Analysis of Hepatitis C Virus Genotypes Among US Blood Donors From 2003 to 2018

Results of a retrospective assessment found that individuals in the US who voluntarily donated blood were at decreased risk for hepatitis C virus (HCV) infection. These findings were published in Clinical Infectious Diseases.

This study, from the American Red Cross (ARC), retrospectively reviewed whole blood or apheresis ARC donations from individuals aged 16 years and older between 2003 and 2018. All samples (N=89,235,851) underwent HCV nucleic acid test-yield surveillance. In addition, the researchers assessed demographic and geographic trends among individual donors who were positive for HCV infection.

Among a total of 89.2 million blood donations, 85% were from repeat donors, 53.4% were from men (53.4%), 84.3% were from individuals who identified as White, and 60.3% were from those aged 40 years and older.

During the study period, donations decreased annually by 1.9%.

A total of 343 HCV infections were detected (incidence rate [IR], 0.38 per 100,000 donations; 95% CI, 0.35-0.43). Between 2003 and 2004, the IR of infected samples per 100,000 donations was 0.40, which subsequently decreased by 40% to 0.24 between 2017 and 2018 (P =.010). However, the IR of infected samples decreased by 27.5% between 2003 and 2008, increased by 54.1% between 2009 and 2014 (P =.014), and decreased by 31.4% between 2015 and 2018 (P =.002).

The researchers found that HCV infection was statistically significantly more common among individuals who were younger (age range, 20-29; odds ratio [OR], 3.60; 95% CI, 2.88-4.48), those with an unknown race or ethnicity (OR, 3.43; 95% CI, 2.55-4.61), and those who were first-time donors (OR, 3.89; 95% CI, 3.14-4.82).

Further analysis showed that the odds for HCV positivity among individuals who donated blood in the US was most increased among those in the South (OR, 2.81), followed by those in the Northeast (OR, 2.56), Midwest (OR, 1.70), and West (OR, 1.00). After stratification by US state, results showed that half of all confirmed HCV infections were among individuals who resided in Alabama, Indiana, Missouri, New York, North Carolina, Ohio, Pennsylvania, and Tennessee.

Among the 334 genotyped samples, 61.5% were HCV genotype 1, 18.9% were genotype 2, 15.5% were genotype 2, 0.9% were genotype 4, and 0.3% were genotype 6. Of note, a mixed genotypic HCV infection was observed in 1 individual. In addition, HCV genotypes 1 and 2 were more common among women (c², 5.96; P =.015).

Among the 316 subgenotyped samples, subgenotype 1a was the most common (49.6%), followed by 3a (18.7%), 2b (12.5%), 1b (8.5%), and 2a (1.7%). An overall positive percentage change was observed for only subgenotype 1a (12.2%).

This study was limited as the researchers did not evaluate potential risk factors associated with HCV infection.

In regard to individuals who donate blood, those who “engage in potentially risky behaviors, particularly at multiple frequencies, are at increased risk [for] exposure to HCV [infection],” the researchers noted.

Disclosure: One author declared affiliations with industry. Please see the original reference for a full list of disclosures.

Reference

Groves J, Dodd RY, Foster GA, Stramer SL. Genotype distribution and demographic characteristics of hepatitis C virus NAT yield cases among US blood donors. Clin Infect Dis. 2022;ciac274. doi:10.1093/cid/ciac274