Healthcare-Associated Infections (HAIs); at what cost?


“Healthcare-Associated Infections” (HAIs)* increase morbidity, mortality and length of hospital stay as well as healthcare costs for the patients, their families and healthcare systems.1 They also lead to long-term disability and increased resistance of microorganisms to antimicrobials. Various studies have attempted to estimate the burden of HAIs. In this context, I came across two recent papers2,3 estimating the cost of HAIs in US acute care hospitals, which prompted me to re-visit the excellent WHO report on the burden on HAIs around the world.1

The WHO report explores the burden of HAIs not only in the high-income countries, where most reported burden estimates come from, but also in low- and middle-income countries, where little data are available. The report indicates that of every 100 hospitalised patients at any given time, 7 in developed and 10 in developing countries will acquired at least one HAI. The prevalence of HAIs in Europe is around 7.1% with more than 4 million patients affected by approximately 4.5 million episodes of HAIs annually and leading to 16 million extra-days of hospital stay, 37,000 attributable deaths and contributing to an additional 110,000. In the US around 1.7 million patients are affected by HAIs annually with a prevalence of 4.5% and accounting for 99,000 deaths. Limited data are available from low and middle-income countries but the prevalence of HAIs in these countries is estimated to be between 5.7 and 19.1%. Increased length of hospital stay associated with HAIs in developing countries range between 5-29.5 days and excess mortality due to these infections in adult patients in Latin America, Asia, Africa were 18.5%, 23.6%, and 29.3%, for CAUTI, CR-BSI, and VAP, respectively.1

HAIs have a huge economic burden. In the WHO report and according to a report from the ECDC,4 these infections account for approximately €7 billion per year in Europe, considering direct costs only. For instance, additional associated costs of a CR-BSI episode in Europe ranged from €4,200 to €13,030, representing annual costs to healthcare systems of €54 million in the United Kingdom and €130 million in France.1 Limited data on the financial cost of HAIs in low- and middle-income countries is available. Reports from Mexican ICUs estimated the overall average cost of a HAIs episode at $12,155 with an excess cost of $11,591 per case of CR-BSI.1 In several ICUs in Argentina, the overall extra cost estimates for CR-BSI and healthcare-associated pneumonia averaged $4,888 and $2,255 per case, respectively.1

In the US, the annual economic impact of HAIs was approximately $6.5 billion in 2004.5 Recently Zimlichman and colleagues2 conducted a systematic review of the literature for the years 1986 through 2013 for an updated estimate of costs associated with the most significant and targetable HAIs in the US. These were CLABSI, VAP, SSI, CR-UTI, and C. difficile infection (CDI). On a pair case basis, CLABSI were found to be the most costly at $45,814 (95% CI, $30,919-$65,245), followed by VAP at $40,144 (95% CI,$36,286-$44,220), SSI at $20,785 (95% CI, $18,902-$22,667), CDI at $11,285 (95% CI, $9,118-$13,574), and CR-UTI at $896 (95% CI, $603-$1,189). Based on 2009 data where approximately 34.7 million adults received inpatient care in US hospitals (totaling 165 million patient days), the total annual cost of the 5 infections was  $9.8 billion (95% CI, $ 8.3-11.5 billion) with SSI and CDI being the most frequent (36% and 30% respectively).

cost prevalence HCAI

Figure: The prevalence and direct cost of HAI in Europe1,4 and the USA.1,2

The study by Marchetti and Rossiter3 went a step further in trying to estimate the true cost of HAIs in US acute care hospitals by assessing the full social burden of these infections including direct medical, non-medical and indirect costs. This was done by updating, combining and expanding previous cost estimates from various studies. Although the study was subject to the same limitations as the studies which contributing data was derived from, it is of importance because the social cost of HAIs is rarely considered. Marchetti and Rossiter estimated the total social cost of HAIs in US acute care hospitals alone (excluding those occurring in non-hospital settings) to range from $96-147 billion. In the face of such a huge cost, the authors concluded “The enormous clinical and economic burden of infection places HAIs high on the list of devastating and costly illnesses, such as cancer, heart attack, stroke, and diabetes, thereby mandating further research and greater efforts to contain a pressing healthcare problem”.

It is clear that HAIs represent a huge burden in the developed world. Due to the limited data available from low- and middle-income countries, the true cost of these infections is undetermined, although it is clear that prevalence is higher in these countries. More research is needed to evaluate the true burden of HAIs worldwide, including their financial cost, to expose a problem that is as devastating and costly as cancer and diabetes. Needless to say, the implementation of practical and effective strategies to reduce the prevalence of HAIs is required.


*Healthcare-Acquired Infections, also known as “Healthcare-Associated Infections”, “Nosocomial Infections” or “Hospital Infections”, are infection acquired by patients in healthcare facilities or appear after discharge from a healthcare facility and are not present or incubating at the time of admission. Their definition also extends to occupational infections among healthcare workers.

