Acute HIV Discovered During Routine HIV Screening With HIV Antigen-Antibody Combination Tests in 9 US Emergency...

Area of Science:

• Infectious Diseases
• Diagnostic Medicine
• Public Health

Background:

• Newer combination HIV antigen-antibody tests detect HIV p24 antigen and antibodies, enabling earlier HIV detection than antibody-only tests.
• The p24 antigen appears in blood before HIV antibodies develop, facilitating earlier diagnosis.

Purpose of the Study:

• To determine the yield of HIV screening using antigen-antibody tests in US emergency departments (EDs).
• To analyze clinical presentations associated with new diagnoses of acute and established HIV infection.

Main Methods:

• Retrospective study of 9 EDs with integrated HIV screening programs (2012-2015).
• Analysis of unique patients with newly diagnosed HIV infection, classified as acute or established based on test results and HIV RNA detection.
• Primary outcomes: number of new HIV diagnoses and proportion of acute HIV infections. Secondary outcomes: reasons for visit and clinical presentation.

Main Results:

• 214,524 patients screened; 839 (0.4%) received new HIV diagnoses.
• 14.5% of new diagnoses were acute HIV infection; 85.5% were established HIV infection.
• Patients with acute HIV infection were younger, had higher RNA and CD4 counts, and more frequently presented with viral syndrome or fever.

Conclusions:

• ED screening with antigen-antibody tests identifies undiagnosed HIV at high proportions, exceeding CDC thresholds.
• These tests yield significant identification of acute HIV infections (approx. 15% of new diagnoses).
• Patients with acute HIV infection often present to EDs with symptoms related to seroconversion.