Migration, public health and compulsory screening for TB and HIV
Richard Coker 8 th October 2003 Slide 2 The purpose of screening
Epidemiological trends What risk? Effective tools, effective
policies? Will compulsion improve effectiveness? Conclusions Slide
3 On the agenda Read This And Get Angry Sun, 29 Jan 2003 The Secret
Threat to British Lives The Spectator, 25 Jan 2003 No System to
Abuse: immigration and health care in the UK Centre for Policy
Studies, May 2003, Before Its Too Late: A New Agenda for Public
Health Conservative Party consultation paper, August 2003 Inquiry
into Imported Infections Cabinet Office, announced Jan 2003
Migration and HIV: Improving Lives in Britain All- Party
Parliamentary Group on AIDS, July 2003 Slide 4 Before Its Too Late
Advocates 3 tests before permission given to remain in the UK:
1.They must not pose a risk of transmitting an infectious disease
to the public 2.They must not create undue demand on restricted
health resources 3.They must not create a long-term drain on the
public purse those entering the UK through the immigration system
would require [sic] to have such tests at the point of application
and to pay for them, whilst those seeking asylum would be detained
until it was clear the criteria had been met Slide 5 Purpose of
Screening To identify individuals with infection in order to
provide the appropriate care and treatment for that individual To
prevent public health consequences of undetected infectious disease
through case detection Slide 6 Tuberculosis: key national facts (1)
Tuberculosis case reports, by geographic origin, England and Wales,
1988 - 2000 Since 1988, number of cases of TB and the rate has
increased Proportion born abroad has also increased Poverty,
overcrowding, exposure risk Treatment of TB costs approx. 6,000
Slide 7 Tuberculosis: key national facts (2) Tuberculosis case
reports born abroad by time since entry into the UK Half of those
born abroad who develop TB do so within 5 years Perhaps 0.3% of
asylum seekers have TB at port screening, and of these only have
infectious disease Number of cases detected through Heathrow
represents less than 0.5% of cases Asylum seekers represent a
fraction of immigrants but it is principally asylum seekers who are
currently screened In one study, screening systems failed to
identify 60% of new immigrants with TB Slide 8 Immigrant-associated
TB: a public health threat? Evidence from many sources US states
with high levels of TB in foreign-born persons do not
correspondingly have high rates in those born in US From DNA
finger-printing, most TB in London is reactivation From Denmark a
study showed that transmission between immigrants and native-born
Danes almost non-existent Correlation between State-Specific
Tuberculosis Case Rates for Foreign-Born Persons and U.S.-Born
Persons in the United States, 1986 to 1993 Slide 9 HIV: key facts
(1) Heterosexually acquired infection by sub-category of
heterosexual exposure At end 2001, estimated 41,000 adults living
with HIV in the UK Proportion infected through heterosexual sex is
increasing Most heterosexually- acquired HIV is acquired or linked
to abroad (71% to Africa) 0 500 1000 1500 2000 2500 3000 3500
198519861987198819891990199119921993199419951996199719981999200020012002
Sex between men & women (total)No evidence "high risk" partner:
Exposure abroad No evidence "high risk" partner: Exposure
UKExposure to "high risk" partner Year of diagnosis Number of
diagnoses Slide 10 Immigrant-associated HIV: a public health
threat? Of 2,046 individuals infected in the UK, at least half were
infected through heterosexual sex with someone originating from
outside Europe London-based study suggested that 9% of
heterosexually-acquired HIV in black Africans acquired in UK
Migrants returning Potentially many people unaware and unsuspecting
of their HIV status (black Africans > white) Slide 11 2 cardinal
questions: Does screening detect those with the condition? Will
screening assist in achieving the desired public health objective?
Slide 12 Does screening detect those with the condition? HIV: it
depends TB: it depends Slide 13 Screening for HIV The tests are
sensitive and specific But focused screening may assume That
immigrants from high prevalence countries have prevalence rates
that reflect donor countries That populations freely able to move
dont pose a threat (new eastern European border) That those not
screened will be served by other systems (illegal immigrants,
transient populations) Slide 14 X-rays to detect TB Theoretical
population with prevalence rate of 600/100,000 10,000 immigrants
screened Theoretical population with prevalence rate of 40/100,000
10,000 immigrants screened Expected number of cases of disease 604
Number of cases of TB detected through X- ray screening 453 Number
of cases of TB missed through X- ray screening 151 Number of people
without TB, but classified as having TB 100 Proportion of people
identified with TB who actually have it 31%3% Slide 15 X-ray at
screening and 6 months later, Swiss asylum seeker Slide 16 Will
screening assist in achieving the desired public health objective?
TB Evidence is lacking No clinical trials DH-funded transmission
and economic model due to report shortly HIV Screening only confers
public health benefit if effective action follows Evidence is
lacking Slide 17 Refusing entry to HIV-infected immigrants May
reduce burden of disease, costs, and future transmission May
stigmatise, ensure evasive practices How often should people be
screened? Illegal in asylum seekers Should they be isolated? For
how long? Does the risk arise because of status or behaviour? Slide
18 Coercion and protection of the public health Slide 19 Long
historical tradition, with little evidence of benefit of detention
or compulsory screening May show that the government is seen to be
taking firm, decisive action and the epidemic appears to be under
control (Panos Institute) Coercive measures may be
counterproductive Slide 20 Public Health Authorities Bear the
Burden of Justification Slide 21 Conclusion (1) Increases in HIV
and TB rates are linked to immigration, but have been difficult to
quantify These changes may reflect, in part, global trends Most TB
occurs in people after entry There is probably a substantial
population of HIV- infected people in the UK unaware of their
status who pose a public health challenge Slide 22 Conclusion (2)
Evidence-base to support TB screening of immigrants is weak
Screening tests for TB lack validity Screening tests for HIV are
reliable Evidence is lacking regarding screening immigrants for HIV
Significant ethical, moral, legal and practical issues are raised
with coercive measures Coercive screening practices may result in
unforeseen perverse consequences Slide 23 Purpose of Screening To
identify individuals with infection in order to provide the
appropriate care and treatment for that individual To prevent
public health consequences of undetected infectious disease through
case detection
