AIDS belt” of much of southern and parts of east Africa

As with any surgical procedure or
cultural or behavioural practice, there are
potential risks as well as benefits related
to male circumcision, and policy
makers are now increasingly turning to
international bodies such as WHO and
UNAIDS for technical and programmatic
guidance10 . It is widely anticipated that
if the two remaining randomized trials in
Kenya and Uganda (results expected
in 2007) confirm the Orange Farm finding,
male circumcision will be officially
endorsed as a useful adjunctive approach
within broader HIV prevention efforts.
The global epidemiology of male
circumcision
Circumcision is performed in many parts
of the world for a variety of religious,
cultural, social, medical and other
reasons. Currently, about 20%-25% of
all males are circumcised, and the
majority of African societies continue to
practice male circumcision. The main
parts of the African continent where
circumcision is generally no longer
practiced are precisely in those countries
which make up the “AIDS belt” of much
of southern and parts of east Africa,
where HIV prevalence is vastly higher
than anywhere else (see map)11 . Similarly,
HIV prevalence in the predominantly
non-circumcising countries of south and
southeast Asia is much higher than
in neighbouring countries where
circumcision is practiced and which
otherwise have similar sexual and
behavioural practices12 .
To date over 40 epidemiological studies,
most of them conducted in Africa, have
found a significant relationship between
the lack of male circumcision and higher
risk of HIV acquisition13 and the most
rigorous (prospective and cohort) types
of studies have found an even more
dramatic protective effect14 . However,
some cross-sectional studies (including
some recent Demographic and Health
Surveys in Africa) have not found a
significant correlation between circumcision
and HIV, perhaps due to issues of
residual confounding, self-report bias,
confounding due to non-heterosexual
forms of HIV transmission, etc.
A systematic review and meta-analysis
of 38 studies by the London School of
Hygiene and Tropical Medicine
estimated that circumcision reduces
HIV risk by approximately 50% overall,
with about 70% reduction among higher
risk populations (see figure)15 . In
addition to HIV, male circumcision
reduces the risk of acquiring some other
sexually transmitted infections,
especially ulcerative types such as
syphilis, chancroid and probably
herpes16 , and new data from Uganda
suggests that circumcision may also
reduce HIV transmission and some
other sexually transmitted infections
such as chlamydia17 from infected men
to their female partners18 . This latter finding
is currently being tested in another
randomized controlled trial in Uganda.
The biology of male circumcision
and HIV infection
Biological investigators have discovered
that the tender mucous membrane
surface of the inner foreskin contains
a high density of immune system cells
such as Langerhans, macrophages
and CD4 cells. From an evolutionary
perspective, the foreskin serves