Lecture 19

Definition: Reluctance or refusal to vaccinate despite the availability of vaccines.
Aristotle’s Persuasion Elements:
- Trustworthy messenger
- Sense-making arguments
- Emotional connection
- A worthy goal for the messenger
Strategies to Address Vaccine Hesitancy:
- Patient-Provider Interactions:
- Listen and respect concerns
- Build common ground
- Be honest about vaccine imperfections
- Diversity in Healthcare:
- Increases trust when healthcare professionals reflect the community's diversity
- Transparency in Healthcare:
- Reducing private industry influence and being clear about relationships with pharmaceutical companies.

Definition: A serology technique used to measure small soluble antigens based on the dependence of antigen-antibody ratios.
Concepts:
- Antigen Excess: When there is too much antigen relative to antibody.
- Antibody Excess: When there is too much antibody relative to antigen.
- Equivalence: The optimal ratio where the number of antigenic sites equals the number of antibody-binding sites.

Definition: A method to measure insoluble antigens on whole cells through cross-linking.
Applications:
- Blood Typing: Mixing patient blood with known antibodies to detect clumping, indicating a positive reaction.
- Pathogen Identification: Adding antibodies to pathogens to observe clumping, confirming the presence of specific antigens.

Functionality:
- Detects either antibodies or antigens in samples.
Types:
- Direct ELISA:
- Detects pathogen antigens directly in the patient’s sample.
- Involves immobilizing antigen to a plate and using enzyme-linked antibodies for detection.
- Indirect ELISA:
- Detects antibodies against a pathogen using a known antigen on the assay plate to capture patient antibodies.
- Requires that antibodies have formed, meaning that it is best used for past infections.
- Sandwich ELISA:
- Involves capturing antigen using a specific antibody and detecting it with a secondary antibody conjugated to an enzyme.
Limitations:
- High levels of antigen required for direct ELISA.
- Indirect ELISA may not work for recent infections due to the time needed for antibody production.

Purpose:
- Identifying the infectious agent of disease is crucial for effective treatment and prevention of complications.
Key Reasons:
- Guide antibiotic treatment based on susceptibility.
- Prevent antibiotic resistance, e.g., Neisseria gonorrhea resistance to penicillin.
- Surveillance of epidemiological outbreaks.
Steps for Identification:
- Collect specimens based on signs/symptoms, medical and travel history, and knowledge of local outbreaks.
- Use clinical tests for pathogen identification, including biochemical methods and serological assays.

Types of Samples:
- Blood, cerebrospinal fluid (CSF), pleural fluid, synovial fluid, and internal organ tissues.
Key Procedures:
- Blood cultures: Collected via venipuncture, careful to avoid contamination.
- CSF: Obtained through lumbar puncture, requiring sterile techniques.

Types of Samples:
- Throat/nasopharynx, sputum, stool, skin lesions, and deep wounds.
Techniques:
- Sterile swabs for throat cultures, special mediums for transport, and using selective media to inhibit normal microbiota growth in cultures.

Caused by: Monkeypox virus (MPXV), an enveloped dsDNA virus from the Poxviridae family.
Current outbreak: Notable for the IIb subclade.

Transmission:
- Through broken skin, mucous membranes, or maternal to fetal transmission.
Symptoms:
- Fever, sore throat, headaches, muscle pain, lymphadenopathy;
- Characteristic skin lesions evolving from flat bumps to blisters.

Risk factors include:
- Young children, pregnant women, and immunocompromised individuals.
Potential complications:
- Secondary infections, pneumonia, sepsis, encephalitis, and possible death.

Treatment:
- Supportive therapy is crucial.
- Monitoring of high-risk individuals.
Prevention:
- Vaccination for those at high risk or after exposure.
- Strict hygiene practices including isolation of symptomatic patients.