User:Alignad123/sandbox

Treatment as prevention (TasP) is a method of HIV prevention that employs the use of antiretroviral treatment (ARVs) to reduce the risk of transmission. When taken correctly, ARVs are able to diminish the presence of the HIV virus in the bodily fluids of an infected person to a level of undetectability. Undetectability ensures that infection does not necessarily have an effect on a person's general health, and that there is no longer a risk of passing along HIV to others. Consistent adherence to an ARV regimen, monitoring, and testing are essential for continued confirmed viral suppression. Treatment as prevention rose to great prominence in 2011, as part of the HPTN 052 study, which shed light on the benefits of early treatment for HIV positive individuals.

TasP's legitimacy has influenced the World Health Organization's (WHO) standards for "test and treat" strategies, which push to alert as many people as possible of their HIV status through testing, and start people infected with HIV on ARVs, no matter their viral load or CD4 count. The diminished rate of new HIV infections brought about by these strategies are marked progress towards UNAIDS' 90-90-90 target to eliminate HIV/AIDS as a public health crisis by 2030. However, key populations in countries in Africa, Asia, and the Middle East still have lower access to treatment and the benefits it brings, as a result of the stigma that surrounds HIV.

Implementation
Treatment as prevention has been used as a form of controlling the spread of HIV since the mid-1990s, initially in the context of preventing the transmission of the virus from mothers to their children. Research in 1994 revealed how the drug zidovudine can reduce vertical transmission. The testing and treatment of HIV-positive mothers during pregnancy, childbirth, and breastfeeding has since led to the reduction of the risk of transmission by up to 95%. A program for offering ARVs for life to any HIV-positive pregnant person called "Option B+" served as a precursor to the "test and treat" strategy that is now being rolled out in various countries. Assessments of the Option B+ program are able to aid in the improvement and further establishment of "test and treat".

From 2013 to 2015, the global amount of people receiving ARV treatment rose by a third, and now is at 18.2 million people. This is a result of increased use of "test and treat". In 2015, about one fourth of the 148 countries informed about national treatment plans had initiated the WHO's "test and treat" approaches, and 44 more countries pledged to implement them by the end of 2016. The five-year HPTN 071 "PopART" study is currently examining the efficacy of TasP in 21 communities throughout South Africa and Zambia. PopART is focused on the advantages and downfalls of providing free voluntary HIV testing in combination with instant treatment for those who test positive. This study has a scope of about 1 million residents, making it the largest executed test of "test and treat".

Pre-exposure Prophylaxis
Pre-exposure prophylaxis (PrEP) is a system similar to that which was popularized by the HPTN 052 study, however the emphasis is placed on providing daily ARVs to HIV-negative people prior to exposure. PrEP reduces instances of HIV infection to nearly zero when utilized specifically as prescribed, which gives it the potential to have a population-wide scope. It is essential that PrEP is offered as part of a combination of preventative tactics, as it does not protect against other sexually transmitted diseases. One form of PrEP is a microbicide treatment, or "topical PrEP". Microbicides are ARVs that come in the form of gels or creams that are put on the vagina to prevent HIV infection. In the CAPRISA 004 trial in South Africa, there were found to generally be 39% fewer infections among women who used microbicide gel, however those results have not been recreated. In 2015, WHO defined a new precedent for offering PrEP to at-risk HIV-negative individuals, which expanded the definition of a high risk individual to include people who have an HIV-positive partner, those who do not have access to condoms, and those who are frequently having unprotected sex. Prior to 2015, PrEP was only initiated for key populations like sex workers, injection drug users, and men who have sex with men.

Post-exposure Prophylaxis
Post-exposure prophylaxis (PEP) is also a form of treatment as prevention that is used after possible exposure to HIV. It has mostly been used by those in healthcare professions that may have come into contact with infected bodily fluids, however PEP has been used more recently as emergency prevention for someone who may have been exposed to HIV in a one-time event, such as unprotected sex or sharing needles. PEP requires further testing and trial before its efficacy is universally accepted, however one experiment in the mid 90s revealed that zidovudine would prevent the transmission of HIV to exposed healthcare workers in 81% of cases. Zidovudine has however since been phased out and replaced by tenofovir in three-drug combinations.

