1. By Dr. Wafaa Kamel Mowafy Professor of Microbiology & Immunology
Viral pneumonia By
Dr. Wafaa Kamel Mowafy
Professor of Microbiology & Immunology

3. Pneumonia is an infection in one or both lungs
Pneumonia is an infection in one or both lungs. It can be caused by a number of different germs, including bacteria, viruses, and fungi. When caused by viruses, it is known as viral pneumonia

4. Viral Pneumonia
Viruses are thought to cause up to 30 percent of adult pneumonia cases . The condition can be hard to diagnose because it may start out with similar symptoms as the common cold.  
Some of the viruses known to cause viral pneumonia in adults and children include:

5.  Influenza viruses
Parainfluenza viruses (which can cause croup)
Human metapneumovirus
Respiratory syncytial virus ( RSV )
Adenovirus
Severe acute respiratory syndrome (SARS)

6. .The Middle East respiratory syndrome coronavirus (MERS-CoV) or simply the novel coronavirus, "Saudi SARS" is recently emerged
Most people get viral pneumonia within the community (this is called community-acquired viral pneumonia). Viral cases are less likely to happen within the hospital

7. Influenza viruses Family : Orthomyxoviridea
Morphology : SS RNA in 8 segments (7 in influenza C). Enveloped with glycoprotein projections called Hemagglutinin (HA) and neuramindase(NA)
.Classification : Influenza A, B and C according to NP and M protein

8. Influenza A is classified into 16 subtypes according to HA and 9 subtypes according to NA
Influenza A virus is essentially an avian virus that has "recently" crossed into mammals.
Birds have the greatest number and range of influenza strains.
Avian haemagglutinins sometimes appear in pig, human

9. and horse (pig is the mixing pot).
Avian flu : H5N1,H7N Swine flu H1N1,H3N2
There is constant antigenic change ( antigenic shift and drift) down the years which means that new vaccines have to be made on a regular basis
Antigenic shift
Major dramatic changes in HA and or NA
It occurs every 10 – 20 years and involves changes in subtype

10. For example from H1N1 to H3N2
Antigenic drift
Minor antigenic changes in the H and NA that occur each year
Don not involve a change in the viral subtype

11. How would a pandemic happen?
Gene exchange between influenza A viruses
Human or swine flu viruses can reassort with bird flu viruses in human or swine (co-infection)
Human H1N2
Chicken H5N1
H5N2 influenza A
H1N1 influenza A
H5N2 influenza A

13. Anti virus for influenza pneumonia:- Osletamivir ( Tamiflu) & Zanamivir . Are neuraminidase inhibitors inhibit release of the virus from infected cells
Treatment :Tamiflu is given 75 mg twice / day orally for adult
Prophylaxis : it is given 75 mg/ day
To be effective as chemoprophylaxis, an antiviral medication must be taken each day for the duration of potential exposure to a person with influenza and continued for 7 days after last known exposure

14. Flu vaccine prevents pneumonia and other problems caused by the influenza virus. It must be given each year to protect against new circulating virus strains.
The vaccine is formalin inactivated prepared as follow:
Large amounts of virus are grown in embryonated eggs (cheap and efficient), purified and formalin inactivated.
The vaccine is given IM,once for adult
For children ,it may given twice 4 weeks apart according to the age.

15. The U.S. Centers for Disease Control and Prevention recommend that everyone over the ages of 6 months should receive the seasonal influenza vaccine. Vaccination campaigns usually focus on people who are at high risk of serious complications if they catch the flu, such as the elderly and people living with chronic illness or those with weakened immune systems, as well as health care workers

16. The U.S. Centers for Disease Control and Prevention recommend that everyone over the ages of 6 months should receive the seasonal influenza vaccine. Vaccination campaigns usually focus on people who are at high risk of serious complications if they catch the flu, such as the elderly and people living with chronic illness or those with weakened immune systems, as well as health care workers

17. Seasonal influenza vaccine( Flu vaccine 2013) contains antigens representing three (trivalent vaccine) influenza virus strains: one influenza type A subtype H1N1 virus strain, one influenza type A subtype H3N2 virus strain, and one influenza type B virus strain

18. 2- Parainfluenza viruses (which can cause croup)
3 -Human metapneumovirus
4- Respiratory syncytial virus ( RSV )
- Family : Paramyxoviridae family
- Morphology : SS RNA non segmented. Enveloped with glycoprotein spikes hemagglutinin or neuramindase or

19. 5 -Severe acute respiratory syndrome (SARS)
both and a fusion protein that causes cell fusion ( form multinuculated synctia or giant cells)
5 -Severe acute respiratory syndrome (SARS)
  6-The Middle East respiratory syndrome coronavirus (MERS-CoV) or simply the novel coronavirus, "Saudi SARS" is recently emerged  .

