Prevalence and risk factors of Occult Hepatitis C infections in blood donors from Mexico City

An Update on Viral Hepatitis B and C in Mexico: Advances and Pitfalls in Eradication Strategies

In Mexico, hepatitis B and C infections are a significant burden on the health system. The aim of this narrative review was to analyze the state of the art on hepatitis B and C in Mexico by searching and studying available data in academic articles and government reports and statements on epidemiology, prevention, treatment, and elimination strategies undertaken by the Mexican government. Even where the government has implemented a hepatitis B vaccination strategy to reduce its incidence, a very low proportion of people complete the vaccination schedule. Regarding hepatitis C, there is a National Elimination Program that emphasizes the importance of screening, diagnosis, and treatment focused on the population at risk. With the implementation of this program, more than a million fast tests have been carried out and the positive cases have been verified by viral load. Infected patients are tested to determine liver function, fibrosis stage, and coinfection with HBV and/or HIV. Patients without cirrhosis and/or coinfections are treated in first-level care centers, while those with cirrhosis and/or comorbidities are referred to specialists. The possibility of hepatitis C eradication in Mexico seems more likely than eradication of hepatitis B; however, major challenges remain to be overcome to reach both infections' elimination.

Occult liver disease: A multinational perspective

Occult liver disease refers to the presence of unrecognized chronic liver disease and cirrhosis. Liver disease is currently the eleventh cause of death globally, representing 4% of all deaths in the world. Alcohol consumption is the leading cause of cirrhosis globally, accounting for approximately 60% of cases. The estimated global prevalence of non-alcoholic fatty liver disease (NAFLD) is 32.4% and has been steadily increasing over the last years. Viral hepatitis B and C accounted for 1.3 million deaths in 2020. Several studies in populations at high risk of chronic liver disease (elevated liver enzymes, type 2 diabetes, excessive alcohol consumption) have found an elevated prevalence of occult liver disease. Attempts should be made to assess the prevalence of occult liver disease in Latin America, a region with one of the highest rates of metabolic diseases and excessive alcohol consumption. Screening for NAFLD in high-risk subjects and screening for excessive drinking and alcohol use disorders at every level of medical care is relevant. Efforts should also focus on the early treatment of occult liver disease to try to reduce liver disease burden and, in the case of occult viral hepatitis infection, prevent further spreading.

Occult hepatitis C infection identified in injection drug users with direct antiviral agents therapy and spontaneous resolution of hepatitis C virus infection

BACKGROUND

Occult hepatitis C infection (OCI) is characterized by the detection of hepatitis C virus (HCV) RNA in hepatocytes and in peripheral blood mononuclear cells (PBMCs) without detection in serum. We aimed to evaluate OCI in drug and no drug users who achieved sustained virological response (SVR) after therapy with direct-acting antivirals (DAAs) and with HCV spontaneous resolution.

METHODS

Twenty-four patients in the AVP group (who achieved a SVR after DAAs therapy), 13 in the NAVP group (with HCV spontaneous resolution) and 7 HCV-RNA positive patients (CPP, control positive group) were included in the study. HCV/OCI-RNA was screened in serum and PBMCs samples of the patients by ddPCR for OCI patients' identification. Plasma and red blood cells (RBCs) samples of the patients were also evaluated for HCV/OCI-RNA detection by ddPCR.

RESULTS

OCI was presented in injection drug users (IDUs) in the AVP (20.8%) and NAVP (23.1%) groups by ddPCR with a higher statistically significant percentage detected in RBCs samples of the patients in the AVP group comparatively to NAVP (p<0.01) and CPP (p < 0.05) groups.

CONCLUSION

OCI was identified in IDUs patients of the AVP and NAVP groups by ddPCR. These results suggest that OCI patients in the AVP group might not be entirely cured, and that OCI patients in the NAVP group were not identified at clinical evaluation time when just serum samples were analysed. A higher percentage of HCV/OCI-RNA was detected in RBCs samples. Overall results recommends that HCV/OCI identification in patients with DAAs therapy and spontaneous resolution of HCV infection should be studied more accurately in future and in larger patient groups if possible. Additionally, suggest also PBMCs and RBCs samples as predictors for HCV/OCI diagnosis and management.

Hepatitis C virus among blood donors in Lubumbashi, DRC: Seroprevalence and molecular characterisation

OBJECTIVES

To date, no study has been done yet on the distribution of Hepatitis C virus genotypes in Lubumbashi, Democratic Republic of Congo. The objective of this work was to determine the seroprevalence and study the distribution of hepatitis C virus (HCV) genotypes among blood donors in Lubumbashi, DRC.

