Case Study: Water-borne & Vector-borne Diseases (DP IB Geography)

Malaria is a vector-borne disease (parasite) carried by mosquitos 

Initially, there are no symptoms

• After a few weeks, or even up to a year, flu-like symptoms appear

• Fever, shaking chills, nausea, headaches, exhaustion, diarrhoea 

• It can be fatal

Roughly 240 million people contract malaria annually 

There are many different contributing factors to high incidences of malaria

However, poverty is the most prominent issue

• Malaria has been eradicated from much of the developed world

• Developed countries mainly worry about disease contraction during travel or as a result of the global spread of the disease

• Malaria is mostly concentrated in Sub-Saharan Africa (the lowest levels of development) 

• Malaria may spread around the world as global temperatures rise 

Anopheles mosquitos can carry the disease, and infect humans by biting

Malaria is more common in tropical and subtropical regions e.g. the Malaria Belt

• The climate is warmer and more humid. It is the ideal environment for mosquitos to thrive and reproduce

• Deforestation in rainforests also increases temperatures

Mosquitos thrive in areas with stagnant water 

• Heavy rainfall and flooding can cause standing water 

• Water collects in mining pits, irrigation channels and rice paddy fields, where mosquitos breed more efficiently 

Vulnerability: 

• Children under the age of 5

• Pregnant women

• Immunocompromised people e.g. HIV

Immunity to malaria may develop over time

• If immunity wanes, cases of malaria will rise

• Travellers or migrants may come from areas with no malaria, so they do not have immunity 

• Mosquitoes are becoming immune to drugs

Urbanisation may increase malaria

• If unregulated development occurs near water bodies, people will come into direct contact with mosquito breeding grounds 

Low income and poverty:

• Lower-income countries have very poor healthcare or reduced access to treatment and vaccines

• Poor sanitation and water sources can result in more standing and stagnant water

• Immune systems are weaker as a result of other diseases like malnutrition

• Education rates are lower, resulting in less awareness about the disease and prevention methods

• Jobs are usually labour-heavy, exposing people to mosquitos outdoors

In 2019, Ethiopia recorded 2.9 million cases of malaria

Roughly 70% of Ethiopia is at risk of malaria contraction 

As of 2020, malaria cost Ethiopia around $200 million per year (about 10% of total outgoings on healthcare)

Education rates will go down as a result of children being off sick from school

People can’t go to work due to sickness

• Directly affects the economy 

• Affects the agricultural sector and food production

• People struggle to afford food

Direct effects on the well-being of the population e.g. anxiety, grief

Malaria impacts Death Rates, Infant Mortality Rates and Maternal Mortality Rates

Pressure on healthcare systems:

• More people require treatment and medication 

• Increased staff shortages

Money goes into healthcare instead of economic or education development

• This results in economic stagnation or decline

Medicines and other preventative measures, like nets or repellants against malaria, are costly 

Lack of education and technology results in a shortage of information or knowledge about malaria epidemics

Some areas in Ethiopia experience a lower incidence of malaria due to arid climates and higher elevations (physical barriers to diffusion) 

Impacts of malaria may also be seasonal, particularly after the rainy season

Insecticides (e.g. Dichlorodiphenyltrichloroethane or DDT) have been useful in Ethiopia

• Insecticides result in water pollution and can enter the food chain

In 2003, malaria cases rapidly increased in Ethiopia 

• UNICEF led the international response, with financial aid coming from the UK, the US and the World Health Organisation 

• It funded drugs, supplies and other responses like training and investigations

• However, the funding was not enough to fully eradicate malaria and has since gone down after the economic crash of 2008

• Malaria is also becoming immune to some of the drugs 

• Malaria won’t be eradicated from Ethiopia without dealing with development issues and poverty

The U.S President’s Malaria Initiative began in 2005

• Helping to provide treatment for malaria

• Working to reduce deaths, stop cases and eradicate the diseases altogether 

Other general solutions include: 

• Travellers can take anti-malaria drugs to stop the infection

• Providing mosquito nets in high-incidence areas

• Education for people about malaria epidemics

• Stopping mosquitos at the source:

