When Should Antiretroviral Therapy be Started for Non-Occupational Exposure to HIV?
A 21-year-old female calls the outpatient clinic stating she had vaginal sexual intercourse 2 days ago. She and her male partner were using condoms and spermicidal foam. The condom broke after ejaculation, and she had already begun emergency contraception. She has just found out that her partner is HIV positive (human immunodeficiency virus) and wants to know what she should do about the risk.
Her past medical history reveals her to be otherwise well and she had her regular health maintenance examination 2 months ago which included a normal pelvic examination, sexually transmitted infection screening and cervical cancer screening. Her immunizations including Hepatitis B are current. She is told to make an appointment for that day.
The diagnosis of non-occupational exposure to HIV is confirmed.
She is counseled about her risk for becoming HIV positive as well as other sexually transmitted infections and pregnancy. She is also counseled about the potential side effects of antiretroviral therapy.
The laboratory evaluation included HIV antibody, complete blood count, liver function testing, blood urea nitrogen, creatinine, pregnancy testing, Hepatitis C serology, and sexually transmitted infection testing for Gonococcus, Chlamydia, and Syphilis. She is begun on nonoccupational postexposure prophylaxis and will followup in 4 weeks.
Acquired Immunodeficiency Syndrome / Human Immunodeficiency Virus (AIDS/HIV) is a retrovirus known for viremia that is persistent, nervous system infection, weak host immune responses, and especially for its latency. HIV binds to CD4 lymphocytes and monocytes and becomes internalized, replicating by reverse transcriptase. The viral DNA becomes incorporated into the host DNA allowing further replication.
After its latency, HIV infection causes profound immune suppression with the disease appearing to be almost uniformly lethal. Progression from HIV infection to AIDS occurs at a median of 11 years after infection. Until recently, persons with AIDS could expect to live 1-2 years, but with the introduction of new medication, medication combinations and prophylaxis against opportunistic pathogens, death rates from AIDS have begun to decline significantly.
The Centers for Disease Control (CDC) released a new guideline in January 2005 for the treatment of non-occupational exposure to HIV, referred to as nPEP or nonoccupational postexposure prophylaxis. Previously only occupational exposures were considered for treatment with post-exposure prophylaxis referred to as PEP (see To Learn More below).
Nonoccupational exposure is any ???”direct mucosal, percutaneous, or intravenous contact with potentially infectious body fluid that occurs outside perinatal or occupational settings. Potentially infectious body fluids are blood, semen, vaginal secretions, rectal secretions, breast milk or other body fluid that is contaiminated with visible blood.” (see To Learn More below)
Evaluation of a person seeking care for nonoccupational exposure to HIV should include:
- Determining the HIV status of the person seeking care as many people do not know if they have already been exposed and are already infected.
- Determining timing and frequency of exposure – nPEP is less likely to be effective if initiated > 72 hours after HIV exposure. After this time, the likelihood of benefit may not outweigh the risks in taking highly active antiretorviral therapy (HAART). nPEP should only be used for infrequent exposures.
- Determining HIV status of the source person – If the source is HIV positive, additional history to determine antiretorviral therapy use and most recent viral load may provide help in determine choice of nPEP medications. If the source status is unknown, but from a group with a high prevalence of HIV infection (e.g. homosexual or bisexual man, injection drug user or commercial sex worker), the risk for transmission might be increased. If the status is unknown and the source is available, testing should be done on the source person, and possiblly begin nPEP until the source’s HIV status is determined.
- Determining transmission risk – the highest risks are for blood transfusions, needle sharing by injection drug users, receptive anal intercourse and percutaneous needle stick injuries.
Exposure Route Rates are per 10,000 exposures to an infected source Blood transfusion 9000 Needle sharing infection drug use 67 Receptive anal intercourse 50 Percutaneous needlestick 30 Receptive penile-vaginal intercourse 10 Insertive anal intercourse 6.5 Insertive penile-vaginal intercourse 5 Receptive oral intercourse 1 Insertive oral intercourse 0.5
- Evaluate for sexually transmitted infections, hepatitis and emergency contraception
- Follow-up includes:
- Testing for HIV antibodies at baseline, 4-6 weeks, 3 months, and 6 months after exposure. Also testing for sexually transmitted diseases including Hepatitis B and C and pregnancy should be offered.
- Patient should be instructed about the signs and symptoms associated with acute HIV infection, especially fever and rash, and told to report them.
- If nPEP is used, monitoring of liver, renal and hematological function as indicated by the exact medications used is recommended.
- Patients should be instructed to avoid possible transmission to others including the practice of "safe sex," to avoid shared drug injection equipment, and not to donate tissues and blood.
- Clinicians should assess the source person's access to medical care and help to obtain care if necessary.
- Confidentiality should be strictly maintained and reporting of new HIV infections to health departments and other sources as dictated by local law.
The most effective means of preventing HIV is preventing exposure. The guidelines should be reviewed and are briefly described below and in Table 8.
For persons seeking care < 72 hours after nonoccupational exposure to a source with known HIV infection, a 28-day course of nPEP is recommened using highly active antiretorviral therapy (HAART) beginning as soon as possible.
For persons seeking care < 72 hours after nonoccupational exposure to a source with unknown HIV status when such exposure represents a substantial risk for transmission if the source were HIV infection, no recommendations are made for using nPEP. This needs to be evaluated on a case by case basis.
For persons seeking care > 72 hours after nonoccupational exposure, or with exposure histories that represent no substantial risk of transmission, nPEP is not recommended.
For persons seeking care > 72 hours after nonoccupational exposure with a substantial risk of infection, nPEP may be considered if the determined potential benefit outweighs the risks for transmission and adverse events of HAART.
HAART regimens can be found by consulting the CDC guidelines. Overall, no specific antiretorviral medicaltion or combinations of medications are optimal for use as nPEP. HAART decreases but does not eliminate the transmission risk of HIV even if begun within 72 hours.
Figure 10. Algorithm for Evaluation and Possible Treatment of NonOccupational Exposure to HIV.
Questions for Further Discussion
1. If nPEP is begun, what laboratory testing is recommended at intervals?
2. How do the guidelines change if the patient is a child or is pregnant?
3. What are the criteria for defining HIV and AIDS?
4. What types of HIV testing are available?
5. What are the risks of HAART?
To Learn More
To view pediatric review articles on this topic from the past year check PubMed.
Antiretroviral Postexposure Prophylaxis After Sexual, Injection-Drug Use, or Other Nonoccupational Exposure to HIV in the United States. MMWR.
Available from the Internet at http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5402a1.htm (rev. 1/25/2005, cited 1/25/2005).
Dubin J. HIV Infection and AIDS. eMedicine.
Available from the Internet at http://emedicine.com/emerg/topic253.htm (rev. 12/14/2004, cited 1/25/2005).
Updated U.S. Public Health Service Guidelines for the Management of Occupational Exposures to HBV, HCV, and HIV and Recommendations for Postexposure Prophylaxis. MMWR.
Available from the Internet at http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5011a1.htm (rev. 6/29/2001, cited 1/25/2005).
Donna M. D'Alessandro, MD
Associate Professor of Pediatrics, Children's Hospital of Iowa
February 14, 2005