scholarly journals Evidence of Circulation of Several HAV Genetic Variants and Emergence of Potential Antigenic Variants in an Endemo-Epidemic Country before Vaccine Introduction

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1056
Author(s):  
Kaouther Ayouni ◽  
Anissa Chouikha ◽  
Oussema Khamessi ◽  
Henda Touzi ◽  
Walid Hammemi ◽  
...  
Keyword(s):  
Genetic Variants ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Vp1 Gene ◽  
Immunization Schedule ◽  
Antigenic Variability ◽  
Vaccine Introduction ◽  
National Immunization ◽  
The World ◽  
Intermediate Endemicity

Similar to several other countries in the world, the epidemiology of hepatitis A virus changed from high to intermediate endemicity level in Tunisia, which led to the occurrence of outbreaks. This study aimed to determine the genetic and antigenic variability of HAV strains circulating in Tunisia during the last few years. Genotyping using complete VP1 gene and VP1-2A junction confirmed the predominance of genotype IA, with co-circulation of several genetic and antigenic variants. Phylogenetic analysis including Tunisian and strains from other regions of the world showed the presence of at least two IA-variants within IA subgenotype. Amino-acid analysis showed several mutations in or close to epitope regions in the VP1-region. This study provides a baseline on the genetic and antigenic variability of HAV circulating strains before the introduction of vaccination into the national immunization schedule.

scholarly journals Hepatitis A virus knowledge and immunization attitudes and practices in the United Arab Emirates community

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kamel A. Samara ◽  
Hiba J. Barqawi ◽  
Basant H. Aboelsoud ◽  
Moza A. AlZaabi ◽  
Fay T. Alraddawi ◽  
...  
Keyword(s):  
United Arab Emirates ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Immunization Schedule ◽  
National Immunization Program ◽  
Immunization Program ◽  
Attitudes And Practices ◽  
Awareness Campaigns ◽  
Positive Attitudes ◽  
National Immunization

AbstractAnnually, 1.5 million cases of hepatitis A infection occur worldwide. The United Arab Emirates (U.A.E.) has seen a decrease in infection rates and seroprevalence coupled with an increase in the average age of infection. This study aimed to assess the U.A.E. society’s hepatitis A knowledge, and attitudes and vaccination practices, with the applicability of its introduction into the local immunization schedule. A self-administered, 50-item questionnaire was used to collect data from the four most populous cities in the U.A.E., between January and March 2020. A total of 458 responses were collected and analysed using IBM-SPSS-26, R-4.0.0 and Matplotlib-v3.2.1. Females had better attitudes (P = 0.036), practices (P < 0.0005), immunization schedule knowledge (AOR = 3.019; CI 1.482–6.678), and appreciation of the immunization schedule (AOR = 2.141; CI 1.310–3.499). A higher level of perceived knowledge was associated with an actual better knowledge (P < 0.0005), better practices (P = 0.011), and increased willingness to get vaccinated (AOR = 1.988; CI 1.032–3.828). Respondents were more likely to vaccinate their children against HAV if the vaccine were introduced into the National Immunization Program (P < 0.0005). Overall, disease knowledge was lacking but with positive attitudes and poor practices. There is high trust in the National Immunization Program and a potential for improving poor practices through local awareness campaigns.

scholarly journals INTERMEDIATE ENDEMICITY OF HEPATITIS A VIRUS INFECTION IN RURAL SETTLEMENT PROJECTS OF SOUTHWEST GOIÁS, BRAZIL

2015 ◽  
Vol 52 (3) ◽  
pp. 200-203 ◽  
Author(s):  
Raquel Silva PINHEIRO ◽  
Lyriane Apolinário de ARAÚJO ◽  
Karlla Antonieta Amorim CAETANO ◽  
Marcos André de MATOS ◽  
Megmar Aparecida dos Santos CARNEIRO ◽  
...  
Keyword(s):  
Virus Infection ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Rural Settlement ◽  
Rural Settlements ◽  
Factors Associated ◽  
History Of ◽  
Midwest Region ◽  
Risk Of Exposure ◽  
Intermediate Endemicity

