Exam 1:1 Flashcards
Cases
people afflicted
Rates
number of events in a given population over a given period of time or given point in time
Population at risk
those susceptible to particular disease or condition
Incidence rate
number of new health-related events or cases of a disease in a population exposed to that risk during a particular period of time, divided by total # in same population
Prevalence rate
number of new and old cases in a given period of time, divided by total # in that population
Attack rate
incidence rate calculated for a particular population for a single disease outbreak, expressed as a percentage
Outbreak investigation
determine number of victims, construct an epidemic curve, calculate attack rate, determine when victims became sick, determine where victims became sick and plot on map, disease investigation interview, case definition for the disease, hypothesis for sources and transmission, lab test results and screening tool to identify exposed, list of prevention and control measures
Infectivity
ability of a biological agent to enter and grow in the host
Pathogenicity
capability of a communicable agent to cause disease in a susceptible host
Communicable disease model
agent, host, environment
Agent
cause of disease or health problem
Host
susceptible person or organism invaded by an infectious agent
Environment
factors that inhibit or promote disease transmission
Chain of infection
pathogen-reservoir-portal of exit-transmission-portal of entry-establishment of infection in new host
Prevention and control efforts
focus on breaking the chain of infection
Pathogen
disease causing agent (virus, bacterium, etc.)
Prevention or control of a pathogen
pasteurization, chlorination, antibiotics, antivirals, etc.
Reservoir
favorable environment for infectious agent to live and grow (human, animal, etc.)
Prevention or control of a reservoir
isolation, surveillance, quarantine, drug tx, etc.
Portal of exit
path by which agent leaves host (blood, respiratory system, digestive system, etc.)
Prevention or control of portal of exit
gowns, masks, hair nets, insect repellants
Mode of transmission
how pathogens are passed from reservoir to next host, direct-direct contact or droplet spread, indirect-airborne, vehicle borne (fomite)
Prevention or control of mode of transmission
isolation, handwashing, vector control, sexual abstinence, etc.
Portal of entry
where agent enters susceptible host (iv, oral, skin, respiratory, digestive system)
Prevention or control of portal of entry
masks, condoms, safety glasses, insect repellants, etc.
New host
susceptible to new infection being established
Prevention or control of new host
immunizations, health education, etc.
US leading causes of death
heart disease, stroke, cancer
Primary prevention
forestall onset of illness or injury during prepathogenesis period
Secondary prevention
early diagnosis and prompt treatment before disease becomes advanced and disability severe
Tertiary prevention
aimed at rehabilitation following significant pathogenesis, retrain, reeducate, rehabilitate
Thermal inversions
a natural phenomenon that occurs in mountain valleys where warm air above holds in cold air near the valley floor, acts as a cap for pollution causing it to accumulate
Clean Air Act of 1963
fed authority to address interstate air pollution problems, emission standards, empowered EPA
Air Quality Index
measures 5 criteria pollutants, tells how clean or polluted air is and associated health effects
Point source water pollution
can be traced to a single source
Nonpoint source water pollution
occurs through runoff, seepage, or falling pollutants into water
Surface water
streams, rivers, lakes, reservoirs
Groundwater
most lies in aquifers many feet below the surface
Salt water
97% or Earth’s water, must be desalinized before use
Coagulation of drinking water
addition of a chemical such as alum to cause solids to attract to one another and form large particles
Flocculation of drinking water
water is allowed to stand so that particles settle to the bottom
Filtration of drinking water
water is passed through sand or charcoal filters
Disinfection of drinking water
addition of chlorine or ozone to kill microbes, some add fluoride which assists in killing microbes and leads to improvements in dental health
Primary wastewater treatment
mechanical process, involves the separation of liquids and solids, screens remove large objects, communitor grinds up solids into uniform pieces, settling ponds or sediment tanks allow sludge to settle to the bottom and scum to form on top
Secondary wastewater treatment
biological process, promotes aerobic bacterial growth, trickling filters sprinkling water over rocks to aerate, activated sludge agitation or stirring of water in order to aerate
Tertiary wastewater treatment
optional process, filtration with sand or charcoal filters, measurement of nitrogen, ammonia, coliform, phosphorus, CO2, oxygen, turbidity-total suspended solids, disinfection using chlorine, discharge into surface water
Clean Water Act
first comprehensive federal water quality law, aims to make all rivers and lakes swimable and fishable, reduce discharge of contaminants into water supply, reduce nonpoint source runoff
Safe Drinking Water Act
EPA set maximum contaminant levels for over 140 pollutants and maintains a list of unregulated contaminants, MCLs categorized
Maximum contaminant levels
category 1-known health hazards and carcinogens, category2-possible hazards and carcinogens, category 3- insufficient or no known carcinogens
Foodborne disease outbreaks
two or more cases of similar illness resulting from ingestion of food
Common causes of foodborne disease
bacterial pathogens, viral pathogens (Hepatitis A)
Resource Conservation and Recovery Act
1976, strict controls over treatment, storage, and disposal of solid and hazardous waste
Managing Solid Waste
source reduction (preferred), reuse and recycling, disposal
Sanitary landfills
locations have to be suitable for the in-ground disposal of solid wastes, required transition from dumps to landfills
Landfills require
a layer of clay on the bottom or a plastic type lining to reduce leachates from entering ground water, fewer sites available, requires venting for methane gas
Combustion or incineration
involves the burning or combustion of solid wastes, waste to energy plants collect energy from burning, concerns-air quality, expense, some toxic ash produced
Deep well injection
pumping of liquid waste into wells below aquifer, 50% of hazardous waste disposed this way
Secured landfill
least expensive method, double-lined, above 100 year flood plain, pipes for monitoring, wells to test ground water, surface water testing
Recycling and neutralization
reusing hazardous waste to produce a usable product, detoxifying waste by adding or removing a substance (microbes to an oil spill or base to acidic waste)
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
1980, superfund, created a national priority list of sites to be cleaned up, government would make responsible parties pay for cleanups when possible, provided money to support the identification and cleanup of sites, supervised by EPA
Brownfields
contaminated abandoned properties where reuse is complicated by the presence of hazardous substances from prior use
Vectors
fleas, lice, ticks, etc., spread disease
Risk of disease
Incidence rate
Burden of disease
Prevalence rate
Fomite
Any inanimate object to which infectious material adheres and can be transmitted.
What put our water treatment plant in violation?
Phosphorus, mostly from soaps and detergents
Landfill
trash not left exposed, covered daily, located where runoff doesn’t go into groundwater
Leachates
toxins draining off
