Pitfalls in current HIV prevention strategies include late HIV testing, vulnerability among youth and females; lack of on treatment, low acceptance of circumcision, and nonavailability of protective vaccines. Preexposure prophylaxis is defined as the administration of antiretroviral drugs to an uninfected person before potential HIV exposure to reduce the risk of infection and continued during risk.
The rationale of this approach is to administer preventive dose of drug s before exposure to HIV so the moment virus enters the body, HIV replication is inhibited and HIV is not able to establish permanent infection. Postexposure prophylaxis PEP following potential sexual exposure is an important form of nonoccupational PEP which is an emergency intervention to abort HIV acquisition arising from exposure to HIV-infected blood or potentially infectious bodily fluids following sexual exposure.
Post exposure prophylaxis sexual exposure the advent of effective antiretroviral therapy ARTHIV is no longer considered a terminal illness but a manageable long-term condition.
Taking a leap further, it is now increasingly being used for prevention-both preexposure prophylaxis PrEP and postexposure prophylaxis PEP. Pitfalls in current HIV prevention strategies include late HIV testing, low awareness of vulnerability among youth and females; lack of emphasis on treatment, low acceptance of circumcision, and nonavailability of protective vaccines. Free HIV and virus-infected cells are present in blood, semen and in lesser quantities in vaginal and cervical secretions [ Table 1 ].
Estimated per-act risk for of HIV by sexual exposure route[ 2 ]. PrEP is defined as the administration of antiretroviral drugs to an uninfected person before potential HIV exposure to reduce the risk of infection and continued during risk.
The rationale of this approach is to administer a preventive dose of drug s before exposure to HIV, so the moment virus enters the body, HIV replication is inhibited and HIV is not able to establish permanent infection. For high-risk individuals who "Post exposure prophylaxis sexual exposure" HIV negative, offering PrEP is recommended in addition to the provision of free condoms, circumcision, education about risk reduction strategies, etc.
Food and Drug Administration on July 16,for PrEP regimen in combination with safer sex practices to reduce the risk of sexually acquired HIV-1 in adults at high risk. Important qualities that make this combination an ideal agent for PrEP include:. Common adverse reactions reported in people who take the drug to prevent HIV infection include nausea, vomiting, diarrhea, headache, respiratory tract infections, arthralgia, and weight loss. Tenofovir has been linked to renal impairment and loss of bone mineral density.
Indications of preexposure prophylaxis- Centers for Disease Control and Prevention guidelines. Maximum intracellular concentrations of tenofovir diphosphate are reached in blood after approximately 20 days of daily oral dosing, in rectal tissue at approximately 7 days, and in cervicovaginal tissues at approximately 20 days.
Done at least every 3 months to provide the following [ Table 4 ]. Test for bacterial STI and renal function should also be done every 6 months.
Patients who had an acute infection when PrEP was initiated have Post exposure prophylaxis sexual exposure highest risk of developing drug resistance. The acute infection can only be excluded if HIV testing follows a period of no potential exposure to HIV, which is not practical in people who have sex often and a delay in initiation of PrEP carries the greater risk of an HIV infection that could be avoided:. Patients discontinue PrEP due to personal choice, intolerable toxicities, chronic nonadherence to the prescribed dosing regimen, or acquisition of HIV infection.
On discontinuation for any reason, HIV status at the time of discontinuation, reason for PrEP discontinuation, recent medication adherence, and reported sexual risk behavior should be documented.
If the patient is HIV positive, estimation "Post exposure prophylaxis sexual exposure" viral load, CD4 count and resistance testing should be done and if HIV negative, linkage to risk reduction support should be done.
Women without HIV in serodiscordant couples are at substantial risk of HIV acquisition during attempts to conceive, and there is also an increased risk of HIV acquisition during pregnancy. PrEP use periconceptionally and during pregnancy by the uninfected partner may offer an additional tool to reduce this risk. Data directly related to the safety of PrEP use during pregnancy and lactation are very limited but indicate no increase in the prevalence of birth defects due to first trimester exposure to either FTC or TDF among HIV-infected pregnant women.
Providers should educate HIV-discordant couples who wish to become pregnant about the potential risks and Post exposure prophylaxis sexual exposure of all available alternatives for safer conception and if indicated make referrals for assisted reproduction therapies. However, more data are required in pericoital oral PrEP. The HIV-1 — seronegative partner in each couple was randomly assigned to one of three study regimens — once-daily tenofovir TDFcombination tenofovir TDF —FTC, or matching placebo — and followed monthly for up to 36 months.
Both study medications significantly reduced the HIV-1 incidence among both men and women. It is a comprehensive management which Post exposure prophylaxis sexual exposure first aid, counseling, risk assessment, relevant laboratory investigations based on informed consent of the source and exposed person; depending on the risk assessment, provision of short-term of ART, follow-up and support.
An important form of nonoccupational PEP is PEP following potential sexual exposure PEPSE which could be due to unprotected sexual exposure, sexual exposure involving a broken or slipped condom, sexual assault, etc. However, data relevant to PEPSE guidelines are available from animal transmission models, perinatal clinical trials, observational studies of health-care workers receiving prophylaxis after occupational exposures, and observational and case studies of PEPSE use.
Therefore, for those with HCV antibody test is negative at baseline but positive at 4—6 weeks after the exposure, HIV antibody tests should be conducted at 3 and 6 months to rule out delayed seroconversion. PEP should be started ideally within 2 h but certainly within 72 h and continued for 28 days.
