Tuberculosis Flashcards
Describe how the tuberculosis pathogen is transmitted to a new host.
- pathogen is in air/airborne or affected individuals breathe out pathogen/droplet
- new host breathes in/inhales pathogen
Direct (from person to person)
Airbourne transmission
Found in tiny droplets when with TB coughpersons, sneezes or speaks
Describe the impact that the tuberculosis pathogen has on the host.
- infects lungs/respiratory system
- causes coughing/lung irritation/breathing problems/tuberculosis * sometimes does not cause symptoms or takes time for
symptoms to develop or can infect brain/nervous system/tissue other than the lungs
Explain how vaccination helps to control the spread of tuberculosis.
vaccination introduces weakened/harmless version of a pathogen into body
* this stimulates production of antibodies/stimulates an immune response
* vaccinated individuals become immune or do not catch the disease
* higher the proportion of the population that is immune, the greater the
protection or the converse
* because infected individuals do not/rarely come into contact with
susceptible individuals or the converse
* herd immunity/high immunity protects susceptible individuals
Best stratergies for managing Tuberculosis
Mainly antibiotics
Either to prevent infection from becoming active
Or to kill active bacteria
Has side effects + can lead to resistant strains
Patients infected identified immediately
Precautions taken to stop spread of airbourne particles
Effective treatment administered
tuberculosis symptoms
a cough that persists, coughing up of sputum or blood, fever/night sweats, steady loss of weight, fatigue. these symptoms are observed in sufferers of active TB disease.
Tuberculosis incubation period
3-9 weeks from infection to development of a significant tuberculin. TB can stay dormant in the body for months or years. while TB is dormant, the host shows no symptoms. this is called ‘latent TB’. The host is not infectious while it is latent.
why is TB more wide spread than malaria
- TB transmission isn’t reliant on a vector
- Distribution isn’t confined to distribution of vector.
- TB is more easily transmitted
- TB infects lungs, causing chronic cough.
- Malaria distribution is confined to areas where the mosquito can live i.e. mainly the tropics.
how does tuberculosis infect host? (basic)
Engulfed by macrophages in alveoli then reproduce
symptoms of tuberculosis (basic)
at least 4 symptoms - cough, fever, weight loss, sweats etc.
Causes pockets of cavities in the lungs
Damage may cause bleeding or infection with other bacteria
Blocks airways
Common symptoms:
Persistent cough, fevers, weight loss, night sweats, fatigue, loss of appetite, bloody sputum, pain
name of the tuberculosis pathogen
Mycobacterium Tuberculosis
Tuberculosis mode of transmission
Direct, close contact via air Bourne droplets inhaled into respiratory system
Indirect if the droplets land on a dusty fomite, become disturbed and are then inhaled.
Life cycle Specification of tuberculosis
Entry via respiratory system
Replication in alveolar macrophages in lungs
Exit via respiratory system through a cough or sneeze.
evolutionary adaptations
Metabolism remains active in host cell macrophage
Can remain dormant in host cell for years
Can mutate in this time resistance
Can break down host immune system + use its lipids undetected
Secretes enzymes + proteins that aid in production of molecules that sit on cell surface
Create very durable cell wall
Sigma factors allowing quick change in response to environment
Sigma A: express new virulence + mutate
factors relating to the spread of it
Breakdown in health services
Spread of HIV/AIDS
Weakens immune system
Emergence of multi-drug resistant TB
Caused by inconsistent / partial treatment
Movement of people
In US, 40% of TB cases are from foregin born
Refugee camps
