Ch #8: Communicable Diseases

Communicable Diseases - Definition

• Caused by an infectious agent (like a virus or bacteria) and can transmitted from one source to another

Communicable Diseases - Transmission Types

• Person to person

• Animal to person

• Person/Animal indirectly via reservoir

… helps distinguish between infectious and noninfectious diseases?

• Laws and regulations

Disease Transmission - Human Reservoir Definition

• Person to person disease transmission without intermediaries

• Ex:

  • STDs

  • Measles

  • Mumps

  • Streptococcal infection

  • Many respiratory pathogens

Disease Transmission - Animal Reservoir Definition

• Animal to animal disease transmission with humans as incidental hosts

Disease Transmission - Environmental Reservoir Definition

• Plants, soil, and water that house diseases

• Ex: Fungal agents

Disease Control - Definition

• Preventative measures, advocating for those affects, protecting the well-being of uninfected persons, and controlling communicable diseases in populations and groups

Disease investigation requires a … approach?

• Systematic

Disease Control - Systematic Approach

• #1) Identify people who may be infected

• #2) Determine the source of infection and means of transportation

• #3) Identify others who are at risk

• #4) Prevent further transmission

• #5) Monitor the response

Disease Control - Nurse’s Role in Systematic Approach

• Review the information → Report what needs to be reported and follow guidelines

• Clarify if disease is suspected or lab-confirmed

• Review the case definition and disease information

• Use disease-specific questionnaire when available

Modes of Transmission - Definition

• How a disease is passed from one source to another

Modes of Transmission - Direct Examples

• Person to person

• Animal to person

Modes of Transmission - Indirect Examples

• Reservoirs → Ex: Contaminated water

Modes of Transmission - Vector Definition

• Living organisms that transmit infectious diseases

Modes of Transmission - Vector Examples

• Insects → Ex: Mosquitos

• Animals → Ex: Rats

Modes of Transmission - Mechanical Transmission to Vector

• Infectious organism that does NOT multiple within the vector

  • Vector Ex: Flies

Modes of Transmission - Biological Transmission to Vector

• Infectious organism multiplies within the vector

  • Vector Ex: Mosquitos and ticks

Modes of Transmission - Food/Water Illness Definition

• Microorganism contamination of food that results in illness

  • Caused by bacteria, viruses, or parasites

Modes of Transmission - Food/Water Illness Tranmission Process

• Occurs at the source through:

  • #1) Unsanitary handling

  • #2) Improper storage

Modes of Transmission - General Info

Influenza - Definition

• Acute communicable viral disease of the respiratory tract

Influenza - S/S

• Fever

• Headache

• Myalgia

• Prostration

• Coryza

• Sore throat

• Cough

Influenza - Types

• A = Severe and widespread

• B = Milder

• *Are other ones, but these are the two biggest ones

Influenza is typically … and happens in the … months. As a result, … is given based on WHO surveillance?

• Seasonal → Winter months

• Annual vaccine

COVID - Transmission

• Respiratory droplets

• Contaminated surfaces

COVID - High Risk Groups

• Older adults

• Immunocompromised or underlying health conditions

• Pregnant individuals

COVID - Protection

• Vaccines

• Boosters

• Testing

Pandemic Prevention

• IMMUNIZATIONS

  • High Risk Groups → Healthcare workers and personal care providers, children under 5 y/o, adults over 65 y/o, pregnant women, and those with chronic diseases

Pandemic Lessons

• Exposed underprepared health systems and societal inequities

• Severe outcomes highlighted health disparities

Pneumonia - General Info

• Pulmonary infection causing inflammation of the lungs

• High Risk Groups = Infants, older adults, and immunocompromised or those with chronic diseases

• S/S = Fever, pleural pain, dyspnea, productive cough, and tachypnea

• Protection = Pneumococcal vaccine

Hepatitis - Definition

• Serious liver disease caused by viral hepatitis infection

Hepatitis A (HAV) - Spread

• Spread through oral-fecal contact

• Highly contagious

Hepatitis A (HAV) - S/S

• Fever

• Malaise

• Anorexia

• Nausea

• Abdominal discomfort

• Jaundice

Hepatitis A (HAV) - Protection

• Inactivated hepatitis A vaccine

Hepatitis B (HBV) - Spread

• Spread through blood or body fluids

• Acute and chronic disease

Hepatitis B (HBV) - S/S

• Fatigue

• Anorexia

• Abdominal pain

• Nausea

• Jaundice

Hepatitis B (HBV) - Protection

• Hepatitis B vaccine

Hepatitis C (HCV) - Spread

• Spread through contact with infected blood

Hepatitis C (HCV) - S/S

• Asymptomatic, but can lead to liver disease

Hepatitis C (HCV) - Protection

• NO vaccine

• Testing and medical treatment are key!

