Episode 70 - HIV Prevention - a podcast by Rio Bravo Family Medicine Residency Program

Episode 70: HIV Prevention. 

Prevention is key in controlling HIV-AIDS. Listen to ways to prevent HIV, mainly by using condoms, PrEP and PEP.

Introduction: HIV and AIDS
By Robert Dunn, MS3.

Introduction: The Human Immunodeficiency Virus (HIV) is a retrovirus that is primarily transmitted via sex, needles or from mother to fetus. Once infected, the virus increases in its copies and decreases the individual’s CD4+ cell count, thus leading to an immunocompromised state known as Acquired Immune Deficiency Syndrome (AIDS). Once with AIDS, the patient is susceptible to opportunistic infections. 

Prevention from AIDS includes several options. Condoms for safe sex practices are the least invasive and most readily accessible option for all patients. Pre-exposure prophylaxis (PrEP) is also an option for men who have sex with men (MSM) and transgender women. If the patient is also exposed to HIV, post-exposure prophylaxis (PEP) may also be an option to prevent infection but must be administer ideally 1-2 hours after exposure but no later than 72 hours after. 

Today we will briefly discuss how to prevent HIV infection.

This is Rio Bravo qWeek, your weekly dose of knowledge brought to you by the Rio Bravo Family Medicine Residency Program from Bakersfield, California. Our program is affiliated with UCLA, and it’s sponsored by Clinica Sierra Vista, Let Us Be Your Healthcare Home.

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HIV Series IV: HIV Prevention. 
By Robert Dunn, MS3.
Participation by Huda Quanungo, MS3; Bahar Hamidi, MS3; and Hector Arreaza, MD.  

HIV Prevention
Introduction

The Human Immunodeficiency Virus (HIV) is a retrovirus that is primarily transmitted via sex, needles or from mother to fetus. Once infected, the virus increases in its copies and decreases the individual’s CD4+ cell count, thus leading to an immunocompromised state known as Acquired Immune Deficiency Syndrome (AIDS). Once with AIDS, the patient is susceptible to opportunistic infections. 

Prevention from AIDS includes several options. Condoms for safe sex practices are the least invasive and most readily accessible option for all patients. Pre-exposure prophylaxis (PrEP) is also an option for men who have sex with men (MSM) and transgender women. If the patient is also exposed to HIV, post-exposure prophylaxis (PEP) may also be an option to prevent infection, but it must be administered ideally 1-2 hours after exposure but no later than 72 hours after. We will concentrate in prevention during this episode. 

 

 

What is HIV?

The Human Immunodeficiency Virus (HIV) is a retrovirus. When the virus gains access to our body via cuts on the skin or mucosa:

The virus injects its 10kb sized RNA genome into our cells. 

The RNA is transcribed to DNA via viral reverse transcriptase and is incorporated into our cellular DNA genome. This causes our cells to become a virus producer. 

Viral proteins translated in the cell are transported to the edge of the cell and can bud off into new viruses without lysing the cell. 

 

Acute HIV symptoms. Some potential early symptoms of HIV can include fever, chills, rash, night sweats, muscle aches, sore throat, fatigue, lymphadenopathy, and mouth ulcers. The most common acute symptom is NO SYMPTOM. Many people do not feel sick with the acute infection of HIV. Some people can live years with HIV in “clinical latency” without knowing they are infected, but they can still be contagious during this time. 

As viral load (the amount of virus copies you have in your blood stream) increases, the CD4+ cells that contribute to our adaptive immunity continues to fall. That’s why the best test during this period is not going to be HIV antibody but you should test for antigens. Specifically, the 4th Generation HIV test, which tests for both antibody and p24 antigens.

Chronic symptoms. Once patients begin to present with opportunistic infections (i.e. Pneumocystis pneumonia – PCP), or have a CD4 count below 200, the patient is considered to have Acquired Immune Deficiency Syndrome (AIDS) and makes them susceptible to more serious infections. Without treatment, patients with AIDS typically survive about 3 years. 

Epidemiology of HIV

HIV incidence: In 2019, there were 34,800 new HIV infections in the United States. This is an 8% decline from 2015. Amongst age groups: 

Age 25-34 had the highest rate of incidence (30.1 per 100,000)

Age 35-44 had the second highest rate (16.5 per 100,000)

Age 45-54 remained stable

Age 13-24 had decreasing rates of incidence

 

Amongst ethnic groups: 

Black/African-American groups has the highest rate of incidence (42.1 per 100,000)

Hispanic/Latino had the second highest rate (21.7 per 100,000)

Person of multiple races had the third highest (18.4 per 100,000)

 

Amongst sex: 

Males had the highest rate of incidence (21 per 100,000)

Females had the lowest rate of incidence (4.5 per 100,000)

 

HIV Prevalence:

In 2019, 1.2 million people (Ages 13 and older) in the US have HIV and 13% of them do not even know it. In 2020, there were an estimated 1.5 million people worldwide that acquired a new HIV infection. This is a 30% decline since 2020. An estimated 66% are receiving some HIV care and 57% were virally suppressed. Mortality: In 2019, there were 15,815 deaths among adults and adolescents diagnosed with HIV in the US. 

