Hepatitis B virus (HBV) is a challenge for global health services, affecting millions and leading thousands to end-stage liver disease each year. This comprehensive review explores the interactions between HBV and the host, examining their impact on clinical outcomes. HBV infection encompasses a spectrum of severity, ranging from acute hepatitis B to chronic hepatitis B, which can potentially progress to cirrhosis and hepatocellular carcinoma (HCC). Occult hepatitis B infection (OBI), characterized by low HBV DNA levels in hepatitis B surface antigen-negative individuals, can reactivate and cause acute hepatitis B. HBV genotyping has revealed unique geographical patterns and relationships with clinical outcomes. Moreover, single nucleotide polymorphisms (SNPs) within the human host genome have been linked to several clinical outcomes, including cirrhosis, HCC, OBI, hepatitis B reactivation, and spontaneous clearance. The immune response plays a key role in controlling HBV infection by eliminating infected cells and neutralizing HBV in the bloodstream. Furthermore, HBV can modulate host metabolic pathways involved in glucose and lipid metabolism and bile acid absorption, influencing disease progression. HBV clinical outcomes correlate with three levels of viral adaptation. In conclusion, the clinical outcomes of HBV infection could result from complex immune and metabolic interactions between the host and HBV. These outcomes can vary among populations and are influenced by HBV genotypes, host genetics, environmental factors, and lifestyle. Understanding the degrees of HBV adaptation is essential for developing region-specific control and prevention measures.

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. 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. 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. 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.

Viral hepatitis is a global health problem with unequal distribution of disease burden in which low-income people are at higher risk for acquisition and underlying liver diseases. This study aimed to seek the prevalence of hepatitis B and C viruses, HIV, and liver damage among low-income patients attending a public tertiary care hospital in West Mexico. A retrospective/cross-sectional study at the Department of Genomic Medicine in Hepatology was conducted between March 1, 2016 to March 30, 2017. A total of 10,352 patients tested for anti-HCV, HBsAg, or anti-HIV (n=23,074) were included. Age, gender, and hospital service were registered. Liver fibrosis was assessed using APRI and FIB-4 scores. Overall, 3.9% were anti-HCV+ (305/7848), 1.0% were HBsAg+ (80/7894), and 2.9% were anti-HIV+ (210/7332). A 43.8% (750/1959) of patients negative for all viruses had either abnormal AST, ALT, or GGT (≥40 UI/L). Also, significant liver fibrosis (APRI ≥ 0.7) was prevalent in 10.6% (191/1804). In patients who tested positive for viral infections, liver fibrosis was detected in 20.4% (11/54) of HBsAg+, 34.2% (53/155) in anti-HCV+ and 15.5% (16/103) in anti-HIV+. Anti-HCV+ was highest in Geriatrics (11.1%), HBsAg+ in HIV patients (3.0%) and anti-HIV+ in Emergency room attendees (33.3%). High seroprevalence of HCV, HBV, and HIV infections was found among the studied population. Significant liver fibrosis was detected in negative and positive patients for viral infections. Medical services need to continuously test for viral infections, promote early detection of chronic liver damage and identify target patients for elimination strategies to decrease disease burden.

The complex epidemiology of hepatitis C virus (HCV) infection among human immunodeficiency virus (HIV) patients in West Mexico remains poorly understood. Thus, this study aimed to investigate the HCV prevalence, HCV-associated risk factors, and HCV genotypes/subtypes and assess their impacts on liver fibrosis in 294 HIV patients (median age: 38 years; 88.1% male). HCV RNA was extracted and amplified by PCR. Hepatic fibrosis was assessed using three noninvasive methods: transient elastography (TE), the aspartate aminotransferase (AST)-to-platelets ratio index score (APRI), and the fibrosis-4 score (FIB4). Patients with liver stiffness of ≥9.3 Kpa were considered to have advanced liver fibrosis. HCV genotypes/subtypes were determined by line probe assay (LiPA) or Sanger sequencing. The prevalence of HIV/HCV infection was 36.4% and was associated with injection drug use (odds ratio (OR) = 13.2; 95% confidence interval (CI) = 5.9–33.6; p < 0.001), imprisonment (OR = 3.0; 95% CI = 1.7–5.4; p < 0.001), the onset of sexual life (OR = 2.6; 95% CI = 1.5–4.5; p < 0.001), blood transfusion (OR = 2.5; 95% CI = 1.5–4.2; p = 0.001), tattooing (OR = 2.4; 95% CI = 1.4–3.9; p = 0.001), being a sex worker (OR = 2.3; 95% CI = 1.0–5.4; p = 0.046), and surgery (OR = 1.7; 95% CI = 1.0–2.7; p = 0.042). The HCV subtype distribution was 68.2% for 1a, 15.2% for 3a, 10.6% for 1b, 3.0% for 2b, 1.5% for 2a, and 1.5% for 4a. The advanced liver fibrosis prevalence was highest in patients with HIV/HCV co-infection (47.7%), especially in those with HCV subtype 1a. CD4+ counts, albumin, direct bilirubin, and indirect bilirubin were associated with liver fibrosis. In conclusion, HCV infection had a significant impact on the liver health of Mexican HIV patients, highlighting the need for targeted preventive strategies in this population.

