leibovici, I. Shraga, M. Drucker, H. Konigsberger, Z. Samra et al., The benefit of appropriate empirical antibiotic treatment in patients with bloodstream infection, J Intern Med. nov, vol.244, issue.5, pp.379-86, 1998.

C. Lee, C. Chang, M. Hong, H. Hsu, and W. Ko, Different impact of the appropriateness of empirical antibiotics for bacteremia among younger adults and the elderly in the ED, Am J Emerg Med. févr, vol.31, issue.2, pp.282-90, 2013.

L. Leibovici, S. D. Pitlik, H. Konisberger, and M. Drucker, Bloodstream infections in patients older than eighty years, Age Ageing. nov, vol.22, issue.6, pp.431-473, 1993.

J. M. Ruiz-giardín, R. M. Martin-díaz, J. Jaqueti-aroca, I. Garcia-arata, S. Martín-lópez et al., Diagnosis of bacteraemia and growth times, Int J Infect Dis IJID Off Publ Int Soc Infect Dis. déc, vol.41, pp.6-10, 2015.

, Population totale par sexe et âge au 1er janvier 2018, France ? Bilan démographique 2017 | Insee

, Projections de population à l'horizon 2060 -Insee Première -1320, p.22, 2018.

M. Feldman, The mature stomach. Still pumping out acid?, JAMA. 27 août, vol.278, issue.8, pp.681-683, 1997.

W. Weitschies, C. Friedrich, R. S. Wedemeyer, M. Schmidtmann, O. Kosch et al., Bioavailability of amoxicillin and clavulanic acid from extended release tablets depends on intragastric tablet deposition and gastric emptying, Eur J Pharm Biopharm Off J Arbeitsgemeinschaft Pharm Verfahrenstechnik EV, vol.70, issue.2, pp.641-649, 2008.

G. Gavazzi and K. Krause, Ageing and infection, Lancet Infect Dis, vol.2, issue.11, pp.659-66, 2002.

T. Mizuno, F. Mizokami, K. Fukami, K. Ito, M. Shibasaki et al., The influence of severe hypoalbuminemia on the half-life of vancomycin in elderly patients with methicillin-resistant Staphylococcus aureus hospital-acquired pneumonia, Clin Interv Aging, vol.8, pp.1323-1331, 2013.

D. L. Schmucker, Liver function and phase I drug metabolism in the elderly: a paradox, Drugs Aging, vol.18, issue.11, pp.837-51, 2001.

L. Couteur, D. G. Mclean, and A. J. , The aging liver. Drug clearance and an oxygen diffusion barrier hypothesis, Clin Pharmacokinet. mai, vol.34, issue.5, pp.359-73, 1998.

A. Corsonello, A. M. Abbatecola, S. Fusco, F. Luciani, A. Marino et al., The impact of drug interactions and polypharmacy on antimicrobial therapy in the elderly, Clin Microbiol Infect. 1 janv, vol.21, issue.1, pp.20-26, 2015.

T. T. Yoshikawa, Antimicrobial resistance and aging: beginning of the end of the antibiotic era?, J Am Geriatr Soc. juill, vol.50, issue.7, pp.226-229, 2002.

W. M. Valenti, R. G. Trudell, and D. W. Bentley, Factors predisposing to oropharyngeal colonization with gram-negative bacilli in the aged, N Engl J Med. 18 mai, vol.298, issue.20, pp.1108-1119, 1978.

J. M. Pereira and J. A. Paiva, Antimicrobial drug interactions in the critically ill patients, Curr Clin Pharmacol. 1 févr, vol.8, issue.1, pp.25-38, 2013.

F. Borrego and R. Gleckman, Principles of antibiotic prescribing in the elderly, Drugs Aging. juill, vol.11, issue.1, pp.7-18, 1997.

S. Claesson, A. Morrison, A. I. Wertheimer, and M. L. Berger, Compliance with prescribed drugs: challenges for the elderly population, Pharm World Sci PWS. déc, vol.21, issue.6, pp.256-265, 1999.

