Disease Dilemmas Flashcards
What are infectious diseases?
Diseases that are spread by pathogens and such as bacteria, viruses, parasites and fungi
What are non-infectious diseases?
Diseases which are not spread from host to host and are caused by external factors such as lifestyle or genetic inheritance (can also be referred to as degenerative diseases and non-communicable diseases)
What is a contagious disease?
Able to be passed directly form one host to another
What is a non-contagious disease?
Not readily transmitted from one host to another
What is a communicable disease?
A disease that can be spread from one person or species to another, directly or indirectly
What is a non-communicable disease?
A disease not capable of being spread from one host to another
What are the type of NCDs?
-Cardiovascular
-Cancer
-Chronic respiratory
-Diabetes
What is an endemic?
Present at a continuous level throughout a population/geographic area
What is a an epidemic?
A widespread outbreak of an infectious disease
What is a pandemic?
Disease that occurs over a wide geographic area and affects a very high proportion of the population
What is a zootonic disease?
A disease communicable from animals to humans under natural conditions; also know as zoonosis
What is morbidity?
Refers to ill health in an individual and the levels of ill health in a population or group
What is a vector?
A third party organism that carries and transmits a communicable disease
What is a pathogen?
An organism that causes a disease
What is a bacteria?
-Living organism
-Unicellular (one cell)
-Larger than virus (1000nm)
-Usually treated with antibiotics
What is a virus?
-Not living, no cells
-smaller than bacteria (20-300nm)
-Means poison in latin
-Antibiotics will not effect the disease
What is a fungi?
-Fungi are a group of eukaryotic organisms that include microorganisms such as yeasts, molds and mushrooms
-Belong to a single kingdom called Fungi
-Only few fungi species cause diseases to
human and plans
-Certain lung! species have commercial
values (ex: yeast mushrooms etc.)
-Yeast, moulds and mushrooms
What is a parasite?
-Parasites are organisms that live on or in a host organism and get foods at the expense of its host
-Belong to several Kingdoms including
Bacteria, Protista, Fungi and Animalia
-All parasites cause injuries or disease to their host
-Do not have a commercial value
-Bacteria, virus, worms: flukes tapeworm and Foundworm, some fungi Species, and arthropods: ticks, lice, etc
What is a degenerative disease?
Degenerative diseases are the result of a continuous process based ondegenerative cell changes, affecting tissues or organs, which will increasingly deteriorate over time, whether due to normal bodily wear or lifestyle choices such as exercise or eating habits
What would cause an increase in the transmission of zootonic diseases?
-Movement of infected animals is unrestricted by physical barriers (e.g. mountain ranges), or in the case of domestic animals, political boundaries
-Controls on the movement of diseased domestic animals within countries are ineffective
-Urbanisation creates suitable habitats for animals
-Vaccination of pets and domestic livestock is sparse
-There is limited control within urban areas of feral dogs, cats, pigeons and other animals
-Hygiene and sanitation are poor, infrastructure is lacking; drinking water is contaminated by animal faeces, blood and saliva
-Man-made habitats (e.g. surface pools, ponds) encourage insect vectors to breed
-There is prolonged contact between humans and animals, e.g. poultry farms and avian flu, cattle farming and anthrax.
-Poverty and high population density contribute to humans and farm animals living in close contact
What is prevalence?
Total number of cases in a population at a particular time
What is incidence?
Number of new cases in a population during a particular time period
What is the global distribution of malaria?
-Heavily concentrated in Africa, Latin America, South Asia and Southeast Asia
-In 2018, 220m were infected
-3.2b are at risk in 97 countries
What is the global distribution of tuberculosis?
-In 2018 there were over 10 million cases of TB worldwide and 1.5m deaths
-Present in all global regions , though 95% of deaths occur in low and middle income countries
-Africa has by far the highest number of TB deaths, with a large proportion of HIV/AIDS sufferers
-Mortality rates from TB in 2018 were 64/100,000 in Nigeria and 72/100,000 Mozambique
-Outside Africa, TB mortality rates are high in many parts of Asia, and especially in Afghanistan, Myanmar and Cambodia
What is the global distribution of HIV/AIDS?
