Lab Matters - Winter 2013

THE STATE OF HIV DIAGNOSTICS IN PUBLIC HEALTH LABORATORIES by Jessica Monmaney, associate specialist, food safety and infectious diseases Public health laboratories have been on the leading edge of advances in HIV testing since the 1980s and, during this time, have faced numerous challenges related to new testing technology and diagnostic algorithms. The 2012 HIV Diagnostics Conference, held December 12-14, provided laboratorians with comprehensive updates on technology and algorithms, as well as the opportunity to share individual experiences and challenges.

Recent changes to the Ryan White Act have created new difficulties for public health laboratories. In 1990, Congress passed the Ryan White CARE (Comprehensive AIDS Resources Emergency) Act, now called the Ryan White HIV/AIDS Program. The bill’s namesake was a young boy who contracted HIV through a contaminated blood transfusion used to treat hemophilia. The efforts of Ryan—who died in 1990, months before the bill was passed—and his mother have provided treatment for people living with HIV and AIDS for more than two decades. 1 Although the majority of the funds are designated for treatment, the bill also provides resources for state and local clinical training and technical assistance programs. 2

Changes to the Ryan White HIV/AIDS Pro-
gram have impacted the Orange County, CA,
public health laboratory. The laboratory re-
ceived financial support through Ryan White
funds for the identification of new HIV cases,
as well as viral load testing for existing pa-
tients to determine drug resistance. In Sep-
tember 2012, the HIV clinic from which the
laboratory received specimens was notified
that a third of their patients were no longer
eligible for Ryan White funds due to health-
care reform. This led to a 34% reduction
in the laboratory’s viral load testing and a
nearly 50% reduction in genotype testing for
drug resistance. Patients no longer covered
by Ryan White funding were transferred to a
new clinic, which had an existing agreement
with a large commercial laboratory. The
Orange County public health laboratory now
serves in a processing capacity between col-
lection at the clinic and testing at the com-
mercial laboratory for viral load and drug
resistance testing, though their HIV screen-
ing levels have remained consistent. This
drop in volume makes it difficult to justify
bringing on new technology or adopting new
testing algorithms.

A map of HIV infections in the lower 48 states (source: www.aidsvu.org)

Another challenge for Alexander’s facility is that California public health laboratories are subject to state-specific regulations that require an algorithm be published in CDC’s MMWR before a lab can use it. Though this particular regulation is unique to California, public health laboratories throughout the country are affected by the dynamic nature of HIV testing algorithms, the benefits of which vary greatly among laboratories and their populations.

The benefits and challenges of adopting the proposed HIV Diagnostic Testing Algorithm were presented and discussed in detail at this conference. Michael Pentella, PhD, from the Iowa public health laboratory, said, “[As] a low incidence state, we do not have as much experience with the tests as others do, therefore, it is even more valuable for us to learn from others.” The Iowa laboratory is now conducting validation testing for the new HIV algorithm. Prior to the HIV Diagnostics Conference, the laboratory planned to save money by confirming rapid test HIV-positive samples through a multi-spot test, bypassing the antigen/antibody screen. After reaching out to laboratorians in other states, CDC and the Iowa Department of Health HIV Coordinator, Pat Youngs, Pentella discovered that, for confirming the rapid tests used most commonly at clinics, the antigen/antibody tests are more cost-effective since they address false positive results.

In addition to these discussions among states, the Diagnostics Conference illustrated the importance of collaboration between program and laboratory staff. For example, Massachusetts began transitioning from 3rd to 4th generation testing in January 2012. Between January and June, the programmatic and laboratory staff worked together to conduct training, standardize terminology, validate processes, and ensure that results could be communicated to providers within 48 hours. Since the algorithm was adopted in June 2012, Massachusetts has already identified three acute infections through 4th generation testing, which were previously reactive on an antibody/antigen test and non-reactive by multi-spot testing. Specific attention must be paid to the following components: laboratory process, time-sensitive shipping protocols, consistent and accessible training, implementation monitoring, and responsive technical assistance. 3 Although the absence of a formal CDC recommendation in MMWR prevents some laboratories, such as Alexander’s in California, from adopting 4th generation testing, the Massachusetts laboratory is encouraged by the successful implementation of 4th generation testing. u

1. HRSA website: http://hab.hrsa.gov/abouthab/ryanwhite.html#legacy 2. HRSA website: http://hab.hrsa.gov/abouthab/aboutprogram.html

3. Goodhue T, Kazianis A, Stiles T, Gaucher M, Callis B, Fukuda HD, Cranston K. 4th Generation HIV Screening in Massachusetts: A Partnership Between Laboratory and Program (Oral Abstract). 2012 HIV Diagnostics Conference. 2012: 29 – 30.