Disease and geography
Study the spatial distribution and impacts of disease, compare prevention strategies, and evaluate monitoring, outbreak response and eradication.
Exam scope and assessment notes
Cambridge International AS & A Level Geography 9696, 2027–2029 syllabus, Topic 14. Across every topic, practise reading both quantitative and qualitative geographical resources, describing patterns before explaining them, evaluating evidence and producing a structured, supported conclusion. These original explanations and self-checks are independent study support, not Cambridge questions, official marks or grades. Centre-selected named examples and detailed case studies still need course-specific evidence packs. Full timed mock papers, official marking or grade prediction, and human subject-teacher review are not provided. Fieldwork is not assessed in this syllabus, but this site does not collect or supervise primary data.
Before you begin
- Cambridge recommends prior Geography at approximately Cambridge IGCSE or Cambridge O Level. Read the source and its scale before explaining patterns; support evaluation with relevant evidence.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
Which disease in this syllabus is a parasitic disease spread by a mosquito vector?
What you will learn
- Use prevalence and spread terms and interpret social and economic impacts
- Explain spatial variation in morbidity through environmental, social, economic and political factors
- Compare influenza, cholera and malaria transmission and prevention geographically
- Evaluate monitoring, pandemic response, confidentiality and disease-eradication programmes
Disease is a geographical pattern, not only a biological process
Prevalence measures the proportion of a defined population affected. An outbreak, epidemic, pandemic and endemic pattern describe different scales or persistence of spread. Compare morbidity, death rate, infant mortality, life expectancy, health spending and workforce effects with attention to population structure and period.
Spatial variation reflects age and sex structure, climate, water, sanitation, vectors, housing, diet, education, poverty, healthcare infrastructure, disasters, governance and travel. Similar income classifications can hide major differences within and between countries. Use consistent definitions and denominators before comparing statistics.
Transmission and risk differ among pathogens and places
Influenza is viral and can spread between people; changing strains affect immunity and vaccine effectiveness. Cholera is bacterial and is strongly linked to contaminated water and sanitation. Malaria is parasitic and spread by mosquitoes whose habitat and seasonality are influenced by environmental conditions.
The syllabus focuses on geographic distribution, risk, prevalence, social/economic effects and prevention, not detailed medical biology. Prevention can include vaccines, sanitation, education, treatment access, testing, mosquito control and protective equipment. Disaster events and displacement may change access and exposure.
Monitoring and response need trust, access and cooperation
Effective monitoring balances cost, testing access and scalability, data quality, disclosure, confidentiality and international collaboration. Responses depend on environmental, social, economic and political conditions; a measure that works in one country may not transfer unchanged.
Compare two countries' responses to one pandemic since 2000, and evaluate a global eradication programme against possible environmental, social, economic or political re-emergence. A case study should state dates, populations, measures and sources; this teaching page does not provide a clinical diagnosis or country-specific case pack.
Sources for this lesson
Pause and explain
Why can high testing capacity still fail to provide effective disease monitoring?
Worked example
A survey finds 180 people with a disease in a population of 12,000. Calculate prevalence per 1,000 and give one reason the figure may not be comparable with another survey.
Show the worked solution
- Prevalence per 1,000 = 180 ÷ 12,000 × 1,000.
- This equals 15 cases per 1,000 people in the defined population.
- Check case definition, survey date, age structure, sampling and whether the numerator records existing or new cases.
Answer Prevalence = 15 per 1,000. Comparisons require matching definitions, populations and time periods.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
Two regions report 30 cases in populations of 2,000 and 15 cases in populations of 500. Calculate prevalence per 1,000 for both and compare cautiously.
Give me a hint
Divide cases by each region's own population, then multiply by 1,000.
Compare my reasoning
- Region A: 30 ÷ 2,000 × 1,000 = 15 per 1,000.
- Region B: 15 ÷ 500 × 1,000 = 30 per 1,000.
- Check case definition, survey coverage, age structure and date before treating the difference as a real risk gap.
The recorded prevalence is 15 per 1,000 in A and 30 per 1,000 in B. Comparability depends on matching methods and populations.
Look for these in your work
- Both denominators used
- Rate units stated
- Comparison caveat included
After a cyclone, a settlement reports rising cholera risk. Explain two geographic conditions that may influence spread and one response that addresses a cause rather than only symptoms.
Give me a hint
Consider water, sanitation, displacement and service access.
Compare my reasoning
- Flood damage can contaminate water supplies or disrupt sanitation.
- Crowding and displacement can increase exposure while health services and clean water access are interrupted.
- Safe water, sanitation repair and accessible hygiene information address exposure pathways; monitoring should protect privacy and include underserved groups.
Damaged water and sanitation systems and displacement can raise risk. Restoring safe water and sanitation addresses transmission conditions, alongside care and monitoring.
Look for these in your work
- Two conditions linked
- Response targets a pathway
- Access and privacy considered
Compare a rapid testing programme with a global vaccination/eradication programme for controlling a disease. Evaluate reach, evidence, fairness and re-emergence.
Give me a hint
Separate the monitoring role from the prevention role and identify what each needs to work.
Compare my reasoning
- Testing can detect spread and guide action but depends on affordability, access, accuracy and timely reporting.
- Vaccination can reduce susceptibility but depends on delivery, acceptance, supply and appropriate coverage; environmental or social gaps may leave groups exposed.
- Eradication claims require surveillance after low case counts and attention to reservoirs, travel, conflict and programme continuity.
The approaches can complement each other. Their success depends on access, trust, evidence quality and sustained cooperation; a short decline in reports is not proof of eradication.
Look for these in your work
- Monitoring and prevention distinguished
- Reach and fairness included
- Re-emergence risk addressed
Common mistakes
- Confusing prevalence with incidence or total deaths
- Explaining disease distribution by climate alone
- Treating LIC, MIC and HIC as internally uniform groups
- Ignoring privacy and trust when discussing surveillance
- Calling an eradication programme successful without checking re-emergence risk
What can you explain now?
What is prevalence?
Compare with the explanation
The proportion of a defined population affected at a specified time or period
The population denominator and case definition must be stated for a fair comparison.
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Make it stick
Compare how water quality, vectors and human mobility shape the geography of two diseases, then explain why monitoring requires confidentiality and trust.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.