-In 2020, 38m people were infected with HIV/AIDS worldwide
-Global distribution of the disease is highly uneven
-Main concentration of the disease is in Sub-Saharan Africa
-South Africa have the largest numbers of HIV/AIDS cases, while in Switzerland and Lesotho more than a quarter of the population carry the disease
What is the global distribution of diabetes?
-Globally the disease afflicts nearly 400m people and it is responsible for nearly 4.2 m deaths annually
-Widespread in both the developed and less developed world but it is mostly concentrated in North America, East and South Asia
What is the global distribution of CVD?
-CVD is a major cause of mortality and morbidity in ageing populations in high-income countries
-Highest CVD mortality rates are found in Russia, sub-Saharan Africa and the Arabian Peninsula
-CVD is responsible for 17 million deaths a year, with 80% occurring in low and middle income countries
What are the 4 Hagerstrands models of diffusion?
-Expansion diffusion
-Relocation diffusion
-Contagious diffusion
-Hierarchical diffusion
What is expansion diffusion?
-Infection spreads out from source in all directions from point of origin
-Expanding disease diffuses outwards into new areas
-The disease often intensifies in the originating area
-E.g.
-1918 Spanish Flu killed an estimated 40 million people worldwide within just a few months
-Also the H1N1 swine flu virus from Mexico
What is relocation diffusion?
-Infection spreads into a new area, leaving behind its origin or source of the disease
-E.g.
-Cholera epidemic in Haiti in 2010, which killed 7000 people. The disease originated in Nepal and was brought to Haiti by international aid workers flown in to tackle the earthquake disaster of that year
-
What is contagious diffusion?
-Infection is spread through direct contact
-Individual hosts carrying the disease pass it on to new contacts
-Strongly influenced by distance, nearby individuals/regions have much higher probability of contact than remote ones
-Contagious spread tends to occur in a centrifugal manner from the source region outward
-E.g.
-The Ebola epidemic in West Africa in 2014-2015 is a classic example of contagious diffusion
What is hierarchical diffusion?
-The infection spreads down through a particular system
-Spreads through an ordered sequence of classes or places
-E.g. from cities to large urban areas to small urban areas
-E.g.
-HIV/AIDS in USA appeared first in San Francisco and then major cities such as L.A./ New York then spread to smaller cities and then towns.
How can diseases be spread?
-Crowded living + working conditions
-Inadequate sanitation
-Unclean water supplies
-Inadequate nutrition> too little or too much!
-Low income> no medical help, no resources [e.g. soap/household cleaners, mosquito net/repellent, antiseptic cream etc.
-Long working hours
-Physically exhausting work
-Lack of or inaccessible health care
-Exposure to health risks at work as legislation is not enforced
-Inadequate education, e.g. HIV/AIDS sufferers not understanding the concept of safe sex
-Movement of people, increasing due to globalisation
What is the neighbourhood effect?
Probability of contact between a carrier and non carrier is determined by the number of people in a 5x5km square. More people = higher probability
What is meant by barriers of diffusion?
Barriers which limit the spread of disease and can be physical or socio-economic
What are the physical barriers to diffusion?
-Neighbourhood effect
-Island or land borders
-Transport links are poor
-Physical geographic barriers (terrain, climate, rivers, water, distance)
-Trade
-Quarantine
-Communication
What are the socio-economic barriers to diffusion?
-Poverty/wealth
-Class separation
-Treatments
-Migration
-Social boundaries (personal space)
What are the factors that have hindered reduction in incidence of disease?
-Social stigma
-Social stigma/fear
-Culture/religion
-Multiple use of water source
-Over-use of pesticides
-Medication side-effects
-Cost
-Poverty/inequality
-Poor education
-Low status of women
-Food source
-Globalization
How does temperature and precipitation effect the global pattern of disease?
