Health Surveillance: Immunizations, Communicable Diseases, and Vulnerability

Comprehensive review flashcards covering immunization principles, epidemiology, communicable diseases across the lifespan, poverty, homelessness, and sexually transmitted infections.

What is the primary function of a vaccine in the body?

Vaccines are used to trigger the immune system before the body is exposed to the full, active pathogen.

What is an inactivated vaccine, and what is its primary limitation?

It uses a killed version of the germ; because it does not provide protection as strong as a live vaccine, multiple doses are required over time for ongoing immunity.

What is a live-attenuated vaccine, and how many doses are typically required for lifetime protection?

It is made from a weakened form of the live virus, is difficult to produce, and typically requires only $1\text{ to }2$ doses for lifetime protection.

Which specific patient populations should avoid receiving live-attenuated vaccines?

Individuals who are immunosuppressed, organ transplant recipients, individuals with long-term health issues, and pregnant women.

What are the storage and handling requirements for live-attenuated vaccines?

They must be kept extremely cold and do not travel well.

How do mRNA vaccines work, and what are their primary benefits?

They instruct cells to make proteins that trigger an immune response; benefits include shorter manufacturing/turnover times and no risk of causing the disease.

How are subunit, recombinant, and polysaccharide vaccines constructed, and what is their limitation?

They isolate specific parts of the germ (such as proteins or sugars) to use as the antigen; they trigger a strong immune response and can be given to almost anyone, but patients may need booster shots.

How does a toxoid vaccine work, and what is an example provided in the lecture?

It uses a toxin made by the germ to create immunity against the toxic product rather than the whole organism; tetanus is an example.

What is a viral vector vaccine?

A vaccine that uses a modified version of a different virus as a vector to deliver genetic instructions and trigger immunity.

How does herd immunity differ from community immunity?

Herd immunity occurs when a large enough proportion of a group is immune to stop disease transmission, whereas community immunity occurs when only a few people are immunized—insufficient to stop the spread.

How is vaccine hesitancy defined, and why was the 1998 autism study discredited?

Vaccine hesitancy is the refusal or delay in acceptance of vaccines despite availability; the 1998 study was rejected because the author hand-picked participants who already had autism prior to the study.

What occurs physiologically during a first exposure to an unknown pathogen compared to a second exposure?

First exposure produces initial symptoms (coughing, sneezing, fever) while the body slowly creates memory cells; second exposure triggers a rapid antibody release and an immediate, effective immune response.

What are the three components of the epidemiological triangle?

Agent, Host, and Environment.

What is the distinction between natural immunity and acquired immunity?

Natural immunity is an innate resistance to infectious agents, whereas acquired immunity is resistance gained through previous natural exposure to an infectious agent.

What is the distinction between active immunity and passive immunity?

Active immunity is produced by the host through the administration of an antigen and antibody production; passive immunity is the temporary transfer of antibodies, such as from mother to baby.

According to the epidemiological triangle agent properties chart shown, what is the definition of virulence?

Ability to produce a severe pathological reaction.

In the epidemiological triangle, how is an agent's infectivity defined?

The ability to enter and multiply in the host.

In the epidemiological triangle, how is an agent's pathogenicity defined?

The ability to produce a specific clinical reaction after the infection occurs.

In the epidemiological triangle, how is an agent's toxicity defined?

The ability to produce a poisonous reaction.

In the epidemiological triangle, how is an agent's invasiveness defined?

The ability to penetrate and spread throughout a tissue.

In the epidemiological triangle, how is an agent's antigenicity defined?

The ability to stimulate an immunological response.

What is an environmental reservoir in communicable disease epidemiology?

A habitat where an infectious agent naturally lives and multiplies without causing issues.

What is vertical transmission of an infectious disease, and through what routes does it occur?

Transmission from parent to infant occurring through breast milk, placenta, sperm, or direct contact with the vaginal canal.

How does direct horizontal transmission differ from indirect horizontal transmission?

