Communicable disease surveillance and management in a globalised world

“Epidemics appear, and often disappear without trace, when a new culture has started … The history of epidemics is therefore the history of disturbances of human culture.”

Rudolf Virchow's sage words 150 years ago have not lost any of their relevance in our 21st-century globalised world. Despite monumental advances in biomedicine and related sciences, our society remains vulnerable to the reemergence of ancient communicable diseases, while the culture and mechanics of sociopolitical and economic globalisation foster the emergence of new threats, their establishment, and rapid spread.

The evolution of the European Union (EU) is a fascinating geopolitical chapter in human history, and the erudite paper by Richard Coker and colleagues in this issue of The Lancet is a timely reminder that such societal developments can have profound public-health consequences. They provide a pertinent review of the impact of these changes on the epidemiology of communicable diseases in eastern Europe, particularly tuberculosis and HIV, and the constraints facing frail health-systems to adequately respond. Threats that appeared distant are now near. Diseases of antiquity (tuberculosis) and those of exotic and far-flung destinations are now a neighbourhood reality. Thus the call for increased political commitment by member states of the EU to tackle the challenges of establishing effective surveillance for communicable disease across frontiers and bolstering the health systems of EU neighbours is sensible, whether prompted by self-preservation, chauvinism, or benevolence. However, this action alone will not suffice to minimise the risk of importation of communicable diseases, particularly those with outbreak potential, into the EU, nor is it morally defensible. A global threat calls for an equitable global response.

Globalisation has resulted in the unparalleled passage of people, animals, and goods across national borders, which in turn has fuelled the international spread of infectious diseases.¹ The liberalisation of trade and movement, with attendant economic migration, political instability, diminished employment opportunities, and social unrest has further widened the chasm between wealthy and deprived communities, and catalysed inequalities in health.² Rapid global communication has penetrated the consciousness of privileged nations with stark images of cholera in southern Africa and Latin America, pneumonic plague in India, diphtheria in eastern Europe, and Ebola haemorrhagic fever in Uganda and the Democratic Republic of the Congo. The resulting concern prompted several key international and regional initiatives, most notably the Global Outbreak Alert and Response Network (GOARN). GOARN was established in 1997 and now has over 120 partners around the world that identify and assist in responses to more than 50 epidemics, predominantly in developing countries, each year.³ The draft revision of the international health regulations places emphasis on effective sharing of epidemiological information on trans-boundary spread of communicable diseases and rapid assistance to member states to support responses.²

The epidemic of severe acute respiratory syndrome provided many lessons for our global village, but none more pertinent than that “inadequate surveillance and response capacity in a single country can endanger national populations and the public health security of the entire world”.⁴ Early detection requires functional sub-national surveillance capacity, and it is time to invest in strengthening sub-national outbreak surveillance and response capacity in developing countries. The value of training key health-personnel at district level to actively monitor the occurrence of a limited number of clinical syndromes and appropriately respond, while sustaining the surveillance system through regular training, networking, and feedback to reporters, weekly zero-reporting, and defined action on all reports, has been convincingly shown in several developing settings.5, 6 Recently, encouraging evidence has been gathered in west Africa to confirm what appears obvious, that strengthening health services to effectively detect and control epidemics of measles, cholera, and meningococcal meningitis is cost effective.⁷

Investments in improving communicable disease surveillance and response capacity are certainly required beyond the leading eastern edge of the expanded EU, and must extend to all developing countries with poor sub-national capacity.