Statistics of the Incidence of Pneumonia in the USA and the World

The incidence of pneumonia varies depending on sub-category, geographical location, patient population and healthcare setting. For example, in the United States of America (USA) from 2010 to 2012 it was estimated that the average incidence of CAP was 24.8 cases per 10,000 adults with a peak prevalence observed in the 65-79 years category (Jain et al., 2015). A more recent study conducted by Ramirez et al in 2017 highlighted that 1.5 million adults are hospitalised in the USA each year due to CAP, and approximately 10,000 of these patients die as a result of the infection. The incidence of HAP in the USA has also been extensively reported, with a rate of 0.12 – 3.63 per 1,000 patient-days quoted in the literature (Baker & Quinn, 2018; Giuliano, Baker & Quinn, 2018). This was emphasised in a multicentre point-prevalence study which concluded that approximately 21.8% of total health care acquired infections (HAI) in 2011 were due to HAP and VAP combined (Magill et al., 2014).

In Europe, the prevalence of CAP varies significantly from country to country, with rates of 1.7-11.6 per 1000 adults per year reported (Cillóniz et al., 2016; Vila-Corcoles et al., 2009). Although this data is readily available from both national databases and prospective studies, there is a significant lack of up-to-date, precise information regarding more recent European trends within the literature. This is also coupled with the fact that currently only Finland, Spain and the United Kingdom (UK) collect and report detailed epidemiological data on CAP (Welte, Torres & Nathwani, 2010). Therefore, the true burden of CAP may be underestimated within the EU and these figures should be interpreted with caution. However, it does appear that similar to trends observed within America, incidence of CAP increases progressively with age, with peaks in those aged >65 years (Rivero-Calle et al., 2017; Trotter et al., 2008).

Limited epidemiological research and national statistics are currently available which highlight the true burden of disease in Ireland. However it has been reported by the central statistics office that 1,109 deaths in 2017 were as a direct result of pneumonia infection. A point prevalence study conducted in 2012 also highlighted that pneumonia was the second most common HCAI in Ireland with a total of 86 cases reported, accounting for 17.2%. This survey also emphasised that nosocomial infection was most commonly acquired in augmented care units with a rate of 16.5% for ICU and HDU combined, perhaps reflecting the routine use of invasive medical devices (Health Protection Surveillance Centre, 2012).