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Case 8: Public Health - Coggle Diagram
Case 8: Public Health
Water resources of EarthProvide an overview with regards to Water Resources on Earth
- SA is by definition, water stressed
- There is a small percentage of fresh water available
- Saline-ground water and Sea water are not considered fresh water reserves as they require treatment before use
- Countries with a higher rainfall tend to have vast water resources
How much water does each person need ?
- According to the WHO each person requires an estimate of 7.5 litres per day for Drinking
- This is based on lactating women doing moderate physical activity in above-average temperatures
- Basic hygiene and basic food hygiene needs a minimum of 20 litres
- United Nations suggests that each person needs 20-50 litres of water a day to ensure their basic needs for drinking, cooking and cleaning
Water and Disease
- John Snow is a famous epidemiologist who figured out the cause of Diarrhoea Epidemic in London
List the types of Water Diseases
- There are 4 types of Diseases associated with Water:
- Water-Borne
- Water-Washed
- Water-Based
- Water-Related
Water-Borne DiseasesDescribe Water-borne Diseases
- Water-borne Diseases are diseases that are caused through the consumption of biologically and chemically contaminated water (can also be food)
- Water-borne diseases are caused by Protozoa, Viruses, Bacteria and Toxins or Metals
- Water-borne Diseases are related to the quality of water.
- Examples of Water-borne Diseases:
- Diarrhoeal Disease (Rotavirus)
- Infectious hepatitis
- Typhoid
- Arsenic toxicity
- Cholera
The 6 F's of Faecal-Oral TransmissionList the 6 F's of Faecal-Oral Transmission
- The 6 F's of Faecal-Oral Transmission:
- Faeces
- Fingers
- Fluids
- Flies
- Fields (Farming, Recreational activities)
- Food
- The 6 F's of Faecal-Oral Transmission is simple way to remember how disease can spread from infected Faeces
- Which may contain contaminate Water or Fingers
- Where the Fingers of an infected person may have Flies land on them and contaminate the Fields where people Walk, Farm or Play
- This means that the pathogen can enter Food and thereby enter a new host
Water-Washed DiseaseDescribe the Water-Washed Diseases
- Water-washed diseases are diseases accused through the use of inadequate volumes of water used for personal hygiene
- Water-Washed Disease are related to the quantity of water
- Examples of Water-Washed Disease:
- Trachoma
- Skin (Scabies)
- Eye Infections
The Life-Cycle of a TrachomaDescribe the Life-Cycle of a Trachoma
- Trachoma is an example of a Water-Washed Disease
- Infecting the Eyes
- Flies carrying the micro-organism (Chlamydia trachomatis) land on children's eyes to feed on discharge
- Or Dirty hands or face cloths also spread the disease causing micro-organism
- Family Contact
- Women taking care of the children also get the infection
- Speeding Out
- Flies that breed in human faeces spread the disease to other
- Trachoma can cause Blindness
- Infections inflame and thicken the eyelid
- Scarred eyelids turn inwards
- The lashes scratch the Cornea, leading to blindness
Deadliest Animal in the World ?
