Prevention of HIV/AIDS
HIV prevention refers to practices that aim to prevent the spread of the human immunodeficiency virus (HIV). HIV prevention practices may be undertaken by individuals to protect their own health and the health of those in their community, or may be instituted by governments and community-based organizations as public health policies.
History[edit]
1980s[edit]
The Centers for Disease Control was the first organization to recognize the pandemic which came to be called AIDS.[79] Their announcement came on June 5, 1981, when one of their journals published an article reporting five cases of pneumonia, caused by Pneumocystis jirovecii, all in gay men living in Los Angeles.[80][81]
In May 1983, scientists isolated a retrovirus which was later called HIV from an AIDS patient in France.[82] At this point, the disease called AIDS was proposed to be caused by HIV, and people began to consider prevention of HIV infection as a strategy for preventing AIDS.
In the 1980s, public policy makers and most of the public could not understand that the overlap of sexual and needle-sharing networks with the general community had somehow lead to many thousands of people worldwide becoming infected with HIV.[79] In many countries, leaders and most of the general public denied both that AIDS and the risk behaviors which spread HIV existed outside of concentrated populations.[79]
In 1987, the United States FDA approved AZT as the first pharmaceutical treatment for AIDS.[83] Around the same time, ACT UP was formed, with one of the group's first goals being to find a way to get access to pharmaceutical drugs to treat HIV.[84] When AZT was made publicly available, it was extremely expensive and unaffordable to all but the most wealthy AIDS patients.[85] The availability of medicine but the lack of access to it sparked large protests around FDA offices.[86][87]
From 2003[edit]
In 2003, Swaziland and Botswana reported nearly four out of 10 people were HIV positive.[88] Festus Mogae, president of Botswana, admitted huge infrastructure problems to the international community and requested foreign intervention in the form of consulting in health care setup and antiretroviral drug distribution programs.[89] In Swaziland, the government chose not to immediately address the problem in the way that international health agencies advised, so many people died.[90] In world media, the governments of African countries began to similarly be described as participating in the effort to prevent HIV actively or less actively.
There came to be international discussion about why HIV rates in Africa were so high, because if the cause were known, then prevention strategies could be developed. Previously, some researchers had suggested that HIV in Africa was widespread because of unsafe medical practices which somehow transferred blood to patients through procedures such as vaccination, injection, or reuse of equipment. In March 2003, the WHO released a statement that almost all infections were, in fact, the result of unsafe practices in heterosexual intercourse.[91]
In response to the rising HIV rates, Cardinal Alfonso López Trujillo, speaking on behalf of the Vatican, said that not only was the use of condoms immoral, but also that condoms were ineffective in preventing HIV.[92] The cardinal was highly criticized by the world health community, who were trying to promote condom use as a way to prevent the spread of HIV.[93][94] The WHO later conducted a study showing that condoms are 90% effective at preventing HIV.[92]
In 2001, the United States began a war in Afghanistan related to fighting the Taliban. The Taliban, however, had opposed local opium growers and the heroin trade; when the government of Afghanistan fell during the war, opium production was unchecked. By 2003, the world market had an increase in the available heroin supply; in former Soviet states especially, an increase in HIV infection was due to injection drug use. Efforts were renewed to prevent HIV related to sharing needles.[95][96][97][98]
From 2011[edit]
In July 2011, it was announced by the WHO and UNAIDS that a once-daily antiretroviral tablet could significantly reduce the risk of HIV transmission in heterosexual couples.[99] These findings were based on the results of two trials conducted in Kenya and Uganda, and Botswana.
The Partners PrEP (pre-exposure prophylaxis) trial was funded by the Bill & Melinda Gates Foundation[100] and conducted by the International Clinical Research Center at the University of Washington. The trial followed 4758 heterosexual couples in Kenya and Uganda, in which one individual was HIV positive and the other was HIV negative.[99] The uninfected (HIV negative) partner was given either a once-daily tenofovir tablet, a once-daily combination tablet of tenofovir and emtricitabine, or a placebo tablet containing no antiretroviral drug. These couples also received counselling and had access to free male and female condoms. In couples taking tenofovir and tenofovir/emtricitabine, there was a 62% and 73% decrease, respectively, in the number of HIV infections as compared to couples who were receiving the placebo.[99]
A similar result was observed with the TDF2 trial, conducted by the United States Centers for Disease Control in partnership with the Botswana Ministry of Health.[101] The trial followed 1200 HIV negative men and women in Francistown, Botswana, a city known to have one of the world's highest HIV infection rates.[101] Participants received either a once-daily tenofovir/emtricitabine combination tablet or a placebo. In those taking the antiretroviral treatment, there was found to be a 63% decrease in the risk of acquiring HIV, as compared to those receiving the placebo.[99]
The HIV-1 virus has proved to be tenacious, inserting its genome permanently into patients' DNA, forcing patients to take a lifelong drug regimen to control the virus and prevent a fresh attack. Now, a team of Temple University School of Medicine researchers have designed a way to "snip out" the integrated HIV-1 genes for good. This is one important step on the path toward a permanent cure for AIDS. This is the first successful attempt to eliminate latent HIV-1 virus from human cells.
In a study published by the Proceedings of the National Academy of Sciences (PNAS), Khalili and colleagues detail how they created molecular tools to delete the HIV-1 proviral DNA. When deployed, a combination of DNA-snipping enzyme called a nuclease and targeting strand of RNA called a guide RNA (gRNA) hunt down the viral genome and excise the HIV-1 DNA. From there, the cell's own gene repair machinery takes over, soldering the loose ends of the genome back together – resulting in virus-free cells.
Since HIV-1 is never cleared by the immune system, removal of the virus is required in order to cure the disease. The same technique could theoretically be used against a variety of viruses. The research shows that these molecular tools also hold promise as a therapeutic vaccine; cells armed with the nuclease-RNA combination proved impervious to HIV infection.