1. Pneumonia

2. Outline Introduction People at risk Epidemiology Signs and symptoms
Children
Signs and symptoms
Causes of pneumonia
Bacterial Pneumonia
Viral Pneumonia
Fungal Pneumonia
Parasitic Pneumonia
Prevention and Vaccination

3. Introduction
Pneumonia is an inflammatory condition of the lung affecting primarily the alveoli
It is usually caused by infection
viruses or bacteria
less commonly
other microorganisms
certain drugs
other conditions
autoimmune diseases

4. Typical symptoms include
cough, chest pain, fever, and difficulty breathing
Diagnostic tools include
x-rays and culture of the sputum
Vaccines to prevent certain types of pneumonia are available
Treatment depends on the underlying cause
Pneumonia presumed to be bacterial is treated with antibiotics
If the pneumonia is severe
the affected person is, in general, admitted to hospital

5. Pneumonia remains a leading cause of death in
Pneumonia affects approximately 450 million people per year
7% of population
results in about 4 million deaths
mostly in third-world countries
The advent of antibiotic therapy and vaccines has seen improvements in survival
Pneumonia remains a leading cause of death in
developing countries
the very old
the very young
the chronically ill

6. People at risk
The following people have a higher risk of developing pneumonia:
babies and very young children
elderly people
smokers
alcoholism
people with other health conditions
people with a weakened immune system
Health conditions that increase the risk of pneumonia developing include:
another lung condition such as asthma or cystic fibrosis
a heart condition
a kidney or liver condition
a lowered immune system
Your immune system can be weakened because of:
a recent illness such as flu
treatment for cancer, such as chemotherapy
medicines that weaken the immune system after an organ transplant
HIV or AIDS

7. Epidemiology
Pneumonia is a common illness affecting about 450 million people a year
Major cause of death among all age groups
resulting in 4 million deaths yearly
7% of the world's total death
rates are greatest in children less than five
adults older than 75 years
Occurs about 5X more frequently in the developing world than in the developed world
Viral pneumonia accounts for about 200 million cases
In the United States, as of 2009, pneumonia is the 8thleading cause of death

8. Pneumonia in Children
In 2008, pneumonia occurred in approximately 156 million children
151 million in the developing world and 5 million in the developed world
In 2010, it resulted in 1.3 million deaths, or 18% of all deaths in those under five years
95% occurred in the developing world
Countries with the greatest burden of disease include
India (43 million), China (21 million) and Pakistan (10 million)
It is the leading cause of death among children in low income countries
many of these deaths occur in the newborn period
WHO estimates that one in three newborn infant deaths is due to pneumonia
Approximately half of these deaths can be prevented
as they are caused by the bacteria for which an effective vaccine is available

9. Symptoms of pneumonia 
The symptoms of pneumonia can develop suddenly (over hours)
or may come on more slowly, over several days
Pneumonia symptoms vary and can be similar to those of other chest infections
such as acute bronchitis

10. Signs and symptoms
Bacterial and viral cases of pneumonia usually present with similar symptoms
symptoms of viral pneumonia may be more numerous
People with infectious pneumonia often have
productive cough
fever accompanied by
shaking chills
shortness of breath
sharp or stabbing chest pain during deep breaths
an increased respiratory rate
In the elderly, confusion may be the most prominent sign
The typical signs and symptoms in children under five are
fever, cough, and fast or difficult breathing

11. Fever is not very specific
occurs in many other common illnesses
may be absent in those with other conditions
Cough is frequently absent in children less than 2 months old
More severe signs and symptoms may include
blue-tinged skin
decreased thirst
convulsions
persistent vomiting
extremes of temperature
decreased level of consciousness

