HC extra: Mycobacterial infections (tuberculosis)
Mycobacterium tuberculosis epidemiology
Mycobacterium tuberculosis is characterized by:
- Droplet nuclei
- Alveolar macrophage
- Intracellular survival
- Spread to lymph nodes
- Hematogenous spread
- T-cell immunity → latent stage
- Reactivation
In regions such as southern Africa, 50% of patients with TB have HIV. HIV affects the CD4 cells, which increases the chance of getting TB enormously.
Pathogen and pathogenesis
Mycobacterium tuberculosis can have 6 different clinical manifestations:
- Latent
- Many patients don't have symptoms but are carriers
- Subclinical
- Cannot only be transmitted during forceful coughs
- Limited disease
- Pneumonia in 1 lung lobe
- Extensive disease
- Pneumonia in both lungs
- Multi-organ
- Spread by macrophages migrating everywhere in the body
- For example masses in the abdomen
- Miliary TBC
- Very rare
- Granulomas all over the body
- The granulomas are visible as speckles
- The necrosis breaks through to the vessel wall → the bacteria are spread via the blood stream
Diagnosis and treatment
Testing:
TB can be diagnosed clinically or via diagnostic tests:
- Clinical
- Complaints
- Cough for longer than 2 weeks
- Fever, night sweats, weight loss
- Depends on organ involvement
- Physical examination
- Complaints
- Diagnostic tests
- Radiography: never specific for TBC
- Histology: unusual
- Granulomas
- Central necrosis
- Looks like cottage cheese
- Multinucleate giant cells
- Microbiological tests: essential for a correct diagnosis
- Acid fast staining
- For example Ziehl-Neelsen
- The cell wall has a high content of complex lipids → mycolic acids
- Acid fast bacteria stay pink, non-acid fast bacteria become blue after decoloring
- PCR
- Culture
- Takes 2 weeks to 2 months until the bacteria have grown
- Antibiotic susceptibility testing
- Genotyping
- Acid fast staining
- Indirect
- Tuberculin skin test
- A small amount of antigens is injected → the T-cell response is measured
- Positive mantoux test → the T-cells respond in the skin
- These tests are not specific for TBC
- Interferon gamma release assay
- Tuberculin skin test
- A small amount of blood is put in 1 positive and 1 negative control tube
- Antigens specific for mycobacterium tuberculosis are put in the tube
- If the cells have produced the cytokine interferon g, the person has been exposed to mycobacterium tuberculosis in the past or present
Therapy:
The treatment of TBC depends on whether it is active or latent. Multiple drugs are prescribed → a patient has to take at least 2 drugs at the same time:
- Active TBC → treatment has to be a combination of:
- Isoniazide
- For 6-9 months
- Rifampicin
- For 6-9 months
- Pyrazinamide
- For 2 months
- Ethambutol
- For 2-9 months
- Latent TBC → it is acceptable to treat with 1 or 2 drugs:
- Isoniazide
- Rifampicin
- Isoniazide and rifampicin
It isn't necessary to remember the names of these drugs.
In case of multi-drug resistant TBC (MDR TB), patients are resistant to the 2 most used drugs against TBC. Some of these patients have to be isolated for many months, because they stay contagious for a very long time. Extensive drug resistant TBC (EDR TB) also exists. In this case, patients are resistant to almost every drug against TBC → these patients are very hard to treat.
Transmission
TBC can be transmitted from person to person. Droplet nuclei can stay in the air for hours, but the infectious dose is very low.
Prevention and control
Hospitals take several measures to prevent transmission:
- Coughing hygiene
- Aerogenic isolation
- Respiratory protection
- For example an FFP2 mask → has very tiny pores that filter the mycobacterium tuberculosis
If someone has been diagnosed with TBC in the Netherlands, every person they have been in contact with, and again every person they have been in contact with, who have latent TBC, are treated. This way, TBC can be contained very well.
About 70% of TBC cases in the Netherlands is among first generation immigrants. The reason for this is thats in other countries TBC isn't contained as well.
Vaccination:
It is possible to be vaccinated against TBC. This vaccine is called Bacille Calmette Guerin (BCG), which is moderately effective against childhood TBC and not protective against adult pulmonary TBC.
Development of a new vaccine is slow. A number of people are working on the development of new vaccines.