-Many diseases including malaria, dengue fever, yellow fever, and sleeping sickness whose epidemiology depends on warm, humid conditions , are endemic to the tropics and subtropics
-Temperature determines rates of vector development and behaviour as well as viral replication
-Precipitation creates aquatic habitats such as ponds and stagnant pools, which allow insects and disease vectors to flourish and complete their life cycles
How does relief and water effect the global pattern of disease?
-Altitude causes abrupt changes in climate and disease habitat
-Thus in Ethiopia, malaria is concentrated in the humid lowlands but is largely absent in the cooler highlands
-In the developing world, millions of people rely on water from wells and surface supplies contaminated by sewage
-Bacteria responsible for cholera and other infectious diseases thrive in these conditions
-Unprotected and stagnant drinking water supplies also provide habitats for disease vectors e.g. copepod vectors which transmit the parasitical disease Guinea worm to humans in West Africa
How can physical factors influence vectors of disease?
-Dengue fever is widespread in the tropics
-Annually it affects around 400m people and is responsible for 25,000 deaths
-Climate controls dengue fever epidemiology and the life cycle of Aede mosquitoes that transmit the dengue virus to humans
-Mosquitoes thrive in warm, humid conditions, which in turn favours the outbreak of dengue
-In the south pacific sustained temperatures of more than 32’C and humidity levels of above 95% trigger waves of dengue epidemic
-These conditions occur in the summer months , but short-term weather changes and exceptional rainfall events can also lead to outbreaks of the disease
How do seasonal variances influence the outbreak of disease?
-In temperate regions in the northern hemisphere, epidemics of influenza, a contagious respiratory illness peak in the winter months
-Transmission of the flu virus is most efficient at lower temperatures and atmospheric humidity is low (winter)
-In the tropics and sub-tropics , vector-borne diseases transmitted by mosquitoes, flies, ticks, fleas and worms often reach a peak during the rainy season e.g. diarrhoeal disease in South Asia surges in pre-monsoon and end of monsoon periods when fly populations are the highest
-Sand flies which transmit the protozoan causing leishmaniasis to humans, are most abundant in the rainy season when infection peaks
How did climate change trigger the WNV in Uganda and what were the effects?
-Warmer and wetter conditions have favoured the conditions the growth and spread of mosquitoes carrying tropical and sub tropical diseases
-WNV was first identified in Uganda in 1937 and was transmitted by culex mosquitoes
-Birds are the main hosts for the virus
-WNV is prevalent throughout Africa; in the Americas its range extends from Venezuela to Canada and it is also found in parts of Europe, West Asia and Austalia
-In 2012, 5500 cases of WNV were reported in the USA
-High temperatures favour transmission, hence Texas is one of the US states most severely affected
How did climate change trigger sleeping sickness in Africa and what were the effects?
-Sleeping sickness is endemic in 36 sub-Saharan countries and affects 70m people
-It is transmitted to humans by the tsetse fly
-Outbreaks of the disease occur when avg temperatures are in the range 20.7-26.1’C
-Future climate change will affect the vectors growth rate and the geographical distribution of the disease
-As temperatures rise, sleeping sickness is likely to spread to southern Africa and according to WHO will affect up to 77m more people by 2090
-However the disease may disappear from East Africa where the climate may become too hot for tsetse larvae to survive
When is the probability of zootonic diseases being transmitted to humans increased?
-The movement of infected wild animals is unrestricted by physical barriers, or in the case of domestic animals, political boundaries
-Controls on the movement of diseased domestic animals within countries are ineffective
-Urbanisation creates suitable habitats for animals such as foxes, raccoons and skunks
-Vaccination of pets and domestic livestock is sparse
-There is limited control within urban areas of feral dogs, cats, pigeons and other animals
-Hygiene and sanitation are poor; drinking water is contaminated by animal faeces, blood and saliva; man-made habitats encourage insect vectors to breed
-There is prolonged contact between humans and animals , e.g. poultry farms and avian flu , cattle farming and anthrax
What is Abdel Omrans model of the epidemiological of transition?
Describes the relationship between development and changing patterns of population age distribution, mortality, fertility, life expectancy and causes of death. Changes are driven by improvements in health care, standards of living and the quality of the environment.
