The hepatitis B virus (HBV), comprising of ten genotypes (A-J), has been a silent threat against humanity, constituting a public health problem worldwide. In 2016, the World Health Organization set forth an impressive initiative for the global elimination of viral hepatitis by 2030. As the target date approaches, many nations, particularly in the Latin American region, face challenges in designing and implementing their respective elimination plan. This review aimed to portray the state of knowledge about the epidemiological, molecular, and clinical characteristics of HBV genotype H (HBV/H), endemic to Mexico. PubMed, Scopus, Web of Science, and Google Scholar were searched to compile scientific literature over 50 years (1970-2022). A total of 91 articles were organized into thematic categories, addressing essential aspects such as epidemiological data, risk factors, HBV genotype distribution, HBV mixed infections, clinical characteristics, and vaccination. The prevalence and its associated 95% confidence interval (95% CI) were estimated using the Metafor package in R programming language (version 4.1.2). We provide insights into the strengths and weaknesses in diagnostics and prevention measures that explain the current epidemiological profile of HBV/H. Training, research, and awareness actions are required to control HBV infections in Mexico. These actions should contribute to creating more specific clinical practice guides according to the region's characteristics. Mexico's elimination plan for HBV will require teamwork among the government health administration, researchers, physicians, specialists, and civil society advocates to overcome this task jointly.

Chronic hepatitis B (HBV) prevalence is highest in foreign-born Asian and African individuals in the US, though Hispanics make up the largest proportion of the immigrant population. Differences in the diagnosis and management of chronic HBV in Hispanics might exist due to the lower awareness of risk. We aim to examine racial/ethnic disparities in the diagnosis, presentation, and immediate management of chronic HBV in a diverse safety net system enriched for Hispanics.

In a large urban safety-net hospital system, we retrospectively identified patients with chronic HBV by serological data and categorized them into mutually exclusive self-identified racial/ethnic groups: Hispanics, Asians, Blacks, and Whites. We then examined differences in screening, disease phenotype and severity, follow-up testing, and referral by race/ethnicity.

Among 1063 patients, 302 (28%) were Hispanics, 569 (54%) Asians, 161 (15%) Blacks, and 31 (3%) Whites. More Hispanics (30%) were screened in the acute setting (defined as inpatient or emergency department encounters) than Asians (13%), Blacks (17%), or Whites (23%) (p<0.01). Hispanics also had lower rates of follow-up testing after HBV diagnosis than Asians including HBeAg status (43% vs. 60%, p<0.01) and HBV DNA levels (42% vs. 58%, p<0.01) and lower rates of linkage to specialty care (32% vs. 55%, p<0.01). Among those with available testing, however, the presence of immune-active chronic HBV was infrequent and similar across racial/ethnic groups. 25% of Hispanics had cirrhosis at initial presentation, proportionally higher than other groups (p<0.01).

Our results underscore the importance of raising chronic HBV awareness and increasing both screening and linkage to care among Hispanic immigrants in addition to the existing risk groups, with the goal of mitigating downstream liver-related complications.

The emergence of SARS-CoV-2, which causes the coronavirus disease (COVID-19) has caused a great impact on healthcare systems worldwide, including hepatitis B and C viruses screening and elimination programs. The high number of COVID-19 hospitalizations represent a great opportunity to screen patients for hepatitis B virus (HBV) and hepatitis C virus (HCV), which was the aim of this study.

Cross-sectional, retrospective study performed between April 2020 and 20201 at a referral center in Mexico dedicated to the care of adults with severe/critical COVID-19. We retrieved clinical, demographic, and laboratory results from each patient´s medical records, including antibodies against HCV (anti-HCV), HBV surface antigen (HBsAg), antibodies against the HBV core antigen (anti-HBcAg), and antibodies against HBsAg (anti-HBsAg).

