Validation of a Point-Of-Care Ultrasound for Hepatitis Among Front-Line Healthcare Workers Managing Chronic Hepatitis B Virus Infection in Zambia

Abstract

To close gaps in implementing care of people with hepatitis B virus (HBV) infection in resource-limited settings, we evaluated the accuracy of a novel liver point-of-care ultrasound (POCUS) protocol for hepatitis (PUSH) among front-line non-radiology healthcare workers in Zambia. At University Teaching Hospital in Lusaka, Zambia, from March to June 2024, we trained four nurses and six physicians with experience in HBV management, but not in ultrasound (US), in the PUSH protocol, which includes visualizing the liver in three windows (epigastric, subcostal and right transcostal) to identify cirrhosis-suggestive features and liver lesions suspicious for hepatocellular carcinoma (HCC). Then, consecutive adult participants with chronic hepatitis B (PWHB) alone or HBV/HIV coinfection underwent PUSH with operators blinded to clinical data. We evaluated the accuracy of PUSH for significant fibrosis and cirrhosis using transient elastography (TE) as the reference standard test (RST) and for liver lesions that were possible HCC using a comprehensive abdominal ultrasound by an experienced radiographer as the RST. Nonparametric analysis of the receiver operating curve (ROC) for PUSH was adjusted for operator type (doctor vs. nurse), sex and HIV status. Among 197 PWHBs analysed, 69.5% were taking HBV antivirals and 27.9% had HBV/HIV. According to RSTs, 17.7% of PWHBs had significant fibrosis, 11.6% had cirrhosis and 3.5% had liver lesions. PUSH had low accuracy for significant fibrosis, with sensitivity of 8.3% (17.5–41.4), specificity of 100.0% (96.1–100) and an area under the curve (AUROC) of 0.54 (0.43–0.65), moderate accuracy for cirrhosis, with sensitivity of 60.9% (38.5–80.3), specificity of 97.7% (94.2–99.4) and AUROC of 0.79 (0.69–0.89), and higher accuracy for liver lesions, with 85.7% (42.1–99.6) sensitivity, 98.4% (95.5–99.7) specificity, AUROC of 0.92 (0.78–1.00). After an expedited training, front-line nurses and physicians treating HBV in Zambia were able to use PUSH to diagnose cirrhosis with moderate accuracy and liver lesions with high accuracy, although confidence intervals around performance estimates were wide. Liver POCUS including PUSH may be useful in HBV management when laboratory systems and TE are lacking.