What are the 4 epidemiological phases according to Omran?
-The age of pestilence and famine
-The age of receding pandemics
-The age of degenerative and man-made diseases
-The age of delayed degenerative diseases
-The era of health regression
What is the age of pestilence and famine?
-Malnutrition
-Infectious disease
-35 yrs (Life expectancy)
- <10% deaths from CV
- Infectious(RHD) /Nutritional (Dominant CVDs)
What is the age of receding pandemics?
-Improved nutrition and public health
-Chronic disease
-Hypertension
-50 years (Life expectancy)
-10-35% deaths from CV
-Infectious(RHD)/ Stroke haemorrhagic (Dominant CVDs)
What is the age of degenerative and man-made diseases?
-High fat and calorie intake
-Tobacco use
-Chronic disease> infectious, malnutrition
- >60 years LE
- 35-65% deaths from CV
-Ischemic heart disease (IHD)/ Stroke-haemorrhagic, ischaemic
What is the age of delayed degenerative diseases?
-Leading causes of mortality CV and cancer deaths
-Prevention and treatment delays onset
- Age-adjusted CV death reduced
- >70 years LE
- 40-50% deaths from CV
-IHD
-Stroke-ischaemic
-CHF
Limitations for the epidemiological transition model?
-Firstly, the rate of improvement in life expectancy is slowing down and in some developed countries, increases have been very slight in recent years or even, as in the UK, actually falling (13 months, fall since 2015 for men, 14 months for women).
-Secondly, there are significant concerns about our ability to cope with viral or bacterial diseases in a globalised world where epidemics can very quickly become pandemics
-Thirdly, there are some who express concerns about the relationship between industrial agriculture, the destruction of natural ecosystems and human health, especially our vulnerability to zoonotic diseases. For many of these critics, Covid-19 had very human origins rather than being a random and so essentially unpredictable event.
How can poverty cause certain types of disease?
-Less access to clean water -> water borne d’s
-Insecure land tenure -> malnutrition
-No money for healthcare -> death
-Poor or expensive transport -> no access to care
-Poor sanitation -> wastes left
-Inadequate housing -> lack of protection from elements and disease vectors
-Lack of immunisation -> more infant deaths
-Low employment -> more work in sex industry -> STIs
-Stress of daily life -> mental health issues
-Child workers -> lack of health and safety
Why do LIDCs have higher prevalence of communicable diseases?
-Stigma and discrimination around diseases of poverty - people have fear of disease and don’t understand how it works, which can have individual socioeconomic consequences. Furthermore, marginalised groups are often deprived of medicine etc.
-Lack of money - lost labour time to disease reduces income (spiral of decline), often treatment costs are diverted to pay for education etc.
-Housing conditions - tend to be more cramped (easier spread), slums have poor sanitation and clean water.
-Hunger, starvation and famine - leads to malnutrition, which can weaken the immune system.
-Economic burden - areas of high transmission of certain diseases (i.e. malaria in Africa) divert significant health expenditure away from development investment, compounding the problem.
-Weak health systems - weaker in poorer countries.
-Lack of economic incentive - perceived “lack of market” has reduced incentive to develop technology against diseases of poverty.
Infrastructure - lack of sanitation or clean water, poor drainage or flood defences provides breeding grounds for mosquitoes.
-Politics - diseases of poverty affect those with little political voice.
-Location - most LIDCs are in tropical regions where most communicable diseases spread
Why do ACs have higher rates of NCDs?
-Less exercise - car ownership, service industry work often involves sitting at a desk for 8 hours.
-High fat and sugar diet - meat becomes common to eat, cheapest food is processed and unhealthy.
-Increased leisure time - people spend this relaxing, binge-watch culture supports extended time not moving, internet permits for social connections without having to move.
-Higher usage of tobacco and alcohol - tobacco use accounts for 6m deaths a year, and alcohol is an expensive luxury made more affordable by increasing incomes.
-Longer life spans - older people are much more likely to be affected by DOAs.