Direct transmission involves immediate person-to-person transfer via physical contact; indirect transmission spreads through an intermediate vehicle such as food, water, secretions, or inanimate objects.

What is vector-borne transmission?

The spread of infectious agents by non-human biological carriers, usually animals or insects.

Which communicable diseases are identified as spreading via airborne droplet transmission?

Tuberculosis (TB), the common cold, influenza (flu), and rubella.

In the chain of transmission, what serves as the number one protector, and what are the main portals of entry and exit?

The skin is the number one protector; portals of entry include the mouth, nose, eyes, and cuts; portals of exit include secretions, sneezing, coughing, broken skin, fecal matter, and vomiting.

What microorganism causes tuberculosis, and how is it transmitted versus not transmitted?

Caused by Mycobacterium tuberculosis; transmitted via airborne droplets; it is NOT spread by shaking hands, touching infected linens, sharing a toothbrush, or kissing.

What risk factors increase susceptibility to tuberculosis, and which illnesses does TB mimic initially?

Low immunity, co-occurring disease, poor nutrition, and crowded living conditions with poor ventilation; initially mimics COVID-19 and HIV.

When reading a tuberculin skin test (PPD), what anatomical sign is measured?

The induration (the raised, firm area), not the surrounding erythema (redness).

What induration measurement is considered positive on a tuberculin skin test for an individual with no known risk factors?

$15\,\text{mm}$.

For which populations is an induration of greater than $10\,\text{mm}$ considered positive on a tuberculin skin test?

Children and intravenous (IV) drug abusers (individuals with a few risk factors).

For which high-risk groups is an induration of $5\,\text{mm}$ considered positive on a tuberculin skin test?

Individuals who are HIV positive, have had recent contact with active TB, have received an organ transplant, or show characteristic changes on a chest X-ray.

What is Latent TB Infection (LTBI), and is it contagious?

TB bacteria live asymptomatically in the body; it is not infectious and cannot spread person to person, but it can later reactivate and multiply.

What distinct adverse effects are associated with Rifapentine (RPT) and Rifampin (RIF) during latent TB therapy?

Rifapentine (RPT) causes red-orange urine and tears, whereas Rifampin (RIF) causes impaired vision.

What does the new 12-week treatment regimen for latent TB consist of, and who is eligible?

Once-weekly isoniazid (INH) and rifapentine (RPT); recommended for individuals aged 12 and older, children aged $2\text{--}11$, and HIV-infected individuals taking antiretroviral therapy.

What medication is indicated for multidrug-resistant TB, and what primary behavior leads to this resistance?

Bedaquiline; caused by nonadherence (repeatedly starting, stopping, and restarting antibiotic treatment).

What clinical interventions help ensure patient completion of a tuberculosis medication regimen?

Reminders/phone prompts, education and counseling, patient incentives (such as gift cards), directly observed treatment (DOT), and staff supervision.

What are the initial clinical manifestations of measles, and what diagnostic oral sign appears?

High fever ($104^\circ\text{F}$), runny nose, cough, red eyes, and sore throat; Koplik spots (tiny white dots in the back of the throat) appear $2\text{--}3$ days after symptoms ($7\text{--}14$ days post-exposure).

When and where does the measles rash develop, and what serious complications can occur?

Breaks out $3\text{--}5$ days after initial symptoms, starting on the face and spreading downward; complications include ear infections, diarrhea, pneumonia, and encephalitis.

What symptoms and potential complications are associated with mumps?

Symptoms include swelling of the salivary glands, fever, headache, and muscle aches; complications include orchitis, hearing loss, and meningitis.

What are the manifestations of rubella (German measles), and why is it dangerous during pregnancy?

Causes low-grade fever, rash, sore throat, swollen glands, and joint discomfort; in pregnancy, up to $70\%$ of women experience stillbirth, miscarriage, or severe chromosomal abnormalities.

What is the standard dosing schedule for the MMR vaccine, and what are its primary contraindications?