G. Pawelec, T-cell immunity in the aging human, Haematologica. mai, vol.99, issue.5, pp.795-802, 2014.

T. Fulop, A. Larbi, J. M. Witkowski, J. Mcelhaney, M. Loeb et al., Aging, frailty and age-related diseases, Biogerontology, vol.11, issue.5, pp.547-63, 2010.

S. K. Butcher, H. Chahal, L. Nayak, A. Sinclair, N. V. Henriquez et al., Senescence in innate immune responses: reduced neutrophil phagocytic capacity and CD16 expression in elderly humans, J Leukoc Biol. déc, vol.70, issue.6, pp.881-887, 2001.

R. Solana, R. Tarazona, I. Gayoso, O. Lesur, G. Dupuis et al., Innate immunosenescence: effect of aging on cells and receptors of the innate immune system in humans, Semin Immunol. oct, vol.24, issue.5, pp.331-372, 2012.

S. C. Castle, Clinical relevance of age-related immune dysfunction, Clin Infect Dis Off Publ Infect Dis Soc Am. août, vol.31, issue.2, pp.578-85, 2000.

P. J. Linton and K. Dorshkind, Age-related changes in lymphocyte development and function, Nat Immunol. févr, vol.5, issue.2, pp.133-142, 2004.

J. J. Goronzy and C. M. Weyand, Understanding immunosenescence to improve responses to vaccines, Nat Immunol. mai, vol.14, issue.5, pp.428-464, 2013.

E. Crétel, I. Veen, A. Pierres, P. Bongrand, and G. Gavazzi,

, Med Mal Infect. juin, vol.40, issue.6, pp.307-325, 2010.

P. Retamar, M. D. López-prieto, F. Rodríguez-lópez, M. De-cueto, M. V. García et al., Predictors of early mortality in very elderly patients with bacteremia: a prospective multicenter cohort, Int J Infect Dis. 1 sept, vol.26, pp.83-90, 2014.

H. J. Keating, J. J. Klimek, D. S. Levine, and F. J. Kiernan, Effect of aging on the clinical significance of fever in ambulatory adult patients, J Am Geriatr Soc. avr, vol.32, issue.4, pp.282-289, 1984.

M. Wasserman, M. Levinstein, E. Keller, S. Lee, and T. T. Yoshikawa, Utility of fever, white blood cells, and differential count in predicting bacterial infections in the elderly, J Am Geriatr Soc. juin, vol.37, issue.6, pp.537-580, 1989.

K. Rockwood, Acute confusion in elderly medical patients, J Am Geriatr Soc. févr, vol.37, issue.2, pp.150-154, 1989.

T. T. Yoshikawa, Epidemiology and unique aspects of aging and infectious diseases, Clin Infect Dis Off Publ Infect Dis Soc Am. juin, vol.30, issue.6, pp.931-934, 2000.

L. E. Nicolle, Urinary tract infection in geriatric and institutionalized patients, Curr Opin Urol. janv, vol.12, issue.1, pp.51-56, 2002.

T. J. Marrie, Community-acquired pneumonia in the elderly, Clin Infect Dis Off Publ Infect Dis Soc Am, vol.31, issue.4, pp.1066-78, 2000.

M. Søgaard, H. C. Schønheyder, A. Riis, H. T. Sørensen, and M. Nørgaard, Short-term mortality in relation to age and comorbidity in older adults with community-acquired bacteremia: a population-based cohort study, J Am Geriatr Soc. sept, vol.56, issue.9, pp.1593-600, 2008.

G. Gavazzi, M. Mallaret, P. Couturier, A. Iffenecker, and A. Franco, Bloodstream Infection: Differences Between Young-Old, Old, and Old-Old Patients, J Am Geriatr Soc, vol.50, issue.10, pp.1667-73, 2002.

T. D. Girard and E. W. Ely, Bacteremia and sepsis in older adults, Clin Geriatr Med. août, vol.23, issue.3, pp.633-680, 2007.

