Respiratory Syncytial Virus

Front 1

What type of respiratory infection is RSV?

Back 1

Lower respiratory infection

Front 2

What are some clues that suggest a patient might have RSV?

Back 2

The patient is young (age), it is winter (season), the patient has had contact with someone who was sick, wheezes and hyperexpansion of the chest. However, NONE of these are specific clues.

Front 3

What is an infection?

Back 3

The action of a microbial agent on the body

Front 4

What is disease?

Back 4

The clinical signs and symptoms manifested by the infection

Front 5

How common is infection with RSV?

Back 5

VERY COMMON! 100% of kids have been infected with RSV by the age of 2. People are re-infected throughout their lives.

Front 6

What does RSV cause in babies? In older people?

Back 6

In babies RSV usually causes Bronchiolitis upon their first exposure to the virus. In older individuals, RSV causes colds.

Front 7

What is the pathogenesis of RSV in babies?

Back 7

1) Infection with RSV
2) Necrosis of the respiratory epithelium (you see increased lymphocytes and increased mucus in the distal airways)
3) Narrowing of the airways (due to the debri of epithelial cells that are lining the airways and being destroyed).

Front 8

What part of the Bronchiole is most affected by RSV?

Back 8

The terminal part of the Bronchiole

Front 9

What is the different between narrowing of the airways with asthma and due to bronchiolitis?

Back 9

Asthma cuases a narrowing of the airways due to muscular constricture. Bronchiolitis causes a narrowing of the airways due to the buildup of debri and edema.

Front 10

What factors increase the severity of RSV disease in children?

Back 10

1) Age- young people have smaller airways
2) Weight for Age- a low weight increases risk
3) Gestational Age- premature babies are at increased risk
4) Underlying disease- cardiac and pulmonary diseases increase your risk
5) Viral load- a higher viral load leads to a more severe disease
6) Immune response- children have exaggerated Th2 responses that lead to activation of B cells, immune complex formation and resulting death of activated cytotoxic T cells

Front 11

Besides children, what other people are at increased risk for RSV infection?

Back 11

Individuals with lowered immune capabilities have a greater risk for a more severe RSV infection. This includes people that are immunosuppressed (stem cell transplant patients, bone marrow transplant patients) or have genetic mutations. Severe RSV disease is associated with polymorphisms in cytokine-chemokine related genes, genes involved in virus-cell surface interactions and cell signaling genes.

Front 12

Can normal adults get RSV?

Back 12

Yes, they just don't get as severe a form of this disease.

Front 13

How is one exposed to RSV?

Back 13

Large particle aerosols getting into the eyes or mouth
Direct contact
Contagious secretions on the hands

Front 14

How long is the incubation period for RSV?

Back 14

1-8 days

Front 15

What is a factor that contributes to more RSV virus?

Back 15

Seasonality- RSV infections PEAK every winter

Front 16

What is the best way prevent/control the spread of RSV?

Back 16

Wash your hands

Front 17

What are the clinical manifestations of RSV infection in children?

Back 17

Bronchiolitis with wheezing

Front 18

What causes the wheezing seen with RSV infection?

Back 18

The airways are obstructed. Air can come in but it is unable to leave the airways well and thus gets trapped in the bronchioles. The diaphragm gets pushed down because of this trapped air in the alveolar sacs.

Front 19

What is seen on an X-ray of a child with Bronchiolitis?

Back 19

They have a lot of black in their lungs due to trapped air and their diaphragm is pushed down.

Front 20

What are some symptoms associated with bronchiolitis associated with RSV infection in babies?

Back 20

Rhinitis, fever, cough (this can continue after the virus is gone), rales, wheezes, hypoxemia (blood is not well aerated), apnea, infiltrates on the chest x-ray, elevated WBC, RSV shedding early on in the progression of the disease. Babies usually end up hospitalized. Rhinitis occurs first followed by a fever and the cough.

Front 21

What are some other respiratory manifestations of RSV infection?

Back 21

In healthy infants it can cause pneumonia or bronchiolotis. In healthy children it can cause upper respiratory infections or bronchitis. In healthy adults it can cause upper respiratory infections or bronchitis. In immunocompromised patients it can cause pneumonia.

Front 22

What is the most common symptom associated with Bronchiolitis, upper respiratory infections, bronchitis and pneumonia?

Back 22

Bronchiolitis- wheezing
Upper respiratory infection- rhinitis
Bronchitis- cough
Pneumonia- tachypnea and shortness of breath

Front 23

What part of the lung is infected with viral pneumonia?

Back 23

The lung parenchyma

Front 24

How can you diagnose a RSV infection?

Back 24

Clinical signs and symptoms. You look for cough, rhinitis, fever, and wheezing and poor feeding in infants.

The virus can also be detected via PCR (best) or EIA (not so good). This is not done in older people but is done in babies so that it is isolated appropriately and is not spread throughout the hospital.

A viral culture can also be done in which you would visualize syncytia (the clumping of cells due to a cytopathic effect of the virus).

Front 25

How do you treat RSV infection?

Back 25

Symptomatic- fluids, O2, mechanical ventilation

Ribavirin aerosol- aerosol is toxic to caregivers and clogs ventilator valves so it must be used with caution. It has limited efficacy but might be good in immunosuppressed adults.

There are NO good vaccines or treatments against RSV

Front 26

How do you prevent RSV infection?

Back 26

Limit exposure for at-risk infants (ex= premature babies)
EVERYONE should wash their hands
No vaccine yet but it is being worked on
Hyperimmune globulin (very expensive; it is a mouse-human chimeric monoclonal antibody against F protein; it has a low efficacy; it is used only for babies at risk and given during their first 2 years of life).

Front 27

As you grow up does RSV infection cause a worse or less severe disease and why?

Back 27

RSV infection causes a less severe disease due to having larger airways.

Front 28

Is a baby gets an RSV infection are they protected from it in the future?

Back 28

No, previous infection is not protective.