Exam 2 — Disease transmission, reservoirs, risk factors, disease patterns, and [partial] harm studies Flashcards
3 factors necessary for disease transmission
- Pathogenic organism (microbe)
- Reactive host (human or animal)
- Environmental conditions (allows host and pathogen to get together)
Name the 3 methods of transmission
- Direct
- Indirect
- Vector
Person to person contact is what kind of transmission?
Direct transmission
In direct transmission of disease, a person can have ______ or _______ types of disease
Clinical (symptomatic) or subclinical (mild symptoms)
An individual that does not exhibit symptoms but harbors organism causing disease
Carrier
The kind of disease transmission that comes from contaminated food or water or fomite
Indirect transmission
Fomite
Inanimate object
Disease transmission method that comes from mosquitos, flies, ticks, etc
Vector transmission
Type of symobiosis in which all parties benefit
Mutualistic
Type of symobiosis in which there is no obvious benefit for involved parties
Commesalistic
Type of symobiosis in which 1 party benefits and 1 party definitely does not benefit
Parasitic
Long term host of pathogen from infectious disease, usually without injury to itself and serves as a source from which other individuals can be infected
Reservoir/source
Inanimate reservoirs: primary vs secondary
Primary: food, soil — microbes are viable and have the capacity to multiply
Secondary: air, soil — viable, do not multiply
Living reservoirs of infection include:
Humans and zoonosis (non-human animals)
Risk for disease are impacted by these 7 factors:
- age
- gender
- ethnicity (genetics)
- nutrition/malnutrition
- pre-existing disease
- occupation
- food and water
Disease patterns are categorized (4) as such
- Endemic: constantly present in the population
- EPIdemic: disease that exceeds expectations
- Outbreak: small, localized EPIdemic
Pandemic - Herd immunity: the more people are immune to disease, the less likely of disease outbreak
What assesses the quantity of oxygen needed by microbes in water?
Biochemical oxygen demand (BOD)
High BOD results in
Aging of body of water
Eutrophication
Aging of body of water
Goal for coliforms in drinking water
0
Water system is in violation if there is over __% coliform positive in a month
5%
Gram positive
Positively blue over you
Removal of solids in sedimentation tanks is done by what kind of treatment
Primary
Effluent sprayed over rocks. Organic material adheres to stone and is digested by microbes present in tank. Slime is added and bacteria digest organic material which reduces BOD. After aeration, water is treated chemically or with UV light and released — this is what kind of sewage treatment?
Secondary treatment
What is tertiary treatment?
Add lime or alum to remove nitrates and phosphates.
What is the downside to tertiary treatment?
Expensive
Septic tanks are only effective for
Small amounts of sewage
How do you do pasteurization?
Old: 30 mins at 62˚C
New: 15 seconds at 72˚C
How do you know pasteurization was effective?
Use phosphatase test — enzymes should be destroyed
Involvement in public health allows chiros to:
- Promote preventative
- Participate in public health efforts
- Interact with other healthcare professionals
- Work within health care system using evidence based approach
- Evaluation and design clinical trials
- Recognize individuals at risk
How do you measure disease occurrence?
- Morbidity (incidence of disease)
- Mortality
- Prevalence
What do harm studies do?
Assess the causal relationship between exposure (treatment) and disease
What is a confounder?
Anything that independently affects the exposure and the outcome
Who discovered alternative to using boiling oil to cauterize wounds?
Ambroise Pare
Who developed a trial with a series of test groups to determine if lime juice treated scurvy?
James Lind
Hill’s 6 Criteria for Causality
- Temporal relationship
- Experimental evidence
- Dose response relationship
- Statistical significance
- Consistency across studies
- Plausibility
What study is useful for studying interactive causes of harm
Cohort study