-Variance in socio-economic status - lower income individuals in ACs are often forced into unhealthy lifestyles due to income effect, and their environment.
-Lack of political will to change - globalisation normalises behaviour and activity that are harmful, and few people are willing to change.
Increased exposure - people are less exposed to CDs at a young age, via immunisation, which makes them more vulnerable to chronic autoimmune and respiratory diseases
Who are the WHO and who do they work with?
-Established in 1948, HQ in Geneva, Switzerland. The WHO is the directing and co-ordinating authority on international health within the UN system (includes 194 member states)
-Governments and international organisations such as UNICEF, the World Bank and a variety of NGOs including the ‘Red Cross and Red Crescent Movement’
What are some of the roles of WHO?
-Gathering health data
-Researching health problems
-Monitoring the international health situation
-Supporting UN member states to devise health strategies
-Providing leadership and identifying priority areas in matters critical to health
-Providing technical support during health crises
The role of WHO in predicting diseases?
Zika virus a recent example emerged in Uganda in 1947, causes birth abnormalities such as small heads. WHO had vaccine programme already in place and operating prior to outbreak in 2016, with clinical and non clinical trials. The virus could potentially spread globally, and the WHO continue to fund vaccine development to deal with it.
The role of WHO in gathering data?
1/3rd of 150 members give data on cause of death. 21 sustainable development goals for health, with data the main method of measuring success. However, 2/3rd of members don’t give cause of death data which makes mitigation difficult. Data is collected by household surveys, routine reporting by health services, civil registration and disease surveillance systems.
The role of WHO in research?
-Mosquito born viral infection, deadliest tropical disease, 100-400m cases per year. Mortality rates <1% with proper access to medical care.
-WHO-led research using GIS data in Fortaleza to map outbreaks and isolate the major mosquito hotspots, allowing specific control of city blocks. Allows prevention by cleaning water storage, covering water stores and sometimes insecticide.
The role of WHO in support programmes?
Drug resistant HIV/AIDS due to uptake in antiretroviral therapy, price has increased by 200% since 2010.
-2015 - WHO recommend the therapy for all HIV patients.
-WHO provide a roadmap for Kenya and other African nations for long term prevention - distributing contraception to mitigate.
-WHO fund programmes to educate the most at risk (sex workers and LGBT people).
-Pushing voluntary male circumcision to reduce chance of infection by 60%, 20k have already done it.
The role of WHO work with other agencies and governments?
-Work to promote universal healthcare - since 2012, WHO have worked in China and now 172m previously uninsured are insured.
-Helped create Peoples Insurance in Mexico, giving universal coverage.
-WHO led programmes in Rwanda has halved child mortality and increased life expectancy by 10 years since 1994.
What are physical barriers?
Factors that lead to isolation of communities and restrictions of population movement. Mountain ranges, large water bodies, areas of aridity (deserts), extreme climates or natural hazards. Self-imposed isolation can also be a barrier
What are some physical barriers?
