Operations

Recent Changes in HIV Testing & Post-Exposure Follow-Up

A tremendous amount has been learned about the human immunodeficiency virus (HIV) since its onset in the late 1970s. Long-term studies of infected persons and their response to new medications has led to several changes in testing and post-exposure medical follow-up. It’s important that EMS and all members of the healthcare team be aware of the current science.

This article is designed to raise awareness of these changes to ensure that an exposed healthcare worker (HCW) receives proper care as outlined in the requirements under the Bloodborne Pathogens Standard (29 CFR 1910.1030) from the U.S. Occupational Safety and Health Administration (OSHA).

Employers must ensure that an exposed employee receives proper care and counseling as outlined by the Centers for Disease Control and Prevention (CDC) post-exposure guidelines and recommendations, which OSHA is tasked with enforcing. Reference to this can be found in the OSHA Enforcement Procedures for the Occupational Exposure to Bloodborne Pathogens (CPL 02-02-069).

A Brief History

The timeline for HIV begins in the 1900s, when the disease transferred from chimpanzees to humans. It was believed that HIV was in the U.S. sometime prior to 1966.

It was in 1984 that the HIV virus was determined to be the cause of AIDS. Deaths among persons reported with AIDS peaked at 50,000 in 1995, when AIDS was as the leading cause of death in the U.S. for persons between 25–44 years of age.

Change began with the development of multi-drug therapy. By 1997, new treatments led to a 47% reduction in death. By 1996, it’s believed that 38,780 persons died as a result of HIV infection, but, by 2000, the death rate had declined to 14,499 due to the availability of drug treatment.

Antiviral medications became the basis for treating HIV-infected persons. It all started with the drug AZT, which was referred to as “monotherapy.” Then, there was a switch to the beginning of multi-drug therapy, which required a very strict schedule for medications. For many patients, this schedule was difficult to maintain. Antivirals worked to prevent the HIV from reproducing, thus the amount of circulating virus diminished. This knowledge brought about the opportunity to move to combination therapy.

This became known as the “triple drug cocktail,” or highly active antiretroviral therapy (HAART). It’s more commonly referred to as antiretroviral therapy (ART). The passage of the Ryan White Care Act of 1990, which funds HIV treatment programs across the country, made triple drug treatment readily available to all in need of treatment and medications. Today, there are a wide variety of funding programs across the country to cover medications and treatment, as well as housing programs.

Changes in Testing

Rapid HIV test kits entered the market in 2003. This test detected infection with 96% accuracy and results were available in 20-30 minutes.

Rapid HIV testing post exposure is the standard of care and is enforced by OSHA. Medical facilities are required to perform rapid HIV testing on a source patient.

Although concerns have been expressed about HIV-negative sources who might be in the so-called “window period” before seroconversion (i.e., the period of time between initial HIV infection and the development of detectable HIV antibodies), no such instances of occupational transmission have been detected in the U.S. to date. Hence, investigation of whether a source patient might be in the window period is unnecessary for determining whether HIV post-exposure prophylactic (PEP) medication is indicated.

Fourth-generation combination p24 antigen–HIV antibody (Ag/Ab) tests produce both rapid and accurate results, and their p24 antigen detection allows identification of most infections during the window period.

The CDC confirmed in 2005, and again in 2013,  that there’s no window phase for HIV testing. Rapid determination of source patient HIV status provides essential information about the need to initiate and/or continue PEP.

Viral Load Testing

Viral load testing has been found to be a more reliable marker in monitoring response to treatment and assists with gauging response to treatment. Successful treatment has been found to show viral load as “undetectable.”

An undetectable viral load refers to less than 500—down to 40 copies of the virus per milliliter of blood. Remember that dose of the organism is key to risk for transmission.

It has been well established that the use of ART not only improves the overall health of an infected person but also is able to reduce the amount of virus in blood and body fluids.

Medication and medical follow up to measure viral load is also important. Medical evidence shows that this combination results in ongoing undetectable viral load.

Viral load testing on a source patient should take about 2-3 hours when performed in the facility. This testing is key to making a determination with regard to offering PEP medications.

In January 2018, the CDC published, in conjunction with the PEP resource center, that there’s up to 72 hours post exposure to offer PEP if the exposure meets established criteria. The PEP Hotline is open from 11 am to 8 pm EST seven days a week.

If you are using the emergency department for your post exposure care, note that Emergency physicians are to call the PEP Hotline for a second opinion before these medications are prescribed. The hotline number is (888) 448-4911. The extended time frame for offering PEP, if indicated, allows for healthcare worker referral for proper care and counseling.

Replicated studies have shown that for people taking ART and following medical care for three to six months have undetectable virus in their blood. What this means is that just because a patient is HIV positive is not enough information to suggest risk for transmission. Viral load is the key testing method. HIV infected persons are now able to live normal lives.

However, if a source patient tests positive with viral load, then baseline testing of the exposed healthcare worker should be performed. The need for PEP would be determined by the type of exposure and the CDC guidelines for post-exposure medical follow up. The healthcare worker would be tested six weeks after the baseline and the last test would be four months after the exposure, with the rapid test being used.

Consent for Testing

Each state has a law governing HIV testing. About half of the states require the patient’s informed consent, while the other half have what is termed “deemed consent.” Deemed consent means that the state has deemed the patient’s consent if there’s been a healthcare worker/emergency responder exposure.

For those in states in which consent for HIV testing is required, it should be taken into account that in 2006 the CDC published new guidelines for HIV testing.

A key statement in these guidelines was that a “separate written consent for HIV testing should not be required; general consent for medical care should be considered sufficient to encompass consent for HIV testing.”

These guidelines also state that prevention counseling should not be required with HIV diagnostic testing or as part for HIV screening programs in healthcare settings. In response to the 2006 CDC HIV testing guidelines, many medical facilities have added a statement on general consent to their form for authorization for care. With this in place, previous issues with consent and counseling are eliminated if there is no conflict with the state testing law.

The state of Washington has updated its HIV testing law to remove any possible conflict with the updated CDC HIV testing guidelines. This should pave the way for other states to follow their lead.

The new section of the Washington law, Senate Bill 6580, states, “The legislature finds that great advances have been made in medical technology and treatment of the human immunodeficiency virus (HIV). HIV is treatable and a person living with HIV can lead a relatively healthy life, if they have access to health care and are able to achieve viral suppression.

Additionally, if a person’s virus is undetectable, he or she is unable to transmit the virus. It’s critical that people are tested for HIV. Therefore, the legislature finds that any and all barriers to HIV testing must be removed.” This law removed the consent requirement for HIV testing.

Resources

1. The History of HIV and AIDS in the United States, Healthline, January, 2018

2. Ryan White Care Act PL 101-381, Enacted by the U.S. Congress, 1990

3. Updated US Public Health Service Guidelines for the Management of Occupational Exposures to Human Immunodeficiency Virus and Recommendations for Postexposure Prophylaxis, David T. Kuhar, MD; David K. Henderson, MD; Kimberly A. Struble, PharmD; Walid Heneine, PhD; Vasavi Thomas, RPh, MPH; Laura W. Cheever, MD, ScM; Ahmed Gomaa, MD, ScD, MSPH; Adelisa L. Panlilio, MD; for the US Public Health Service Working Group

4. Michael Shernoff and Raymond A. Smith, HIV Treatments: A History of Scientific Advance, The Body, July, 2001

5. HIV Treatment and an undetectable viral load to prevent HIV transmission, CATIE, December, 2018

6. PEP Quick Guide for Occupational Exposures, Clinician Consultation Center, January 1, 2018