Week 5 (Infectious diseases) Flashcards
Infectious diseases
-illnesses caused by pathogens/microorganisms (bacteria, viruses, fungi, parasites)
-Still a cause of mortality and morbidity in many regions, particularly in LMICs
-Preventable with vaccines, improved sanitation, hygiene practices, and early treatment
Transmission of infectious diseases
-Airborne (covid-19, tuberculosis)
-Vector-borne (malaria, dengue)
-food/waterborne (cholera, salmonella)
-Direct contact (HIV, Ebola)
Non-communicable diseases (NCDs)
-diseases that are not contagious and cannot be spread from person to person
-Also known as chronic diseases, because they tend to last 1 year or more and require ongoing medical attention or limit activities of daily living or both
-Includes cardiovascular diseases, chronic respiratory diseases, diabetes, cancer
-Often linked to lifestyles, genetics, and environmental factors
Risk factors associated with NCDs
Smoking, poor nutrition, physical inactivity, and excessive alcohol use
Acute illness
-have a very rapid onset, but usually clear up within a month, easy to diagnose and treat most times
-Examples: the flu, broken bones, urinary tract infections, pink eye
Chronic illness
-last for months/years/lifetime, becomes more of an issue as you get older, not easily diagnosed or treated
-Examples: diabetes, heart disease, obesity, cancer, stroke, arthritis
-Usually non-communicable and long-lasting
Chronic infectious diseases
-some infectious diseases can persist and become chronic infections
-Examples:
-HIV/AIDS: a viral infection that requires lifelong treatment
-Hepatitis B and C: chronic viral liver infections
-Tuberculosis (TB): can become latent and reactivates years later
Epidemic
-sudden increase in cases (above normal expectations) in one region
-Localized to city, country, or region
-Can be caused by new infectious agents or changes in existing pathogens, can be short lived or persistent, requires rapid containment
-Example: Ebola outbreak in west Africa
Pandemic
-disease spreads globally
-Multiple regions or continents simultaneously
-Involves high transmission rates, often has significant social, economic, and health impacts, needs global coordination and response strategies
-Example: COVID-19
Endemic
-disease (or PH problem) is always present in a region at a stable rate
-Specific area, persistent
-Predictable and persistent, can have seasonal variations, local public health measures keep it controlled but requires long-term management
-Example: the flu
Disability Adjusted Life Years (DALYs)
-one DALY represents the loss of the equivalent of one year of full health
-DALYs for a disease or health condition are the sum of the years of life lost due to premature mortality (YLLs) and the years lived with a disability (YLDs) due to the prevalent cases of the disease or health condition in a population
Purpose of DALYs
-Helps compare the burden of different diseases (helps prioritize diseases that cause most suffering)
-Guides public funding and policies
-Highlights the impact of disabilities, not just death
-Helps track global health progress
Global trends in infectious diseases
-Declining diseases: measles, polio, HIV/AIDS
-Emerging/re-emerging threats: ebola, Zika, H1N1, AMR
Current global trends in NCD illnesses
-Cardiovascular diseases account for the most NCD deaths (19 million), followed by cancers (10 million), chronic respiratory diseases (4 million), and diabetes (over 2 million, including kidney diseases caused by diabetes)
-NCDs killed at least 43 million people in 2021 (75% of non-pandemic related deaths)
-Of all NCD deaths, 73% are in low/middle income countries
-3 leading risk factors for early death were high blood pressure, smoking, and high blood sugar
Epidemiological transition
-the shift in disease patterns that occurs as a country develops economically, moving from high rates of infectious diseases and early deaths to higher rates of chronic diseases
-Describes how mortality and disease patterns change over time in response to societal development, including improvements in sanitation, economic growth, and lifestyle changes
5 Stages of Epidemiological Transition
-Stage 1: pestilence and famine
High infectious disease burden
Main cause of death: plagues, famine, malnutrition, childbirth-related deaths
Pre-industrial societies
-Stage 2: receding pandemics
Decline in infectious diseases
Main causes of death: improvements in sanitation, vaccines, and nutrition
Early industrial societies
-Stage 3: degenerative and man-made diseases
Increase in chronic NCDs
Main cause of death: heart disease, cancer, stroke, obesity-related conditions
middle-income countries (brazil, china)
-Stage 4: delayed degenerative diseases
NCDs dominate, but mortality decreases
Main cause of death: longer life expectancies, better treatment
High-income countries (US, Canada, UK)
-Stage 5: re-emerging infectious diseases
Infectious diseases resurge due to new treatments
Main causes of death: antimicrobial resistance (AMR), pandemics, climate-related diseases
Globalized world (COVID-19, antibiotic resistance)
double burden of disease
-simultaneous presence of both infectious and NCDs, often in LMICs
-Overwhelms health systems, increases “syndemics” (one increases the other HIV and heart disease), required integrated preventative measures
Disease patterns and global health
-Enables public health professionals, policymakers, and healthcare systems to predict, prevent, and manage diseases more effectively
-Its essential for building resilient health systems, shaping policies, and protecting global health populations form both known and emerging health threats
-Without this knowledge, public health interventions cannot be targeted effectively, leading to preventable deaths and economic losses