, Ageing and health

, World Health Organization, p.22, 2018.

D. Sur,

M. Goto and M. N. Al-hasan, Overall burden of bloodstream infection and nosocomial bloodstream infection in North America and Europe, Clin Microbiol Infect. 1 juin, vol.19, issue.6, pp.501-510, 2013.

A. Vlek, M. Bonten, and C. Boel, Direct Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry Improves Appropriateness of Antibiotic Treatment of Bacteremia, PLoS ONE, vol.7, issue.3

T. C. Horan, M. Andrus, and M. A. Dudeck, CDC/NHSN surveillance definition of health care-associated infection and criteria for specific types of infections in the acute care setting, Am J Infect Control. 1 juin, vol.36, issue.5, pp.309-341, 2008.

U. Eigner, M. Holfelder, K. Oberdorfer, U. Betz-wild, D. Bertsch et al., Performance of a matrix-assisted laser desorption ionization-time-of-flight mass spectrometry system for the identification of bacterial isolates in the clinical routine laboratory, Clin Lab, vol.55, issue.7-8, pp.289-96, 2009.

E. Bessède, M. Angla-gre, Y. Delagarde, S. Hieng, S. Ménard et al., Matrix-assisted laserdesorption/ionization biotyper: experience in the routine of a University hospital, Clin Microbiol Infect Off Publ Eur Soc Clin Microbiol Infect Dis. avr, vol.17, issue.4, pp.533-541, 2011.

L. Scola, B. Raoult, and D. , Direct identification of bacteria in positive blood culture bottles by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry, PloS One, vol.4, issue.11, p.8041, 2009.

V. Schmidt, A. Jarosch, P. März, C. Sander, V. Vacata et al., Rapid identification of bacteria in positive blood culture by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, Eur J Clin Microbiol Infect Dis Off Publ Eur Soc Clin Microbiol. mars, vol.31, issue.3, pp.311-318, 2012.

. Maldi-tof, MS for the Diagnosis of Infectious Diseases | Clinical Chemistry, 2018.

D. Sur,

D. M. Wolk, M. J. Struelens, P. Pancholi, T. Davis, P. Della-latta et al., Rapid detection of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in wound specimens and blood cultures: multicenter preclinical evaluation of the Cepheid Xpert MRSA/SA skin and soft tissue and blood culture assays, J Clin Microbiol. mars, vol.47, issue.3, pp.823-829, 2009.

S. Gröbner, M. Dion, M. Plante, and V. Kempf, Evaluation of the BD GeneOhm StaphSR assay for detection of methicillin-resistant and methicillin-susceptible Staphylococcus aureus isolates from spiked positive blood culture bottles, J Clin Microbiol. juin, vol.47, issue.6, pp.1689-94, 2009.

W. C. Lindsey, E. S. Woodruff, D. Weed, D. C. Ward, and R. D. Jenison, Development of a rapid diagnostic assay for methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative Staphylococcus, Diagn Microbiol Infect Dis. juill, vol.61, issue.3, pp.273-282, 2008.

O. Clerc, G. Prod'hom, L. Senn, K. Jaton, G. Zanetti et al., Matrix-assisted laser desorption ionization time-of-flight mass spectrometry and PCR-based rapid diagnosis of Staphylococcus aureus bacteraemia, Clin Microbiol Infect. 1 avr, vol.20, issue.4, pp.355-60, 2014.

A. L. Wester, O. Dunlop, K. K. Melby, U. R. Dahle, and T. B. Wyller, Age-related differences in symptoms, diagnosis and prognosis of bacteremia, BMC Infect Dis. 24 juill, vol.13, p.346, 2013.

A. Darowski, Z. Najim, J. Weinberg, and A. Guz, The febrile response to mild infections in elderly hospital inpatients, Age Ageing. mai, vol.20, issue.3, pp.193-201, 1991.

