Major article| Volume 41, ISSUE 12, P1205-1208, December 2013

Download started.


Seasonal variation in health care-associated bloodstream infection: Increase in the incidence of gram-negative bacteremia in nonhospitalized patients during summer

Published:August 23, 2013DOI:


      Recent research has suggested that episodes of gram-negative (GN) bloodstream infection (BSI) are more common in the population during summer months. Our objective was to determine if the same phenomenon could be observed in patients with health care-associated (HCA) BSI, and if so, whether a summer peak was less apparent in patients accommodated in a climate-controlled hospital environment.


      Data from episodes of HCA BSI spanning an 11-year period were analyzed. To test for seasonal variation in HCA BSI among hospitalized and nonhospitalized patients, and between GN and gram-positive organisms, the χ2 goodness-of-fit test was used.


      There were 440 episodes of HCA GN BSI of which 259 (59%) occurred in inpatients and 181 (41%) occurred in noninpatients. A significant increase in the frequency of HCA GN BSI was observed in nonhospitalized patients during the summer months (P = .03) but not in climate-controlled hospitalized patients. The most common source of infection in these patents was an intravascular device (38%).


      We found an increased incidence of GN HCA BSI during summer that was not apparent in our inpatient cohort. The cause is unknown. It might be prudent to advise patients at risk of BSI (eg, those receiving intravascular infusions) to minimize exposure to high environmental temperature and to educate on possible behavioral factors that may increase risk.

      Key Words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to American Journal of Infection Control
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


      1. The Centre for Healthcare Related Infection Surveillance and Prevention (CHRISP) surveillance manual. Supplement 3. 3rd ed. Queensland [Australia]: Centre for Healthcare Related Infection Surveillance and Prevention; 2010. p. 1-4.

      2. Australian Government Bureau of Meteorology. Climate statistics for Australian locations. Available from: Accessed July 2012.

        • Perencevich E.N.
        • McGregor J.C.
        • Shardell M.
        • Furuno J.P.
        • Harris A.D.
        • Morris Jr., J.G.
        • et al.
        Summer peaks in the incidences of gram-negative bacterial infection among hospitalized patients.
        Infect Control Hosp Epidemiol. 2008; 29: 1124-1131
        • Eber M.R.
        • Shardell M.
        • Schweizer M.L.
        • Laxminarayan R.
        • Perencevich E.N.
        Seasonal and temperature-associated increases in gram-negative bacterial bloodstream infections among hospitalized patients.
        PLoS One. 2011; 6: e25298
        • Anderson J.
        • Richet H.
        • Chen L.F.
        • Spelman D.W.
        • Hung Y.J.
        • Huang A.T.
        • et al.
        Seasonal variation in Klebsiella pneumoniae bloodstream infection on 4 continents.
        J Infect Dis. 2008; 197: 752-756
        • Kaier K.
        • Frank U.
        • Conrad A.
        • Meyer E.
        Seasonal and ascending trends in the incidence of carriage of extended-spectrum ß-lactamase-producing Escherichia coli and Klebsiella species in 2 German hospitals.
        Infect Control Hosp Epidemiol. 2010; 31: 1154-1159
        • Al-Hasan M.N.
        • Lahr B.D.
        • Eckel-Passow J.E.
        • Baddour L.M.
        Seasonal variation in Escherichia coli bloodstream infection: a population-based study.
        Clin Microbiol Infect. 2009; 15: 947-950
        • McDonald L.C.
        • Banerjee S.N.
        • Jarvis W.R.
        Seasonal variation of Acinetobacter infections: 1987-1996. Nosocomial Infections Surveillance System.
        Clin Infect Dis. 1999; 29: 1133-1137
        • Cho Y.
        • Badve S.V.
        • Hawley C.M.
        • McDonald S.P.
        • Brown F.G.
        • Boudville N.
        • et al.
        Seasonal variation in peritoneal dialysis-associated peritonitis: a multi-centre registry study.
        Nephrol Dial Transplant. 2012; 27: 2028-2036
        • Al-Harbi A.H.
        Faecal coliforms in pond water, sediments and hybrid tilapia Oreochromis niloticusX Oreochromis aureus in Saudi Arabia.
        Aquaculture Res. 2003; 34: 517-524
        • Burke V.
        • Robinson J.
        • Gracey M.
        • et al.
        Isolation of Aeromonas hydrophila from a metropolitan water supply: seasonal correlation with clinical isolates.
        Appl Environ Microbiol. 1984; 48: 361-366
        • Ogden I.D.
        • MacRae M.
        • Strachan N.J.
        Is the prevalence and shedding concentrations of E coli O157 in beef cattle in Scotland seasonal?.
        FEMS Microbiol Lett. 2004; 233: 297-300
        • Munoz M.A.
        • Ahlström C.
        • Rauch B.J.
        • Zadoks R.N.
        Fecal shedding of Klebsiella pneumoniae by dairy cows.
        J Dairy Sci. 2006; 89: 3425-3430