12. Some causes are associated with classic, but non-specific, clinical characteristics
pneumonia caused by Legionella
abdominal pain, diarrhea, or confusion
pneumonia caused by Streptococcus pneumoniae
rusty colored sputum
bloody sputum may also occur with
tuberculosis
gram-negative bacterial pneumonia
lung abscesses
acute bronchitis
Mycoplasma pneumonia may occur in association with
swelling of the lymph nodes in the neck, joint pain, or a middle ear infection
Viral pneumonia presents more commonly with wheezing than does bacterial pneumonia

14. Common symptoms of pneumonia
Likely to have a cough
dry, or may produce thick mucus that is yellow, green, brownish or blood-stained
Other common symptoms include:
difficulty breathing
breathing may be rapid and shallow and may feel breathless, even when resting
rapid heartbeat
fever
feeling generally unwell
sweating and shivering
loss of appetite
pain in your chest

15. Less common symptoms Less commonly, symptoms of pneumonia can include:
coughing up blood (haemoptysis)
headaches
fatigue
nausea
vomiting
wheezing
pain in joints and muscles
feeling confused and disorientated
particularly in elderly people

16. Causes of pneumonia Pneumonia depends on germs where first caught
Pneumonia is most commonly caused by an infection, usually a bacterial infection
Pneumonia depends on germs where first caught
Pneumonia germs caught in hospitals are different to those caught in the community
Germs that cause an infection are usually breathed in
In rare cases
pneumonia can develop from an infection elsewhere in the body
germs enter the lungs through the bloodstream

17. Bacterial pneumonia

18. Gram-positive Streptococcus pneumoniae
most common bacterial cause of pneumonia
Other important Gram-positive causes of pneumonia
Staphylococcus aureus
Bacillus anthracis

19. Gram-negative Gram-negative bacteria are seen less frequently
Haemophilus influenzae
Klebsiella pneumoniae
Escherichia coli
Pseudomonas aeruginosa
Bordetella pertussis
Moraxella catarrhalis
These bacteria often live in the gut
enter the lungs when contents of the gut are inhaled
such as vomit or feces

20. Atypical They are "atypical" as they do not gram stain
as well as gram-negative and gram-positive organisms
Atypical bacteria are
Coxiella burnetii
Chlamydophila pneumoniae
Mycoplasma pneumoniae
more commonly in children and young people
Legionella pneumophila
Pneumonia caused by Yersinia pestis is usually called pneumonic plague

21. Pathophysiology Bacteria typically enter the lung with inhalation
though they can reach the lung through the bloodstream if other parts of the body are infected
Often, bacteria live in parts of the upper respiratory tract and are continuously being inhaled into the alveoli
Once inside the alveoli, bacteria travel into the spaces between the cells and also between adjacent alveoli through connecting pores
This invasion triggers the immune system to respond by sending white blood cells responsible for attacking microorganisms (neutrophils) to the lungs

22. The neutrophils engulf and kill the offending organisms but also release cytokines that result in a general activation of the immune system
This results in the fever, chills, and fatigue common in bacterial and fungal pneumonia
The neutrophils, bacteria, and fluid leaked from surrounding blood vessels fill the alveoli and result in impaired oxygen transportation
Bacteria often travel from the lung into the blood stream and can result in serious illness such as septic shock, in which there is low blood pressure leading to damage in multiple parts of the body including the brain, kidney, and heart
They can also travel to the area between the lungs and the chest wall, called the pleural cavity

23. Treatment
Antibiotics are the treatment of choice for bacterial pneumonia
ventilation as supportive therapy
The antibiotic choice depends on
nature of the pneumonia
microorganisms most commonly causing pneumonia in the geographical region
immune status and underlying health of the individual
Local patterns of antibiotic-resistance should always be considered
In hospitalized individuals or those with immune deficiencies
local guidelines determine the selection of antibiotics
typically given through an intravenous line

24. Gram-positive organisms
Streptococcus pneumoniae
amoxicillin
or erythromycin in patients allergic to penicillin
cefuroxime and erythromycin in severe cases
Staphylococcus aureus
flucloxacillin

