Global health Study Guide

📖 Core Concepts Global health – health of populations worldwide; aims for equity and tackles problems that cross borders. One Health – integrates human, animal, and environmental health to boost global health security. DALY (Disability‑Adjusted Life Year) – 1 DALY = 1 lost year of “healthy” life (sum of years lived with disability + years of life lost). QALY (Quality‑Adjusted Life Year) – weights each year by health quality (1 = perfect health, <1 = reduced quality). Bellwether procedures – caesarean delivery, laparotomy, and open‑fracture care; indicate a system’s surgical capacity. Multimorbidity – presence of ≥ 2 chronic conditions in one person; driven by ageing, obesity, urbanisation. Antimicrobial resistance (AMR) – microbes survive drugs meant to kill them; includes MDR, XDR, and pan‑drug‑resistant categories. 📌 Must Remember Global health ≠ international health – the latter focuses on aid to developing nations; global health is universal equity. WHO founded 1948; key WHO tools: Model List of Essential Medicines, DALY metric. MDGs (2000‑2015) → SDGs (2016‑2030) – 17 goals; SDG 5 targets gender equality & ending violence against women. Major financing initiatives: Gavi (2000), Global Fund (2002), PEPFAR (2003), USPMI (2005). Top infectious killers: respiratory infections (TB, measles, influenza, pneumonia), diarrheal disease (2nd leading cause of under‑5 death), HIV (≈0.8 % of adults 15‑49 infected), malaria (≈90 % of deaths in WHO African Region). Non‑communicable disease burden: 80 % of NCD deaths occur in low‑/middle‑income countries; obesity = 16 % of global DALYs. Surgical care gap: 5 billion people lack safe, affordable surgery; only 3.5 % of global surgeries performed in poorest nations. AMR mortality: 1.27 million deaths directly in 2019; projected ≤10 million/yr by 2050 if unchecked. Climate‑health links: heat illness, expanded vector habitats, increased water‑borne disease, food‑security threats. 🔄 Key Processes Calculating DALY \( \text{DALY} = \text{YLL} + \text{YLD} \) YLL = \( \text{Number of deaths} \times \text{Standard life expectancy at age of death} \) YLD = \( \text{Prevalence} \times \text{Disability weight} \) Responding to a Pandemic (GHSA framework) Detect: surveillance, laboratory capacity, early‑warning systems. Assess: Joint External Evaluation → identify gaps. Respond: rapid containment, stockpiles, coordinated communication. Prevent: wildlife trade regulation, One Health monitoring, biosafety protocols. Implementing a National Surgical, Obstetric and Anesthesia Plan (NSOAP) Baseline indicator analysis → stakeholder mapping → consensus goal setting → language refinement → costing → dissemination → implementation & monitoring. Oral Rehydration Therapy (ORT) for Diarrhea Mix 1 L clean water with 6 teaspoons sugar + 0.5 teaspoons salt → give 50‑100 mL /kg / day until rehydrated. 🔍 Key Comparisons Global health vs. International health – Scope: universal equity vs. aid to developing nations. DALY vs. QALY – Focus: lost healthy years (population burden) vs. gained quality‑adjusted years (individual benefit). One Health vs. Traditional public health – Integration: human‑animal‑environment nexus vs. human‑only focus. MDR vs. XDR vs. Pan‑drug‑resistant – Resistance breadth: ≥1 drug in ≥ 3 classes vs. resistance to all but ≤2 classes vs. resistance to all agents. ⚠️ Common Misunderstandings “Global health only concerns poor countries.” – Wrong; equity is universal and high‑income nations also face global threats (e.g., AMR, climate). “DALY counts deaths only.” – It also includes years lived with disability; a death = YLL, a disability = YLD. “All surgical procedures are equally cost‑effective.” – Only bellwether procedures are proven high‑impact; many elective surgeries have lower cost‑effectiveness. “Vaccines eliminate disease completely.” – They reduce incidence and severity; herd immunity thresholds vary. 🧠 Mental Models / Intuition “Health equity = a level playing field.” – Imagine a race where everyone starts at the same line; global health removes structural barriers. “DALY = a budget of healthy years." – Think of each DALY as a dollar you spend on disease burden; reducing DALYs saves “health dollars.” “One Health = a three‑leg stool.” – Remove any leg (human, animal, environment) and the stool (global health security) collapses. 🚩 Exceptions & Edge Cases DALY calculations may use different disability weights across studies → compare only within the same methodology. QALY valuations can differ by cultural preferences for quality of life → not universally comparable. Vaccination impact: rotavirus vaccine is cost‑effective if coverage > 70 %; low‑coverage settings may not achieve herd immunity. AMR projections assume no major new antibiotic classes; breakthrough drugs would shift the curve. 📍 When to Use Which Assess disease burden → use DALY for population‑level comparisons; use QALY for evaluating cost‑effectiveness of interventions. Design health‑system strengthening → apply One Health when zoonotic spillover risk is high; use traditional public‑health tools for non‑zoonotic issues. Prioritize surgical investments → first ensure bellwether procedures capacity before expanding elective services. Select AMR mitigation strategies → combine antimicrobial stewardship (human/animal) with environmental controls (wastewater treatment) under One Health. 👀 Patterns to Recognize High‑mortality infectious diseases cluster in settings with crowding + poor sanitation (e.g., TB, diarrheal disease). NCD rise follows urbanisation + dietary shifts → look for simultaneous obesity and diabetes spikes. Outcome gaps often appear where health‑workforce density < 2.5 per 1,000 population (sub‑Saharan Africa). Climate‑sensitive diseases (malaria, dengue) expand northward as average temperatures rise. 🗂️ Exam Traps Distractor: “Global health only deals with infectious diseases.” – Wrong; includes NCDs, surgery, climate, etc. Distractor: “DALY = years of life lost only.” – Misses YLD component. Distractor: “All WHO initiatives are funded by member‑state dues.” – Many are financed by external partners (e.g., Gavi, Global Fund). Distractor: “One Health addresses only animal disease.” – It also targets environmental and human health links. Distractor: “Antimicrobial resistance will be solved by new drugs.” – Without stewardship and One Health actions, resistance will persist. --- If a heading seemed thin on source material, the bullet list above still captures the core high‑yield points relevant for exam preparation.