BackgroundRural populations present an elevated risk of exposure to hepatitis A virus.ObjectiveThe objective of this study was to estimate the prevalence and risk factors associated with hepatitis A virus infection among residents of rural settlement projects of southwest Goiás, Central Brazil.MethodsA total of 466 residents were interviewed and tested for the detection of anti- hepatitis A virus antibodies by ELISA.ResultsThe global prevalence of anti- hepatitis A virus was 82.2%. In individuals aged 5-9 years and 10-19 years, the prevalence was 15% and 58.8%, respectively. Persons in the 10-19 age group, with a history of life in encampments, with more than five people per residence consuming well water, were predictors for exposure to hepatitis A virus.ConclusionOur results suggest that the hepatitis A virus endemicity in rural settlements in southwest Goiás similar to that found in the urban population of the Midwest Region, confirming the implementation of universal hepatitis A vaccination in children.

scholarly journals Susceptibility to Hepatitis A Virus Infection in the United States, 2007–2016

2020 ◽  
Vol 71 (10) ◽  
pp. e571-e579 ◽  
Author(s):  
Shaoman Yin ◽  
Laurie Barker ◽  
Kathleen N Ly ◽  
Greta Kilmer ◽  
Monique A Foster ◽  
...  
Keyword(s):  
United States ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Risk Groups ◽  
The United States ◽  
Poverty Level ◽  
Health And Nutrition ◽  
National Immunization ◽  
Vaccination Recommendations ◽  
Sex With Men

Abstract Background Despite national immunization efforts, including universal childhood hepatitis A (HepA) vaccination recommendations in 2006, hepatitis A virus (HAV)–associated outbreaks have increased in the United States. Unvaccinated or previously uninfected persons are susceptible to HAV infection, yet the susceptibility in the US population is not well known. Methods Using National Health and Nutrition Examination Survey 2007–2016 data, we estimated HAV susceptibility prevalence (total HAV antibody negative) among persons aged ≥2 years. Among US-born adults aged ≥20 years, we examined prevalence, predictors, and age-adjusted trends of HAV susceptibility by sociodemographic characteristics. We assessed HAV susceptibility and self-reported nonvaccination to HepA among risk groups and the “immunization cohort” (those born in or after 2004). Results Among US-born adults aged ≥20 years, HAV susceptibility prevalence was 74.1% (95% confidence interval, 72.9–75.3%) during 2007–2016. Predictors of HAV susceptibility were age group 30–49 years, non-Hispanic white/black, 130% above the poverty level, and no health insurance. Prevalences of HAV susceptibility and nonvaccination to HepA, respectively, were 72.9% and 73.1% among persons who reported injection drug use, 67.5% and 65.2% among men who had sex with men, 55.2% and 75.1% among persons with hepatitis B or hepatitis C, and 22.6% and 25.9% among the immunization cohort. Susceptibility and nonvaccination decreased over time among the immunization cohort but remained stable among risk groups. Conclusions During 2007–2016, approximately three-fourths of US-born adults remained HAV susceptible. Enhanced vaccination efforts are critically needed, particularly targeting adults at highest risk for HAV infection, to mitigate the current outbreaks.

Person-to-Person Transmission of Hepatitis A Virus in an Urban Area of Intermediate Endemicity: Implications for Vaccination Strategies

2005 ◽  
Vol 163 (3) ◽  
pp. 204-210 ◽  
Author(s):  
J. C. Victor ◽  
T. Y. Surdina ◽  
S. Z. Suleimenova ◽  
M. O. Favorov ◽  
B. P. Bell ◽  
...  
Keyword(s):  
Urban Area ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Vaccination Strategies ◽  
Intermediate Endemicity

scholarly journals Molecular Evolution of Hepatitis A Virus: a New Classification Based on the Complete VP1 Protein