Limitations
While TasP has a huge potential to prevent the further spread of HIV worldwide, the most vulnerable populations are not seeing these benefits as a result of a social and political climate that is deterrent to seeking testing and treatment, in addition to making it difficult to stick with the ARV regimen. Additionally, the window of time between initial infection and first getting tested is too large in some areas, meaning that people with HIV have a higher chance of passing along the virus while their viral load is high, even if they do eventually seek TasP. Even once TasP is initiated, its success depends on adherence to the treatment. If interrupted, the more sensitive strains of HIV become suppressed, while leaving the more resistant and harder to treat strains to become more dominant. Even in areas where access to treatment is fairly eased, adherence has emerged as an issue. For example, a study in 2011 revealed that in the United States, 15 years after the implementation of highly active antiretroviral therapy (HAART), and 4 years after the initial use of combination prevention, only 19% of the 1.1 million HIV-positive people in the country had reduced their viral load to reach undetectability. There have been studies of key populations in communities like Cape Town, South Africa that assert the benefits of community-based approaches, like adherence "clubs", where participants meet every two months for group counseling and the distribution of their ARV treatments.

HIV drug resistance has also come to the forefront of worries in regards to how effective TasP can be against the spread of the virus. The widespread global use of ARVs is feared to lead to an increase in drug resistance as a result of interrupted treatment and a lack of adherence. Again, this is largely an issue in the global south, where the health infrastructure is not conducive to support those participating in the life-long and intensive treatment of HIV/AIDS.

Moving Forward
Treatment as prevention has the ability to shift the paradigm of how HIV is received and treated. The effects of universal testing and treatment, and connecting people with resources for care will allow for global effects in terms of reduced rates of new HIV infections. The success of TasP is contingent upon innovation in strategies to increase the rate of HIV testing, along with exploring other dimensions of improving adherence, such as including cognitive and emotional support in those efforts. The cost of viral load testing is another factor in TasP's longevity, and increased access to that resource will allow for greater access to the beneficial effects of treatment as prevention.

New Forms of Treatment
Another hurdle to widespread and consistent adherence to TasP is the necessity to take daily doses of pills, which can be costly and difficult for people with HIV to remember. In August of 2018, ViiV Healthcare, a collaboration between GlaxoSmithKline and Pfizer revealed the findings of a study that found that receiving monthly injections of two long-acting ARVs over a course of 48 weeks is just as effective as taking daily pills. However, logistical questions still remain about cost, the effect of missed shots, and side effects of taking monthly injections. The study, which is called Antiretroviral Therapy as Long-Acting Suppression (ATLAS) is experimenting with the drugs cabotegravir--made by ViiV--and rilpivrine, which is a licensed drug from Janssen Sciences Ireland UC. ATLAS has a scope of 618 HIV-positive individuals from 13 countries, all of which had reached undetectability. Half of the participants continued with daily pills, while the others switched to receiving an injection each month. Viral suppression was the same in both groups. The results of the ATLAS study may also impact those who are not yet infected and are participating in PrEP, yet are reluctant to take daily pills. Other studies are underway which are testing viral suppression in HIV-positive people who have never taken antiretrovirals, and whether the injectables are still effective when only taken once every 8 weeks. With the introduction of long-acting drugs come questions on the optimal dose and timing, and how the virus may mutate to become resistant to the new form of treatment.

If you are doing treatment as prevention as your article that is fine, but be sure to conform to the Wikipedia guidelines on medical topics RJBazell (talk) 18:15, 14 October 2018 (UTC) Also Rebecca D wants to work on the same article we will discuss this in class RJBazell (talk) 18:23, 14 October 2018 (UTC)