Animal studies have shown initiating PEP within 12, 24, or 36 h of exposure was more effective than initiating PEP 48 h or 72 h following exposure. Centers for Disease Control and Prevention guidelines for postexposure prophylaxis day course of 3-drug regimen Post exposure prophylaxis sexual exposure 32 ].
Furthermore, protection against acquiring resistant virus would be greater with a 3-drug regimen compared with a 2-drug regimen. Zidovudine is no longer recommended in the preferred PEP regimen because it is believed to have no clear advantage in efficacy over tenofovir while having significantly higher rates of treatment-limiting side effects. Persons evaluated for PEPSE should also be provided any indicated prevention, treatment, or supportive care for other exposure-associated health risks and conditions e.
Individuals at risk for frequently recurring HIV exposures e. Although effective ART is now accessible, high-risk sexual behavior is continued as reflected by the occurrence of new cases. Vulnerable population like victims of nonconsensual high-risk sexual activities are in need of aggressive preventive approach in terms of pre- and post-sexual exposure prophylaxis.
Potential disadvantages of this approach include misuse of such drugs as a substitute of safe behavior, drug toxicities, and drug resistance.
National Center for Biotechnology InformationU. MarfatiaSheethal K. JoseReema R. Baxiand Ruchi J. Author information Copyright and License information Disclaimer. Abstract Pitfalls in current HIV prevention strategies include late HIV testing, vulnerability among youth and females; lack of emphasis on treatment, low acceptance of circumcision, and nonavailability of protective vaccines.
Emtricitabine, HIV, postexposure prophylaxis following potential sexual exposure, preexposure prophylaxis, tenofovir. Open in a separate window. TDF is rapidly converted to tenofovir after absorption, which is metabolized to active tenofovir diphosphate, which is a competitive inhibitor of HIV-1reversetranscriptaseandterminates the growing DNA chain.
Drugs such as acyclovir, valacyclovir, cidofovir, aminoglycosides, high-dose or multiple nonsteroidal anti-inflammatory drugs or other drugs that reduce renal function or compete for active renal tubular secretion may increase serum concentrations of TDF. Emtricitabine An analog of cytidine. Inhibits reverse transcriptase; helps to lower the viral load and indirectly increase the number of T-cells or CD4 T-cells. Important qualities that make this combination an ideal agent for PrEP include: Potent antiretroviral activity against all HIV subtypes.
Once-daily dosing with few drug interactions. Clinical eligibility for preexposure prophylaxis [ Table 3 ][ 4 ] Table 3 Clinical eligibility for preexposure prophylaxis.
Post exposure prophylaxis sexual exposure visits Done at least every 3 months to provide the following [ Table 4 ]. Table 4 Follow-up visits. They must be counseled to strictly adhere Post exposure prophylaxis sexual exposure medication along with specific behavioral and structural modifications such as limiting number of sexual partners and condom use with each sexual encounter.
Monitoring for adverse outcomes and development of resistance are also important. Start-up syndrome — Gastrointestinal symptoms in the 1 st month consisting of primarily nausea, diarrhea, vomiting abdominal pain. Can be caused due to both Post exposure prophylaxis sexual exposure. Behavioral disinhibition will only increase HIV transmission if the prevention strategy has low efficacy. Lack of substantial health service infrastructure and staffing for PrEP implementation and community education for MSM.
Discontinuation of preexposure prophylaxis Patients discontinue PrEP due to personal choice, intolerable toxicities, chronic nonadherence to the prescribed dosing regimen, or acquisition of HIV infection.
Bangkok Tenofovir Study demonstrated significantly reduced risk of HIV in intravascular ultrasound on daily oral tenofovir and suggested that TDF alone can be considered as an alternative in these groups. Advantages of topical PrEP include higher rate of adherence and increased intravaginal tissue concentrations of tenofovir[ 16 ].
Time of postexposure prophylaxis PEP should be started ideally within 2 h but certainly within 72 h and continued for 28 days. Plasma HIV viral load high load in the source increase the risk.
Due to high HIV viral load, the probability of transmission when the source person is in the acute and early stage of HIV infection first 6 months has been shown to be 8- to almost fold higher than exposures that take place after the viral set point[ 2324 ]. Viral loads in genital tract-correlate with plasma viral loads[ 23 ].
Breaches in mucosal barrier such as mouth or genital ulcer disease and trauma following sexual assault or first intercourse may increase the risk of HIV acquisition[ 25 ]. Menstruation or other bleeding-facilitate transmission[ 26 ]. However, this may not occur in individuals on effective ART[ 25 ]. Circumcision significantly reduces risk of HIV acquisition among heterosexual men in high prevalence countries[ 2728 ].
Cervical ectopy[ 26 ]. Table 8 Centers for Disease Control and Prevention guidelines for postexposure prophylaxis day course of "Post exposure prophylaxis sexual exposure" regimen [ 32 ].
ISSUES False sense of protection and therefore reduction in primary preventive measure and further increase in high-risk behavior. Despite its short duration, completion rates for PEP are low. Therefore, Post exposure prophylaxis sexual exposure and other adherence support measures are recommended. Cost of care, payment for medications and feasibility of implementation of guidelines the risks and benefits of prophylactic ART.
Transmissions may occur in few cases despite being on PEP. Compartmentalization of HIV, in particular within the genital tract, may result in differential virus evolution or evolution of resistance, which may have implications for transmission.