Public Health - Control of TB Flashcards
Describe TB.
- Airborne bacterial infection
- Not easily transmitted from person to person
- Depends on infected individual being in close proximity to others
Describe active TB.
- Symptomatic disease
- Bacteria multiplying, attacking the lung(s) / other parts of the body.
Describe latent TB.
Infected individuals are asymptomatic
(Disease not active for long time - unless patient immunocompromised)
What are the steps of TB transmission?
- Person with active TB and susceptible individual come into sufficient contact for transmission to occur
- Person with active TB aerolises enough particles to induce infection
- Eventual progression to disease
Describe disease burden of TB.
- About 1.8 billion people infected with tuberculosis - most have latent TB.
- About 10 million people have active TB worldwide.
Who is most at risk of TB infectioln?
- Family and friends of infected person
- People from parts of the world with high TB rates
- People in groups with high rates of TB transmission, including the homeless, injection drug users and people living with HIV
- People who work or reside in facilities that house high risk people
Who is most at risk of active TB disease?
Those with a weak immune system, including:
- Babies and young children
- People with chronic conditions
- People with HIV/AIDS
- Organ transplant recipients
- Cancer patients undergoing chemotherapy
- People receiving certain treatments for autoimmune disorders
Describe the BCG vaccine.
- Currently only effective TB vaccine
- Live attenuated vaccine - derived fro Mycobacterium bovis
- Provides long-term protection
Describe risk-based provision of the BCG vaccine.
Program targeted at:
- Children who have a parent or grandparent who was born in a country where there’s a high rate of TB
- Children who have recently arrived from countries with high levels of TB
- Children who will be living with locals for 3 months or longer in countries with high rates of TB
- Children who are close contacts of someone with infectious TB
Describe latent TB treatment
- Done by chemoprophylaxis
- Completed in association with contact tracing and testing of risk groups
- Recommended for patients taking treatment that weakens immune system
Describe latent TB diagnosis.
- Mantoux skin test
- Interferon gamma assay
- Tested for active TB infection
Describe current treatment plans for latent TB infections.
- Isoniazid plus rifampicin for 3 months
- OR isoniazid for 6 months (if interactions with rifampicin are of concern)
What are some red flags where TB should be considered as a potential diagnosis?
- Anyone with a cough lasting more than 3 weeks
- Anyone with social risk factors e.g the homeless (because more at risk of worse outcomes)
Describe TB case management and the aims of treatment.
- Referral to a TB specialist and MDT
AIMS - Ensure completion of treatment lasting at least 6 months
- Identify and follow up risk contacts by discussion
What can be used in patients with active TB without CNS involvement?
- Isoniazid (with pyridoxine), rifampicin, pyrazinamide and ethambutol for 2 months then
- Isoniazid (with pyridoxine) and rifampicin for a further 4 months.
(Varies depending on drug susceptibility testing)
