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

Malaria 

• 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 

Causes of Malaria

• 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

The Malaria Belt

Impacts of Malaria in Ethiopia

• 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

Solutions to Malaria in Ethiopia 

• 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

• 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

Global cholera cases in 2023

Causes of Cholera

• 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 

Impacts of Cholera in Haiti

• 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

Solutions to Cholera in Haiti  

• 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