Every era in healthcare has its own defining issues which shape public, professional and political dialogue. In sociologic terms these take the form of ‘discourses’ which provide order to the world in which we operate, attach meaning to the work that we engage in and allow us to communicate its importance to others.1 “Discourses are ways of seeing the world. They act like lenses or filters, and they make it possible for us to say some things but not others”.1 A discourse is held to be the best approximation of the truth until it is accepted to be wrong and replaced by another. For example, a dominant miasmatic discourse determined that London’s epidemics of cholera in the mid-19th century arose from polluted air even after John Snow’s observations in relation to the Broad Street water pump were widely publicised.2 London’s sewer system was commissioned solely to deal with its intolerable ‘miasma’, not its faecally contaminated water.
With World Sepsis Day marked on the 13th September, what is the state of our current discourse with respect to infectious diseases and their complications? In the second half of the 20th century, the advent of the antibiotic era led to hubristic determinations that the “war on infectious disease has been won”. For years this quote was mistakenly attributed to the US Surgeon General William H Stewart based on a series of misunderstandings, but was widely taken up by others in academia around the time that Omran’s transition theory was first proposed.3 This asserted that chronic non-communicable diseases will replace infections as the main threat to population health as growing incomes and trade permit food security and effective programs of public health.4 Have chronic diseases replaced infectious disease as the dominant cause of morbidity and mortality? Are infectious diseases “gone but not forgotten”? This question was tested empirically by Michael Baker and others, who demonstrated that infectious diseases still accounted for 1 in 4 hospital admissions in New Zealand in 2008, and had actually increased from 1 in 5 admissions in 1989.5
A feature of infectious disease and sepsis epidemiology globally is the increase in incidence among indigenous peoples and those who experience high levels of socio-economic deprivation and exclusion. Between 2003 and 2013, New Zealand’s ‘rock star’ economy was not one that could prevent a 19% relative increase in the proportion of Māori and Pacific earners in the lowest quintile of incomes (compared with a 3.6% rise among New Zealand Europeans).6 The effect of being Māori in relation to infectious disease risk (compared with non-Māori) is remarkably consistent. In the study by Baker et al, Māori people were 2.15 times more likely than non-Māori to be hospitalised with infection.5 In the Waikato District Māori are 3.2 times more likely than non-Māori to be admitted with sepsis, the most serious complication of infection.7 Against this backdrop of inequality, it is arresting but perhaps unsurprising to read of the strong association between scabies and impetigo. Impetigo and skin infections are common among Māori and Pacific young people. If as suggested there is a 93% overlap between scabies and impetigo, more work is clearly needed to understand the interaction of scabies infestation with streptococcal and post-streptococcal disease. Infectious diseases associated with socio-economic disadvantage may be largely forgotten (or under-reported) but are by no means gone.
If due to the effects of poverty, ageing and chronic co-morbid illness we are admitting more people with infection, it should follow that the health of our population is increasingly affected by their most severe manifestations. In the world of research into sepsis epidemiology, admissions with primary ‘infectious disease’ codes that are associated with secondary organ failure are extracted from hospital discharge statistics and matched to census population data. Applied to acute hospitalisations in the Waikato, this approach has shown that around 1 per 1,000 of the population are hospitalised with sepsis annually,7 accounting for 2% of all admissions in 2017/18 (Moosa S, personal communication). Sepsis is therefore commonly experienced and well understood by frontline healthcare workers, with the spectre of untreated or undertreated disease proving difficult to balance against efforts to preserve antimicrobial efficacy through programs of stewardship. Green et al provide insights into the other personal and environmental factors creating the conditions for antimicrobial overuse and misuse in public hospitals. To the practitioners surveyed, broad spectrum antimicrobials (clindamycin, quinolones and 3rd generation cephalosporins) were widely available without prescribing advice or restriction; audit and education were patchy; antimicrobial stewardship (AMS) efforts were felt to be important but more at a national than a personal level; most practitioners had faced the difficulties of managing multi-drug resistant bacterial disease or Clostridium difficile infection. To borrow the words of the authors, sustainable AMS strategies in rural and tertiary practice in New Zealand will “depend on bespoke solutions and fostering a sense of personal and local importance”. Greater efforts are needed to equip the healthcare workforce with the knowledge, skills and support services necessary to blend effective management of infection and sepsis with antimicrobial parsimony.
Looking to infection prevention at a population level, it is clear that chronic diseases interact with health behaviours and the environment to increase the risk of serious infection. Almost all of the conditions worthy of recording in a patient’s past medical history are associated with an increased risk of hospitalisation with infection and/or sepsis.8 For this reason it is encouraging that the New Zealand government has funded several programs of treatment and prevention for chronic viral infections. Large-scale implementation of pre-exposure prophylaxis (PrEP) is associated with significant reduction in new HIV infection. The justifications for PrEP are clearly laid out by Peter Crampton, with the opportunity to prevent transmission coming at a time of rising incidence among those groups most at risk. While it might be tempting to look to a future where the complications of HIV are a thing of the past, there are other potential pathogens on the horizon for which we may be less well prepared. Illustrating this well, Charania and Turner summarise the principal effects of the 1918–19 influenza pandemic for the Journal’s readership, demonstrating not only the potential global effects of epidemic viral illness but also the disproportionate impacts that fall on developing countries, marginalised populations and underfunded health systems.
In summary, thanks to well-funded public and primary health programmes focusing on hygiene, food safety and vaccination, the infectious disease landscape in New Zealand is no longer dominated by the epidemic infectious diseases of the early 20th century. However, infection and sepsis still stalk people made vulnerable by age, poverty, co-morbidity and well-intentioned medical therapy. Our response needs to be reflected in a new public and professional discourse emphasising that infectious diseases and their severe sequelae are not gone, and not forgotten. To this end, at the 70th World Health Assembly in May 2017, a resolution was adopted requiring member governments to improve the prevention, diagnosis and treatment of sepsis.9 The resolution recognises the crucial overlaps between improving sepsis care, preventing infection and preserving available antimicrobial therapy. These are “wicked problems” that need to be tackled by multi-disciplinary, multi-sector and multi-agency approaches. None of these will emerge without professional and political leadership. For example, The World Health Organization recommends facilitation and funding for a national sepsis action plan, something which has already been achieved in Australia.10 Given the findings presented in this edition of the Journal and their broader context, a sepsis action plan to complement antimicrobial stewardship, public health and infection prevention efforts should be an essential component of our approach to contemporary infectious disease challenges.