Do Now Last Lesson Last Week Why is

  • Slides: 13
Download presentation
Do Now Last Lesson Last Week Why is malaria so rife in tropical areas?

Do Now Last Lesson Last Week Why is malaria so rife in tropical areas? Why are some diseases more common at particular times of the year? Last Week Last Topic Why is there a seasonal pattern to some vectorborne disease? Why are people migrating away from Laos and where are they going to?

Learning Objectives: q To consider how climate change influences the diffusion of emerging infectious

Learning Objectives: q To consider how climate change influences the diffusion of emerging infectious diseases. (EID)

q What does this map show? q Climate change – increases in temperature, rainfall

q What does this map show? q Climate change – increases in temperature, rainfall and humidity – has stimulated the transmission of vector-borne diseases and extended their geographic range. q Warmer and wetter conditions have favoured the growth and spread of mosquitoes carrying tropical and sub-tropical diseases. E. g. malaria; dengue fever and WNV

What is West Nile Virus?

What is West Nile Virus?

What is Lyme Disease?

What is Lyme Disease?

What is trypanosomiasis?

What is trypanosomiasis?

Tasks 1. 2. 3. 4. 5. 6. 7. 8. Read page 341. What is

Tasks 1. 2. 3. 4. 5. 6. 7. 8. Read page 341. What is WNV? Where and when was it first identified? Where is it now found? How has climate change facilitated the diffusion of this disease to increase its geographic range? What is Lyme disease? Explain how climate change has facilitated the spread of Lyme disease to a wider geographic area. What is trypanosomiasis? Explain how climate change has facilitated the spread of trypanosomiasis to a wider geographic area.

Learning Objectives: q To consider the conditions required to facilitate the spread of zoonotic

Learning Objectives: q To consider the conditions required to facilitate the spread of zoonotic diseases.

What are zoonotic infections?

What are zoonotic infections?

What are zoonotic infections? q List as many as you can- identify the carrier

What are zoonotic infections? q List as many as you can- identify the carrier as well as the disease. ü Malaria – Anopheles mosquito. ü Dengue Fever – Aede mosquito ü Sleeping sickness – tsetse fly ü Bilharzia – flatworm/freshwater snails. ü WNV – Culex mosquito. ü Dogs – rabies. ü Poultry – Asian bird flu

What conditions increase the probability of zoonotic disease being spread to humans? Unrestricted movement

What conditions increase the probability of zoonotic disease being spread to humans? Unrestricted movement of infected wild animals. Ineffective controls on the movement of diseased domestic animals. Urbanisation which creates suitable habitats for foxes, skunks etc. Limited vaccination of domestic animals. Limited control of feral animals in urban areas e. g. cats; pigeons; dogs. Hygiene and sanitation is poor and drinking water is often contaminated by animal faeces; blood & saliva. ü Ponds of stagnant water encourage insect vectors such as mosquitoes to breed. ü There is prolonged contact between humans and animals e. g. poultry farms and Asian flu. ü ü ü

Exam style Questions 1. Using examples, explain how climate change could influence the spread

Exam style Questions 1. Using examples, explain how climate change could influence the spread of disease to a wider geographical area. [6 marks]. 2. Use examples to explain why the probability of zoonotic diseases being transmitted to humans is likely to increase? [6 marks].

Q 3. Explain how physical factors affect patterns of disease. [20] § Discuss how

Q 3. Explain how physical factors affect patterns of disease. [20] § Discuss how temperature and precipitation are important drivers of vector borne diseases (also comment upon seasonal variations). § Discuss how climate change provides conditions for emerging infectious diseases (EID) diseases which have emerged in last 20 years. § Many EID are spread by mosquitoes e. g. malaria; dengue fever; Zika virus; WNV. § Outbreak and diffusion of these diseases can result form changes in climatic conditions in which vectors survive and develop. § Disease of concern for the WHO and health authorities in the Americas include Zika virus, WNV and Lyme disease. § Global warming has had the effect of extending the geographical area in which these vector-borne diseases are developing. § WNV and Lyme disease are expected to spread northwards within the USA and possibly into Canada in the 21 st century. § Increased temperatures bought about by global warming have led to the re-emergence of dengue fever in Florida where previously public health authorities had eradicated the mosquito population. § Shorter-term climate change bought about by El Nino has led to higher temperatures, heavier rainfall and greater frequency of tropical cyclones and flooding. This creates conditions for the transmission of disease like malaria, cholera or dengue fever. § Discuss the impact of relief on disease incidence and diffusion.