Surveillance vital for tackling antibiotic resistance
International surveillance systems are needed to curb the rise of antibiotic resistance.
Public health experts have been warning for over a decade that a ‘post-antibiotic era’ is rapidly approaching when the spread of antibiotic resistance means that effective antibiotic therapy will no longer be effective — and the situation is deteriorating with ever-increasing speed.
Despite the scale of the threat, resistance is still not taken sufficiently seriously by many in the health sector. Surveillance is needed to monitor the spread of resistance, and thus understand the scale of the problem, in order to provide crucial data for the development of containment strategies.
The major driving force behind the emergence and spread of antibiotic-resistant pathogens is the rapid rise of antibiotic consumption. This trend reflects the growing medicalisation of societies worldwide, with its identification of microbial pathogens as the cause of infectious diseases.
Antibiotics promise cure. This — together with their ease of use, the usually short treatment requirements, and, for many parts of the world, availability without prescription by a doctor — results in a demand that is increasingly met by a growing supply of generic drugs produced in emerging market economies.
The same escalation in consumption has occurred in the animal welfare sector, prompting concerns about the transmission of antibiotic resistance through the food chain. Hundreds of tonnes of antibiotics used each year are sweeping through the global microbial populations that colonise and infect humans and farm animals, resulting in accelerating evolution and spread of drug-resistant pathogens.
In developed countries, resistance has until now been found mainly in pathogens that can be transmitted without causing disease. They can be carried for long periods and might cause an infection only when coming into contact with parts of the body that would normally be free from bacterial colonisation — that is, introduced by medical interventions, or in children or people with poor immune systems.
Problems with resistant organisms are therefore mainly found in hospitals and nursing homes where patients are treated for acute or chronic conditions.
In developing countries, on the other hand, antibiotic resistance often occurs in microorganisms transmitted in communities by person-to person contact, through contaminated food, unsafe drinking water or by insects. Resistance can mean that people infected with such organisms do not respond to conventional drugs and, if no other treatment options are available, must depend on their immune system overcoming the disease.
An additional set of threats that facilitate the spread of antibiotic-resistant pathogens comes from unpredictable disasters that disrupt human livelihoods and bring about crowding, mass migration, famine and unsafe water supplies. Conflicts within and between states, environmental degradation and climate change can provide scenarios in which infectious diseases thrive and antibiotic resistance may come to the forefront.
A pandemic influenza would be equally grave. Given the difficulty faced by hospitals in tackling the problem of antibiotic resistance, a flu pandemic would probably be followed by a secondary epidemic of bacterial superinfections, most notably MRSA (methicillin-resistant staphylococcus aureus), acquired during treatment in overburdened hospitals struggling to maintain their standard infection control measures. The plausibility of such an outcome became clear in the aftermath of the Indian Ocean tsunami in December 2004 when several injured tourists were repatriated to European hospitals, having been infected with pan-resistant strains of Acinetobacter bacteria acquired during their stay in emergency hospitals.
The WHO estimates that the effect of communicable diseases on global health will fall steadily over the next 25 years. But these projections are based largely on estimates of economic, social and demographic developments, and their historical association with mortality rates. These predictions are extrapolations of improvements in the last 50 years, largely through pharmaceutical interventions. But the forecasts do not take into account one of the most striking trends in recent years — the reversal of antibiotic effectiveness.
Estimates of global health are one of the most important instruments for decision-makers on national and global health issues. But current predictions underestimate the potential role of antibiotic resistance in the emergence and resurgence of infectious diseases in the coming decades.
Underestimates are usually due to lack of data, making it difficult to generalise about the impact of antibiotic resistance on treatment outcomes, and on global health and economic burdens.
It would thus be justifiable and timely to encourage the implementation of international surveillance systems on antibiotic resistance. This could be achieved by connecting already existing national and international initiatives and by agreements on data collection and exchange.
The Pan American Health Organization, which successfully supports national surveillance in all Latin American countries by providing quality control and diagnostic standards, has shown that this can be achieved in low-income and middle-income countries.
An international exchange of surveillance data like the one currently funded by the European Centre for Disease Prevention and Control would be the ultimate aim — and indeed a formidable task — for the WHO.
Hajo Grundmann is project leader of the European Antimicrobial Resistance Surveillance System (EARSS) at the National Institute for Public Health and the Environment (RIVM), The Netherlands.