-Relief
-Natural hazards
-excess water
-Remoteness of communities
What are the positive effects in mitigation strategies and response efforts? (relief)
-Stop the spread of disease through vectors such as mosquitos due to climate
-Restrict movement of people between areas
What are the negative effects in mitigation strategies and response efforts? (relief)
-Difficult to access communities to respond to the outbreak
-Communication difficulties between agencies
What are the positive effects in mitigation strategies and response efforts? (natural hazards)
-Can restrict movement of people
-Heavy rainfall / winds e.g. Hurricanes can wipe out some vectors
-Can mobilise response units quicker particularly from NGOs
What are the negative effects in mitigation strategies and response efforts? (natural hazards)
-Contaminated water supply after earthquakes / tsunamis / hurricanes leading to stagnant water => water borne disease
-Homes / hospitals destroyed so large numbers of people displaced into close proximity e.g. refugee camps => quicker spread of disease
Injuries caused by natural disaster can lead of open wounds and a greater vulnerability to diseases
-Infrastructure destroyed => lack of routes to move equipment
-Hazards e.g. volcanic eruption could lead to danger for response teams
-Medical personnel could have been injured / killed in the natural hazard
What are the positive effects in mitigation strategies and response efforts? (excess water)
-Potentially can be used to clean / sanitise areas
-Could reduce impact of fires / volcanic eruptions
-Access to medical support via medical ships
-Evacuation route if air travel is not available
-Ability to impose quarantine e.g. Chesapeake Bay restricted measles from 1917-1938
What are the negative effects in mitigation strategies and response efforts? (excess water)
-Stagnant water => can lead to water borne diseases
-Contaminated water supplies
-Inaccessible to emergency relief efforts
-Flooding could then damage buildings and lead to mass evacuation
-Breeding ground for vectors such as mosquitos
-Equipment could be destroyed
What are the positive effects in mitigation strategies and response efforts? (remoteness of communities)
-Restrict population movements
-Reduce the risk of communicable disease due to lack of contact e.g. tribes in the Amazon were not in contact with western diseases
-Natural quarantine of certain diseases e.g. Ebola in the 1980’s was naturally contained amongst the Congo rainforest communities
What are the negative effects in mitigation strategies and response efforts? (remote of communities)
-Delay the arrival of medical supplies e.g. Gorka region of Nepal – settlements a day+ walk away from medical support
-Populations may not have natural resistance to diseases e.g. Nahua tribe, Peru, first contacted in 1980’s was wiped out by disease brought by oil exploration workers
-Lack of wider immunisation programs
-Focus on subsistence farmers so more prone to zoonotic diseases transferred from their animals
-Lack of immunity leads to rapid spread of the diseases in the area
-Lack of education could lead to difficultly spreading mitigation information / sanitation issues
HIV/AIDS stats ?
-Spreads though bodily fluid transmission, but not saliva or urine.
-35m+ deaths since start of pandemic.
-25% of 15-50 year olds in Botswana have it.
-1.1m in USA.
Organisations involved in the mitigation of HIV/AIDS?
-UN MDG 6a was to reverse the spread of disease by 2015 - achieved
-6billion to achieve universal AIDS healthcare by 2010, not achieved.
-WHO and UNICEF fund government strategies.
Prevention strategies by government organisations for HIV/AIDS?
-Reduce high risk behaviour through education on spread.
-Encouraged use of physical (not chemical) contraception.
-Don’t needle share.
-Promotes equality for groups at risk - gay men, sex workers, migrant workers/refugees and drug users.
-Better data gathering by governments to help each country target those most at risk.
-Campaigns to remove social stigma - big success
What are the HIV/diagnosis strategies formed by government organisations?
-Screening for antibodies the main method used in ACs - reduces risk of HIV developing into AIDS.
-Education pushes people into getting tested.
-These tests are expensive, so many lower income countries can’t afford it
Treatment of HIV/AIDS by government organisations?
Highly active anti-retroviral therapy (HAART) - 8m globally use these drugs, 6m in developing countries through a global fund. Still too expensive for many in the poorest countries.
How is the bark of white willow useful in medicine?
-The drug salicin comes from this plant
-Pain relief, gout and osteoarthritis
-Location:
River banks, floodplains and wetlands in temperate zones - mostly Europe and West/Central Asia
Light sands to heavy clays, pH 5.5-8
6-18C, with seasonal changes, 500-800mm precipitation
How are cocoa plants useful in medicine?
-The drug caffeine comes form this plant
-CNS, heart and muscle stimulant, used for migraines, epidurals and anaesthesia
-Location:
Tropical and subtropical climates
Well drained and organic soil, pH 4-6.5
20-27C, 1000-2000mm rainfall
How is the Dried bark of cinchonas evergreen tree useful in medicine?
-The drug quinine comes from this plant
-Kills malarial parasites in red blood cells
-Location:
Tropical Andean forests of West S America, in cool and humid mountain regions, 1200-3000m
Well drained fertile soil with organic matter, pH 5.5-6.5
How is the Autumn crocus useful in medicine?
