Transcript Latent TB among Displaced Populations. Rapid Diagnosis and

Latent Tuberculosis among Displaced
Populations
Rapid Diagnosis and Control
Nikolaou Aristidis
MD, MSc
MIGRATION VS TB
Immigrants :

↑ risks of transmission infectious diseases
(TB)
i) overcrowded camps
ii) poor living conditions
iii) poor access to healthcare provision

At entry: 40 times more at risk active TB ≠
local general population
(Figuera-Munoz, 2008)
(Rieder, 1994)
(Arshad, 2010)
TB incidence

Burden ↓ in industrialized countries ≠ high in developing

Immigrants carry LTBI → at increased risk of reactivation

EU: up to 82% foreign-born cases (among overall TB cases)

In low-incidence countries → % increasing since 1990s

↑ risk among foreign-born even 20 yrs after migration
(Dasgupta, 2000)
(Klinkenberg, 2009)
Factors influencing TB incidence
country of origin
 age
 sociodemographic factors
 exposure and travel to country of origin
 access to care
 drug resistance
 immune incompetence

(Klinkenberg, 2009)

Reactivation of prior TB infections

Recent TB infection or reinfection due to
travel to the home country

Recent infection or reinfection within the
new country
(Klinkenberg, 2009)
Special Health Needs/Obstacles
Language
 Stigmatization
 Poor cultural awareness
 Psychological distress
 Disruption of families and social networks
 Economic difficulties
 Difficult to trust doctors

(Figuera-Munoz, 2008)
LATENT TB INFECTION
LTBI

Exposure to Mycobacterium tuberculosis →
Latent TB Infection

Usually, healthy life without developing active TB
disease

2 billion people LTBI ≠ <10 million a year active
TB disease

5 - 10% infected persons develop active TB
disease
50%, within the first two years
(CDC, 2010)
LTBI

Usually, Skin Test (Mantoux) or Blood Test
(Quantiferon) → TB infection

Normal chest x-ray and Negative sputum
test

TB bacteria in body (alive but inactive)

Not feel sick – No symptoms

Cannot spread TB bacteria
(CDC, 2010)
SCREENING
Medical Screening

Objective → early preventive or curative
intervention

Disease → relatively common and treatable

Test →
i) inexpensive
ii) easy to administer
iii) cause no discomfort to the
patient
iv) high sensitivity and specificity
(Dasgupta, 2005)
(Rieder, 1994)
TB screening
Targeted groups:
i)
persons with a high risk of being infected by
tuberculosis (curative treatment)
ii)
persons at high risk of developing tuberculosis
(preventive intervention)


i)
ii)

Screening tools :
chest radiography
tuberculin skin-testing
relatively high sensitivity
limited specificity
Tuberculin skin test = identification of these groups +
indicator of need of radiographic examination
(Rieder, 1994)
Screening strategies

Pre-entry/ pre-migration screening

Port of arrival screening

Reception/ holding/ transit centre screening

Community post-arrival screening

Occasional screening

Follow-up screening
(Klinkenberg, 2009)

Active screening among foreigners → before
dispersed in the country

Screening for tuberculosis (before or after
arrival) → prevent unnecessary transmission
(specifically designed centers)

Targeted screening of immigrants (country of
origin) + surveillance for recently arrived
populations
(Figuera-Munoz, 2008)
TB screening among EU

TB screening in 22/24 (96%) countries
Compulsory basis in 12/22 (55%) countries

Only 4 systematically collecting data

The Nordic: to all new asylum seekers
The Netherlands: on arrival (again 6, 12, 18, and 24 months)
Austria, France, Spain, and Britain: induction or reception
centers
Italy and Germany: Regional variations in the provision
Greece: immigrants who applied for a work permit
(Norredam, 2005)
Suggestions

Systematic recording and reporting of screening
performance

Preventive strategy :
i)
ii)
iii)

improving housing conditions (decrease the risk
of tuberculosis transmission)
enhancing tuberculosis case finding
setting case management within Directly
Observed Treatment program
Good follow-up system
(Arshad, 2010)
(Klinkenberg, 2009)
Ideal long-term TB control strategy
Global investment TB control in high-incidence
countries →
Global reduction in tuberculosis incidence →
↓ TB risk (migrants from high incidence to low
incidence regions)
More Humanitarian / More Cost-effective
(Dasgupta, 2005)

Equal Rights for health NOT entrance
rejection or expelling and repatriating
Active screening + access to healthcare
facilities:
i) shorten the infectious periods
ii) interfere with the transmission network
iii) reduce risk of developing active TB
iv) improve the control of potential
tuberculosis reservoirs

(Arshad, 2010)
(Rieder, 1994)
Thank you