When the field was first, established global health or as it was then known, tropical medicine consisted almost entirely of doctors for the Royal Navy, Home and Indian Armies, Colonial Service, Foreign Office Service and trading and mining corporations. These newly minted medicos arrived in the colonies with the perfect understanding that their enemy was infectious endemic disease, the “principle obstacle to the colonization of the tropics by Europeans.”[1] Even as colonialism waned, the emphasis on infectious disease remained, giving rise to the malaria pill, the antibiotic and the successful vaccination campaign. In summary, the magic bullets of medicine that defined the 20th century. In modern practice we see how that the era of the magic bullet has given way to that of complex chronic illness and lifestyle management.
Despite the shift in priorities, medicine all too often searches for magic bullet solutions to complex problems as though chronic diseases were monolithic entities when this is patently not the case. Take the example of heart disease; despite a common label different racial groups present with vastly different pathophysiology. In Caucasian populations heart failure is primarily due to ischemia while hypertension and is the primary root cause in those of African descent. In addition, mortality for patients 45 to 64 years of age is significantly higher in blacks, as are rates of hospitalization[2]. Response of medication differs greatly as well. Crucially, those of African descent display a diminished response to angiotensin-converting enzyme inhibitors (ACEIs) and β-blockers in lowering blood pressure[3]. These drugs have represented the standard interventions for the management of hypertension for almost three decades. Consequently, African Americans who have the “highest morbidity and mortality from hypertension of any population group in the United States” have been inadequately treated even when being provided standard of care. Similar oversights have occurred with cancer, renal disease and a variety of other conditions.
In light of the success in battling infectious disease and rise of globalization, it is tempting to attempt to simply export biomedical approaches in responding to the emergence of “pathologies of modernity” in the developing world. Humans however, will always retain key pathophysiological differences, a fact overlooked even within health systems of developed nations. As we work towards combating the wave of chronic disease now sweeping the globe, it is useful to return to Osler’s words if not his meaning in stating that “It is much more important to know what sort of a patient has a disease than what sort of a disease a patient has.”
[1] Gibbs, Philip. “The London School of Tropical Medicine.” Journal of the Royal African Society 2, no. 7 (1903): 316-25.
[2] Yancy CW. Heart failure in African-Americans: a cardiovascular enigma. J Card Fail. 2000; 6: 183–186.
[3] Wright JT, Dunn JK, Cutler JA, Davis BR, Cushman WC, Ford CE, Haywood LJ, Leenen FH, Margolis KL, Papademetriou V, Probstfield JL, Whelton PK, Habib GB, for the ALLHAT Collaborative Research Group. Outcomes in hypertensive black and nonblack patients treated with chlorthalidone, amlodipine, and lisinopril. JAMA. 2005; 293: 1595–1608.