25. Gram-negative organisms
Haemophilus influenzae
doxycycline
3rd generation Cephalosporins such as Cefaclor
Klebsiella pneumoniae
Escherichia coli
Pseudomonas aeruginosa
ciprofloxacin
Moraxella catarrhalis

26. Atypical organisms Chlamydophila pneumoniae — doxycycline
Chlamydophila psittaci — erythromycin
Mycoplasma pneumoniae — erythromycin
Coxiella burnetti — doxycycline
Legionella pneumophila — erythromycin, with rifampicin sometimes added.
People who have difficulty breathing due to pneumonia may require extra oxygen
An extremely sick individual may require artificial ventilation and intensive care as life-saving measures
while his or her immune system fights off the infectious cause with the help of antibiotics and other drugs

27. Prevention Prevention of bacterial pneumonia is by vaccination
Against Streptococcus pneumoniae
pneumococcal polysaccharide vaccine for adults and pneumococcal conjugate vaccine for children
Haemophilus influenzae type B
Meningococcus
Bordetella pertussis
Bacillus anthracis
Yersinia pestis

28. Viral pneumonia

29. Viral pneumonia Viral pneumonia is a pneumonia caused by a virus
Viruses are one of the two major causes of pneumonia
the other being bacteria
less common causes are fungi and parasites
Viruses are the most common cause of pneumonia in children
while in adults bacteria are a more common cause

30. Signs and symptoms Symptoms of viral pneumonia include
fever
non-productive cough
runny nose
systemic symptoms
e.g. myalgia, headache
Different viruses cause different symptoms

31. Cause Common causes of viral pneumonia are:
Influenza virus A and B
Respiratory syncytial virus (RSV)
Human parainfluenza viruses
in children
Rarer viruses that commonly result in pneumonia include:
Adenoviruses
Metapneumovirus
Severe acute respiratory syndrome virus (SARS coronavirus)

32. The most commonly identified agents in children are
Viruses that primarily cause other diseases, but sometimes cause pneumonia include
Herpes simplex virus (HSV)
mainly in newborns
Varicella-zoster virus (VZV)
Measles virus
Rubella virus
Cytomegalovirus (CMV)
mainly in people with immune system problems
The most commonly identified agents in children are
respiratory syncytial virus, rhinovirus, human metapneumovirus, human bocavirus, and parainfluenza viruses

33. Pathophysiology Viruses must invade cells in order to reproduce
Typically, a virus will reach the lungs by traveling in droplets through the mouth and nose with inhalation
There, the virus invades the cells lining the airways and the alveoli
This invasion often leads to cell death either through direct killing by the virus or by self-destruction through apoptosis
Further damage to the lungs occurs when the immune system responds to the infection

34. WBC, in particular lymphocytes, are responsible for activating a variety of chemicals (cytokines)
cause leaking of fluid into the alveoli
The combination of cellular destruction and fluid-filled alveoli interrupts the transportation of O2 into the bloodstream
In addition to the effects on the lungs, many viruses affect other organs and can lead to illness affecting many different bodily functions
Viruses also make the body more susceptible to bacterial infection; for this reason, bacterial pneumonia often complicates viral pneumonia

35. Prevention The best prevention against viral pneumonia is vaccination
influenza, adenovirus, chickenpox, herpes zoster, measles, and rubella

36. Treatment
In cases of viral pneumonia where influenza A or B are thought to be causative agents, patients who are seen within 48 hours of symptom onset may benefit from treatment with oseltamivir or zanamivir
Respiratory syncytial virus (RSV) may be treated with ribavirin 

37. Herpes simplex virus and varicella-zoster virus infections are usually treated with aciclovir, whilst ganciclovir is used to treat cytomegalovirus
There is no known efficacious treatment for pneumonia caused by SARS coronavirus, adenovirus, hantavirus, parainfluenza or H1N1 virus; treatment is largely supportive

38. Epidemiology Viral pneumonia occurs in about 200 million people a year
which includes about 100 million children and 100 million adults