Two doses given at $12\text{--}15$ months and $4\text{--}6$ years; contraindicated in pregnancy, immunocompromise, HIV with CD4 count $< 200\,\text{cells/mm}^3$, gelatin or neomycin allergy, recent blood transfusion, or bleeding disorders.

According to the CDC 2025 Recommended Immunizations schedule shown, what is the recommended timing for Dose 1 of the Hepatitis B vaccine?

At birth.

What clinical manifestations characterize varicella (chickenpox), and what chronic neurological complication can follow?

Itchy rash with blisters, papules, or ulcers, fever, and headache; $10\%\text{--}13\%$ of individuals experience postherpetic neuralgia.

How does shingles (herpes zoster) present clinically, and what anatomical concern arises if it appears on the face?

A very painful, unilateral rash with blisters that scab over in $4\text{--}6$ weeks, preceded by tingling/burning; facial shingles carries a risk of permanent blindness.

When is shingles contagious, and how does its transmissibility compare to chickenpox?

It is only contagious once the rash appears, spreading via direct contact with blister fluid; it is less contagious than chickenpox.

What is the modern vaccine recommended for shingles, and what is its dosing schedule?

Shingrix (recombinant, approved 2017), replacing the live Zostavax; recommended for adults aged $50$ and older in a $2$-dose series given $2\text{--}6$ months apart.

How is Hepatitis A transmitted, and what are its classic symptoms?

Transmitted via foodborne/fecal-oral routes; symptoms include fever, fatigue/tiredness, vomiting, and stomach pain.

How is Hepatitis B transmitted, and how long can the virus survive on environmental surfaces?

Transmitted through blood, semen, and other body fluids; it can survive outside the body for up to $7$ days.

What intervention is required at birth for an infant born to a Hepatitis B-positive mother?

The newborn must receive the Hepatitis B immune globulin (HBIG) along with the first dose of the Hepatitis B vaccine at birth.

What infant weight threshold serves as a contraindication to initiating the Hepatitis B vaccine at birth?

Birth weight under $2000\,\text{g}$ (the infant must weigh over $2000\,\text{g}$ before starting).

How is rotavirus transmitted, in what season is it most prevalent, and what are its clinical symptoms?

Transmitted via the fecal-oral route; most common in the winter; causes severe diarrhea, vomiting, abdominal pain, dehydration, and fever.

What type of vaccine is the rotavirus vaccine, and what handling precaution must be taken following administration?

An oral, live-attenuated vaccine; immunocompromised individuals should not change the diapers of vaccinated infants due to viral shedding.

What are the contraindications to receiving the rotavirus vaccine?

Acute gastrointestinal illness, immunocompromise, and age older than $8$ months.

What respiratory hallmark characterizes diphtheria, and what systemic damage can occur if the toxin enters the bloodstream?

A thick gray coating (pseudomembrane) over the throat, nose, tonsils, and voice box; toxin entry into the bloodstream can damage the heart, kidneys, and nerves.

How does tetanus enter the body, and what classic neurological symptom does it cause?

Enters through broken skin or puncture wounds; causes painful muscle spasms, particularly in the jaw (lockjaw).

What are the three clinical stages of pertussis (whooping cough) and their respective durations?

Catarrhal stage ($1\text{--}2$ weeks; stuffy nose, cough, conjunctivitis), Paroxysmal stage ($2\text{--}8$ weeks; violent coughing fits, bruising), and Convalescent stage (up to $3$ months; decreasing cough).

What is the recommended administration schedule for the childhood DTaP vaccine?

Intramuscular injections administered at $2$, $4$, $6$, $15\text{--}18$ months, and $4\text{--}6$ years of age.

When is Tdap administered to adolescents, and how often is a booster recommended throughout adulthood?

Administered at age $11\text{--}12$, with a Td or Tdap booster recommended every $10$ years thereafter.

What infections are caused by Haemophilus influenzae type b (Hib), and what is the minimum age for vaccination?