METHODS

This was a cross-sectional descriptive study among blood donors. The detection of anti-HCV antibodies was carried out by rapid diagnostic test (RDT) then confirmed by Chemiluminescent immuno-assay (CLIA). Viral load was determined by Nucleic Acid Amplification test (NAT) on Panther system and genotyping by Next Generation Sequencing (NGS) on Sentosa platform.

RESULTS

The obtained seroprevalence was 4.8%. Genotypes 3a (5.0%), 4 (90.0%) and 7 (5.0%) and a few drug resistance mutations were identified in the study population. Significant disturbances of some studied biochemical parameters (HDL-cholesterol, direct bilirubin, transaminases, ALP, GGT and albumin) have been observed in positive HCV blood donors. Irregular family and volunteer donors have been found as the socio-demographic characteristics associated with hepatitis C.

CONCLUSION

With a seroprevalence of 4.8% obtained among blood donors, Lubumbashi is in an area with medium endemicity for HCV, highlighting the need to implement strategies aiming to improve transfusion safety among blood recipients in Lubumbashi. This study reports for the first time the presence of HCV strains of genotypes 3a, 4 and 7. These results might allow better therapeutic management of HCV infections and contribute to the development of the mapping of HCV genotypes in Lubumbashi and DRC as well.

[History of the 60 years of the 21th Century National Medical Center's Central Blood Bank]

The Blood Bank of the 21th Century National Medical Center is an important piece in the field of transfusion medicine at the national level. Its history shows that it has been in constant change to be able to meet the needs in an adequate and safe manner for both donors and patients. This article shows the advances that the Central Blood Bank has had since its inauguration. This bank has areas of Immunohematology, Donors Assistance, Serology, Fractionation and Storage Studies. These areas have been improving constantly and areas dedicated to molecular biology have been implemented, which makes the bank remain a reference center at the national level. The bank has qualified personnel who have also been involved in teaching courses for personnel from other units of the Instituto Mexicano del Seguro Social (Mexican Institute for Social Security), as well as in disseminating research studies carried out within the bank. The Blood Bank of the 21th Century National Medical Center is a pillar in transfusion medicine care at the national level and it is a reference center for specialized studies.

Global prevalence of occult hepatitis C virus: A systematic review and meta-analysis

BACKGROUND

Occult hepatitis C infection (OCI) is characterized by the presence of hepatitis C virus (HCV) RNA in the liver, peripheral blood mononuclear cells (PBMC) and/or ultracentrifuged serum in the absence of detectable HCV-RNA in serum. OCI has been described in several categories of populations including hemodialysis patients, patients with a sustained virological response, immunocompromised individuals, patients with abnormal hepatic function, and apparently healthy subjects.

AIM

To highlight the global prevalence of OCI.

METHODS

We performed a systematic and comprehensive literature search in the following 4 electronic databases PubMed, EMBASE, Global Index Medicus, and Web of Science up to 6th May 2021 to retrieve relevant studies published in the field. Included studies were unrestricted population categories with known RNA status in serum, PBMC, liver tissue and/or ultracentrifuged serum. Data were extracted independently by each author and the Hoy et al tool was used to assess the quality of the included studies. We used the random-effect meta-analysis model to estimate the proportions of OCI and their 95% confidence intervals (95%CI). The Cochran's Q-test and the I² test statistics were used to assess heterogeneity between studies. Funnel plot and Egger test were used to examine publication bias. R software version 4.1.0 was used for all analyses.

RESULTS

The electronic search resulted in 3950 articles. We obtained 102 prevalence data from 85 included studies. The pooled prevalence of seronegative OCI was estimated to be 9.61% (95%CI: 6.84-12.73) with substantial heterogeneity [I² = 94.7% (95%CI: 93.8%-95.4%), P < 0.0001]. Seropositive OCI prevalence was estimated to be 13.39% (95%CI: 7.85-19.99) with substantial heterogeneity [I² = 93.0% (90.8%-94.7%)]. Higher seronegative OCI prevalence was found in Southern Europe and Northern Africa, and in patients with abnormal liver function, hematological disorders, and kidney diseases. Higher seropositive OCI prevalence was found in Southern Europe, Northern America, and Northern Africa.

