Public Health Biology and Human Disease Risk CPH Exam Questions and Answers 100% Pass

Public Health Biology and Human Disease Risk CPH Exam Questions and Answers 100% Pass Epidemiological Triangle - agent, host, environment disease occurs when an outside agent (entity that causes disease, can be chemical, physical, or biological) capable of causing the disease interacts with a vulnerable host (susceptible organism, human, animal) in an environment (conditions that are not part of the agent and/or host but influence their interaction) chain of transmission - illustrates how infectious agents develop and spread 1. causative agent- any microorganism that causes infection 2. reservoir source- the environment where the agent resides; water, feces, bodily secretions 3. portal of exit- how the agent leaves the reservoir of the host 2Disclaimer: Original Content, No Copyright Infringement, All Rights Reserved © 2025 4. mode of transmission- how the agent travels to another host; may be direct or may include an intermediate or indirect contact 5. portal of entry- where the infectious agent enters susceptible host 6. susceptible host- individual or animal that os susceptible to infection 5. DALY - disability adjusted life years measure of the burden of disease that takes into account morbidity AND mortality one DALY equals to one year of healthy life lost due to premature death or time lived with illness, disease or injury DALYs for a disease or health condition are the sum of the years of life lost to due to premature mortality (YLLs) and the years lived with a disability (YLDs) due to prevalent cases of the disease or health condition in a population. used as a way to measure the cost-effectiveness of interventions 3Disclaimer: Original Content, No Copyright Infringement, All Rights Reserved © 2025 QALY The basic idea underlying the QALY is simple: it assumes that a year of life lived in perfect health is worth 1 QALY (1 Year of Life × 1 Utility = 1 QALY) and that a year of life lived in a state of less than this perfect health is worth less than 1. Modes of Infectious Disease Transmission - 1. direct contact- transmission requires direct contact with tissues, blood, bodily fluids, or secretions from an infected individual or animal 2. indirect contact- similar to direct contact, but direct contact with bodily secretions or fluids is not required; the pathogen may be capable of surviving on objects or surfaces for some period of time and can be transmitted when an infected person comes into contact with the contaminated surface or object (inanimate objects capable of transmitting a pathogen are known as fomites) 3. airborne- transmission through the air, usually accomplished through droplets expelled from an infected person from a cough or sneeze; effectiveness is a fxn of droplet size and susceptibility of the pathogen to desiccation 4Disclaimer: Original Content, No Copyright Infringement, All Rights Reserved © 2025 4. water- and soil-borne- pathogens transmitted in this manner can survive for relatively long periods of time in either soil or water and are transmitted when an individual ingests contaminated soil, food, of water 5. vector-borne- represents that most significant class of infectious agents worldwide (can be viruses, bacteria, unicellular eukaryotes, or multicellular invertebrates); insects are the most common vectors of infectious disease kinds of vectors - mechanical- pathogens are carried from host to host by the vector without infecting the vector biological- more common and dangerous, the pathogen is able to infect, develop, and amplify within the vector, resulting in a far more efficient transmission; however, this requires that the pathogen can infect both invertebrate and human hosts, which are very different environments vectorial capacity - metric that determines if a give