Environmental Factors Flashcards
6 Examples of environmental risk factors
Air
Water
Soil pollution
Chemical exposures
Climate change
Ultraviolet radiation
3 Top causes of environmental related deaths due to microorganisms
Diarrhoeal diseases
Respiratory infections
Malaria
4 Abiotic environmental factors
wind
water
inhalation of spores
entry into skin
What are the 3 common ways pathogens are spread from one person to another?
Direct contact
Respiratory aerosols
Faecal-oral transmission
What are the 3 main categories of how we become infected by the microorganisms in the environment?
Natural phenomena or disasters bring individuals in contact with opportunistic pathogens
Human activity brings people into contact with opportunistic pathogens
Human activity contaminates the environments with the pathogens
Where do potential pathogens originate from natural disasters?
From dust storms which damage the respiratory airway
From earthquakes which destroy public health systems
From storms which lead to severe flooding
Describe Vibrio vulnificus (4 things)
Aquatic organism
halophile
gram -ve
comma shaped
What 2 types of infections does Vibrio vulnificus cause and where do they occur?
- Wound infections
- Fulminant sepsis
- occur in areas where water temperature remains high all year
What type of wound infections does Vibrio vulnificus cause? (4)
cellulitis - infection in deeper layer of skin
oedema - swelling due to build up of fluid
erythema
necrosis
What % of individuals get fulminant sepsis from Vibrio vulnificus
5%
Vibrio vulnificus is associated with the..
Consumption of raw shell fish
Describe Legionella pneumophilia
ubiquitous aquatic saprophyte
found in lakes, rivers and streams
thin
pleomorphic
gram-ve
bacillus
obligate aerobe
What does pleomorphic mean?
changes, morphology, reproductive and other metabolic behaviours in response to environmental changes
What is an obligate aerobe?
Fussy about nutrition
hard to grow
will only grow in the presence of oxygen
What is a primary pathogen + examples
A pathogen whose role is to cause disease
example S. aureus
What is an opportunistic pathogen?
A pathogen that is not really mean to cause disease but will do in the right environment
example V. vulnificus
What is a viable pathogen?
A pathogen that is not dead but may not necessarily be able to cause disease
metabolically inactive
What are spores?
Tough structures designed to survive tough/harsh environments
How does human activity contaminate the environment with pathogens? + examples (2)
Healthcare environments are reservoirs of pathogens
example MRSA
Poverty, deprivation and overcrowding
example of how poverty, deprivation and overcrowding lead to disease?
inadequate sanitation leads to faecal contamination of drinking water and cholera outbreaks
What is Hepatitis E? (5)
viral infection
asymptomatic
mild-severe fulminant hepatitis
typically self limiting, no treatments required
typically waterborne but can be foodborne
How does Hepatitis E spread?
Faecal-oral transmission
What are the symptoms of Hepatitis E? (4)
Nausea
Loss of appetite
Jaundice
Dark urine