Article citations:

  1. WHO. Report on the burden of endemic Health Care-Associated Infection Worldwide. WHO. 2011.
  2. Zimlichman E, Henderson D, Tamir O et al. Health Care-Associated Infections: A Meta-analysis of Costs and Financial Impact on the US Health Care System. JAMA Intern Med 2013.
  3. Marchetti A, Rossiter R. Economic Burden of Healthcare-Associated Infection in US Acute Care Hospitals – Societal Perspective. J Med Econ 2013.
  4. Annual epidemiological report on communicable diseases in Europe 2008. Report on the state of communicable diseases in the EU and EEA/EETA countries. Stockholm, ECDC. 2008.
  5. Klevens RM, Edwards JR, Richards CL Jr et al. Estimating health care-associated infections and death in US hospitals, 2002. Public Health Reports 2007;27:817-824.

8 thoughts on “Healthcare-Associated Infections (HAIs); at what cost?

  1. “…The prevalence of HAIs in Europe is around 7.1% with more than 4 million patients affected by approximately 4.5 million episodes of HAIs annually and leading to 16 million extra-days of hospital stay, 37,000 attributable deaths and contributing to an additional 110,000. In the US around 1.7 million patients are affected by HAIs annually with a prevalence of 4.5% and accounting for 99,000 deaths…” Shocking and yet still we allow workers not to follow rules and guidelines. What is it that explains the difference between Europe and the US?

    We all know that just following the rules and guidelines will bring down these numbers by 30%. I feel that there are no excuses not to do so; we still accept bad outcomes and gigantic costs and we know how to prevent them!


    • Dear Henk, the difference between the prevalence rates in the US and Europe could be due to a number of reasons, including: how the data is collected, how HAIs were defined and surveyed, and which HAIs were included in the various studies from which the 7.1 and 4.5% figures were derived. The ECDC report derived the 7.1% prevalence rate from a number of prevalence surveys on HAIs in various European countries and the prevalence range was 3.5-10.5%. Hence, aside from the various limitations and differences in these surveys, there are differences in rates within Europe itself.

      Having been to some hospitals in several Europe countries, I have encountered different attitudes towards infection prevention and quite marked variation in adherence to guidelines, which may also explain these differences in rates. Regardless of the reasons for the difference in prevalence rates between Europe and US, I agree with you that more can be done to reduce the prevalence and burden of HAIs on both sides of the Atlantic, including stricter adherence to infection prevention guidelines.


  2. A few important things to remember:
    1) Reported HAI costs are incremental, or additive. They represent the additional expense of managing acquired infections and do not include the cost of treating the original illnesses that necessitated the hospital admissions in the first place.
    2) Douglas Scott, health economist at the Centers for Disease Control in Atlanta, GA, USA, estimated incremental HAI-related direct hospital costs to be US$28-$45 billion (2007 dollars).
    3) The HAI costs reported in our study are societal and represent the full incremental economic burden of HAIs on the American society, not just the incremental cost to acute-care hospitals. They do not include the costs for infections occurring in long-term care facilities (nursing homes), outpatient clinics, dialysis centers, and all other healthcare delivery locations. To include costs from these other points of care would dramatically add to our annual estimate of US$96-$147 billion.
    4) Many HAIs are preventable, but prevention requires dedicated education and initiative directed at improving hygiene and safety within healthcare facilities. Current efforts are admirable but insufficient.


  3. Dr Marchetti, thank-you for taking the time post this helpful comment.

    Regarding your second point, interesting to note that Douglas Scott’s estimate of direct incremental HAI costs ($28-45 bn) is two to four times higher than the upper 95% confidence interval of the Zimlichman systematic review ($11 bn). Perhaps this represents the difference between the costs of the main 5 HAI included by Zimlichman (CLABSI, VAP, SSI, CR-UTI, and CDI) and all HAI?

    Reflecting on your third point, do you know if anybody has ever tried to evaluate the overall burden of healthcare-associated infection including those acquired outside of acute hospitals?


  4. Actually I am doing my Masters in Pharmacy on this same subject (the economic impact of healthcare-associated infections globally) but I can not find enough data from developing countries. This post is very beneficial and helped me a lot.


    • Thank you for the comment Seyma and I am glad to hear that the post was helpful. Indeed there is limited data on the cost of HAIs in low and middle income countries and the WHO’s report highlights this point. More studies investigating this topic in developing countries and indeed developed countries are warranted. These should aim to determine the true cost of HAIs, including the cost of treating the infections as well as other economic and social costs. Good luck with your Masters.


  5. This blog is refreshingly candid! I have dedicated the last four year to trying to grasp the enormity of the HAI problem. I have struggled to uncover the true incidence and prevalence of HAIs, and have been astounded by the “murkiness” of statistics. To approach this deadly problem in a scientific, data based way, we need to have a reliable baseline. As a physician, I am also confused and disturbed by the reporting methods in US hospitals which under-report as many as 90% of these infections. Keep up the good work Micro Blog!


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