In 2016 WHO member states endorsed the 69th World Health Assembly's Global Health Sector Strategies (GHSS) towards eliminating Hepatitis B (HBV) infections by 2030. Substantial progress has been made in Mexico regarding HBV vaccination, blood safety and health-care setting injection safety but minor progress has been identified regarding timely HBV birth-dose coverage, access to diagnostic testing and treatment. Most importantly, Mexico's lack of a national plan for the fight against viral hepatitis was identified as a major obstacle for the development and implementation of actions and procuring funding. Insight of these deficiencies, we propose six actions that are in line with GHSS strategic directions to better allow Mexico to reach the goal of eliminating viral hepatitis by 2030. 1) the creation of a National Viral Hepatitis Task Group capable of providing direction, recommendations as well as innovative solutions in the fight against viral hepatitis in Mexico; 2) the drafting of a National Plan for viral hepatitis; 3) establishing a national viral hepatitis information database; 4) development of Clinical Practice Guidelines; 5) appeal for governmental responsibility and accountability; 6) promote basic, applied science projects as well as clinical research to determine the viral, epidemiological, genomic, ethnic and cultural peculiarities of viral hepatitis infections in Mexico. These basic actions will better equip Mexico to meet GHSS targets, lead to high-impact health interventions and ultimately enhance the cascade of care, from diagnosis to chronic care. Political commitment is a requirement to the implementation of these actions but civil society involvement is also seen to be crucial.

The Hepatitis C Virus (HCV), with its diverse genotypes and subtypes, has significantly impacted the health of millions of people worldwide. Analyzing the risk factors is essential to understanding the spread of the disease and developing appropriate prevention strategies. This study aimed to identify risk factors associated with HCV subtype transmission and calculate the emergence time of subtype 1a in Mexico. A cross-sectional study was conducted from January 2014 to December 2018, involving 260 HCV-infected adults. HCV infection was confirmed via Enzyme-Linked Immunosorbent Assay, and viral load was measured by real-time PCR. Genotyping/subtyping tools were the Line Probe Assay and Sanger sequencing of the non-structural region 5B (NS5B). The most frequent HCV subtype was 1a (58.5%), followed by subtypes 1b (19.2%), 3a (13.1%), 2b (5.4%), 2a/2c (2.7%), 2a (0.8%), and 4a (0.4%). Intravenous drug use and tattoos were significant risk factors for subtypes 1a and 3a, while hemodialysis and blood transfusion were linked with subtype 1b. For the evolutionary analysis, 73 high-quality DNA sequences of the HCV subtype 1a NS5B region were used, employing a Bayesian coalescent analysis approach. This analysis suggested that subtype 1a was introduced to Mexico in 1976, followed by a diversification event in the mid-1980s. An exponential increase in cases was observed from 1998 to 2006, stabilizing by 2014. In conclusion, this study found that HCV subtypes follow distinct transmission routes, emphasizing the need for targeted prevention strategies. Additionally, the findings provide valuable insights into the origin of HCV subtype 1a. By analyzing the history, risk factors, and dynamics of the HCV epidemic, we have identified these measures: limiting the harm of intravenous drug trafficking, enhancing medical training and infrastructure, and ensuring universal access to antiviral treatments. The successful implementation of these strategies could lead to an HCV-free future in Mexico.