Global Change and microbial infectious disease Flashcards
why need we be concerned about opportunistic pathogens in emerging infectious disease?
- may be little herd immunity for infection
- can become a frank pathogen if there is mutation caused by environment or host ( becomes immuno compromised)
Alterations in our environment may expose us to new pathogens– why ?
- causing mutations in their nature (opprotunisitic vs frank) and mode of transmission ( ie. from vector-borne to airborne)
ie. Hospital environment, we select for antibiotic resistance in pathogens therefore they become more of a threat. - change in the indigenous microflora
ie. Increase of environment temperature allows for Zika carrying mosquito could survive here in BC and allow for human infection.
Comment on the effect of infectious disease as a cause of death in both the developed and developing world. Explain why/how global warming may have an effect in the current epidemiological data.
- global warming may increase the envronmental availiability for some pathogens to spread and survive.
- changing water availability may increase pathogen in these water. or increase contaminated water soruces ( ie diarrhoeal diseases in low income countries)
- change the types of infectious disease (in developed)
- -> based on emerging and re-emerging, see later slides
Is a direct threat to humans the only concern?
- no, livestock, poultry and plants are threatened –> indirect threat to humans ( affecting food source)
Why are there more emerging or re-emerging diseases?
- human demographics and behaviour
- Technology and Industry
- Economic development and land use
- International travel and commerce
- Microbial adaptation and change
- Breakdown of public health measures
- Human vulnerability
- Climate and weather
- Changing ecosystems
- Poverty and social inequality
- War and famine
- Lack of political will
- Intent to harm
Reasons for emerging infectious disease?
- not seen in humans before ( species jumping)
- have occurred previously but affected small numbers prior
- only recently recognised caused by a microbes
- others :
Discuss why there are more emerging or re-emerging infectious diseases, and describe contributing factors for this phenomenon (give specific examples) ?
- refer to previous slides when giving specific examples
ie. slides with examples
*** know for final
Influence or global warming on MID (Mechanism –> Impact –> example)
- severe weather –> vector- and waterborne diseases increase –> most waterborne outbreaks ocur after above normal rainfall (cholera)
- enhanced freshwater temperature –> water-based pathoogen # increase –> enhanced growth of protozoan Naegleria fowleri
- decreased potable water sources–> waterborne disease increase–> use of source water of a lower quality
Infection
-process of infecting or the state of being infected
infectious disease
-infection caused by organism ( bacteria, viruses, fungi parasites)
pathogen
bacterium, virus or microbe that can cause disease
Frank pathogens
can cause disease in otherwise healthy individuals
Opportunistic pathogens
can only cause disease in compromised individuals (burn victims, AIDS patients, the young or elderly, etc.)
Virulence
is the degree of pathogenicity of a parasite determined in part by minimal infective dose, the number of organisms needed to cause an infection
- bacteria > viruses > parasites
Modes of transmission
- Waterborne (drinking, swimming water –> normally injested) : fecal contamination from municipal or feedlots runoff
- foodborne (fecal-oral route) : insufficiently cooked foods
- person to person (direct physical contacts b/n hosts): sexually-transmitted, respiratory infections
- airborne (aerosols created by wastewater treatment plants ect. ): ie Legionellosis or fungal infections
- vector-borne (by bite of an animal host) : malaris, yellow fever ect.