Out of 3620 patients that were admitted to the hospital, 24 (0.66%), 4 (0.11%), and 72 (1.99%) tested positive for anti-HCV, HBsAg, and anti-HBcAg, respectively. Of all seronegative patients, 954 (27%) had undetectable anti-HBsAg and 401 (12%) had anti-HBsAg at protective levels. Blood transfusion was the most relevant risk factor. Only 9.7% of the anti-HBc positive, 25% of the HBsAg positive, and 52% of the anti-HCV positive were aware of their serological status.

In this study we found a prevalence of anti-HCV of 0.66%, HBsAg in 0.11%, and isolated anti-HBcAg in 1.99%. We also found that HBV vaccination coverage has been suboptimal and needs to be reinforced. This study gave us a trustworthy insight of the actual seroprevalence in Mexico, which can help provide feedback to the Hepatitis National Elimination Plan.

The latest studies on the epidemiology of diverse types of cancers have located in the scene the relevance of liver tumors, particularly hepatocellular carcinoma (HCC). HCC is a life-threatening malignancy triggered by chronic exposure to hepatitis B and C viruses, excessive alcohol intake, hepatic lipid droplet accumulation, and aflatoxins that lead to persistent liver damage. The occurrence of such etiological risk factors deeply marks the variability in the incidence of HCC worldwide reflected by geography, ethnicity, age, and lifestyle factors influenced by cultural aspects. New perspectives on the primary risk factors and their potential gene-environment interactions (GxE) have been well-addressed in some cancers; however, it continues to be a partially characterized issue in liver malignancies. In this review, the epidemiology of the risk factors for HCC are described enhancing the GxE interactions identified in Mexico, which could mark the risk of this liver malignancy among the population and the measures needed to revert them. Updated healthcare policies focusing on preventive care should be tailored based on the genetic and environmental risk factors, which may influence the effect of the etiological agents of HCC. Robust regional investigations related to epidemiological, clinical, and basic studies are warranted to understand this health problem complying with the rules of ethnic, genetic, environmental, and social diversity.

Hepatitis B virus (HBV) infection can lead to cirrhosis, hepatocellular carcinoma, and death if untreated. In Mexico, HBV vaccination for all children and adolescents was implemented in 1999. In 2000 the estimated HBV was 0.21% in the population aged 20 years and older. We estimated the national prevalence for hepatitis B surface antigen (HBsAg) and its association with sociodemographic characteristics, including sexual behavior information for those aged 20 to 49 years.

From the 2018 National Health and Nutrition Survey, blood samples were collected from a subsample of 2,280 adults to determine HBsAg. We estimated the national prevalence for HBsAg and evaluated its association with sociodemographic characteristics, adding sexual behavior information for those aged 20 to 49 years. We performed a multiple logistic regression to estimate the association of HBsAg and relevant variables.

The 2018 estimated prevalence of HBsAg in the Mexican adult population was 0.51% (95%CI 0.19, 2.33), which represents 411,000 cases. This prevalence was higher than previously estimated and it was higher in women than in men (0.54% versus 0.46%, respectively). We did not find an association between HBsAg and sociodemographic characteristics or sexual behaviors.

Vaccination and screening strategies towards the elimination of viral hepatitis should be reinforced to further reduce the prevalence over the next years.

Hepatitis B virus (HBV) infection continues to be a worldwide public health problem. In Mexico, at least three million adults are estimated to have acquired hepatitis B (total hepatitis B core antibody [anti-HBc]-positive), and of those, 300,000 active carriers (hepatitis B surface antigen [HBsAg]-positive) could require treatment. Because HBV is preventable through vaccination, its universal application should be emphasized. HBV infection is a major risk factor for developing hepatocellular carcinoma. Semi-annual liver ultrasound and serum alpha-fetoprotein testing favor early detection of that cancer and should be carried out in all patients with chronic HBV infection, regardless of the presence of advanced fibrosis or cirrhosis. Currently, nucleoside/nucleotide analogues that have a high barrier to resistance are the first-line therapies.