Preventative Screening

The USPSTF gives a Grade A recommendation for HIV screening for: Pregnant people and everyone between 15-65 years of age. 

All pregnant people at any point of their pregnancy, including those who present in labor or delivery and have an unknown status of HIV.

The USPSTF only recommends a one-time screening and shows no benefit of repeat screening thereafter. Women may also be screened for subsequent pregnancies

Also screen all Adolescents and adults ages 15-65. 

 

An effective approach is routine opt-out HIV screening. This approach includes HIV screening as part of the standard preventive tests. This approach removes the stigma associated with HIV testing, it promotes earlier diagnosis and treatment, reduces risk of transmission, and it is cost-effective.

 

The determination for repeated screening of individuals should take into account the following risk factors: 

-Men who have sex with men (MSM)

-Individuals who live in areas with high prevalence of HIV

Including attending to tuberculosis clinics, stay in a correctional facility, or homelessness

-Injection drug use

-Transactional/commercial sex work

-1 or more new sexual partners 

-History of previous STIs

 

Annual screening for HIV is reasonable, however, clinicians may want to screen patients every 3-6 months if they have an increased risk of HIV. 

 

Condoms

A simple and very effective method in HIV prevention is the use of condoms for safe sex practices. In 2009, the American College of Physicians (ACP) and the HIV medicine Association called for the wider availability of condoms and education to minimize HIV transmission. 

A meta-analysis of 12 HIV studies amongst heterosexual couples demonstrated the use of condoms in all penetrative sex acts reduced the risk of HIV transmission 7.4 times in comparison to those who never used condoms. Other studies show a 90-95% effectiveness in HIV prevention when “consistently” using condoms. 

A Cochrane review shoed that the use of a male latex condom in all acts of penetrative vaginal sex reduced HIV incidence by 80%. Overall, condoms are effective in HIV prevention.

Pre-Exposure Prophylaxis (PrEP)

Truvada and Descovy:

Another option for prevention amongst HIV negative individuals is the use of Pre-Exposure Prophylaxis (PrEP). It is an anti-retroviral pill that is taken daily to maintain a steady-state level of the medication in the blood stream. The medication specifically a combination of 2 antiretroviral medications – Tenofovir and Emtricitabine. Both medications are nucleoside reverse transcriptase inhibitors (NRTIs) that work by blocking the viral reverse transcriptase from HIV and prevent the enzyme from copying the RNA genome into DNA. Therefore, it stops viral replications. 

There are 2 formulations of PrEP: Truvada and Descovy. Truvada’s primary side effects are renal and bone toxicity with long-term use. Descovy’s primary side effects are mild weight gain and dyslipidemia. Truvada is the most commonly prescribed PrEP because it has the most data since it has been around the longest. 

However, extra consideration should be taken for: 

Adolescents should weigh at least 35 kg before being prescribed PrEP

Descovy may be preferred for adolescents by the prescribing physician as it is not associated with reduction in bone density, as Truvada is. 

Estimated GFR between 30 – 60

Truvada is associated with acute and chronic kidney disease whereas Descovy is safe for patients with a GFR greater than 30

Patients with osteoporosis

Truvada is associated with bone toxicity, whereas Descovy is not.

 

It is important to note that PrEP has only been studied in men or people who were assigned men at birth. So, its efficacy in vaginal sex and with vaginal fluids cannot be generalized at this time. 

Future of PrEP: In May 2020, the HIV Prevention Trials Network (HPTN) 083 randomized trial demonstrated the potential of an injectable PrEP. Carbotegravir, is an integrase inhibitor, which prevents the HIV integrase from incorporating the HIV genome into the cellular genome. This study demonstrated its efficacy as PrEP in comparison to Truvada with few new infections (13 versus 39, respectively). Carbotegravir would be given via injection once every 8 weeks. 

In September 2021, the pharmaceutical company Moderna will begin 2 human clinical trials for an HIV vaccine that use mRNA technology. Previous studies conducted with non-mRNA vaccines demonstrated that B cells can be stimulated to create antibodies against HIV. Since HIV becomes integrated in the cellular genome within 72 hours of transmission, a high level of antibodies must be produced and present in the body to offer an adequate level of immunity. 

Post-Exposure Prophylaxis (PEP)

If an individual is exposed to blood or bodily fluids with high risk of HIV via percutaneous, mucus membrane or nonintact skin route, post-exposure prophylaxis (PEP) may be an option. 

