What is the recommended approach for diagnosing and treating an inpatient suspected of having Human Immunodeficiency Virus (HIV)?

From the Guidelines

The recommended approach for diagnosing and treating an inpatient suspected of having HIV begins with prompt HIV testing using a fourth-generation antigen/antibody combination test, followed by confirmatory testing if positive, as recommended by the USPSTF 1. For diagnosis, obtain informed consent, perform pre-test counseling, and collect a comprehensive history focusing on risk factors, symptoms of acute retroviral syndrome, and opportunistic infections. Laboratory workup should include:

• CD4 count
• HIV viral load
• Complete blood count
• Comprehensive metabolic panel
• Hepatitis serologies
• Tuberculosis screening
• STI testing, as outlined in the 2024 recommendations of the International Antiviral Society-USA panel 1. For treatment, antiretroviral therapy (ART) should be initiated as soon as possible, ideally within 24-48 hours of diagnosis, even in the inpatient setting, with preferred initial regimens including integrase strand transfer inhibitor (INSTI)-based combinations 1. Prophylaxis for opportunistic infections should be initiated based on CD4 count (e.g., Pneumocystis pneumonia prophylaxis with trimethoprim-sulfamethoxazole if CD4 <200 cells/μL). Early ART initiation improves clinical outcomes by preserving immune function, reducing inflammation, decreasing risk of transmission, and preventing AIDS-defining illnesses, as supported by the 2024 recommendations 1. Multidisciplinary care involving infectious disease specialists, pharmacists, and social workers is essential for comprehensive management and ensuring continuity of care after discharge. Key considerations in the inpatient setting include:
• Prompt initiation of ART
• Opportunistic infection prophylaxis
• Comprehensive laboratory workup
• Multidisciplinary care, all of which are crucial for optimizing patient outcomes and reducing morbidity and mortality associated with HIV infection 1.

From the FDA Drug Label

HIV testing: HIV antibody testing should be offered to all HBV-infected patients before initiating therapy with tenofovir disoproxil fumarate. Tenofovir disoproxil fumarate should only be used as part of an appropriate antiretroviral combination regimen in HIV-infected patients with or without HBV coinfection.

The recommended approach for diagnosing HIV in an inpatient suspected of having Human Immunodeficiency Virus (HIV) is to offer HIV antibody testing.

• Key steps for treating an inpatient with suspected HIV include:
  • Confirming the diagnosis through HIV testing
  • Initiating an appropriate antiretroviral combination regimen if the patient is found to be HIV-infected, with or without HBV coinfection 2 2.

From the Research

Diagnosing HIV in Inpatients

• The recommended approach for diagnosing HIV in inpatients involves the use of HIV-1/2 antigen/antibody (Ag/Ab) tests, followed by an HIV-1/2 antibody (Ab) differentiation test and, if necessary, a diagnostic HIV-1 nucleic acid test to resolve discordant or indeterminate results 3.
• An alternative laboratory-based HIV diagnostic testing algorithm using HIV-1 RNA viral load has been proposed, which can potentially decrease the total number of tests performed and reduce turnaround time, thereby streamlining HIV diagnosis and initiation of treatment 3.
• Routine HIV testing in the inpatient setting can identify new and previously diagnosed HIV-infected individuals who are not in care, and has the potential to identify HIV earlier, lower community viral load, and decrease transmission of HIV 4.

HIV Testing Algorithms

• The use of nucleic acid amplification tests (NATs) can minimize the time from HIV infection to diagnosis, reducing transmission during acute HIV 5.
• The cobas HIV-1/HIV-2 qualitative test is a novel qualitative nucleic acid amplification test that can detect HIV-1 and HIV-2 in plasma, serum, and dried blood spot specimens, and can enable early and accurate diagnoses of HIV-1 and HIV-2 in adults and children 5.
• The performance of different HIV testing algorithms, including the use of Ag/Ab tests, Ab differentiation tests, and NATs, can vary depending on the population being tested and the specific tests used 6, 3, 5.

Considerations for HIV Diagnosis in Inpatients

• The implementation of NAT and Ag/Ab tests in PrEP/PEP programs relying on Ab-only RDTs should be balanced according to feasibility and public health impact 6.
• Blood transfusion services using Ab-only RDTs for HIV screening should adopt higher sensitivity tests, and surveillance and further research are needed to determine the need for novel HIV testing algorithms for those already using NAT and Ag/Ab screening assays 6.
• The use of routine HIV testing in the inpatient setting can help identify individuals who are not in care and provide an opportunity for linkage to care and treatment 4.