-The drug colchicine comes from this plant
-Cancer and gout treatment
-Mediterranean climate, in woodland and meadows, sea level to Alpine tundra in Med basin
Deep and well-drained soils, pH 6.5
10-27C, 350-700mm precipitation, rainy winter and dry summer
How is the tobacco plant useful in medicine?
-The drug nicotine comes from this plant
-Treats wounds and Alzheimer’s
-Tropical and subtropical Americas
Light to medium textured soil with good drainage, pH 5.8
20-30C, 600-800mm rainfall, frost free
What is a wild population?
one that grows in natural surroundings and is not looked after by people
What is meant by cultivation?
planting, tending and harvesting of plants
What is meant by pharmaceutical
a compound manufactured for sale as a medicinal drug
What is meant by synthesised?
something is made chemically
Facts about the conservation of some medicinal plants?
-Medicinal plants are generally sourced from wild populations
-The majority of pharmaceutical drugs are made from synthesised products
-TCM often use the root of plants rather than the leaves/flowers which increases the risk of extinction
-Some plants are cultivated for medicinal use, for example the Rosy periwinkle and foxglove
-Traditional medicines, including traditional Chinese medicines (TCM) are still made from wild plants
-Demand for traditional medicines is huge. 80% of the world rely on traditional medicines – 5 billion people
Conservation issue figures?
-1970s there were already 21,000 medicinal plants listed
-In China 4,941 of 26,092 native species are used for medical purposes (18.9%)
-Certain plant families more likely to be of use for medical purposes
-1300 native European species are used for medical purposes, 90% of which are harvested from the wild
-25% of drugs in ACs are derived from wild plant species
Why is it better to wild harvest?
-it puts wild plant populations in the continuing interest of local people
-It provides an incentive to protect and maintain wild populations and their habitats and the genetic diversity of MAP populations
What are the the problems with wild harvesting?
-Uncontrolled harvest may lead to the extinction of ecotype and even species
-Common access to the resource makes it difficult to adhere to quotas and the pre-cautionary principle
-In most cases knowledge about the biology of the resource is poor and the annual sustained yields are not known
-In most cases resource inventories and accompanying management plans do not exist
Why is it better to cultivate?
-It relives harvesting pressure on very rare and slow growing species which are most susceptible to threat
What are the problems with cultivating?
-Devaluates wild plant resources and their habitats economically and reduces incentive to conserve ecosystems
-Narrow genetic diversity of gene pool of the resource because wild relatives of cultivated species become neglected
-It may lead to conversion of habitat for cultivation
-Cultivated species may become invasive and have negative impacts on the ecosystem
-Reintroducing plants can lead to genetic pollution of wild populations
what are the conservation issues of wild and cultivated medicinal plants?
-Over harvesting – reducing plant populations and genetic diversity
-Some plants are at risk of extinction
-Slow-growing plants and those in highly specialised niches are particularly vulnerable e.g. Himalayan yew tree produces Taxol (a chemotherapy drug) but takes 20 years to mature
-4,000 medicinal plants are threatened
-14 are listed as acutely endangered by CITES – Convention on International Trade of Endangered Species of Wild Flora and Fauna. E.g. goldenseal a native species of the USA used in herbal medicines.
What is biopiracy?
Referring to unethical or unlawful gathering and exploitation of biological materials e.g. plants
What have some pharmaceutical companies done and what is wrong with this?
-Exploited the rainforests
-Targeted medicinal plants for cultivation
-Synthesised the plants for chemical compounds
-Plants are highly profitable for the pharmaceutical companies but little money or investment goes back into the local indigenous communities
-To some this is seen as theft
What are the solutions to biopiracy?
-Pharmaceutical companies divert part of their profits from drug royalties to help local communities
-E.g.
-In 1980s scientists identified and extracted a powerful new drug for treating HIV, from the bark of the mamala tree found in the Samoan rainforests
-Part of the revenues from the drug are returned to Samoa as compensation for protecting the rainforests and to assist economic development in forest communities
-The national cancer institute in the USA and the Swedish international development Authority have also provided funds for economic development and forest protection in Samoa