  • Covering standing water

  • Removing irrigation channels no longer in use

  • Adding marine life to bodies of water to consume mosquito larvae

  • Mosquito Breathing Traps 

Cholera is a water-borne disease

Cholera has existed for hundreds of years

• In the 19th century, cholera outbreaks were common 

• 7 major cholera pandemics have occurred over the last 200 years

• The most recent is said to have started in the 1960s and is still ongoing

• Much of the world’s cholera decreased in the 1990s, however, regions of Africa and Asia still experience high incidences of cholera

Symptoms of cholera include: 

• Watery diarrhoea (rice-water stools)

• Vomiting

• Thirst

• Leg cramping

Symptoms develop quickly, from anywhere between 12 hours and 5 days (or not at all)

Cholera bacteria stays in the stools after illness, which can cause further contamination

Cholera is mainly caused by dirty/unsafe water, poor sanitation, poor hygiene practices and low food safety 

• Vibrio cholerae bacteria contaminate water sources and enter the food chain

• The bacteria is usually found in fecal matter

• Unsafe water and poor sanitation typically occur in less-developed countries 

• If sanitation systems are not adequate, cholera can spread 

Natural disasters can increase cholera:

• Flood or tsunami waters may contain sewage and enter drinking water sources

• Earthquakes or hurricanes can damage sanitation systems, resulting in sewage leaks and contamination

War and conflict can damage sanitation infrastructure

Migrants may bring cholera into a country

Vulnerability:

• Travellers who are not wary of food and water safety

• Healthcare or aid workers

• Certain blood types e.g. O blood type

• Lower levels of stomach acid e.g. older people

• Children under the age of 5 

• Malnourishment 

In 2010, a severe earthquake hit Haiti

The United Nations aid response caused a deadly cholera outbreak

• Nepal was experiencing a cholera outbreak 

• UN peacekeepers from Nepal brought cholera to Haiti 

• Waste from the peacekeeping camp was discharged into the river used by local Haitians

• There was poor sanitation and no water treatment 

• Haiti also had low immunity, so the outbreak hit hard

Between 2010 and 2019, Haiti recorded roughly 820,000 cholera cases, with just under 10,000 deaths

The earthquake exacerbated the outbreak:

• Poor health and sanitation infrastructure meant disease spread was quick

• Overcrowding in makeshift camps 

• Diahrroea and vomit waste were not contained, causing cholera to spread 

Certain areas were hit hardest e.g. rural areas/high poverty levels:

• The Bocozel community in the Artibonite Valley was severely hit

• They relied on the river for drinking, washing and agriculture 

• There was poor hygiene and limited healthcare access

Economic losses from lack of productivity (sickness and death)

Education rates can go down as children miss school or entire schools close

People must travel far to find safe water, meaning they cannot go to work or school

Cholera was eradicated from Haiti in February 2022

• In October 2022, new cases were discovered 

• Haiti is currently experiencing a humanitarian crisis 

  • Fuel blockades, violence and unrest, lack of food and clean water and a cholera outbreak 

• With hospitals closing, not enough medical staff, lack of fuel, food and water, the cholera outbreak could worsen

Internationally, cholera is a threat to the world

• However, it mainly impacts the developing world

Rapid Response in Haiti in 2013:

• After a case is reported, a team visits the family and works through a questionnaire on hygiene, sanitation and water sources

• This locates the source of the outbreak quickly

• Teams disinfect houses and show locals how to stay safe

• Provision of chlorine for a month and antibiotics for all family members 

• The team creates a sanitary zone

• The team returns later to assess the situation

• In 2017, Haiti had 88 rapid-response teams

2013 National Plan for the Elimination of Cholera with UNICEF and the government of Haiti

• Funding from the European Commission Department for Civil Protection and Humanitarian Aid (ECHO)

Other general solutions include;

• Improvements to healthcare systems that can cope better with outbreaks

• Improvements to the access to water, sanitation and hygiene systems (WASH)

• Drinking sealed water 

• Boiling water before use or using chlorine treatments

• Cooking food well, particularly seafood

• Consistent handwashing

• Disposing of waste at a distance from water sources or communities 

• Track and surveil outbreaks

• Community support and education e.g. health practices

• Cholera vaccine