Pneumonia Flashcards
What is pneumonia?
-
Inflammation of one or both lungs
- Commonly bacterial or viral cause
- Fungi, parasites or non-infectoius
- Alveoli filled with fluid or pus
- Infiltrates observed via x-ray
What are the symptoms of pneumonia?
- Dry or productive cough (phlegm)
- Difficulty breathing
- Increased respiratory rate
- Chest pain on coughing or breathing
- Fever, sweating or chills
- Depending on the nature of the organism
Why is pneumonia a global health problem?
Every year, it kills 1 million children under 5
One of the leading causes of death in young children (about 18% of deaths in U5s, which is worse than diarrhoeal diseases)
A number of bacteria, viruses and fungi cause pneumonia
Healthcare access, malnutrition HIV and indoor air pollution
S.pneumoniae causes 40% of all pneumonia and is a vaccine preventable disease
What is the GAPP project?
To protecy, prevent and treat all forms of pneumonia
Reduce the risk of pneumonia in the environment
Avoid illnesses from developing
Improved care for the sick
What is the burden of disease with regards to pneumonia?
- Burden of disease is either in the very young or the very old
- Therefore, the burden of disease is present in the U5s or the over 70s
- This is because either the immune system has not developed fully, or the immune system is weakened
- When looking at the death rate pneumonia, you can tell that it is not equitably spread
- The continents/regions with the largest death rates of pneumonia is subsaharan Africa, India, microasia and south America
When observing the deathrate from pneumonia for children and the gdp per capita, you can see that poorer countries particularly in SSA and southern Asia have the greatest death rate
What are the child deaths by risk factor?
- Our world in data suggests that child wasting is one of the largest contributors for childhood pneumonia
- Some of the risk factors include:
- Child wasting
- Indoor air pollution and solid fuels
- Low birth weight
- No access to handwashing facility
- Short gestation
- Child stunting
- Child underweight
- Non-exclusive breastfeeding
- Lower respiratory tract infections
What is S.pneumoniae ?
- GRAM +VE cocci: pneumococcus
- Polysaccharide capsule is the key virulence factor
- This is a key characteristic which interferes with the host’s immune system
- Over 90 different serotypes due to capsule structure
- You can observe budding entities in electron microscopy
What is the carriage and disease aspect of S.pneumoniae?
- Carriage and invasive disease
- Colonises nasopharynx for carriage in healthy individuals
- This may develop into a number of different diseases like
- Otitis media
- Pneumonia
- Meningitis
- Septicaemia
What is the treatment and protection of pneumonia?
- There are a range of antibiotics available and associated resistance in antibiotics
- There are polysaccharide (PPV) AND conjugate (pcv) vaccines in use
What are the different types of vaccines available for pneumonia?
-
Polysaccharide vaccine-PPV23
- There are 23 serotypes and a capsule polysaccharide [Pneumovax-23 produced by Merck]
- This vaccine will protect against 23 serotypes
- Mainly used in elderly, poor immune response in children
- There are 23 serotypes and a capsule polysaccharide [Pneumovax-23 produced by Merck]
-
Pneumococcal conjugate vaccine (PCV7, PCV10, PCV13)
- 7 or 13 pneumococcal serotypes [Prevnar-7/13 produced by Pfizer)
- 10 serotypes, H.influenzae protein conjugate [Synflorix produced by GSK)
- The PCV 7, PCV10 & PCV13 are extensively used for childhood immunisation)
What are the new pneumonia vaccines that are being developed today?
- Protein vaccines based on universal protein antigens
- Vaccines against all serotypes
-
Inactivated pneumococcal whole cell killed vaccine
- Cheap to make more proteins involved
- Capsule polysaccharideàthe coating has been conjugated ->improved immunogenity-> more expensive process
Describe the relationship between transmission, carriage and disease in pneumonia
- There is a relationship between the nasopharyngeal transmission, carriage and disease.
- Transmission and carriage are related to each other.
- You could cause transmission of the S.pneumoniae and this could lead to carriage (vice versa)
- Carriage and disease are related to each other. This is only in one direction (you cannot revert disease back into carriage because you already harbour the disease causing organism)
- Under certain circumstances can carriage develop into active disease
Describe the nasopharyngeal transmission of S.pneumoniae
- New hosts
- Replacement
- MOUSE MODEL:
- Influenza A virus (IAV) coinfection!
- Toll-like receptor 2 (TLR2)-deficiency, which is associated with an increased viral load (IAV) and, subsequently, greater inflammation, results in higher rates of transmission, and this effect is specific to the index mice (transmission of
- Competition
- Confounders (like if you live in more cramped conditions)
- Nasal inflammation in response to infection with respiratory viruses like influenza a modulates expression of proinflammatory cytokines,
- upregulates the epithelial receptors used for S.pneumoniae adherance.
Describe the nasopharyngeal disease that S.pneumoniae causes
- Otitis media
- Pneumonia
- Meningitis
- Septicaemia
Biofilms
- The role of biofilms in the ability of S. pneumoniae to persist at various sites of infection is not well understood, and their contribution to invasive disease remains controversial
- Most studies of pneumococcal biofilms have been carried out in vitro, and in vivo data are limited
- In biopsy samples from volunteers colonized in experimental human studies, S. pneumoniae was found in microcolonies
Ions
iron (Fe), manganese (Mn) and zinc (Zn), is crucial for growth and survival of S. pneumoniae in multiple host niches
How do vaccines impact transmission disease and carriage?
Transmission
- Indirect effects
- Herd immunity
- Dynamix flux
- Confounders
Carriage:
- Decrease in vaccine serotypes
- You have immunity against some serotypes
- Non vaccine type replacement
- Co colonising species impact
- New invasive species potential
Disease
- Does not occur because of the vaccine
What is the effect of the pneumococcal vaccine on Invasive pneumococcal disease (IDP ) in the UK?
IPD PCV7 under 2 years
- In the first graph, you see that it shows the cumulative frequency of notfications of invasive pneumococcal disease
- Each line represents a year
- Once the Prevenar 7 vaccine is introduced in 2006, there is a decrease in pneumococcal disease attributed to the serotypes that the vaccine covers
IPD PCV13 not PCV7 under 2 years
- You can see that subsequent post vaccine years, you can see increase in disease caused by other serotypes not covered by the vaccine in 2010
