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Barrett et al. 1998

Introduction

  • Emerging infectious diseases: seen as a big problem currently
  • Emerging infections: are not a recent phenomenon but have always played a major role throughout human history
  • 3 epidemiologic transitions
  • Importance of anthropology for research

An Overview of Epidemiological Transitions

  • Omran’s model criticisms
    • Implies each stage of the transition is more advanced and desirable than the previous stages
    • Using whole nations as units of analysis: buries the differential experience according to race, gender, and class
    • Restricted to a particular set of historical circumstances in the recent shift

Epidemiological Transitions: From the Late Paleolithic Age to the Industrial Revolution

Paleolithic Age Baseline

  • Populations were too small and dispersed to support communicable pathogens
  • Pinworm
  • Ectoparasites
  • Enteric pathogens
  • Rate of emergence of diseases: may have increased as tool use allowed exploitation of novel ecological niches and as migration increased

The First Epidemiologic Transition

  • Sedentism: led to larger groups + more interaction between people
  • Increase in infectious disease mortality
  • Accumulation of human waste
  • Appearance of domesticated animals: provided a reservoir for zoonoses
  • Agricultural practices
  • Nutrient deficiencies
  • Groups that most suffered: women, children, lower classes
  • Increased severity of diseases
  • Crowding in urban centers
  • Epidemic outbreaks
  • Increasing migration + trade: transmission of diseases
  • Exploration + conquest: infections of Native Americans leading to pandemics

The Second Epidemiologic Transition

  • Industrial Revolution
  • Decline in infectious disease mortality within developed countries
    • Landmark for modernization
  • Nutritional factors
  • Extension of life expectancy: increased morbidity from chronic diseases
    • Cancer, diabetes, etc.
  • Increasing of water + air pollution
  • Differences in mortality based on social inequalities
  • Improvements in child survival and life expectancy at birth in less developed nations
    • Immunizations + antibiotics

The Third Epidemiologic Transition

  • Emerging infectious diseases
  • New diseases: contribute to adult mortality
  • Increased incidence and prevalence of pre-existing infectious diseases that were thought to be under control
  • Generation of antimicrobial-resistant strains at a faster rate than safe new drugs is developed

Recently Emerging Infections

  • 29 newly emerged pathogens since 1973
    • May be due to increases in detection rates
  • Examples: HIV, Ebola, Marburg, Lyme disease, dengue fever, malaria, tuberculosis
    • Earlier transmission of HIV to urban Haiti: by more affluent Westerns engaging in sex tourism
  • These new outbreaks are linked to climatic fluctuations and ecological disruptions
  • Re-emerging infections causes: warmer climates, climatic fluctuations, poorly developed urban environments, increase in mosquito populations, decreases public health expenditures, poverty,
  • Inevitability of genetic adaptations of microorganisms to the selective conditions posed by human technology and behaviors
  • Host susceptibility and comorbidity
  • Overuse of antibiotics in industrial animal: causes the rise of multi-drug resistant strains of food-borne pathogens
  • Human populations are converging into a single global disease ecology