Rates of AIDS-defining illnesses in the
first year of antiretroviral therapy are significantly higher among migrant
than non-migrant populations in resource-rich countries, investigators report
in the online edition of AIDS. The
difference was mainly driven by higher rates of tuberculosis (TB) among migrant
populations. The results of the study show the importance of screening people
for TB before commencing HIV therapy, say the investigators.
Improvements in treatment and care mean
that rates of AIDS-defining illnesses and deaths have fallen substantially in
Europe and North America. However, AIDS-related illness and mortality is still
common in resource-limited countries. This is even the case among people who
have recently started HIV therapy.
A large number of HIV infections in
resource-rich countries involve migrants from resource-limited settings.
Investigators from Europe, Canada and the United States wanted to see if rates
of AIDS-related illnesses and death differed between migrant and non-migrant
patients in the first 12 months after the initiation of antiretroviral
treatment. They therefore analysed outcome data obtained from 12 cohort
studies involving over 48,000 people who started HIV treatment between 1996 and
Just of over a quarter of participants (26%)
were migrants, including 16% from sub-Saharan Africa, 6% from Latin America, 2%
from North Africa/Middle East and 2% from Asia.
Compared to non-migrants, migrants were
younger (median age 34 vs 38 years), more likely to be female (51 vs 22%)
and to have been infected with HIV through heterosexual sex (76 vs 33%).
During the first year of HIV therapy,
approximately 2300 participants (5%) developed an AIDS-defining illness. The
overall incidence of such illnesses was 61
per 1000 person-years, but was significantly higher among migrant (70 per 1000
person-years) than non-migrant (58 per 1000 person-years) participants.
After taking into account other factors
that can affect the risk of HIV disease progression, the authors found that
migrants were 21% more likely to be diagnosed with AIDS compared to
non-migrants (HR = 1.21; 95% CI, 1.08-1.40). A similar result was observed when
analysis was limited to participants whose probable route of HIV infection was
heterosexual intercourse (HR = 1.23; 95% CI, 1.08-1.40).
Mortality rates during the first year of
HIV treatment were somewhat lower among migrants than non-migrants. However,
the difference was largely explained by the older age of non-migrant patients
(40 vs 30 years). Once this was taken into account, mortality rates were
similar between the two groups.
The investigators also examined the risk of
specific AIDS-defining illnesses according to migrant status.
They found that migrants were almost twice
as likely as non-migrants to be diagnosed with TB (HR = 1.94; 95% CI,
1.53-2.46). Incidence of TB was especially high among people from sub-Saharan
Africa (16 per 1000 person-years), North Africa/Middle East (16 per 1000
person-years) and Latin America (12 per 1000 person-years).
“Tuberculosis was the most common ADE
[AIDS-defining event] among migrants during the first year of ART,” comment the
They believe their results have important
implications for patient care, highlighting the importance of screening for TB
before the initiation of HIV therapy. They add that the results “also raise
issues regarding the choice of initial regimen among migrants, given known
interactions between anti-tuberculosis medications and protease inhibitors”.
Rates of several other AIDS-defining
illnesses were also elevated among migrants. These included cryptococcosis,
Kaposi’s sarcoma and candidiasis.
“In this large study of HIV-positive
patients initiating ART in multiple sites…patients who had migrated from
Africa, Latin America, or the Middle East tended to have higher rates of ADEs
during the first year of ART,” conclude the investigators. “These findings
could influence screening for specific ADEs prior to ART initiation in