Water-Based DiseasesDescribe the Water-Based Diseases
- Water-Based Diseases are diseases caused by a pathogen that requires or spends part of its life in an intermediate aquatic host
- Water-Based Diseases are related to contact with or proximity to water
- Example of Water-Based Diseases:
- Guinea worm into copepods (water fleas)
- Schistosomiasis mansoni, Schistomiasis japonicum and Schistomiasis haematobium (bilharzia) into snails
- Schistosomiasis is common in children who play in contaminated water
Outline the the Life Cycle of a Guinea Worm
- Human drinks unfiltered water containing copepods with L3 larvae
- Larvae are released when the copepods die
- Larvae then penetrate the host's stomach and intestinal wall
- They mature and reproduce
- Fertilized female worms migrates to surface of the skin, causes a blister, and discharges larvae
- L1 larvae released into water from the merging female worm
- Female worm begins to emerge from the skin one year after infection
- L1 larvae consumed by copepods
- Larvae undergoes two molts in the copepod and become L3 larvae
Water-Related VectorDescribe the Water-Related Disease
- Water-related which are spread through insect vectors associated with water
- Examples of Water-Related Diseases:
- Malaria (Plasmodium)
- Dengue fever
- Chikungunya
- Zika
Distribution: Global Burden of Water-Related DiseaseGlobal Burden of Diarrhoeal DiseaseOutline the Global Burden of Diarrhoeal Disease
- According to the WHO, there is an estimate of 2 million deaths per year due to Diarrhoeal Disease
- Diarrhoea is the 3rd highest cause of infectious disease deaths
- Diarrhoea causes the most deaths amongst children under the age of 5 years
- Diarrhoea has an Average Attack Rate of 3.2 episodes a year
- But in some developing countries it has an Average Attack Rate of 12 episodes per year
- Diarrhoea has Long-term consequences of such heavy disease burden in early childhood:
- Impairs physical and mental development of children
- Impairment in human fitness as adults
Under 5 Diarrhoeal IncidenceExplain the Under 5 Diarrhoeal Incidence
- Under 5 Diarrhoeal Incidence is an indicator that measures the episode of diarrhoea in children under five years per 1000 population under five years
- Diarrhoea is defined as the passage of three or more watery loose stools in 24 hours
- BUT any episode diagnosed and/or treated as diarrhoea after an interview with an adult accompanying the child should be counted
- The outcome of this Indicator serves as a vital domestic indicator in tracking efforts directed towards reducing mortality in South Africa
Determinants/Risk Factors: Socio-Ecological FrameworkOutline the Socio-Ecological Framework of Diarrhoea
- Biological
- Greatest risk in infants
- Immunosuppression
- Inadequate Nutrition
- Behavioural
- Lack of Breastfeeding
- Hygienic practices
- Cooking practices
- Societal
- Lack of parental education
- Cultural norms and belief
- Structural
- Poverty and poor living conditions
- Over-crowding
- Poor water and sanitation
- Inadequate water supply
- Poor waste disposal
- Poor access to healthcare
List the Risks of Diarrhoea
- Unsafe drinking water
- Poor hygiene
- No place to discard washing water, which ends up running into storm water drains
South African Situation
- More than 90% of SA have access to clean public water
- More than 70% use a latrine or toilet
- However, approximately 6 million households do not have access to piped water in their homes
- 1.4 million households still lack access to sanitation services
Global Burden of Water-Related Diseases
- Malaria
Outline the Epidemiology of Malaria
- The annual incidence of Malaria varies widely
- World Malaria Report 2017:
- 216 million episodes in 2016
- Malaria deaths were 445 000 in 2016
- 90% in African regions, other affected areas such as South-East Asia, Eastern Mediterranean Regions
- 91% of Malaria infections are due to Plasmodium falciparum
- But the number of cases may be much more as number of confirmed cases reported by national programme was only 11% estimated cases
- Prevention Method of Malaria is Vector Control
- Schistosomiasis (Bilharzia)
Outline the condition: Schistosomiasis (Bilharzia)
- Schistosomiasis (Bilharzia) is due to two main Schistosome species:
- Schistosomiasis haematobium
- Schistosomiasis mansoni
- Schistosomiasis infection is often followed by acute fever or non-specific symptoms
- If left untreated Schistosomiasis infection develops into a Chronic Condition characterised by a Hepatosplenic disease and impaired physical and cognitive development
- Global Burden of Disease study estimates 1.7 million disability adjusted life years lost in 2002 mainly as a result of morbidity
Global Burden of Water Disease
- Trachoma
- 500 million people are at risk from Trachoma
- Helminth Infections
- 133 million people suffer from high intensity intestinal helminth infections which often leads to severe consequences such as:
