Benefits & Limitations of Strategies to Control Water-Related Diseases (Cambridge (CIE) IGCSE Environmental Management): Revision Note

Benefits & limitations of strategies to control water-related diseases

• Water-related diseases such as malaria and cholera can be reduced through prevention, control of transmission, and treatment

  • These strategies vary in cost, effectiveness and whether they rely on individual actions or large-scale government systems

• Understanding the benefits and limitations helps explain why some diseases are easier to control than eradicate

Malaria

Benefits of malaria control strategies

• Personal protection (nets, repellents, vaccination, antimalarial drugs) reduces mosquito-to-human transmission

  • This lowers the number of infections and protects vulnerable groups

• Vector control (draining stagnant water, spraying insecticides, biological control) reduces mosquito populations

  • This decreases the number of bites and slows the spread of the parasite

• Strategies that destroy the Plasmodium parasite (drugs and vaccines) target the disease directly

  • This can reduce the parasite in the human population

  • This increases the chance of long-term reduction in malaria cases

Limitations of malaria control strategies

• Destroying the parasite is more effective in the long term

  • This is because removing the parasite could eliminate malaria entirely

  • But these strategies are expensive and often require medical professionals

• Controlling mosquito breeding (e.g. draining stagnant water) is cheaper and can be done by communities

  • However, these methods only reduce mosquito numbers temporarily and do not remove the parasite

• Mosquitoes are developing resistance to insecticides

  • This makes spraying less effective over time

• The malaria parasite is becoming resistant to some antimalarial drugs

  • This reduces the effectiveness of treatment and prevention

• Improvements in diagnosis, treatment and prevention have reduced deaths but this has not led to full elimination because transmission continues where mosquitoes remain

Cholera

Benefits of cholera control strategies

• Personal actions such as handwashing and boiling water are effective at preventing infection

  • These strategies are inexpensive and can be done by individuals or families

• Chlorination of water supplies kills cholera bacteria

  • This helps protect entire communities where safe water is provided

• Vaccines reduce the number of severe cases during outbreaks

  • They provide important short-term protection in high-risk regions

• Improved sanitation and sewage treatment stop faecal contamination of water

  • This removes the source of the bacteria and greatly reduces long-term risk

Limitations of cholera control strategies

• Personal actions are useful but depend on consistent behaviour

  • Outbreaks may occur when people cannot access soap, fuel for boiling water or chlorine tablets

• Large-scale sanitation systems are more effective

  • These are very expensive and require government funding, planning and maintenance

  • Without proper maintenance, sewage can leak and reintroduce cholera bacteria

• Cholera vaccines do not give lifelong immunity

  • They must be used alongside other strategies, such as sanitation and clean water supply

• Areas lacking safe sewage disposal are at continuous risk

  • This means that outbreaks may return quickly if water quality drops