CONCLUSION

In conclusion, in the present study, it appears that the burden of OCI is high and variable across the different regions and population categories. Further studies on OCI are needed to assess the transmissibility, clinical significance, long-term outcome, and need for treatment.

Occult Infection with Hepatitis C Virus: Looking for Clear-Cut Boundaries and Methodological Consensus

The sustained virologic response and elimination of HCV is widely viewed as a true cure of chronic hepatitis C as it associates with amelioration of histological liver damage and improved clinical outcomes. Therefore, the existence and clinical burden of occult HCV infection (OCI) has been a controversial issue for many years. In this review, we summarize recently published data that adds new information on the molecular and clinical background of OCI and its epidemiological significance. We also identify and discuss the most important methodological pitfalls, which can be a source of inconsistency between studies. Data that have accumulated so far, strongly support the existence of extrahepatic HCV replication in individuals negative for serum HCV-RNA by conventional clinical tests. OCI emerges as a condition where the immune system is unable to fully resolve infection but it is continuously stimulated by low levels of HCV antigens, leading to progression of liver pathology and extrahepatic HCV-related complications. Moreover, the development of monitoring strategies or management guidelines for OCI is still hampered by the lack of clear definition and the confusion regarding its clinical significance. Careful study design and the introduction of uniform protocols for the detection of low-level HCV-RNA are crucial for obtaining reliable data on OCI.

A comprehensive update of the status of hepatitis C virus (HCV) infection in Mexico-A systematic review and meta-analysis (2008-2019)

INTRODUCTION AND OBJECTIVES

HCV infection is targeted by the WHO's Global Health Sector Strategy on Viral Hepatitis to be reduced notably by 2030. However, renovated epidemiological data is needed to line up with such goals. Herein, we provide an updated review of incidence, prevalence, genotypes (GTs), and risk factors (RFs) of HCV infection in Mexico to build elimination strategies.

MATERIAL AND METHODS

HCV incidence was charted using the cumulative new cases/year at week 52. Prevalence, GTs, and RFs data from low-risk (LR-G) and high-risk (HR-Gs) groups were searched in PubMed/MEDLINE/Medigraphic/Scielo databases from January 2008 to December 2019 as per PRISMA guidelines. Weighted mean prevalence (WMP) was estimated; GTs and RFs were registered.

RESULTS

In this study, 25,247 new cases were reported. Ten states accumulated 76.32% of HCV incidence that peaked in men at 50-59 years and women at 60-64 years. Thirty-four studies revealed a WMP between 0.774%-2.5% in LR-Gs and 11.8%-39.6% in HR-Gs that included mainly prison inmates, drug users, and dialyzed patients. GT1 and GT2 were predominant; GT3a emerged. Subtypes 1a and 1b circulate differentially, whereas novel GT2 subtypes appeared. Unsafe blood transfusion was infrequent in younger groups, but parenteral/intravenous transmission through drug-related risk behaviors has arisen.

CONCLUSIONS

HCV transmission increased notably among LR-Gs and HR-Gs in Mexico. Novel genotypes/subtypes emerged as well as risky behavioral routes of transmission. A national elimination strategy will require pro-active screening in designated risk groups, research in molecular epidemiology, medical training, robust epidemiological databases, and antiviral treatment available to all eligible HCV-infected patients.

Understanding occult hepatitis C infection

BACKGROUND

Occult hepatitis C infection (OCI) is a type of hepatitis C virus (HCV) infection, defined as the presence of HCV RNA in hepatocytes or peripheral blood mononuclear cells (PBMCs) and the absence of HCV RNA in serum.

STUDY DESIGN AND METHODS

A literature review was conducted to identify articles that characterized OCI as a disease, including its epidemiology, mode of transmission, pattern of infection, progression, and treatment.

RESULTS

OCI patients experience a milder degree of inflammatory and cirrhotic changes than patients with chronic hepatitis C. OCI is transmissible parenterally both in vivo and in vitro, however the duration and outcome of OCI remains unclear. OCI is most consistently found in patients with previous hepatitis C disease and hemodialysis patients. Beyond the at-risk populations, OCI has also been demonstrated among healthy individuals and blood donors.

CONCLUSIONS

This review summarises our current understanding of OCI and suggests areas for further research to improve our understanding of this phenomenon, including a better understanding of its epidemiology and full clinical course. The current understanding of OCI and its clinical implications remain limited. Further standardized detection methods, ongoing surveillance, and investigation of its potential transmissions are required.