Hepatitis C Virus (HCV) RNA screening and sequencing using dry plasma spots

Area of Science:

• Virology
• Epidemiology
• Public Health

Background:

• Hepatitis C Virus (HCV) RNA screening in large sample repositories is crucial for understanding epidemic patterns and informing control policies.
• However, in resource-limited settings, traditional methods involving sample shipment and individual testing can be prohibitively expensive.

Purpose of the Study:

• To evaluate the utility of pooled and individual dried plasma spots (DPS) for detecting and sequencing HCV RNA in a large cohort of HIV-positive individuals in Kumasi, Ghana.
• To assess the cost-effectiveness and reproducibility of DPS for HCV screening in a low-prevalence population.

Main Methods:

• Dried plasma spots (DPS) were prepared from plasma samples stored at -80°C.
• A validation phase involved testing DPS with known concentrations of the 4th International Standard for HCV.
• In the testing phase, 875 HIV-positive subjects' DPS were pooled for initial screening, followed by individual testing of positive pools. HCV genotyping was performed using Sanger sequencing of core and NS5B regions.

Main Results:

• The sensitivity of HCV RNA detection using DPS was determined to be ≥2500 IU/ml, with high reproducibility (intra- and inter-assay coefficients of variation ≤1.4%).
• HCV RNA was detected in 5/875 individuals (0.57% prevalence), identified through pooled and individual DPS screening.
• Sequencing identified the detected HCV strains as genotypes 2l and 2r.

Conclusions:

• Dried plasma spots (DPS) provide a reproducible method for Hepatitis C Virus (HCV) RNA detection and sequencing.
• Pooling DPS significantly reduces the cost and labor associated with screening previously untested, low-prevalence cohorts, making it suitable for resource-limited settings.