The authors believe that simple country-by-country analysis
can help prevent the worldwide spread of AIDS. "Almost all new
HIV infection occurs when an infected person shares body fluids
with an uninfected person, so prevention programs must focus on
situations in which this is happening," the researchers wrote.
"This should be obvious, but ... many countries do not even collect
the information they need to determine which behaviors are
responsible for most new HIV infections. We believe that
relatively simple analyses can highlight the differences in
categories of exposure between prevalent and incident cases of
HIV, can point to important shifts in patterns of transmission,
and can in turn lead to better prevention programming."
The researchers examined current levels and trends in
prevalence patterns in Cambodia, Indonesia, Honduras, Russia, and
Kenya. Even countries considered to have the same type of
epidemic -- i.e., low-level, concentrated, or generalized -- showed
wide variation of incidence by category of exposure. "Failure to
examine current patterns of incidence can lead to inappropriate
prevention efforts," they wrote.
Although drug injection and sex work accounted for
approximately the same proportion of infections in Indonesia in
2002, according to the study, an escalating epidemic of injection
drug use is likely to account for more than 75 percent of new HIV
infections in 2003.
In Cambodia, an active sex industry accounted for much HIV
infection. Efforts to decrease unprotected sex-work transactions
have been successful. Total new infections dropped from an
estimated 40,000 in 1994 to 6,500 in 2002. However, the authors
noted, "Because HIV infection resulting from sex work has fallen
so radically the proportion of new infections transmitted within
marriage has grown from 11 percent to 46 percent. Clearly, more
attention should now be given to prevention strategies aimed at
reducing transmission between spouses who may previously have
been exposed to HIV through buying or selling sex, while
sustaining existing prevention efforts focused on sex work."
Cambodia is classified as having a generalized epidemic,
meaning that the nexus of infection has shifted beyond
identifiable high-risk groups. But most people becoming infected
have partners who exhibited high-risk behavior in the past. The
scientists suggested that if Cambodia continues its success in
reducing risky sex-work transactions and succeeds in reducing
transmission between spouses, HIV prevalence could fall to the
low endemic levels of many industrialized nations.
Kenya is also classified as having a generalized epidemic.
By 1989, national HIV prevalence in adults reached nearly 4
percent. HIV prevalence among Nairobi sex workers then was 60-70
percent. Despite prevention efforts and an increase in condom use
with non-marital partners, sex work remains a key factor in the
spread of HIV.
Although recent emphasis has been on altering structural
factors such as poverty and sexual inequality that prevent people
from protecting themselves from HIV, the study stated, "an
understanding of the dynamics of a country's HIV epidemic, how it
changes over time, and who is currently at greatest risk is
essential to guiding decisions about effective prevention." The
authors pointed out that structural change takes time. They urged
public health officials to focus on new infections and let
political and religious leaders take the lead on initiating
changes in the social and cultural factors that influence sexual
and drug-taking habits.
Back to other news for August 19, 2003
This article was provided by CDC National Prevention Information Network.
It is a part of the publication CDC HIV/Hepatitis/STD/TB Prevention News Update.