PEP is indicated when the HIV status of the exposure source is unknown and are awaiting test results, or if the exposure source is HIV positive. Therapy should be started within 1 or 2 hours of exposure and it is not effective after 72 hours of initial exposure. The recommended duration of therapy is 4 weeks but no evidence has been shown for an optimal duration. 

Occupational exposure. There are 2 regimens for PEP: 

Truvada with Dolutegravir 

Truvada  with Raltegravir

 

Both Doltegravir and Raltegravir are integrase inhibitors which block the integration of the viral genome into the cellular DNA. The regiments are chosen based on efficacy, side effects, patient convenience, and completion rates. Dolutegravir is chosen because it is given once daily. While Raltegravir is taken twice daily, most experience with PEP has been with Raltegravir. Other risk with Raltegravir are potential skeletal muscle toxicity and systemic-cutaneous reactions resembling Steven-Johnson syndrome. 

One final word about prevention of vertical transmission is making sure pregnant women are treated during pregnancy and if the baby is delivered from a patient whose viral load is “detectable”, the baby needs to be treated, but we’ll let that topic for another time to discuss. 

Joke: What do you call the patient zero of HIV? First Aids.

HIV incidence is decreasing thanks to many prevention measures taken globally, and we discussed screening, condoms, PrEP and PEP as part of this prevention efforts. Stay tuned for more relevant medical information in our next episode. 

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Now we conclude our episode number 70 “HIV Prevention.” Robert, Huda and Bahar explained some ways to prevent HIV, mainly by screening those at risk, using condoms, PrEP (pre-exposure prophylaxis) and PEP (post-exposure prophylaxis). Let’s also remember that having a monogamous relationship and avoiding high risk sexual behaviors confer significant protection against HIV. Even without trying, every night you go to bed being a little wiser.

Thanks for listening to Rio Bravo qWeek. If you have any feedback about this podcast, contact us by email RBresidency@clinicasierravista.org, or visit our website riobravofmrp.org/qweek. This podcast was created with educational purposes only. Visit your primary care physician for additional medical advice. This week we thank Hector Arreaza, Robert Dunn, Huda Quanungo, and Bahar Hamidi. Audio edition: Suraj Amrutia. See you next week! 

 

 

References:

About HIV. Center for Disease Control and Prevention, CDC.gov, June 1, 2021. https://www.cdc.gov/hiv/basics/whatishiv.html . Accessed September 21, 2021.

 

Simon V, Ho DD, Abdool Karim Q. HIV/AIDS epidemiology, pathogenesis, prevention, and treatment. Lancet. 2006 Aug 5;368(9534):489-504. doi: 10.1016/S0140-6736(06)69157-5. PMID: 16890836; PMCID: PMC2913538. [https://pubmed.ncbi.nlm.nih.gov/16890836/]  

 

US Statistics. HIV.gov, June 2, 2021. https://www.hiv.gov/hiv-basics/overview/data-and-trends/statistics . Accessed September 21, 2021. 

 

The global HIV/AIDS Epidemic. HIV.gov, June 25, 2021. https://www.hiv.gov/hiv-basics/overview/data-and-trends/global-statistics. Accessed September 21, 2021. 

 

Human Immunodeficiency Virus (HIV) Infection: Screening. U.S. Preventative Services Task Force, June 11, 2019. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/human-immunodeficiency-virus-hiv-infection-screening. Accessed September 21, 2021. 

 

Holmes KK, Levine R, Weaver M. Effectiveness of condoms in preventing sexually transmitted infections. Bull World Health Organ. 2004 Jun;82(6):454-61. PMID: 15356939; PMCID: PMC2622864. [https://pubmed.ncbi.nlm.nih.gov/15356939/]

 

Weller S, Davis K. Condom effectiveness in reducing heterosexual HIV transmission. Cochrane Database Syst Rev. 2002;(1):CD003255. doi: 10.1002/14651858.CD003255. PMID: 11869658. [https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD003255/full]

 

Mayer, Kenneth H, MD, and Douglas Krakower, MD. Administration of pre-exposure prophylaxis against HIV infection. UpToDate, June 24, 2020. Accessed September 21, 2021. [https://www.uptodate.com/contents/administration-of-pre-exposure-prophylaxis-against-hiv-infection?search=8)%09Administration%20of%20pre-exposure%20prophylaxis%20against%20HIV%20infection&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1]

 

Zachary, Kimon C, MD. Management of health care personnel exposed to HIV. UpToDate, June 07, 2019. Accessed September 21, 2021. [https://www.uptodate.com/contents/management-of-health-care-personnel-exposed-to-hiv?search=9)%09Management%20of%20health%20care%20personnel%20exposed%20to%20HIV&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1]

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