HIV - Definition

• Retrovirus attacking the immune system

AIDS - Definition

• Severe, life threatening condition representing late clinical stage of infection with HIV

HIV/AIDS - High Risk Groups

• Gay and bisexual males

• Black/African American

• Hispanic/Latin American

HIV/AIDS - Causes

• Unprotected sex

• Sharing drug injection equipment

HIV/AIDS - Protection

• PrEP and PEP

  • PrEP = Preexposure Prophylaxis

  • PEP = Postexposure Prophylaxis

HIV/AIDS - Rx

• Antiretroviral Therapy → To reduce viral load and transmission risk

TB - Definition

• Infection caused by Mycobacterium Tuberculosis that primarily affects the lungs

TB - High Risk Groups

• HIV positive

• Young age

• Close contact

• Comorbidities

• Residence in high-risk settings

Latent TB - Definition

• In the body, but no S/S

  • Without S/S, can not spread it!

• Will have a positive TB skin or blood test

Multidrug Resistant TB - Definition

• TB that is resistant to first-line drugs like isoniazid or rifampin

• Caused by noncompliance to therapy

TB - Screenings

• Mantoux Tuberculin Skin Test )TST)

• Blood Tests (IGRAs)

TB - Dx

• Presence of acid-fast bacilli in sputum

• Confirmation by culture revealing MTB

TB is being targeted via the … blueprint?

• Global Plan to End TB 2023-2030 Blueprint

  • Focus = Prevention, screening, treatment, and patient-centered care

How are HIV and TB connected?

• HIV increases the risk of developing TB

  • *HIV patients may not react to TB skin test due to autoimmune response of the HIV

One major issue with TB and managing cases is …?

• Medication compliance

Chlamydia - General Info

• #1 most reported STD

• Usually NO S/S

• Rx = Antibiotics and no sex during treatment

Gonorrhea - General Info

• #2 most reported STD

• S/S = Purulent drainage, painful urination, and mild vaginal discharge

• Concerned about antimicrobial resistance when Rx

Syphilis - General Info

• #3 most reported STD

• Has 4 distinct stages

Syphilis - Complications

• Fetal death

• Premature birth

• CNS complications

Genital Herpes - General Info

• Cause = HSV-1 and HSV-2

• S/S = Systemic, bilateral lesions, fever, malaise

• Rx = NO cure, but can take antiviral meds to reduce duration

STD - High Risk Groups

• Underrepresented groups

• Low-income populations

• Those with less access to medical services

STD - Prevention

• Promote healthy sexual behaviors

• Strengthen community capacities

• Increase access to quality services

Bioterrorism - Definition

• Deliberate release of biologic agents to cause harm

Bioterrorism - Examples

• Anthrax

• Smallpox

• Mpox (Monkeypox)

Anthrax - Definition

• Acute bacterial disease affecting skin or respiratory tract

Anthrax - General Info

• Inhalation is nearly ALWAYS fatal

• Disseminated through US mail

• Vaccine available and stored in Strategic National Stockpile

Smallpox - Definition

• Disease caused by the variola virus that was eradicated in 1980

Smallpox - Spread

• Spread via direct and close contact

Smallpox - S/S

• Fever

• Rash

• *Contagious until the last scab falls off

Smallpox - Rx

• Vaccine and antivirals → For a potential reemergence

Monkeypox - General Info

• Disease caused by orthopoxvirus genus

• S/S = Flu-like symptoms, rash, and fluid-filled blisters

• Spread through close contact, contaminated items, and infected anims

• Vaccine and antivirals for high risk groups

Measles - Causes

• Rubeola virus

Measles - Transmission

• Airborne

• Direct contact

• *Can get it from just being in the same room where a person with measles has been

Measles - S/S

• PROMINENT RASH

• Early → 4-7 days after exposure

  • Runny nose, cough, red and watery eyes, small white spots inside the cheeks

When do Measles S/S usually start?