Hepatitis B virus (HBV) infection continues to be a worldwide public health problem. In Mexico, at least three million adults are estimated to have acquired hepatitis B (total hepatitis B core antibody [anti-HBc]-positive), and of those, 300,000 active carriers (hepatitis B surface antigen [HBsAg]-positive) could require treatment. Because HBV is preventable through vaccination, its universal application should be emphasized. HBV infection is a major risk factor for developing hepatocellular carcinoma. Semi-annual liver ultrasound and serum alpha-fetoprotein testing favor early detection of that cancer and should be carried out in all patients with chronic HBV infection, regardless of the presence of advanced fibrosis or cirrhosis. Currently, nucleoside/nucleotide analogues that have a high barrier to resistance are the first-line therapies.

To identify blood donors with occult hepatitis B infections (OBIs), determine the prevalence of antibody to hepatitis B core antigen (anti-HBc) positivity and estimate the impact of anti-HBc screening on donor deferral at CETS-Veracruz (Mexico).

Hepatitis B virus infection is a major concern in transfusion medicine. Mexican regulations only mandate screening for hepatitis B surface antigen (HBsAg), and there are no requirements regarding testing for anti-HBc or use of a nucleic acid test (NAT). There is, therefore, limited information about the prevalence of anti-HBc positivity and occult hepatitis B among blood donors in Mexico.

This retrospective study examined individuals who donated blood to CETS-Veracruz from June 2014 to June 2017. All donors were serologically examined according to Mexican health regulations, and the prevalence of anti-HBc positivity was determined. A NAT was used to identify individuals with OBIs.

We analysed the data of 28 016 blood donors. Over 4 years, the average prevalence of anti-HBc positivity was 1.05%. The risk factors for anti-HBc positivity were low education and age over 50 years. There were nine donors with OBIs.

The presence of donors with OBIs in CETS-Veracruz and other Mexican blood banks highlights the need to mandate the implementation of anti-HBc screening in Mexico.

There are few data regarding the clinical and serologic features of chronic hepatitis B (CHB) infection among Hispanics in the United States. The aims of this study were to compare and contrast clinical characteristics of Hispanic and Asian CHB patients.

Demographic, clinical, and laboratory data were collected from Hispanic and Asian CHB patients seen between January 2013 and May 2014 at Los Angeles County Hepatitis Clinic.

A total of 55 Hispanic and 342 Asian CHB patients were identified. Almost all were foreign-born. Compared with Asians, Hispanics were more likely to report heterosexual transmission (P<0.0001) and blood transfusion history (P<0.0001) as risk factors. Overall, 31% of Hispanics had HBV>2000 IU/mL compared with 54% of Asians (P=0.004).Significantly more Asian HBeAg-negative/anti-HBe-positive CHB patients had high HBV DNA levels (>2000 IU/mL) with elevated ALT compared with Hispanic patients (P=0.04). Compared with Asians, Hispanic CHB patients were more likely to have elevated ALT and low HBV DNA levels (P=0.001). Among CHB patients who received antiviral therapy, response was comparable among Hispanics and Asians. There were no Hispanic CHB patients who experienced spontaneous reactivation or developed hepatocellular carcinoma.

There were important differences in the clinical, demographic, and serologic characteristics between Hispanic and Asian CHB. Response rate to antiviral therapy was comparable. Further studies of Hispanic CHB patients in the United States are warranted.

The hepatitis B virus (HBV) causes chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. Surface antigen (HBsAg) detection is a definitive test that can confirm HBV infection, while the presence of antibodies against the core protein (anti-HBc) suggests either a previous or ongoing infection or occult hepatitis B infection (OBI).

The aim of the present study was to determine the prevalence of anti-HBc and HBsAg in blood donors. Further, the study aimed to estimate the anti-HBc level at which HBV DNA is detected in putative OBI cases, as well as to search for mutations in the "a" determinant associated with the non-detection of HBsAg in serum.

