Specific infection characteristics: Infectious disease, ch.5 (Part 2 of 2)

Impetigo

Caused by group A streptococci (GAS)

Impetigo

Commonly occurs in children aged 2 to 5 years old

Impetigo

Predisposing factors...

1. Close contact in school

2. Overcrowded living quarters

3. Poor skin hygiene

4. Minor skin trauma

Impetigo

Good hygiene is essential

Impetigo

Clinical manifestation...

Mascules > vesicles > pustular and encrusted

Impetigo

Scratching spreads infection

Antibiotics

Impetigo treatment

Streptococcal Cellulitis

Rapidly spreading acute inflammation with infection of the skin and subcutaneous tissue that spreads

Streptococcal Cellulitis

Clinical manifestations...

1. Presence of red, tender, linear streaks directed towards enlarged, tender regional lymph nodes

2. Systemic symptoms

- chills

- fever

- malaise

- headache

Streptococcal Cellulitis treatment

Treatment...

1. IV antibiotics (primary)

2. Oral antibiotics (can be effective)

Streptococcal necrotizing fasciitis

Serious infection that progresses rapidly along fascial planes

Streptococcal necrotizing fasciitis

Usually in the legs causing severe tissue damage as it spreads

Streptococcal necrotizing fasciitis

clinical manifestations...

1. Pain and fever

2. Infection spreads rapidly, causing edema and tenderness

3. Blood clots can occur

4. Skin turns dark red with loss of elasticity and pliability

5. Bullae form and fill with dark fluid

6. Skin becomes friable and turns maroon or black color consistent with ischemia

Streptococcal necrotizing fasciitis

Bacteria causes severe breakdown of tissue in multiple organs

Streptococcal necrotizing fasciitis

High mortality rate

Streptococcal necrotizing fasciitis

Diagnosis...

Gram stain and culture of infected site to identify organism

Streptococcal necrotizing fasciitis

Treatment...

Immediate surgery w/ agressive debridement of all necrotic tissue

Streptococcal necrotizing fasciitis

Treatment...

Appropriate intensive IV antibiotics are essential to save muscles and limbs

Streptococcus pneumoniae

Organisms colonize the oropharynx and nasopharynx

Streptococcus pneumoniae prevelance

Found in 5 to 10% of health adults; 20 to 40% of children

Streptococcus pneumoniae

can cause pneumonia

Streptococcus pneumoniae complications

can cause sepsis

Streptococcus pneumoniae

can cause otitis media

Streptococcus pneumoniae

can cause meningitis

Streptococcus pneumoniae transmisson

Transmission from person to person is by direct contact or inhalation of droplets of respiratory secretions

Streptococcus pneumoniae causes

Most common cause of community-acquired pneumonia

Streptococcus pneumoniae

clinical manifestation...

acute onset fever and chills

Streptococcus pneumoniae

clinical manifestation...

Pleuritic with chest pain

Streptococcus pneumoniae

Dyspnea with productive cough or purulent sputum that may be blood tinged

Streptococcus pneumoniae

Disease rapidly progresses rapidly over 24 to 48 hours and mortality rate is high w/o treatment

Streptococcus pneumoniae

Diagnosis...

1. Lab exam of sputum

2. CSF or blood with gram stain and culture of organism

Streptococcus pneumoniae treatment

Antibiotics

Immunization available

Streptococcus pneumoniae immunization

Hepatitis

Inflammatory process within the liver

Hepatitis

Most common viral infection

Hepatitis

Etiology...

1. Chemical and drug reactions

2. Alcohol abuse

Hepatitis

Signs and symptoms...

1. Fever

2. Flu-like symptoms

Hepatitis

signs and symptoms...

Abrupt onset fatigue

Hepatitis

Signs and symptoms...

Anorexia, headache, jaundice

Hepatitis

signs and symptoms...