• 10-14 days after the exposure

Most people who get measles die from … related to the disease?

• Complications!

Measles - Complications

• Blindness

• Encephalitis

• Severe diarrhea and dehydration

• Ear infections

• Severe breathing problems → Includes pneumonia

Rubella is also known as … and it is caused by …?

• “German Measles”

• Caused by rubivirus

Rubella - General Info

• Spread through direct or droplet contact from nasopharyngeal secretions

• Humans are only natural hosts

• Spikes in late winter and early spring

Pertussis is also known as … and is caused by …?

• “Whooping Cough”

• Caused by Bordatella Pertussis

Pertussis - General Info

• Human disease

• Spread through respiratory or airborne droplets

• Rx = Antibiotics and postexposure prophylaxis (PEP)

Polio - General Info

• Is an enterovirus → Are transient inhabitants of the GI tract and are stable at acidic pH

• Enters the mouth and multiplies in oropharynx and GI tract

• Rx = NO CURE → Children get 4 doses of the vaccine to prevent against

HPV - General Info

• Caused by papillomaviridae

• Very common infection

• Spread through intimate skin to skin contact

• HPV vaccine at ages 11-12 y/o

Foodborne Illnesses - Timeline

• Infection = 12 hours to several days after ingestion of infected food

• Intoxication = Minutes to hours after ingestion

Salmonellosis - General Info

• Caused by salmonella bacteria that lives in the intestines of people and animals

  • Grows best in warm weather and unrefrigerated

• Spread through eating contaminated food/water or touching animals, animal feces, and places where animals live

• Leading cause of foodborne illnesses, hospitalizations, and deaths

• S/S = Diarrhea, abdominal pain/cramps, fever, N/V

Escherichia Coli - General Info

• Most forms are harmless and a part of the general GI tract, but some cause infection

• Spread through contaminated food/water or contact with animals, environments, or other people

Major reservoir for E. Coli is …?

• Cows

Lyme Disease - Definition

• Bacterial infection spread to people through the bite of a blacklegged tick

• Caused by Borrelia Burgdorferi

In Lyme Disease, the tick must be attached for more than … to transmit an infection?

• 24 hours

Where is Lyme Disease most common?

• Forested areas

Lyme Disease - S/S

• Fever, chills, headache, fatigue, muscle and joint aches

• Swollen lymph nodes

• ERYTHEMA MIGRANS (EM) RASH → Looks like a bullseye

Lyme Disease treatment is all based on what …?

• S/S are present!

Lyme Disease - Rx

• EM Rash → Doxycycline (Amoxicillin) for 14 days

• Neurological Lyme Disease → Doxycycline (Amoxicillin) for 21 days

• Lyme Carditis

  • Mild → Doxycycline (Amoxicillin) PO for 21 days

  • Severe → Ceftriaxone IV for 21 days

Diseases of travelers are … and …?

• Malaria

• Zika

Malaria - General Info

• Caused by Plasmodium parasite species

• Categorized as uncomplicated or severe/complicated

  • Severity and duration can depend on species of malaria parasite and immunity level

• S/S = Fever, chills, sweats, headache, N/V, myalgias, and malaise

• Dx = Blood smear, PCR, and antigen

• Get risk assessment prior to travel

Zika Virus - General Info

• Spread through Aedes species mosquitos

  • Can also spread perinatal, in utero, sexual, and blood or lab exposure

  • Main concern is congenital infection → Pregnancy!

• S/S = 80% asymptomatic

• Complications = Rare → Guillian-Barre, encephalopathy, myelitis, uveitis, and thrombocytopenia

Rabies - General Info

• Caused by lyssavirus

• Spread via animal bit or scratch → Carried in saliva or mucus and spreads through the broken skin

• Fatal in not treated!

• S/S = Myalgias, weakness, fever, headache, anxiety, confusion, agitation, and hallucinations

  • Once S/S present, are always ALWAYS fatal

Primary Prevention - Two Approaches

• Education

• Immunizations

Primary Prevention - Education Focus

• Health promotion/prevention methods

• Use a health equity lens

Primary Prevention - Health Equity Principles for Education

• Identify intended audience

• Determine education level

• Consider culture, race, and ethnicity

• Pretest materials for attractiveness, comprehensibility, and persuasiveness

• Give material at appropriate reading level

• Avoid dehumanizing language

• Avoid saying terms with violent connotation