Rationale: Point-of-care ultrasound (POCUS) is increasingly used by various specialists in the Netherlands, but its role in managing patients with HIV is unclear. In settings endemic for tuberculosis, Fast Assessment with Sonography for HIV/Tuberculosis (FASH) has proven its value to detect extrapulmonary tuberculosis in patients with HIV. However, there is no data to support POCUS for patients with HIV in resource affluent settings.

Objective: The investigators aim to determine the feasibility and diagnostic value of POCUS in detecting opportunistic disease in HIV patients with advanced disease stages in the Netherlands.

Study design: The investigators will perform a prospective observational pilot study.

Study population: The investigators will include new adult patients with HIV presenting with a cluster of differentiation 4 (CD4) T-cell count below 350 cells/mm3, and all adult HIV patients requiring admission to hospital. Intervention (if applicable): The investigators will perform a focused ultrasound examination including FASH, and ultrasound of the lung, liver and kidneys. In case of positive findings additional examinations will be undertaken to determine the underlying pathology and/or treatment started as indicated. In case of negative findings, patients will be followed for 12 months to observe for (possibly missed) opportunistic infections.

Main study parameters/endpoints: Our primary outcomes include acceptability of POCUS by patients, interobserver variation in interpretation of POCUS images, and number of diagnosed AIDS and non-AIDS related problems. Secondary outcomes include sensitivity and specificity, negative predictive value and positive predictive value of our POCUS protocol. In addition, incidence rates of opportunistic infections will be compared to a historical matched control group.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The ultrasound examination is painless and without risk to the participants. It will take approximately 30 minutes and will be combined with routine visits to the hospital. Benefits include potential earlier detection of opportunistic disease, while adverse effects may arise from false positive findings requiring further examinations which may cause stress or anxiety. The rate of false positive findings in POCUS has not been formally investigated, but appears low. The effect of POCUS in advanced HIV/AIDS can only be studied in HIV patients.

Inclusion Criteria:

• new patients with HIV presenting with a CD4 T-cell count below 350 cells/mm3
• patients with HIV who are admitted to hospital

Exclusion Criteria:

- absence of informed consent