We conducted a cross-sectional study from 2003-2009. The study included 120,552 blood donors from the state of Puebla, Mexico. Different commercial systems based on microparticles (enzymatic (MEIA) or chemiluminescent (CMIA)) were used to determine the HBsAg and anti-HBc levels. For the detection of HBV DNA, a nested polymerase chain reaction (nested PCR) was used and the genotypes were determined using Sanger sequencing.

Of the 120,552 blood donors, 1437 (1.19%, 95% CI: 1.12 - 1.26) were reactive to anti-HBc, while 82 (0.066%, 95% CI: 0.053 - 0.079) were reactive to HBsAg. Some 156 plasma samples collected in 2009 from anti-HBc-positive/HBsAg-negative blood donors were submitted for HBV DNA detection in a search for probable OBI. Viral DNA was detected in 27/156 (17.3%, 95% CI: 11.5 - 23.1). Our results show an association between HBV DNA or HBsAg and anti-HBc S/CO levels ≥ 4.0. All DNA samples were identified as genotype H and some "a" determinant mutations were identified, although none corresponded to mutations previously reported to hinder the detection of HBsAg by commercial immunoassays.

We observed that as the anti-HBc levels increase, there is a higher prevalence of the viral protein HBsAg in blood donors. Samples testing positive for HBV-DNA were seen to exhibit a ten-fold higher presence of anti-HBc S/CO ≥ 4 than those with S/CO ≥ 1 and < 4.0, which highlights the relevance of anti-HBc determination in blood donor samples.

Although preventable with vaccination, Hepatitis B virus (HBV) infection is a major health concern, with ∼400 million people at risk of developing the chronic form of the disease worldwide. The anti-HBV vaccine consists of a recombinant HBV surface antigen (HBsAg), which induces specific anti-HBs antibodies and confers 95% protection for >20 y. The aim of the present study was to analyze the response to HBV vaccination by measuring anti-HBs antibodies in serum samples from medical students of a public university in Puebla, Mexico. HBV infection markers HBsAg and anti-HBs, were also determined. A total of 201 students were included and vaccination coverage was found at 54%. Overall seropositivity for HBsAg, anti-HBc and anti-HBs determined by ELISA was 0.5%, 1.0% and 47%, respectively. Protective levels of anti-HBs >10 mIU/mL were found in 93.2% of subjects vaccinated with 2 or 3 doses and in 40% of those vaccinated with a single dose; while only 4.8% of unvaccinated subjects were anti-HBs positive. The response to the HBV vaccine was different in each participant, despite similar vaccination scheme. A history of blood transfusion/organ transplant or more than 2 sexual partners was significantly associated with anti-HBc positivity, OR = 399 (p = 0.010) and OR = 19.9 (p = 0.044), respectively. HBV immunization coverage was low in our sample compared with reports from countries with similar HBV prevalence, but anti-HBs in vaccinated individuals were in the expected range. It is important to promote HBV vaccination and awareness among medical students, due to their exposure risk.

The hepatitis B virus (HBV) represents a worldwide public health problem; the virus is present in one third of the global population. However, this rate may in fact be higher due to occult hepatitis B virus infection (OBI). This condition is characterized by the presence of the viral genome in the liver of individuals sero-negative for the virus surface antigen (HBsAg). The causes of the absence of HBsAg in serum are unknown, however, mutations have been identified that produce variants not recognized by current immunoassays. Epigenetic and immunological host mechanisms also appear to be involved in HBsAg suppression. Current evidence suggests that OBI maintains its carcinogenic potential, favoring the progression of fibrosis and cirrhosis of the liver. In common with open HBV infection, OBI can contribute to the establishment of hepatocellular carcinoma. Epidemiological data regarding the global prevalence of OBI vary due to the use of detection methods of different sensitivity and specificity. In Latin America, which is considered an area of low prevalence for HBV, diagnostic screening methods using gene amplification tests for confirmation of OBI are not conducted. This prevents determination of the actual prevalence of OBI, highlighting the need for the implementation of cutting edge technology in epidemiological surveillance systems.

To assess the knowledge and preventive practices regarding hepatitis and liver disease among a sample of participants in the Mexican Health Worker Cohort Study.

