L70 – Tuberculosis: a re-emerging public menace Flashcards
(66 cards)
What is the estimated human population infected with MTB?
Estimated 2-3 billion people (~1/3 human population) has been infected with
Mycobacterium tuberculosis
How does TB rank as a cause of death?
5th leading cause
What is the disease ratio of TB (ratio of new infection to
development of overt disease) ?
Recall Tb has primary (dormant, host immune not activated) and post-primary infections:
5% > primary infection within 5 years
Further 5% > post-primary disease
What is the main diagnosis for TB?
Clinical
other include rapid molecular tests, sputum smear, culture, sensitivity testing …etc
What are the methods to estimate TB incidence?
Registration system
National notification/ prevalence survey
Surveillance system
What does the huge difference between estimated incidence and number of TB notifications mean?
That many TB patients have not been diagnosed/ treated in healthcare systems
How does estimate TB mortality rate differ in HIV patients?
HIV = more susceptible to TB
What is the trend of TB mortality in HIV-ve and +ve patients?
Both decline:
HIV -ve declines at a much higher rate than HIV +ve
What is the decline in TB mortality rate between 2000 and 2015?
34%
What is the target for TB incidence rate decline by 2020
4-5%
Which global regions have the fastest and slowest decline in TB mortality?
Fastest = Eastern mediterranean and Europe
Slowest = Africa
What is the difference between the countries at the top of Incidence: absolute numbers chart and Incidence: Rate chart?
Incidence: absolute numbers chart»_space; occupied by developing/ developed countries with huge populations (e.g. China, India) but situation is IMPROVING
Incidence: Rate chart» occupied by undeveloped countries where situation is NOT IMPROVING
The top 6 countries with the largest number of incident cases account for __ % of global total ?
60
What are some predisposing factors to TB?
Age (adult predominant) Sex (male predominant) HIV, diabetes Prior mycobacterial infection Immunocompromise host
Confounded by socio-economic and environmental conditions
What are the stats on TB propagation in a community? (how many people can infection pass onto…)
Each infection on average produces ≥ 1 secondary infection
Each untreated infects 20-28 persons
6-10% develop active disease
How many cases of infectious TB is considered an endemic?
1 case
How does the supply of susceptible individuals compare to the rate of being infected by TB?
Supply of susceptible ≥ Rate of being infected
Supply can be from birth, immigration..etc to increase population size
What is the reproductive ratio (r0)?
Estimation of the rate of infection spread
Given TB declined before medication or vaccines, what causes the most impact in reducing TB incidence?
Improve hygiene and public health
What are the 5 risk factors of POVERTY that affects rate of community acquired TB?
E H PSP
Ed Has a PSP
Economic Human Political Socio-cultural Protective
How does poverty lead to increased risk of getting TB?
Poverty itself cannot cause TB,
but poor living conditions in many complex interacting pathways could affect the risk of getting TB
What are the 3 components of living condition?
- Community (e.g. housing density, planning, access, pollution…)
- Household (e.g. crowded, ventilation, security…)
- Individual (e.g. economic status, smkoing, cancer, abus…)
How many TB cases are due to smoking?
20% attributable to TB
How many times greater is the risk of TB given HIV=ve?
20-30x greater than HIV
negative persons
