the Plasmodium parasite. The mosquito only carries it.

What is the vector of malaria?

the female Anopheles mosquito. Only the female bites to feed on blood.

How is cholera spread?

by water contaminated with faeces. The bacterium is swallowed.

Which is personal protection against malaria?

sleeping under a net. The others are vector control.

Why does draining still water reduce malaria?

mosquitoes lose the place where they lay eggs. No breeding sites, fewer mosquitoes.

Which strategy helps to control cholera but not malaria?

chlorination of drinking water. Chlorine kills the cholera bacterium in the water supply.

Water-related diseases: malaria and cholera · Cambridge IGCSE Environmental Management

In plain words

Two of the world's great killers depend on water, in different ways. One is carried by an insect that breeds in still water. The other is swallowed with water that has sewage in it. Break the link with water and both can be beaten.

8 things to know

Malaria is caused by a parasite called Plasmodium. The vector, the organism that carries it from person to person, is the female Anopheles mosquito.
The parasite is passed to a person when an infected mosquito bites. A mosquito that is not infected picks the parasite up when it feeds on the blood of an infected person.
Mosquitoes lay their eggs in still water, so malaria is common where there are ponds, swamps and puddles in a warm climate.
Personal protection against malaria: sleeping under nets, using insect repellent, vaccination, and taking antimalarial drugs.
Vector control: covering or draining the places where mosquitoes breed, spraying large areas with insecticide, releasing sterilised male mosquitoes so that eggs do not hatch, and biological control, such as fish that eat the larvae.
Cholera is caused by a bacterium. It spreads when people drink water or eat food contaminated with the faeces of an infected person. It causes severe diarrhoea.
Strategies to control cholera: handwashing, adequate sanitation and sewage treatment, a supply of potable water made safe by boiling or chlorination, and vaccination.
Limitations. Nets, drugs and vaccines cost money and must reach remote areas. Mosquitoes become resistant to insecticides, and the spray kills other insects. Draining wetlands destroys habitats. Sewers and treatment works are costly to build.

Worked example

A village beside a swamp has many cases of malaria. Suggest one strategy of each type, and one limitation.

Personal protection: give each family bed nets, since the mosquitoes bite at night.
Vector control: put fish that eat mosquito larvae into the swamp, a form of biological control.
Limitation: nets wear out and have to be replaced, which costs money every few years.

Tips and tricks

The mosquito does not cause malaria. The Plasmodium parasite does. The mosquito is the vector that carries it.
Malaria is spread by an insect bite, so clean drinking water does not prevent it. Cholera is spread through water, so nets do not prevent it.

6 questions, about 2 minutes.

It lands in your notebook with its questions as flashcards.

Water-related diseases: malaria and cholera: 6 questions and answers

These are the quiz’s questions. Do the quiz first, then come back here for the ones that got you.

What causes malaria?
- a bacterium in dirty water
- a virus in the air
- the Plasmodium parasite (the answer)
- a chemical in sewage
The mosquito only carries it.
What is the vector of malaria?
- the male Anopheles mosquito
- the female Anopheles mosquito (the answer)
- the housefly
- contaminated water
Only the female bites to feed on blood.
How is cholera spread?
- by mosquito bites
- by breathing polluted air
- by sunlight
- by water contaminated with faeces (the answer)
The bacterium is swallowed.
Which is personal protection against malaria?
- draining a swamp
- spraying a whole region with insecticide
- sleeping under a net (the answer)
- sterilising male mosquitoes
The others are vector control.
Why does draining still water reduce malaria?
- the parasite lives in the water
- mosquitoes lose the place where they lay eggs (the answer)
- people stop drinking it
- the water was carrying bacteria
No breeding sites, fewer mosquitoes.
Which strategy helps to control cholera but not malaria?Stretch
- chlorination of drinking water (the answer)
- vaccination
- insect repellent
- antimalarial drugs
Chlorine kills the cholera bacterium in the water supply.

6 questions

Tap an answer and you’ll see straight away whether it’s right, and why.

Worksheet

3 questions, 9 marks. Write your answers on paper, then check them.

Water-related diseases: malaria and cholera

Cambridge IGCSE Environmental Management 0680 · 9 marks · papermunch.org

Name ______________________________ Date ______________

Describe how malaria is transmitted from one person to another.[3]
Show answerHide answer
A female Anopheles mosquito feeds on the blood of an infected person and takes in the Plasmodium parasite. The mosquito then bites another person. The parasite passes into that person's blood.
I got this one
State three methods of vector control for malaria.[3]
Show answerHide answer
Any three: cover or drain breeding areas; spray large areas with insecticide; sterilise male mosquitoes; use biological control.
I got this one
Describe three strategies to control cholera.[3]
Show answerHide answer
Any three: handwashing; adequate sanitation and sewage treatment; supplying potable water, by boiling or chlorination; vaccination.
I got this one

Answers: Water-related diseases: malaria and cholera

1. A female Anopheles mosquito feeds on the blood of an infected person and takes in the Plasmodium parasite. The mosquito then bites another person. The parasite passes into that person's blood.
2. Any three: cover or drain breeding areas; spray large areas with insecticide; sterilise male mosquitoes; use biological control.
3. Any three: handwashing; adequate sanitation and sewage treatment; supplying potable water, by boiling or chlorination; vaccination.