The study population consisted of 892 participants from Cuernavaca, Mexico. Demographic characteristics, knowledge about hepatitis B, hepatitis C, and liver disease in general, as well as information about prevention practices were obtained from self-reported questionnaires. Participants were grouped into categories that were created using information about their professional background and patient contact status. Knowledge and prevention practices were compared within these categories.

Inadequate levels of knowledge and preventive practices were found, even within the more highly educated group. Nearly 57 % of the participants had inadequate knowledge about liver disease in general, while 76 and 79 % had inadequate knowledge about Hepatitis B virus (HBV) and Hepatitis C virus (HCV), respectively. For general liver disease, the mean knowledge score increased significantly with education, history of HCV screening, and low alcohol consumption.

Health workers should be better educated about hepatitis and liver disease so they can reduce their own risk and share their knowledge of how to prevent liver disease with patients.

Hepatitis B virus (HBV) genotypes have distinct genetic and geographic diversity and may be associated with specific clinical characteristics, progression, severity of disease and antiviral response. Herein, we provide an updated overview of the endemicity of HBV genotypes H and G in Mexico. HBV genotype H is predominant among the Mexican population, but not in Central America. Its geographic distribution is related to a typical endemicity among the Mexicans which is characterized by a low hepatitis B surface antigen seroprevalence, apparently due to a rapid resolution of the infection, low viral loads and a high prevalence of occult B infection. During chronic infections, genotype H is detected in mixtures with other HBV genotypes and associated with other co-morbidities, such as obesity, alcoholism and co-infection with hepatitis C virus or human immunodeficiency virus. Hepatocellular carcinoma prevalence is low. Thus, antiviral therapy may differ significantly from the standard guidelines established worldwide. The high prevalence of HBV genotype G in the Americas, especially among the Mexican population, raises new questions regarding its geographic origin that will require further investigation.

The distribution of HBV genotypes is associated with populations of specific geographical regions of the world. We show data from the GenBank sequence database and medical reports, which indicate that HBV genotype H (HBV/H) is mainly distributed in Mexico, whereas HBV genotype F (HBV/F) is distributed in countries from Central America. The phylogenetic analysis and historical records suggest that HBV/H has been present in Mexico even before the arrival of the Spaniards. Interestingly, occult hepatitis B is a common finding in both natives and patients with chronic liver disease in Mexico. This suggests that an immunogenic background could be important during the natural history of liver diseases. The estimated large number of HBV/H-infected patients in Mexico does not correlate with the total number of patients with chronic liver disease and cirrhosis reported in the country. This may be because of the fact that HBV infection is often masked by alcoholic liver disease, HCV coinfection and/or obesity. Here, we analyse the data concerning the distribution of HBV/F and HBV/H genotypes in Central America and Mexico. Specifically, we focus on the effect of molecular epidemiology and pathogenesis of HBV/H. These recent findings reveal new areas of study with therapeutic potential in viral liver diseases.

Mexico is considered to be a low endemic country for HBV infection. However, a high anti-HBc against a low hepatitis B surface antigen (HBsAg) seroprevalence is the reported characteristic of native Mexicans. HBV diagnosis and genotype distribution was examined in native populations (Nahuas and Huichol, n = 306), and compared to a non-native population (Mestizos, n = 17). Overall, 6% of the natives were positive for HBsAg and 33% had detectable anti-HBc. HBsAg prevalence was lower in Nahuas compared to Huichols (1.4% vs. 9.4%, P < 0.002). Occult hepatitis B was detected in 14.2% (41/289) of natives, who either tested positive (5.88%, 17/289 HBsAg-negative) or negative for anti-HBc marker (8%, 24/289 HBsAg-negative). Age-adjusted anti-HBc seroprevalence and HBsAg quantitation revealed a sub-optimal sensitivity of conventional immunoassays. Nahuas had HBV/H and Huichol had HBV/A as the predominant genotypes followed by genotypes D, C, B, A, and D, G and H, respectively. A less variable HBV/H was characteristic in Mestizos, compared to a much variable HBV/H identified among the Nahuas. In conclusion, these findings indicate a high HBV endemicity among native Mexican groups where occult B infection is common. The different distribution of HBV genotypes among natives suggests multiple reservoirs of HBV from which these genotypes spread into the local communities. High anti-HBc seroprevalence against a low HBsAg prevalence rate may be due to the limited sensitivity of the immunoassays for the detection of HBsAg that are available in Mexico and/or unknown immunogenetic characteristics of native Mexicans.