- Cognitive impairment
- Massive Dysentery
- Anaemia
- Clinical Hepatitis A
- There are 1.5 million cases of clinical hepatitis A
- Arsenic Toxicity
- Arsenic contamination of ground water has been found in many countries such as China, Chile, Bangladesh, India, Mexico
Prevention of Diseases associated with WaterList and Outline the Levels of Prevention
- Primordial
- Primordial prevention involves targeting the entire population
- Primary
- Primary prevention involves preventing the occurrence of a disease in at risk individuals
- Secondary
- Secondary prevention which involves treating and screening individuals with the disease but may be asymptomatic
- Tertiary
- Tertiary prevention involves reducing morbidity and mortality in individuals with the disease
Primordial Intervention in the prevention of Water associated DiseasesOutline the types of Primordial Interventions used in the prevention of Water associated Diseases
- Primordial Interventions fall under Upstream Interventions
- Primordial Interventions used in the prevention of Water associated Diseases are as follows:
- Increase the quantity of water available
- Recognise the right to water through appropriate policy
- Ensure access to clean water supply
- Safe storage of water
- Treatment of water at source
- Treatment of water at the point of use (Chemicals, boiling, pasteurisation and solar disinfection)
- Ensure adequate sanitation facilities
- Proper maintenance of sanitation facilities
- Safe disposal of faeces via sewerage system
- Septic tanks
- Pour-flush latrines
- Pit latrines
- Other poverty-alleviating strategies
- Strengthen health system - strengthen prevention programmes, improve health care
Primary InterventionsOutline the types of Primary Interventions used in the prevention of Water associated Diseases
- Primary interventions fall under Downstream Interventions
- Primary Interventions used in the prevention of Water associated Diseases are as follows:
- Food Hygiene
- Wash food
- Protect food from flies
- Improve personal hygiene behaviour such as handwashing
- Promote and support breastfeeding
- Micronutrition supplementation - Vitamin A
- Vaccinate against Rotavirus (RotaRix, RotaTeq)
Secondary/Tertiary PreventionOutline the types of Secondary/Tertiary Interventions used in the prevention of Water associated Diseases
- Secondary/Tertiary Interventions fall under Downstream Interventions
- Secondary/Tertiary Interventions used in the prevention of Water associated Diseases are as follows:
- Treat diarrhoea promptly
- ORS
- Zinc
- Feeding
- Antibiotics for Dysentery
- Treat co-morbidities
Rotavirus VaccineOutline the Rotavirus Vaccine
- In 2009 South Africa was the first country in Sub-Saharan Africa to include the Rotavirus vaccine in routine immunisations
- Rotavirus vaccination is an Upstream Commitment in preventing Diarrhoeal Disease
- It is difficult to measure the impact of the Rotavirus Vaccine
- It is important to note how to Assess and Measure the impact and effectiveness of an intervention such as Vaccine using study designs
BreastfeedingOutline the relation of Breastfeeding to Water
- In 2011, the South African Breastfeeding Policy was revised
- Phasing Out Free Infant Formula to babies born to HIV positive mothers
- Promotion of breastfeeding in all, including HIV positive mothers
- This is because research indicated that the risks of Diarrhoeal Disease were higher in Formula Fed HIV-exposed Babies
- As the formula was often prepared with unclean water
- Although, there is a small risk of HIV transmission through Breastfeeding
- The adequate use of ARVs makes the risk of HIV transmission very small
- However, the risk of Diarrhoeal Disease in Breastfed babies is notable diminished
- This demonstrated the impact of Surveillance and Research on policy
Emerging Challenges of Water: Climate ChangeOutline the Effects of Climate Change
- Climate Change refers to the economic activities that increase the emission of greenhouse gases (GHG)
- Resulting in raised Carbon Dioxide (CO2), Methane, and Greenhouse Gases increasing the heat-trapping capacity of the lower atmosphere resulting in global warming
- Climate Change presents as:
- Raised Surface Temperature with more dry days and increased number of hot nights
- Increased frequency and intensity of extreme weather events (storms, droughts, floods)
- Rise in sea levels
- Change in rainfall patterns
Outline the Effects of climate Change on Water Supply
- Water insecurity: Affecting crop yields
- Poor water quality
- Heavy rains leads to storm water discharge of contaminants compounded by discharge of untreated sewage mixed in water sources
- Water scarcity
- Which results in higher concentrations of salt and chemical contaminants in the water
- Rising sea levels results in salination of fresh water supplies, loss of productive farm land and changes in breeding habitats for vectors
- Eg: Mosquitoes and snails