Geography of Disease -Malaria

What is malaria?

An infectious disease caused by parasites, which are transmitted by mosquitoes.

Where do most cases of Malaria occur?

In tropical areas e.g. sub-Saharan Africa.

In 2015, there were more than 200 million cases of malaria worldwide - around 90% occurred in Africa.

What do cases of malaria show?

They show seasonal variation in some regions - most cases occur at the peak of or just after the rainy season.

However, in tropical regions with little seasonal variation in climate, there is a risk of malaria all year round.

What is the incidence of malaria affected by?

Both physical and socio-economic factors.

What is important about the mosquitoes that carry malaria?

They can only survive in warm countries e.g. in Africa.

What do higher temperatures do regarding malaria?

Higher temperatures decrease the time taken for the parasite to develop inside the mosquito, so increase the likelihood of infection.

Mosquitoes also breed and feed more often when it’s warmer, so it’s more likely that people will be infected.

Where do mosquitoes like to breed?

In still bodies of freshwater, e.g. swamps or pools.

The rainy season creates lots of small puddles and turns low-lying areas into wetlands, providing an ideal habitat for breeding.

Regarding education, what is a socio-economic reason for incidence of malaria?

Limited health education.

People aren’t informed about how to avoid malaria (e.g. by using bed nets).

What may low incomes mean?

May mean that people cannot afford treatment or means of prevention.

What is the case in areas where healthcare is limited?

There are more people infected with malaria, and more sources of the parasite for mosquitoes to pick up and transmit.

What effect does poor health have?

Reduces the body’s ability to fight infection.

What about housing can put people at risk?

Poor quality housing, e.g. windows and doors that don’t fit well, puts people at risk.

What can human activities do?

Human activities e.g. digging irrigation ditches or canals, can increase the number of breeding sites.

What do malaria’s symptoms include?

Fever, chills, nausea and headaches.

Organ failure, respiratory problems, coma and death can follow in severe cases of the disease or if it’s left untreated.

Apart from physical symptoms, what other effects does malaria have?

Malaria has a wide range of impacts on the well-being of individuals.

What can happen to income due to malaria?

May be lost income from inability to work, as well as the financial cost of treatment and hospital visits.

What can happen to child’s education due to malaria?

Children may have extended absences from school - this affects their education and future job prospects.

What can repeated bouts result in?

Can affect children’s development.

What may malaria hinder?

May hinder a country’s development - the government has to spend money on treating the disease, and productivity falls when workers are ill.

This means there is less to spend on improving living standards.

What did the WHO do in 2015?

They set 3 goals for 2030.

What 3 goals did the WHO set in 2015 for 2030?

• reduce global malaria incidence and mortality rates by at least 90%.

• eliminate malaria in at least 35 countries.

• prevent malaria returning to countries who are currently malaria free.

What is the most effective strategy in reducing malaria incidence?

To get rid of the mosquitoes that carry it.

What methods are used to get rid of mosquitoes that carry it?

• by spraying the inside walls of buildings with with insecticide (Indoor Residual Spraying, IRS)

• by spraying mosquito nets with insecticide. Providing bed nets also prevents people from being bitten (malarial mosquitoes are mainly active from dusk to dawn).

What is a downside of using IRS?

• It can be very expensive and may have to be repeated several times a year.

• The chemicals used can have ecological impacts and effects on people’s health, e.g. DDT kills aquatic insects and fish, and can lead to cancers and miscarriages in humans.

What is important to note about the downside of insecticides?

Mosquitoes can evolve resistance to insecticides, so new insecticides need to be developed.

What other 3 methods are used to prevent malaria?

• giving anti-malarial drugs and vaccines to vulnerable people e.g. women and young children.

• monitoring breeding of mosquitoes, e.g. so insecticides can be used where they are needed most.

• improving diagnosis (making accurate tests more widely available) so that people are given prompt treatment.

How successful are these 3 strategies?

Can be very effective.

However, many people live in remote rural areas with limited access to healthcare. In practice, a combination of strategies are needed.