Burden of HCAI worldwide According to a literature review of national or multicentre studies published from 1995 to 2008, the overall prevalence of HCAI in developed countries varies between 5.1% and 11.6% (Figure 1) and approximately the same proportion of hospitalized patients acquire at least one HCAI. The European Centre for Disease Prevention and Control reported an average prevalence of 7.1% in European countries and estimated that 4131000 patients are affected by approximately 4544100 episodes of HCAI every year in Europe. The estimated HCAI incidence rate in the United States was 4.5% in 2002, corresponding to 9.3 infections per 1000 patient-days and 1.7 million affected patients. According to a recent European multicentre study, the proportion of infected patients in intensive care units can be as high as 51%; the majority of these are HCAI and the risk of infection increases with duration of stay in intensive care. While HCAI surveillance systems are in place at national/sub-national level in many developed countries, only 23 developing countries (23/147 [15.6%]) reported a functioning national surveillance system in a survey conducted by the WHO First Global Patient Safety Challenge. Therefore, very scanty data are available from the vast majority of low- and middle-income countries. Only nine published studies reported HCAI data at national level. Studies conducted in health-care settings in developing countries report hospital-wide HCAI rates markedly higher than those in developed countries. Hospital-wide prevalence rates vary from 5% to 19%, but most studies report values higher than 10% (Figure 2). The burden of HCAI is also much more severe in high-risk populations, such as adults housed in critical care and neonates, with overall infection rates and device-associated infection rates several-fold higher than in developed countries. The incidence of infection acquired in critical care in developing countries is at least twice that of the United States. In particular for some deviceassociated infections (e.g., bloodstream infection and ventilatorassociated pneumonia), incidence densities can be up to 19 times higher than in developed countries. Neonatal infection rates in developing countries are 3-20 times higher than in industrialized countries. Comparisons of device-associated infection rates in adult and paediatric ICUs reported from the United States and multicentre studies in developing countries are shown in Table 1. Surgical site infection (SSI) represents the most surveyed and most frequent type of infection in developing countries. According to the literature, the incidence of SSI ranges from 1.2 to 23.6 per 100 surgical procedures. This level of risk is significantly higher than in developed countries where SSI rates average around 2-3%. Although HCAI global estimates are not yet available, by integrating the data reported above from studies conducted in both developed and developing countries, it is clear that hundreds of millions of patients are affected by HCAI every year around the world and that the burden of disease in low- and middleincome countries is much higher than in developed countries. Source
