prevention and control of infectious disease

pop health

What is the difference between an infectious and communicable disease?

Infectious diseases are caused by pathogens. Communicable diseases can spread from person to person.

What are the three components of the epidemiological triangle?

Agent, host, and environment.

What is infectivity vs. virulence?

Infectivity is the ability to enter and replicate in a host. Virulence is the ability to cause severe disease.

Which disease has high infectivity but low virulence according to the lecture?

Varicella (chickenpox).

What is passive immunity?

Transfer of antibodies that provides short-term protection. Examples include maternal antibodies and immunoglobulin (RhoGAM).

What is active immunity?

Immunity developed after exposure to an antigen through infection or vaccination. May provide long-term protection.

What is cross-immunity?

Immunity to one infectious agent provides protection against another related agent.

What is herd immunity?

Population-level protection that increases when more individuals are immune, reducing opportunities for disease spread.

What factors increase host susceptibility to infection?

Impaired immunity, age extremes, malnutrition, genetics, and environmental factors.

What is vertical vs. horizontal transmission?

Vertical is parent-to-offspring transmission through placenta or breast milk. Horizontal is person-to-person or animal-to-person transmission.

What is the difference between direct and indirect transmission?

Direct involves immediate transfer from reservoir to host. Indirect involves an intermediary such as a vector, fomite, or vehicle.

What is the incubation period vs. communicable period?

Incubation is exposure to symptom onset. Communicable is the period when infection can be transmitted to others.

What are the community health nurse's main responsibilities for increasing immunization coverage?

Assess vaccination status at every encounter, organize outreach, educate families, and track under-immunized children.

What is the Vaccines for Children (VFC) program?

A program providing free vaccines to eligible children.

What is the difference between disease elimination and eradication?

Elimination means transmission stops in a specific geographic area but can return. Eradication means disease is permanently eliminated worldwide.

Which human disease has been eradicated worldwide?

Smallpox.

What is the MMRV vaccine schedule emphasized in the lecture?

First dose at 12–15 months. Second dose at 4–6 years.

How is measles transmitted?

Airborne inhalation or direct contact with infected nasal or throat secretions.

What are the hallmark symptoms of measles?

High fever, cough, coryza, conjunctivitis, Koplik spots, and a blotchy rash.

When is measles contagious?

From 4 days before rash onset through 4 days after the rash appears.

What causes pertussis and what is its hallmark symptom?

Bordetella pertussis. Paroxysmal coughing with a characteristic whooping sound.

What is the DTaP childhood vaccination schedule in the lecture?

At 2, 4, 6, and 15–18 months, and 4–6 years.

Does natural pertussis infection or vaccination provide permanent immunity?

No. Immunity wanes, allowing recurring outbreaks.

What are the hallmark symptoms of varicella (chickenpox)?

Fever, malaise, and an itchy vesicular rash beginning on the chest, back, or face and progressing to crusted lesions.

When can a child with varicella return to school?

When all lesions have crusted over, typically 5–7 days after rash onset.

What disease can result from reactivation of varicella-zoster virus?

Shingles (herpes zoster).

Which populations are especially vulnerable to varicella complications?

Pregnant individuals without immunity and newborns exposed around delivery.

Why can influenza outbreaks recur?

Neither natural infection nor immunization provides permanent immunity.

How are waterborne illnesses commonly transmitted?

Through drinking or recreational water contaminated by human or animal feces.

What are common manifestations of foodborne illness?

Fever, headache, abdominal pain, nausea, vomiting, and diarrhea.

What are examples of foodborne pathogens discussed in the lecture?

Norovirus, Salmonella, and Campylobacter.

What interventions help prevent foodborne illness?

Wash raw vegetables, reheat leftovers, refrigerate foods appropriately, avoid unpasteurized dairy, and use proper cooking and cleaning techniques.

What causes tuberculosis and how is it transmitted?

Mycobacterium tuberculosis. Airborne transmission.

What are the hallmark symptoms of active pulmonary TB?

Persistent cough, hemoptysis, chest pain, shortness of breath, fever, night sweats, and fatigue.

What is the difference between latent and active TB?

Latent TB is not contagious. Active TB disease can be contagious and requires treatment.

What screening methods are used for tuberculosis?

Mantoux tuberculin skin test (PPD) and TB blood testing (QuantiFERON).

Why is TB blood testing preferred in individuals vaccinated with BCG?

BCG vaccination can cause a false-positive TB skin test.

What is directly observed therapy (DOT) for TB and why is it used?

A healthcare worker observes medication administration to promote adherence and prevent drug resistance.

What are priority community nursing interventions for tuberculosis?

Promote early diagnosis, educate about transmission and treatment, support medication adherence, and implement isolation when necessary.

What is a zoonotic illness?

An infection naturally transmitted from a vertebrate animal to a human.

What is a vector-borne disease?

An infection transmitted through a living carrier such as a mosquito, tick, or flea.

What are the hallmark manifestations of rabies?

Fever and headache progressing to neurological dysfunction, agitation, confusion, hallucinations, and hydrophobia.

What is the main community prevention strategy for rabies?

Vaccination of domestic animals and avoiding contact with potentially infected wildlife.

How are pinworms transmitted and what is the characteristic symptom?

Ingestion of eggs from contaminated hands or surfaces. Itching around the anus.

What are the hallmark manifestations of Lyme disease?

Fever, headache, fatigue, and a bull's-eye skin lesion. Untreated infection may progress to neurological or cardiac complications.

What interventions prevent Lyme disease?

Wear protective clothing, use EPA-registered repellents, remove ticks promptly, and reduce tall grass and brush.

