137: International Perspectives on Medical Toxicology

INTRODUCTION

Poisoning is a worldwide problem, but the major effects are felt in the developing world. At least 250,000 to 350,000 people die every year from acute pesticide poisoning,⁷² and an estimated 20,000 to 94,000 humans die each year from snake bites,⁹⁷ the vast majority of whom lives in rural farming areas of lower and middle income countries. Hundreds of thousands of people are affected by groundwater arsenic contamination in Bangladesh and India,¹⁴⁹ and outbreaks of poisoning from contaminated food⁴⁰ and environmental pollution from poorly regulated industrial activity^49,135 affect whole communities throughout the developing world.

The resources for dealing with these problems are limited in many countries. Public health education about poisons and infrastructure limiting access and exposure to the most highly toxic chemicals are practically absent in much of the developing world. Access to medical care is often limited for financial, cultural, and geographic reasons. Medical toxicology is frequently not a recognized specialty and patients are evaluated by general physicians with little training—although often with great experience. Diagnostic facilities are few, effective treatment options even more rare. Where antidotes exist, there is rarely enough knowledge or experience to use them effectively.³⁰ Intensive care beds for invasive monitoring and long-term ventilation are scarce. This chapter outlines some of the major poisoning risks and challenges for medical toxicology in the developing world.

POISONING AND THE GLOBAL BURDEN OF DISEASE

The World Health Organization (WHO) has ranked injury, including poisoning, among the top 15 causes of death worldwide for persons aged 5 to 44 years.^114,174 Recent reanalysis of data from the Global Burden of Disease project estimated that acute and chronic exposure to chemicals caused over 4.9 million deaths and 86 million disability-adjusted life years (DALYs) worldwide in 2004—more than cancer, sexually transmitted diseases, or diabetes.^135,179 Children younger than 15 years of age bore more than one half of this burden.

Tremendous regional disparities in the health impact of poisoning are apparent. The global mortality burden from poisoning is disproportionately shouldered by lower and middle income countries. Overall, as much as 75% or more of all poisoning related deaths occur in the developing world,⁸¹ and an estimated 95% of children who die each year from acute poisoning live in low- and middle-income countries.¹⁷⁴ Children living in Sub-Saharan Africa are at highest risk, with an estimated annual mortality rate of four children per 100,000 population. This is double the global average and higher than that in any other region.¹⁴²

These figures are striking, yet most likely underestimate the contribution of poisoning to the global burden of disease and disability. Much of the existing data on poisoning epidemiology from lower income countries reflects the experience in larger hospital centers. By contrast, most of the population lives in rural areas, and many patients ...