C. Lee, S. Chen, C. Chen, S. Wu, and S. , Comparison of clinical manifestations and outcome of community-acquired bloodstream infections among the oldest old, elderly, and adult patients, Medicine (Baltimore). mai, vol.86, issue.3, pp.138-182, 2007.

J. E. Green, Y. Ariathianto, S. M. Wong, C. Aboltins, and K. Lim, Clinical and inflammatory response to bloodstream infections in octogenarians, BMC Geriatr. 23 avr, vol.14, p.55, 2014.

T. Taniguchi, S. Tsuha, Y. Takayama, and S. Shiiki, Shaking chills and high body temperature predict bacteremia especially among elderly patients, vol.2, 2013.

C. Lee, S. Chen, C. Chen, S. Wu, and S. , Comparison of clinical manifestations and outcome of community-acquired bloodstream infections among the oldest old, elderly, and adult patients, Medicine (Baltimore). mai, vol.86, issue.3, pp.138-182, 2007.

C. Lai, S. Chen, C. Wang, J. Wang, C. Su et al., Diagnostic Value of Procalcitonin for Bacterial Infection in Elderly Patients in the Emergency Department, J Am Geriatr Soc. 1 mars, vol.58, issue.3, pp.518-540, 2010.

R. Riquelme, A. Torres, M. El-ebiary, J. P. De-la-bellacasa, R. Estruch et al., Community-acquired pneumonia in the elderly: A multivariate analysis of risk and prognostic factors, Am J Respir Crit Care Med. nov, vol.154, issue.5, pp.1450-1455, 1996.

P. B. Fontanarosa, F. J. Kaeberlein, L. W. Gerson, and R. B. Thomson, Difficulty in predicting bacteremia in elderly emergency patients, Ann Emerg Med. juill, vol.21, issue.7, pp.842-850, 1992.

A. Artero, A. Esparcia, J. M. Eiros, M. Madrazo, J. Alberola et al., Effect of Bacteremia in Elderly Patients With Urinary Tract Infection, Am J Med Sci. 1 sept, vol.352, issue.3, pp.267-71, 2016.

C. Hyernard, L'atypie sémiologique, facteur de risque de mortalité des bactériémies chez le sujet âgé, 2017.

A. C. Windsor, Bacteraemia in a geriatric unit, Gerontology, vol.29, issue.2, pp.125-155, 1983.

C. L. Beckett, S. Harbarth, and B. Huttner, Special considerations of antibiotic prescription in the geriatric population, Clin Microbiol Infect Off Publ Eur Soc Clin Microbiol Infect Dis. janv, vol.21, issue.1, pp.3-9, 2015.

P. Pfitzenmeyer, H. Decrey, R. Auckenthaler, and J. P. Michel, Predicting bacteremia in older patients, J Am Geriatr Soc. mars, vol.43, issue.3, pp.230-235, 1995.

D. H. Wyllie, I. Bowler, and T. Peto, Relation between lymphopenia and bacteraemia in UK adults with medical emergencies, J Clin Pathol. 1 sept, vol.57, issue.9, pp.950-955, 2004.

L. Marti, C. Cervera, X. Filella, J. L. Marin, M. Almela et al., Cytokine-release patterns in elderly patients with systemic inflammatory response syndrome, Gerontology, vol.53, issue.5, pp.239-283, 2007.

T. Taniguchi, S. Tsuha, Y. Takayama, and S. Shiiki, Shaking chills and high body temperature predict bacteremia especially among elderly patients, SpringerPlus, vol.2, p.624, 2013.

B. Coburn, A. M. Morris, G. Tomlinson, and A. S. Detsky, Does this adult patient with suspected bacteremia require blood cultures?, JAMA. 1 août, vol.308, issue.5, pp.502-513, 2012.

M. Rebelo, B. Pereira, J. Lima, J. Decq-mota, J. D. Vieira et al., Predictors of in-hospital mortality in elderly patients with bacteraemia admitted to an Internal Medicine ward, Int Arch Med, vol.4, issue.1, p.33, 2011.