Darkened urine, lighter stool, enlarged spleen and liver

Hepatitis A

Flu-like symptoms represent an acute infection

Hepatitis A treatment

Usually recover w/o treatment

Hepatitis B

Treatment..

immunoglobin for the unvaccinated pt within 24 hrs of exposure (followed by vaccination)

Hepatitis C

One of the primary etiologies for chronic liver disease and eventual liver failure

Hepatitis C treatment

Currently no vaccination but medication assists treatment

Hepatitis A

HAV

Hepatitis B

HBV

Hepatitis C

HCV

Varicella Zoster Virus

VZV

Varicella

AKA Chicken pox

Herpes Zoster

AKA shingles

Varicella Zoster Virus

Pathogenesis...

Acquired from contact with infected airborne droplets into the respiratory tract

Varicella Zoster Virus

Pathogenesis...

Direct contact with vesicular fluid to the respiratory tract or eye

Varicella Zoster Virus

Once exposed, the infection can remain dormant for years

Varicella Zoster Virus

Has an incubation period

Varicella

Clinical manifestation...

Rash, pain, itching

Varicella

Dewdrop on rose petal rash

Varicella

Lesions= muscles > papules > vesicles > pustules > crusting

Varicella

Usually appears first on scalp and moves to the trunk and then extremities

Herpes Zoster

Clinical manifestation...

Blister-like lesion that develop along the dermatome

Herpes Zoster

Highest concentration of lesions on the trunk corresponding with dermatomes from T3 to L3

Herpes Zoster

Clinical manifestation...

Pain and itching

Herpes Zoster

Clinical manifestation...

Post-herpetic Neuralgia (PHN)

Herpes Zoster

Clinical manifestation...

Malaise and fever with other potential complications

Recommended

Varicella Zoster Virus vaccine

Shingles vaccine

Zostavax

Shingles vaccine

Shingrix

Zostavax

older shingles vaccine, licensed 2006

Shingrix

Newer shingles vaccine, licensed by FDA 2017

Varicella Zoster Virus

Highly contagious

Varicella Zoster Virus

Only HCWs with immunity should tend to these pts

Varicella Zoster Virus

Potentially infectious from day 10 to 21 after exposure

Influenza

viral respiratory infection

Influenza

Caused by influenza viruses A or B

Influenza

Occurs in epidemics between late fall and early spring

Influenza

Clinical manifestation...

High fever lasting 1 to 7 days

Influenza

clinical manifestations...

Chills, malaise, muscular aching

Influenza

Clinical manifestations...

Headache, sore throat, nasal congestion, and non productive cough

Influenza

Can progress rapidly in the first few days, causing pneumonia and respiratory failure

recommended before the beginning of each flu season

Influenza vaccine

Influenza

Treatment...

Antiviral agents can be given in conjunction with vaccine

Influenza

Treatment...

Antiviral agents help decrease the duration of severity of signs and symptoms

Influenza

Duration is 3 to 7 days

Influenza

Individuals older than 65 are at risk for greater complications

Influenza

Residents of healthcare facilities are at risk for greater complications

Influenza

People with DM are at risk for greater complications

Lyme disease

Infectious multi systemic disorder

Lyme disease

Deer or black-legged tick transmit infection in NE and North central US

Lyme disease

Western black-legged tick transmit infection on west coast

Lyme disease

Pathogenesis...

Generally acquired from ticks attaching to skin to feed

Lyme disease

36 to 46 hours before bacteria is passed into host from infectious agent

Lyme disease

Bacteria can cause inflammatory process

Lyme disease

3 stages of clinical manifestation

Lyme disease stage 1

Early, localized stage

Lyme disease stage 1

Occurs within days of bite

Lyme disease stage 1

Bulls eye rash

Lyme disease stage 2

disseminated infection

Lyme disease stage 2

Occurs days or weeks when bacteria spreads to the nervous system, heart and joints

Lyme disease stage 2

Neurologic symptoms may be first to arise

Lyme disease stage 2

Migratory musculoskeletal pain in joints, bursae, tendons, muscle, and bone