2002 ◽  
Vol 76 (18) ◽  
pp. 9516-9525 ◽  
Author(s):  
Mauro Costa-Mattioli ◽  
Juan Cristina ◽  
Héctor Romero ◽  
Raoul Perez-Bercof ◽  
Didier Casane ◽  
...  
Keyword(s):  
Amino Acid ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Rna Virus ◽  
Amino Acid Level ◽  
Amino Acid Sequences ◽  
Vp1 Gene ◽  
Antigenic Variant ◽  
Genetic Lineages ◽  
Novel Variant

ABSTRACT Hepatitis A virus (HAV) is a positive-stranded RNA virus in the genus Hepatovirus in the family Picornaviridae. So far, analysis of the genetic variability of HAV has been based on two discrete regions, the VP1/2A junction and the VP1 N terminus. In this report, we determined the nucleotide and deduced amino acid sequences of the complete VP1 gene of 81 strains from France, Kosovo, Mexico, Argentina, Chile, and Uruguay and compared them with the sequences of seven strains of HAV isolated elsewhere. Overall strain variation in the complete VP1 gene was found to be as high as 23.7% at the nucleotide level and 10.5% at the amino acid level. Different phylogenetic methods revealed that HAV sequences form five distinct and well-supported genetic lineages. Within these lineages, HAV sequences clustered by geographical origin only for European strains. The analysis of the complete VP1 gene allowed insight into the mode of evolution of HAV and revealed the emergence of a novel variant with a 15-amino-acid deletion located on the VP1 region where neutralization escape mutations were found. This could be the first antigenic variant of HAV so far identified.

scholarly journals Genetic variability of hepatitis A virus strain HAF-203 isolated in Brazil and expression of the VP1 gene in Escherichia coli

2006 ◽  
Vol 101 (7) ◽  
pp. 759-766 ◽  
Author(s):  
Marcia L Baptista ◽  
Messias Silva ◽  
Maria Amélia de Lima ◽  
Clara FT Yoshida ◽  
Ana Maria C Gaspar ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genetic Variability ◽  
Virus Strain ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Vp1 Gene

scholarly journals Immunological and Epidemiological Aspects of the Immunogenicity of Streptococcus Pneumoniae Serotype 3 Capsular Polysaccharide in Pneumococcal Vaccines

2020 ◽  
Vol 97 (1) ◽  
pp. 72-82
Author(s):  
A. E. Zaitsev ◽  
E. A. Kurbatova ◽  
N. B. Egorova ◽  
E. V. Sukhova ◽  
N. E. Nifantiev
Keyword(s):  
Streptococcus Pneumoniae ◽  
Chemical Structure ◽  
Capsular Polysaccharide ◽  
Pneumococcal Vaccines ◽  
Immunization Schedule ◽  
Prophylactic Efficacy ◽  
National Immunization ◽  
The World ◽  
Synthetic Oligosaccharides ◽  
Immunization Programmes

The introduction of pneumococcal vaccines into national immunization programmes around the world has reduced the incidence of pneumococcal vaccine serotypes, but had no influence on the incidence of Streptococcus pneumoniae serotype 3 included in their composition. The results of evaluation of epidemiological efficacy and immunogenicity of capsular polysaccharide of S. pneumoniae serotype 3 capsular polysaccharide (CP) in conjugated and polysaccharide pneumococcal vaccines are contradictory. Some studies have shown the effectiveness of vaccination, other studies indicate insufficient immunogenicity and prophylactic efficacy of S. pneumoniae serotype 3 CP. The authors’ analysis of the results of clinical studies showed that the prophylactic efficacy of S. pneumoniae serotype 3 CP depends on the type of vaccine, nosological form of the disease, age, immunization schedule. According to the literature data, the most informative parameter of the protective activity of S. pneumoniae CP in pneumococcal vaccines, including serotype 3, is opsonophagocytosis. The experimental data of the low immunogenicity of serotype 3 CP, presumably associated with an unusual way of synthesis of its CP, are considered. To increase the im muno genicity of S. pneumoniae serotype 3 CP, the use of synthetic oligosaccharides of a strictly defined chemical structure corresponding to the protective fragments of serotype 3 CP and conjugated with a carrier protein for induction of T-dependent immune response and immunological memory is promising.

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