S. J. Crane, D. Z. Uslan, and L. M. Baddour, Bloodstream Infections in a Geriatric Cohort: A Population-Based Study, Am J Med. 1 déc, vol.120, issue.12, pp.1078-83, 2007.

M. Sonnenblick, C. M. Rudenski, B. Friedlander, Y. Van-dijk, and J. M. , Septicemia in the elderly: incidence, etiology and prognostic factors, Isr J Med Sci. avr, vol.26, issue.4, pp.195-204, 1990.

N. H. Ismail, P. K. Lieu, C. T. Lien, and M. L. Ling, Bacteraemia in the elderly, Ann Acad Med Singapore. sept, vol.26, issue.5, pp.593-601, 1997.

C. R. Baudron, X. Panhard, O. Clermont, F. Mentré, B. Fantin et al., Escherichia coli bacteraemia in adults: age-related differences in clinical and bacteriological characteristics, and outcome, Epidemiol Infect. déc, vol.142, issue.12, pp.2672-83, 2014.

L. Leibovici, Bacteraemia in the very old. Features and treatment, Drugs Aging. juin, vol.6, issue.6, pp.456-64, 1995.

B. R. Meyers, E. Sherman, M. H. Mendelson, G. Velasques, E. Srulevitch-chin et al., Bloodstream infections in the elderly, Am J Med. 1 avr, vol.86, issue.4, pp.379-84, 1989.

S. Tal, V. Guller, S. Levi, R. Bardenstein, D. Berger et al., Profile and prognosis of febrile elderly patients with bacteremic urinary tract infection, J Infect. 1 mai, vol.50, issue.4, pp.296-305, 2005.

R. J. Ackermann and P. W. Monroe, Bacteremic urinary tract infection in older people, J Am Geriatr Soc. août, vol.44, issue.8, pp.927-960, 1996.

A. L. Esposito, R. A. Gleckman, S. Cram, M. Crowley, F. Mccabe et al., Community-acquired bacteremia in the elderly: analysis of one hundred consecutive episodes, J Am Geriatr Soc. juill, vol.28, issue.7, pp.315-324, 1980.

D. A. Whitelaw, B. L. Rayner, and P. A. Willcox, Community-acquired bacteremia in the elderly: a prospective study of 121 cases, J Am Geriatr Soc. oct, vol.40, issue.10, pp.996-1000, 1992.

C. Big and P. N. Malani, Staphylococcus aureus Bloodstream Infections in Older Adults: Clinical Outcomes and Risk Factors for In-Hospital Mortality, J Am Geriatr Soc. 1 févr, vol.58, issue.2, pp.300-305, 2010.

L. A. Ruiz, R. Zalacain, A. Capelastegui, A. Bilbao, A. Gomez et al., Bacteremic pneumococcal pneumonia in elderly and very elderly patients: host-and pathogen-related factors, process of care, and outcome, J Gerontol A Biol Sci Med Sci. août, vol.69, issue.8, pp.1018-1042, 2014.

C. Brun-buisson, F. Doyon, and J. Carlet, Bacteremia and severe sepsis in adults: a multicenter prospective survey in ICUs and wards of 24 hospitals. French Bacteremia-Sepsis Study Group, Am J Respir Crit Care Med. sept, vol.154, issue.3, pp.617-641, 1996.

A. Payeras, M. García-gasalla, M. Garau, J. I. Roca, M. Pareja et al.,

, Enferm Infecc Microbiol Clin. déc, vol.25, issue.10, pp.612-620, 2007.

A. Lefort, X. Panhard, O. Clermont, P. Woerther, C. Branger et al., Host Factors and Portal of Entry Outweigh Bacterial Determinants To Predict the Severity of Escherichia coli Bacteremia, J Clin Microbiol. 1 mars, vol.49, issue.3, pp.777-83, 2011.

G. Gavazzi, P. Escobar, F. Olive, P. Couturier, and A. Franco, Nosocomial bacteremia in very old patients: predictors of mortality, Aging Clin Exp Res. août, vol.17, issue.4, pp.337-379, 2005.