Causes pneumonia, bacteremia, cellulitis, and middle ear infections; the Hib vaccine should not be administered earlier than $6$ weeks of age.

What common childhood condition is caused by Streptococcus pneumoniae in up to half of all cases?

Middle ear infections (otitis media).

What proportion of polio infections result in paralysis, and how is the virus transmitted?

Approximately $1/200$ people experience paralysis; spread through contact with infected feces or respiratory droplets.

What type of vaccine is IPV, and what are its contraindications?

An inactivated (killed whole virus) vaccine; contraindicated in pregnancy (unless at high risk), active polio infection, untreated pneumothorax, and severely impaired immune function.

What is the typical effectiveness of the annual influenza vaccine, and how are strains selected?

$40\%\text{--}60\%$ effective; scientists analyze the previous year's most prevalent viruses to formulate the current year's vaccine.

At what age is the COVID-19 vaccine recommended to begin?

Ages $6$ months and older.

What is the contagious window for Respiratory Syncytial Virus (RSV), and how long can immunocompromised hosts shed it?

Contagious for $3\text{--}8$ days (shedding begins before symptoms); individuals with weakened immune systems can spread RSV for $4$ weeks or longer.

When should the maternal RSV vaccine be administered during pregnancy to protect the infant?

Between $32\text{ and }36$ weeks of gestation.

How is poverty defined, and on what basis is the Federal Poverty Level determined?

Insufficient financial resources to meet basic living expenses (food, shelter, clothing, transportation, healthcare); the federal poverty level is determined by family size and composition.

What does the acronym ALICE stand for in public health and economic assessments?

Access Limited (or Asset Limited), Income Constrained, Employed.

How is an ALICE household defined regarding income and local cost of living?

A household earning above the federal poverty level, yet earning less than the basic cost of living in their county.

How do 'near poor', 'persistent poverty', and 'neighborhood poverty' differ?

'Near poor' live above federal guidelines but on ALICE margins; 'persistent poverty' is multi-generational and long-term; 'neighborhood poverty' refers to geographically bound areas with poor housing and high unemployment.

What is the definition of homelessness?

Nighttime residency in a supervised shelter or institution providing temporary residence, or lacking resources and community ties to provide for one's own shelter.

How does crisis poverty differ from persistent poverty within homeless populations?

Crisis poverty is temporary, episodic, or transitional (often affecting ALICE households); persistent poverty is chronic, often affecting veterans and those with chronic illness or substance use.

What specific health problems disproportionately affect homeless children?

Asthma, ear infections, GI issues, high obesity rates, emotional/behavioral problems, disabilities, and violence.

What health conditions disproportionately affect homeless young adults?

Risk-taking behaviors, physical and sexual abuse, increased STI rates, substance abuse, mental illness/suicide, and violence/trauma.

What health issues disproportionately affect homeless older adults?

Physical deformities, untreated chronic illnesses, tuberculosis, malnutrition, substance abuse, poor oral health, and hypothermia.

What four dimensions comprise the Vulnerability Model in homelessness?

Biological (age, race, mental illness), Behavioral (diet, exercise, addictions, sexual practices), Sociocultural (wages, education, insurance), and Environmental (housing, domestic violence, redlining).

According to the communicable disease chart shown, which diseases are highlighted in red for children, young adults, and adult/older adults?

Children: Salmonellosis and Pertussis; Young Adults: MRSA and Salmonellosis; Adults/Older Adults: HIV/AIDS and Tuberculosis.

According to the immunizations across the lifespan table shown, which vaccines are recommended for young adults?

Tdap, Flu, HPV, Meningocceal, Pneumococcal, Hep A&B, and MMR.

What is the overall prevalence of STIs, and which demographic age group carries the largest burden?

$1\text{ in }5$ individuals have an STI, with the highest prevalence among youth aged $15\text{--}24$.

What type of organism causes chlamydia, and which anatomical regions can it infect?

A bacterial pathogen that can infect the vaginal, oral, anal, and eye regions.