20. ( 5,6) Family : Coronaviridae family
- Morphology : SS RNA , enveloped . Club- haped surface projections are seen , giving the particles their charctersitic fringed appearance 
7- Adenovirus
Family : adenoviride
- Morophology : DS DNA and non enveloped

22. Paramyxoviruse

23. Coronaviruse

25. MERS-CoV

26. Adenovirus

27. What are symptoms of viral pneumonia?
  When viruses affect the lungs, they can cause inflammation and swelling, which leads to many of the symptoms seen with viral pneumonia
Some common symptoms can include:
A cough (it may be dry, but can produce green or yellow phlegm)
A rapid heart rate and/or breathing rate
Fever .

28. Trouble breathing
Chest pain when breathing or coughing
Shortness of breath.

29. . Person with viral pneumonia may also have signs or symptoms that affect other parts of the body. These can include:
Headache
Diarrhae
Muscle aches
Sore throat
Fatigue
Nausea
Vomiting

30. Difference Between Viral and Bacterial Pneumonia
There are many similarities to be found when comparing viral and bacterial  pneumonia. For example
They are both contagious, potentially serious infections of one or both lungs. Both types cause cough, fatigue,fever,headache and other symptoms.
However, bacterial and viral pneumonia also have many differences. For example :

31. 1-The symptoms of bacterial pneumonia usually come on rapidly and tend to be more severe
Viral pneumonia symptoms tend to appear more gradually and not be as intense. Often, symptoms of viral pneumonia will begin a couple of days after a person has developed upper respiratory symptoms, such as congestion or a sore throat.

32. 2- Bacterial and viral pneumonia also have different treatment options
2- Bacterial and viral pneumonia also have different treatment options . Bacteria respond to antibiotics. If a medicine is prescribed for viral pneumonia, it is usually an antiviral drug.

33. Exams and Tests physical exam Chest x ray. Complete blood count (CBC)
CT scan of the chest
Blood cultures
Sputum culture
Diagnose of specific viruses
Bronchoscopy (rarely needed)

34. Laboratory diagnosis of the causative virus
Sample : sputum, bronchoalveolar lavage, nasopharegeal aspirate
1- Direct diagnosis
Detection of the virus particle by ElM
Detection of the virus antigen by IF, EIA.
Detection of virus nucleic acid by PCR
2- Virus isolation :
Cell culture to detect cytopathic effect of the virus e.g
adenovirus causes rounding of the cells

35. Inoculation of influenza virus in embryonated egg
3- Serological diagnosis
Detection of virus antibodies by IF, EIA, RIA and HAI

36. Cytopathic effect of adenovirus: rounding of the cells and clusters

37. Cytopathic effect of RSV : Syncitum formation

38. Complications:
Complications from viral pneumonia, while rare, can occur. These include:
Respiratory failure or Acute Respiratory Distress Syndrome (a severe form of respiratory failure)
Sepsis
Emphysema or a lung absces
Death

39. These complications are most common in people in high risk groups like infants, adults over age 65, people with chronic health conditions such as heart disease and smokers.

40. Treatment
Antibiotics do not treat viral pneumonia. Antiviral works only against influenza pneumonia.
Treatment may also involve:
Increased fluids
Oxygen
Use of humidified air
A hospital stay may be necessary to prevent dehydration and to help with breathing if the infection is serious

41. Viral Pneumonia Prevention
Germs are spread both by aerosolized droplets that you breathe in (such as from a sneeze) and through body fluids left on surfaces like door handles. SO,
Avoid people who are coughing or sneezing,
Wash your hands frequently.
Avoid smoking
If you get flu shot every fall, you reduce your chances of getting influenza pneumonia