Hepatitis B virus (HBV) infection is a problem in several regions of the world with limited resources. Blood samples dried on filter paper (DBS) have been successfully used to diagnose and monitor several infectious diseases. In Mexico there is an urgent need for an affordable and easy sampling method for viral load (VL) testing and monitoring of chronic HBV infection. The purpose of this work was to validate the utility of DBS samples for monitoring HBV infection in patients from Mexico City.

Matched samples of plasma and DBS on filter paper from 47 HBV infected patients from the Instituto Mexicano del Seguro Social (IMSS), were included. To evaluate the DNA stability and purity from DBS stored at different temperature conditions, samples from ten patients were stored at 4 degree, 25 degree, and 37 degree C for 7 days. After DBS elution and DNA extraction, the purity of these samples was determined measuring the O.D. rate 260/280. The DBS utility for molecular studies was assessed with PCR assays to amplify a 322 bp fragment from the "a" determinant region of the HBV "S" gene. The VL from all samples was determined to evaluate the correlation between plasma and DBS matched samples.

The quality of the DNA from DBS specimen is not adversely affected by storage at 4 degree, 25 degree and 37 degree C for up 7 days. Statistical ANOVA analyses did not show any significant difference. The same amplification efficiency was observed between DNA templates from samples stored at different temperatures. The Pearson correlation between the VL from DBS and plasma matched samples was 0.93 (p = 0.01). The SD was 1.48 for DBS vs.1.32 for Plasma, and an average of log10 copies/mL of 5.32 vs. 5.53. ANOVA analysis did not show any statistically significant difference between the analyzed groups (p = 0.92).

The results provide strong evidence that the isolation and quantification of DNA-HBV from DBS is a viable alternative for patient monitoring, and molecular characterization of the virus variants circulating in Mexico.

To address the relationship between hepatitis B virus (HBV) endemicity and HBV-related liver diseases in Mexico. Research literature reporting on HBsAg and antibody to hepatitis B core antigen (anti-HBc) prevalence in Mexican study groups were searched in NLM Gateway, PubMed, IMBIOMED, and others. Weighted mean prevalence (WMP) was calculated from the results of each study group. A total of 50 studies were analyzed. Three nationwide surveys revealed an HBsAg seroprevalence of less than 0.3%. Horizontal transmission of HBV infection occurred mainly by sexual activity and exposure to both contaminated surgical equipment and body fluids. High-risk groups exposed to these factors included healthcare workers, pregnant women, female sex workers, hemodialysis patients, and emergency department attendees with an HBsAg WMP ranging from 1.05% (95% confidence interval [CI], 0.68-1.43) to 14.3% (95% CI, 9.5-19.1). A higher prevalence of anti-HBc in adults than those younger than 20 years was associated with the main risk factors. Anti-HBc WMP ranged from 3.13% (95% CI, 3.01-3.24) in blood donors to 27.7% (95% CI, 21.6-33.9) in hemodialysis patients. A heterogeneous distribution of HBV infection was detected, mainly in native Mexican groups with a high anti-HBc WMP of 42.0% (95% CI, 39.5-44.3) but with a low HBsAg WMP of 2.9% (95% CI 2.08-3.75). Estimations of the Mexican population growth rate and main risk factors suggest that HBsAg seroprevalence has remained steady since 1974. A low HBsAg prevalence is related to the low incidence of HBV-related liver cirrhosis and hepatocellular carcinoma (HCC) previously reported in Mexico.