Join with a free account for more service, or become a member for full access to exclusives and extra support of WorldSupporter >>
Mechanisms of Disease 1 2020/2021 UL
- Mechanisms of Disease 1 HC1: Introduction to G2MD1
- Mechanisms of Disease 1 HC2: Introduction to the immune system
- Mechanisms of Disease 1 HC3: Innate and adaptive immune responses & key cytokines
- Mechanisms of Disease 1 HC4: Pathology of normal immune response
- Mechanisms of Disease 1 HC5: B- and T-cell generation and diversity
- Mechanisms of Disease 1 HC6: Mechanisms of adaptive immunity
- Mechanisms of Disease 1 HC7: Effector mechanisms of antibodies
- Mechanisms of Disease 1 HC8: B-cell development and antibodies
- Mechanisms of Disease 1 HC9: Tissue injury and repair
- Mechanisms of Disease 1 HC10: Repair mechanism
- Mechanisms of Disease 1 HC11: Pathology of inflammatory reactions
- Mechanisms of Disease 1 HC12: Introduction to infectious diseases
- Mechanisms of Disease 1 HC13: Bacteria
- Mechanisms of Disease 1 HC14: Viruses
- Mechanisms of Disease 1 HC15: Fungi and parasites
- Mechanisms of Disease 1 HC16: Invaders
- Mechanisms of Disease 1 HC17: Host versus invader
- Mechanisms of Disease 1 HC18: Immune deficiencies and infection risk
- Mechanisms of Disease 1 HC19: Pathology of infectious diseases
- Mechanisms of Disease 1 HC20: Diagnostics of infectious diseases
- Mechanisms of Disease 1 HC21: Essential microorganisms
- Mechanisms of Disease 1 HC extra: Mycobacterial infections (tuberculosis)
- Mechanisms of Disease 1 HC22: Antimicrobial therapy
- Mechanisms of Disease 1 HC23: Principles of antibiotic pharmacotherapy
- Mechanisms of Disease 1 HC24: Introduction MOOC
- Mechanisms of Disease 1 HC25: Epidemiology
- Mechanisms of Disease 1 HC26: Prevention and control
- Mechanisms of Disease 1 HC extra: COVID-19
- Mechanisms of Disease 1 HC27: Mechanisms of hypersensitivity reactions
- Mechanisms of disease 1 HC28: Pathology of allergy
- Mechanisms of Disease 1 HC29: Asthma
- Mechanisms of Disease 1 HC30: Pathology of autoimmunity
- Mechanisms of Disease 1 HC31: HLA and autoimmunity
- Mechanisms of Disease 1 HC32: Vasculitis
- Mechanisms of Disease 1 HC33: Systemic Lupus Erythematosus
- Mechanisms of Disease 1 HC35: Infections and autoimmunity
- Mechanisms of Disease 1 HC36: Immune cells in rheumatoid arthritis
- Mechanisms of Disease 1 HC37+38: Pharmacology: immunosuppression
- Mechanisms of Disease 1 HC39: Pathology of transplantation
Contributions: posts
Spotlight: topics
Mechanisms of Disease 1 2020/2021 UL
Deze bundel bevat aantekeningen van alle hoorcolleges van het blok Mechanisms of Disease 1 van de studie Geneeskunde aan de Universiteit Leiden, collegejaar 2020/2021.
This bundle contains notes of all lectures from the module Mechanisms of Disease 1, Medicine, Leiden
...Online access to all summaries, study notes en practice exams
- Check out: Register with JoHo WorldSupporter: starting page (EN)
- Check out: Aanmelden bij JoHo WorldSupporter - startpagina (NL)
How and why use WorldSupporter.org for your summaries and study assistance?
- For free use of many of the summaries and study aids provided or collected by your fellow students.
- For free use of many of the lecture and study group notes, exam questions and practice questions.
- For use of all exclusive summaries and study assistance for those who are member with JoHo WorldSupporter with online access
- For compiling your own materials and contributions with relevant study help
- For sharing and finding relevant and interesting summaries, documents, notes, blogs, tips, videos, discussions, activities, recipes, side jobs and more.
Using and finding summaries, notes and practice exams on JoHo WorldSupporter
There are several ways to navigate the large amount of summaries, study notes en practice exams on JoHo WorldSupporter.
- Use the summaries home pages for your study or field of study
- Use the check and search pages for summaries and study aids by field of study, subject or faculty
- Use and follow your (study) organization
- by using your own student organization as a starting point, and continuing to follow it, easily discover which study materials are relevant to you
- this option is only available through partner organizations
- Check or follow authors or other WorldSupporters
- Use the menu above each page to go to the main theme pages for summaries
- Theme pages can be found for international studies as well as Dutch studies
Do you want to share your summaries with JoHo WorldSupporter and its visitors?
- Check out: Why and how to add a WorldSupporter contributions
- JoHo members: JoHo WorldSupporter members can share content directly and have access to all content: Join JoHo and become a JoHo member
- Non-members: When you are not a member you do not have full access, but if you want to share your own content with others you can fill out the contact form
Quicklinks to fields of study for summaries and study assistance
Main summaries home pages:
- Business organization and economics - Communication and marketing -International relations and international organizations - IT, logistics and technology - Law and administration - Leisure, sports and tourism - Medicine and healthcare - Pedagogy and educational science - Psychology and behavioral sciences - Society, culture and arts - Statistics and research
- Summaries: the best textbooks summarized per field of study
- Summaries: the best scientific articles summarized per field of study
- Summaries: the best definitions, descriptions and lists of terms per field of study
- Exams: home page for exams, exam tips and study tips
Main study fields:
Business organization and economics, Communication & Marketing, Education & Pedagogic Sciences, International Relations and Politics, IT and Technology, Law & Administration, Medicine & Health Care, Nature & Environmental Sciences, Psychology and behavioral sciences, Science and academic Research, Society & Culture, Tourisme & Sports
Main study fields NL:
- Studies: Bedrijfskunde en economie, communicatie en marketing, geneeskunde en gezondheidszorg, internationale studies en betrekkingen, IT, Logistiek en technologie, maatschappij, cultuur en sociale studies, pedagogiek en onderwijskunde, rechten en bestuurskunde, statistiek, onderzoeksmethoden en SPSS
- Studie instellingen: Maatschappij: ISW in Utrecht - Pedagogiek: Groningen, Leiden , Utrecht - Psychologie: Amsterdam, Leiden, Nijmegen, Twente, Utrecht - Recht: Arresten en jurisprudentie, Groningen, Leiden
JoHo can really use your help! Check out the various student jobs here that match your studies, improve your competencies, strengthen your CV and contribute to a more tolerant world
1395 |
Add new contribution