7: Communicable Diseases
- Page ID
- 237531
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Even though non-communicable diseases now dominate the health landscape in many regions, public health as a discipline originated largely to combat the spread of communicable diseases, infectious agents that move from person to person or through the environment. The connection between communicable diseases and public health is deeply historical (you may review section 1.2, "History of Public Health", to gain a picture of this connection) and remains a primary focus of global health security.
In the following pages, we will categorize the top communicable diseases and discuss the public health modalities used to prevent their spread in the population.
- 7.1: Communicable Diseases and Public Health
- This page discusses communicable diseases that can spread between hosts, highlighting their global impact, especially from HIV/AIDS, tuberculosis, and malaria. In the U.S., various categories exist, including endemic and vaccine-preventable diseases, contributing to significant healthcare costs and societal burden. Childhood vaccinations are crucial in preventing illnesses, with the COVID-19 pandemic underscoring the need for continued vaccination efforts.
- 7.2: Endemic, Epidemic, and Pandemic
- This page outlines the differences between endemic, epidemic, and pandemic diseases, highlighting their significance in communicable disease prevention. It defines endemic diseases as consistently present at expected levels, epidemics as sudden increases beyond those levels, and pandemics as global outbreaks. Additionally, the page details four levels of disease prevention: primordial, primary, secondary, and tertiary, each aimed at reducing disease risk and improving management strategies.
- 7.3: Tools of Public Health- Barrier
- This page emphasizes barrier methods for preventing communicable diseases, including handwashing, insecticide-treated nets, masks, and isolation of symptomatic individuals. It discusses quarantine for asymptomatic exposure and references the first Ebola outbreak in the U.S. to illustrate these practices. Overall, it highlights the significance of these strategies in public health.
- 7.4: Tools of Public Health- Screening
- This page discusses the importance of screening in managing infectious diseases by identifying infected individuals, especially asymptomatic cases. It highlights methods like mass and selective screening with various tests, particularly for tuberculosis (TB) and sexually transmitted diseases (STDs) such as gonorrhea and chlamydia.
- 7.5: Tools of Public Health- Immunization
- This page discusses the importance of immunization in preventing communicable diseases by enhancing the immune system's ability to combat pathogens. It highlights individual immunity, herd immunity for protecting vulnerable populations, and the reduction of disease burden. While vaccines have significantly reduced diseases like polio and smallpox, challenges persist for rapidly mutating viruses such as HIV/AIDS and influenza.
- 7.6: Tools of Public Health- Treatment
- This page covers the treatment of communicable diseases, emphasizing the use of antibiotics for bacterial infections and antivirals for viral infections. It discusses the issue of antibiotic overprescription and resistance, along with the importance of the immune system in treating viral infections, especially HIV. The page also introduces epidemiological treatment, highlighting medication administration based on possible exposure to manage disease spread effectively.
- 7.7: How can elimination or eradication be attained?
- This page distinguishes between disease elimination and eradication, defining elimination as halting transmission in a specific area, while eradication is the complete global absence of a disease. Smallpox and rinderpest are noted as the only eradicated diseases.
- 7.8: Pandemic Prevention
- This page discusses the far-reaching health and socio-economic effects of pandemics, highlighting historical examples like the Plague of Athens and COVID-19, which resulted in millions of deaths and shifts in life expectancy. It emphasizes the importance of effective prevention strategies, such as detection, containment, and immunization, to manage the spread of diseases.