J. M. Caterino, S. G. Weed, J. A. Espinola, and C. A. Camargo, National trends in emergency department antibiotic prescribing for elders with urinary tract infection, Acad Emerg Med Off J Soc Acad Emerg Med. juin, vol.16, issue.6, pp.500-507, 1996.

A. Burlaud, D. Mathieu, B. Falissard, and C. Trivalle, Mortality and bloodstream infections in geriatrics units, Arch Gerontol Geriatr. déc, vol.51, issue.3, pp.106-109, 2010.

K. B. Laupland, L. W. Svenson, D. B. Gregson, and D. L. Church, Long-term mortality associated with community-onset bloodstream infection. Infection, vol.39, pp.405-415, 2011.

P. J. Lillie, J. Allen, C. Hall, C. Walsh, K. Adams et al., Long-term mortality following bloodstream infection, Clin Microbiol Infect, vol.19, issue.10, pp.955-60, 2013.

S. L. Nielsen, A. T. Lassen, K. O. Gradel, T. G. Jensen, H. J. Kolmos et al., Bacteremia is associated with excess long-term mortality: A 12-year population-based cohort study, J Infect. 1 févr, vol.70, issue.2, pp.111-137, 2015.

D. W. Bates, K. E. Pruess, and T. H. Lee, How bad are bacteremia and sepsis? Outcomes in a cohort with suspected bacteremia, Arch Intern Med. 27 mars, vol.155, issue.6, pp.593-601, 1995.

K. B. Laupland, D. B. Gregson, D. L. Church, T. Ross, and J. Pitout, Incidence, risk factors and outcomes of Escherichia coli bloodstream infections in a large Canadian region, Clin Microbiol Infect Off Publ Eur Soc Clin Microbiol Infect Dis, vol.14, issue.11, pp.1041-1048, 2008.

D. Anand, S. Das, S. Bhargava, L. M. Srivastava, A. Garg et al., Procalcitonin as a rapid diagnostic biomarker to differentiate between culture-negative bacterial sepsis and systemic inflammatory response syndrome: a prospective, observational, cohort study, J Crit Care. févr, vol.30, issue.1, pp.218-225, 2015.

J. Garnacho-montero, M. J. Huici-moreno, A. Gutiérrez-pizarraya, I. López, J. A. Márquez-vácaro et al., Prognostic and diagnostic value of eosinopenia, C-reactive protein, procalcitonin, and circulating cell-free DNA in critically ill patients admitted with suspicion of sepsis, Crit Care Lond Engl. 5 juin, vol.18, issue.3, p.116, 2014.

B. A. Wibrow, K. M. Ho, J. P. Flexman, A. D. Keil, and D. L. Kohrs, Eosinopenia as a diagnostic marker of bloodstream infection in hospitalised paediatric and adult patients: a case-control study, Anaesth Intensive Care. mars, vol.39, issue.2, pp.224-254, 2011.

K. M. Ho and S. C. Towler, A comparison of eosinopenia and C-reactive protein as a marker of bloodstream infections in critically ill patients: a case control study, Anaesth Intensive Care. mai, vol.37, issue.3, pp.450-456, 2009.

M. J. Setterberg, W. Newman, A. Potti, and R. A. Smego, Utility of Eosinophil Count as Predictor of Bacteremia, Clin Infect Dis. 1 févr, vol.38, issue.3, pp.460-461, 2004.

K. Abidi, J. Belayachi, Y. Derras, M. E. Khayari, T. Dendane et al., Eosinopenia, an early marker of increased mortality in critically ill medical patients, Intensive Care Med. juill, vol.37, issue.7, pp.1136-1178, 2011.

C. A. Merino, F. T. Martínez, F. Cardemil, and J. R. Rodríguez, Absolute eosinophils count as a marker of mortality in patients with severe sepsis and septic shock in an intensive care unit, J Crit Care. août, vol.27, issue.4, pp.394-403, 2012.

