Related Experiment Video
Updated: May 26, 2025
Dried Blood Spots - Preparing and Processing for Use in Immunoassays and in Molecular Techniques
Published on: March 13, 2015
Dried blood spot as alternative specimen for molecular epidemiology studies among HCV/HIV coinfected patients
Geane Flores1, Barbara Vieira Lago2, Amanda R Caetano1
1Instituto Oswaldo Cruz (Fiocruz), Laboratório de Hepatites Virais, Rio de Janeiro, RJ, Brazil.
Insights
Dried Blood on Spot (DBS) samples are effective for tracking Hepatitis C Virus (HCV) genetic diversity in co-infected individuals. This method aids viral genomic surveillance in vulnerable populations, improving access to diagnosis and treatment.
Area of Science:
- Virology
- Public Health
- Molecular Epidemiology
Background:
- Hepatitis C Virus (HCV) and Human Immunodeficiency Virus (HIV) share transmission routes, complicating viral hepatitis elimination efforts.
- An estimated 2.3 million individuals globally live with HIV/HCV co-infection, often in resource-limited settings.
- Dried Blood on Spot (DBS) sampling offers a viable alternative for diagnosis and treatment access in these populations.
Purpose of the Study:
- To evaluate the genetic variability of HCV in individuals co-infected with HIV.
- To correlate findings from paired serum and DBS samples for HCV molecular tracking.
- To assess the utility of DBS in genomic surveillance of HCV in vulnerable populations.
Main Methods:
- Phylogenetic analysis of HCV NS5B gene sequences from paired serum and DBS samples.
- RT-PCR amplification and sequencing of HCV RNA from 14 HIV/HCV co-infected individuals in Rio de Janeiro, Brazil.
- Comparison of HCV genotype distribution and resistance-associated mutations between sample types.
Main Results:
- High concordance was observed between serum and DBS samples for HCV genetic characterization (genetic distance: 0.0 to 0.16).
- The predominant HCV genotypes/subgenotypes identified were 1a, 1b, 3a, and 4d.
- The 316 N Resistance Associated Mutation (RAS) was detected in both sample types in three individuals.
Conclusions:
- Dried Blood on Spot (DBS) is applicable for molecular tracking of HCV in HIV/HCV co-infected patients.
- DBS facilitates viral genomic surveillance in key and vulnerable populations.
- This approach enhances accessibility for HCV diagnosis and treatment monitoring.
Background:
Immunodeficiency Virus (HIV) and Hepatitis C Virus (HCV) share the same routes of transmission, therefore, co-infection by both viruses represents a challenge to the goal of eliminating viral hepatitis as a public health threat. There are an estimated 2.3 million people living with HIV/HCV worldwide. Most of these cases affect vulnerable populations located in places with low infrastructure. Because of this, the use of alternative samples such as Dried Blood on Spot (DBS) would facilitate access to diagnosis and HCV treatment. The aim of this study is to evaluate the HCV genetic variability in HIV/HCV individuals by correlating paired serum and DBS samples.
Methods:
A total of 14 HIV/HCV individuals, recruited from reference outpatient clinics in the city of Rio de Janeiro/Brazil, were included. From them, 64 % were man, mean of age 54±7. HCV RNA from both serum and DBS samples was RT-PCR amplified and sequenced with HCV NS5B-specific oligonucleotides. All positive samples were submitted to phylogenetic analysis.
Results:
Serum mean HCV load was 6.2 ± 0.5 log IU/mL. All patients presented undetectable HIV RNA. The distribution of HCV genotypes/subgenotypes was 1a (4/14); 1b (5/14); 3a (4/14); and 4d (1/14). Most paired serum and DBS samples showed concordant results (genetic distance: 0.0 to 0.16). One individual showed discordance in the subtypes between serum and DBS. Three individuals presented the 316 N Resistance Associated Mutation (RAS) in both serum and DBS.
Conclusion:
Our results demonstrate the applicability of DBS for HCV molecular tracking in HIV/HCV coinfected patients for viral genomic surveillance in key and vulnerable populations.