What clinical manifestations are associated with chlamydial infection in women and men?

Often asymptomatic; women may have abnormal discharge and burning during urination; men experience penile discharge, dysuria, and testicular pain or swelling.

What is the first-line oral treatment for chlamydia, and how are pregnant women treated?

Doxycycline $100\,\text{mg}$ orally twice daily for $7$ days; pregnant women are treated with azithromycin.

What diagnostic laboratory test is used to identify both chlamydia and gonorrhea?

Nucleic Acid Amplification Test (NAAT).

What are the common symptoms of gonorrhea in men, and which women require annual screening?

Men experience dysuria, white/yellow penile discharge, and testicular swelling; annual screening is recommended for all sexually active women aged $25$ and younger.

What is the recommended pharmacological treatment for gonorrhea, and what is the alternative for allergic patients?

An intramuscular injection of ceftriaxone; gentamicin is used as an alternative in cases of cephalosporin allergy.

What long-term reproductive complications can result from untreated gonorrhea?

Pelvic inflammatory disease (PID), ectopic pregnancy, and reduced fertility/infertility.

What is the primary clinical difference between Herpes Simplex Virus Type 1 (HSV-1) and Type 2 (HSV-2)?

HSV-1 is traditionally associated with oral lesions (cold sores), whereas HSV-2 is primarily responsible for genital herpes.

How do genital herpes lesions evolve, and how long does an active primary outbreak typically last?

Lesions begin as papules that break open to form painful ulcers, often accompanied by fever and headache, lasting up to $20$ days.

What pharmacological regimens are prescribed for treating active HSV-2 infections?

Acyclovir $400\,\text{mg}$ three times daily or famciclovir $250\,\text{mg}$ three times daily.

What clinical protocol is required during pregnancy and delivery for a mother infected with genital herpes?

Suppressive antiviral therapy must begin at $36$ weeks of gestation, and a Cesarean section (C-section) is indicated if active lesions are present during delivery.

What clinical features characterize Phase 1 (Acute Infection) and Phase 2 (Clinical Latency) of HIV?

Phase 1: rapid viral production causing flu-like symptoms within $3$ months; Phase 2: low viral replication, often asymptomatic, lasting $8$ years or longer until viral load rises and CD4 drops.

What laboratory threshold defines Phase 3 (AIDS), and what is the prognosis without treatment?

A CD4 helper T-cell count falling below $200\,\text{cells/mm}^3$; without antiretroviral therapy, life expectancy is approximately $3$ years.

What are the therapeutic goals for CD4 cell count and viral load in HIV antiretroviral therapy (ART)?

Maintain helper T-cell (CD4) counts between $200\text{--}500\,\text{cells/mm}^3$ to prevent opportunistic infections, and suppress viral load to undetectable levels ($< 50\,\text{copies/mL}$).

What is the efficacy of Pre-Exposure Prophylaxis (PrEP) in preventing HIV, and what is its primary side effect?

PrEP is $95\%$ effective at preventing HIV transmission by interrupting viral replication; its main reported side effect is nausea.

What clinical lesion defines the primary stage of syphilis, and when does it appear?

A single painless ulcer (chancre) appearing at the inoculation site $9$ days to $3$ months post-exposure and persisting for $3\text{--}4$ weeks.

What clinical signs characterize secondary and tertiary syphilis?

Secondary: macular rash on palms, soles, and tongue, fever, alopecia, and joint pain ($4\text{--}10$ weeks post-chancre); Tertiary: destructive gummatous lesions appearing $20\text{--}30$ years after initial infection.

How is syphilis diagnosed and treated?

Diagnosed via a two-step blood antibody testing process; treated with an intramuscular injection of penicillin.

What type of pathogen causes trichomoniasis, what are its symptoms, and how is it managed?

A parasite; causes itching, burning, yellow discharge, dysuria, and dyspareunia; treated in women with oral metronidazole ($500\,\text{mg}$ twice daily for $7$ days or a single dose).