R. Terradas, S. Grau, J. Blanch, M. Riu, P. Saballs et al., Eosinophil count and neutrophil-lymphocyte count ratio as prognostic markers in patients with bacteremia: a retrospective cohort study, PloS One, vol.7, issue.8, p.42860, 2012.

H. L. Kotecha, A. Arora, R. Chawlani, J. Toshniwal, N. Bansal et al., Low eosinophil count predicts in-hospital mortality in cirrhosis with systemic inflammatory response syndrome, Eur J Gastroenterol Hepatol. juin, vol.25, issue.6, pp.676-82, 2013.

M. Holland, M. Alkhalil, S. Chandromouli, A. Janjua, and M. Babores, Eosinopenia as a marker of mortality and length of stay in patients admitted with exacerbations of chronic obstructive pulmonary disease. Respirol Carlton Vic, janv, vol.15, issue.1, pp.165-172, 2010.

Y. S. Hori, S. Kodera, Y. Sato, and T. Shiojiri, Eosinopenia as a Predictive Factor of the Short-Term Risk of Mortality and Infection after Acute Cerebral Infarction, J Stroke Cerebrovasc Dis Off J Natl Stroke Assoc. juin, vol.25, issue.6, pp.1307-1319, 2016.

G. Gürol, ?. H. Çiftci, H. A. Terizi, A. R. Atasoy, A. Ozbek et al., Are there standardized cutoff values for neutrophil-lymphocyte ratios in bacteremia or sepsis?, J Microbiol Biotechnol. avr, vol.25, issue.4, pp.521-526, 2015.

C. De-jager, P. Van-wijk, R. B. Mathoera, J. De-jongh-leuvenink, T. Van-der-poll et al., Lymphocytopenia and neutrophil-lymphocyte count ratio predict bacteremia better than conventional infection markers in an emergency care unit, Crit Care Lond Engl, vol.14, issue.5, p.192, 2010.

R. Lowsby, C. Gomes, I. Jarman, P. Lisboa, P. A. Nee et al., Neutrophil to lymphocyte count ratio as an early indicator of blood stream infection in the emergency department, Emerg Med J EMJ. juill, vol.32, issue.7, pp.531-535, 2015.

A. Loonen, C. De-jager, J. Tosserams, R. Kusters, M. Hilbink et al., Biomarkers and Molecular Analysis to Improve Bloodstream Infection Diagnostics in an Emergency Care Unit, PLoS ONE, vol.27, issue.2014, p.17, 2018.

L. Herzig, T. Bischoff, B. Favrat, P. Vaucher, B. Gencer et al.,

, Rev Med Suisse. 18 mai, vol.7, issue.295, pp.1082-1085, 2011.

, Serment d'Hippocrate « Au moment d'être admis à exercer la médecine, je promets et je jure d'être fidèle aux lois de l'honneur et de la probité

, Mon premier souci sera de rétablir, de préserver ou de promouvoir la santé dans tous ses éléments, physiques et mentaux

, Je respecterai toutes les personnes, leur autonomie et leur volonté, sans aucune discrimination selon leur état ou leurs convictions. J'interviendrai pour les protéger si elles sont affaiblies, vulnérables ou menacées dans leur intégrité ou leur dignité. Même sous la contrainte

, J'informerai les patients des décisions envisagées, de leurs raisons et de leurs

, Reçu a? l'intérieur des maisons, je respecterai les secrets des foyers et ma conduite ne servira pas à corrompre les moeurs

, Je ferai tout pour soulager les souffrances. Je ne prolongerai pas abusivement les agonies. Je ne provoquerai jamais la mort délibérément

, Je n'entreprendrai rien qui dépasse mes compétences. Je les entretiendrai et les perfectionnerai pour assurer au mieux les services qui me seront demandés

, J'apporterai mon aide à mes confrères ainsi qu'à leurs familles dans l'adversité

, Que les hommes et mes confrères m'accordent leur estime si je suis fidèle à mes promesses ; que je sois déshonoré et méprisé si j'y manque