Diseases of the Lower Respiratory Tract (Part 2) - Exam 5

What are 4 viral diseases of the LRT?

1. Respiratory syncytial virus (RSV)

2. Influenza virus

3. SARS/MERS

4. COVID-19

What organism causes respiratory syncytial disease?

respiratory syncytial virus (RSV)

Prevention of respiratory syncytial disease

Vaccine for select groups (pregnant mothers and the elderly)

Epidemiology of respiratory syncytial disease

infants and elderly at risk

What organism causes influenza A?

influenza A virus

Culture/Diagnosis of influenza A

lateral flow immunoassay for antigens; PCR

The different influenza strains are A, B, and C. Which is the most common?

A

How do flu viruses get their names?

Influenza subtypes

1. Hemagglutinin spikes (H)

2. Neuraminidase spikes (N)

When antigenically different...

new subtype

What is antigenic drift?

genomes mutate over time

-minor mutations where subtype remains the same

-increases viral spread

-vaccines become less effective over time

What is antigenic shift?

influenza can swap RNA segments with other influenza viruses

-large changes over a short period of time

-happens infrequently but often the source of epidemics

Why do you have to get the flu vaccine every year?

Each year, flu scientists meet and predict the next seasons flu strains and subtypes

-takes 1 year to make the flu vaccine (inactivated vaccine)

The inactivated flu vaccine is made in _______________

chicken eggs

Each seasonal flu vaccine is....

trivalent

-protect against 3 different flu viruses

What is SARS AND MERS?

Severe Acute Respiratory Syndrome and Middle East Respiratory Syndrome

-2 separate diseases caused by 2 separate coronaviruses

Why is SARS-CoV-2 (COVID-19) a bigger problem than SARS and MERS?

SARS-CoV-2 was more contagious and less deadly than SARS/MERS

What are 4 fungal diseases of the LRT?

1. Histoplasmosis

2. Coccidiomycosis

3. Aspergillosis

4. Pneumocystis pneumonia

What organism causes histoplasmosis?

Histoplasma capsulatum

Histoplasmosis can be confused with ________________ . Why?

TB

-granulomas form in lung

Who is at high risk for histoplasmosis?

AIDS and immune compromised

What organism causes coccidioidomycosis (Valley Fever)?

Coccidioides immitis

Coccidioidomycosis (Valley Fever) is a ______ like infection and is often misdiagnosed

TB

How is Coccidioidomycosis (Valley Fever) spread?

by soil and wind

-prevalent in the Southwest US

Who is at high risk for Coccidioidomycosis (Valley Fever)?

AIDS patients

What does Aspergillosis cause/produce?

produces aflatoxins which are carcinogens

Pneumocystis pneumonia causes...

cysts to form in lung tissue that MUST be treated

Who is at high risk for pneumocystis pneumonia?

often occurs in infected infants and immunocompromised individuals (AIDS)

Parasitic infection of the LRT

Paragonimiasis

What organism causes Paragonimiasis?

lung flukes (Paragonimus sp.)

How is Paragonimiasis spread?

from undercooked crabs or crayfish

How is Paragonimiasis diagnosed?

look for eggs in sputum