How is West Nile virus transmitted?

Mosquitoes acquire the virus from infected birds and transmit it through bites. People do not spread the virus to one another.

What interventions help prevent West Nile virus infection?

Mosquito control, insect repellent, protective clothing, window screens, and removing standing water.

What causes malaria and how is it transmitted?

The parasite Plasmodium, transmitted by infected Anopheles mosquitoes.

What is a characteristic manifestation of malaria?

Recurrent cycles of fever and chills.

What are the major routes of HIV transmission?

Sexual contact, shared needles, infected blood products, and perinatal transmission including breastfeeding.

What are the three stages of HIV infection described in the lecture?

Primary infection, clinical latency, and symptomatic disease.

What is the difference between HIV and AIDS?

HIV is the virus that attacks the immune system. AIDS is the late clinical stage characterized by severe immune damage and opportunistic infections.

What is PrEP and who should receive it?

Pre-exposure prophylaxis. Medication used by HIV-negative individuals at risk of acquiring HIV.

What is the purpose of antiretroviral therapy (ART)?

To manage HIV infection, delay disease progression, and improve survival.

What must a community health nurse do when a client is newly diagnosed with HIV?

Report the diagnosis to the state health department as required by law.

Teaching an AIDS patient's family to prevent skin breakdown, diarrhea complications, and malnutrition is what level of prevention?

Tertiary prevention because it minimizes complications of established disease.

What are the major community health nursing responsibilities for clients with HIV/AIDS?

Counseling, education, advocacy, infection prevention, medication teaching, and promoting quality of life.

Which types of hepatitis are transmitted by the fecal-oral route?

Hepatitis A and E.

Which types of hepatitis are primarily associated with bloodborne transmission?

Hepatitis B, C, and D.

What are common manifestations of viral hepatitis?

Fever, fatigue, anorexia, nausea, abdominal pain, and jaundice.

What are the main prevention strategies for hepatitis A?

Vaccination, proper sanitation, safe food and water, and hand hygiene.

How is hepatitis B transmitted?

Exposure to infected blood or body fluids through sexual contact, shared needles, or occupational exposure.

Which hepatitis infections are preventable through vaccination according to the lecture?

Hepatitis A and B. Hepatitis B vaccination also protects against hepatitis D.

Which hepatitis infection has no vaccine but can be treated with antiviral medications?

Hepatitis C.

Why does hepatitis D vaccination prevention depend on hepatitis B vaccination?

Hepatitis D is associated with hepatitis B infection. Preventing hepatitis B also prevents hepatitis D.

Which hepatitis infection is particularly concerning during pregnancy?

Hepatitis E, especially during the third trimester.

A community has inadequate sanitation and contaminated drinking water. Which hepatitis infections are most concerning?

Hepatitis A and E because they spread through the fecal-oral route.

What are the hallmark symptoms of gonorrhea?

Dysuria and thick purulent drainage. Women may be asymptomatic or have mild symptoms.

What complications can untreated gonorrhea cause?

Pelvic inflammatory disease (PID), infertility, and neonatal infection.

What antibiotic is identified in the lecture for gonorrhea treatment?

Ceftriaxone.

Why is chlamydia especially concerning in community health?

It is often asymptomatic and can cause PID, infertility, ectopic pregnancy, and neonatal complications.

What antibiotic treatments are listed for chlamydia?

Azithromycin or doxycycline.

What is the hallmark finding of primary syphilis?

A painless chancre at the site of infection.

What are the manifestations of secondary and tertiary syphilis?

Secondary: fever, sore throat, muscle pain, weight loss. Tertiary: blindness, psychosis, and cardiovascular damage.

What is the treatment for syphilis?

Penicillin.

How does genital herpes typically present?

Painful vesicles that ulcerate and crust. Tingling or shooting pain may occur before lesions develop.

Can genital herpes spread without visible lesions?

Yes. Viral transmission can occur during asymptomatic periods.

Is genital herpes curable?

No. Antivirals such as acyclovir or valacyclovir help manage infection.

What are the hallmark manifestations of HPV-related genital warts?

Painless cauliflower-like growths on the genital or anal area.

Why is HPV vaccination important?

It prevents infection with HPV types associated with genital warts and cervical cancer.

What HPV vaccination schedule is listed in the lecture?

Ages 9–14: two doses. Ages 15–45: three doses.

Which STIs are identified as reportable in the lecture's practice questions?

Syphilis, gonorrhea, and chlamydia.

What are the three levels of STI prevention according to the lecture?

Primary: education, immunization, condom use. Secondary: screening, case finding, contact investigation, treatment. Tertiary: infection-control measures and preventing complications.

Why should community health nurses discuss sexual behaviors openly during STI counseling?

Avoiding these discussions prevents identification of risky behaviors and potential exposure risks.

What is the incubation period for pertussis (whooping cough)?

7–10 days.

What is the incubation period for varicella (chickenpox)?

14–16 days.

What is the incubation period for influenza?

1–5 days.

What is the incubation period for tuberculosis (TB)?

Weeks to 2 years.

What is the incubation period for rabies?

Weeks to months.

What is the incubation period for hepatitis A?

28 days.

What is the incubation period for hepatitis B?

2–5 months (average listed as 60 days).

What is the incubation period for hepatitis C?

2 weeks to 6 months (average 6–9 weeks).

What is the incubation period for gonorrhea?

2–14 days.

What is the incubation period for chlamydia?

1–3 weeks.

What is the incubation period for syphilis?

10–90 days (average 21 days).

What is the incubation period for genital herpes?

6–8 days.

What is the incubation period for HPV (genital warts)?

Weeks to years (average 3 months).