Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 156
Article in English | WPRIM | ID: wpr-828989


Objective@#Long-term seroprotection the hepatitis A vaccine is essential for the prevention of disease from the hepatitis A virus (HAV). Due to documented difficulties during decade-long follow-ups after receiving vaccines, statistical-modeling approaches have been applied to predict the duration of immune protection.@*Methods@#Based on five-year follow-up data from a randomized positive-controlled trial among Chinese children (1-8 years old) following a 0, 6 months vaccination schedule, a power-law model accounting for the kinetics of B-cell turnover, as well as a modified power-law model considering a memory-B-cell subpopulation, were fitted to predict the long-term immune responses induced by HAV vaccination (Healive or Havrix). Anti-HAV levels of each individual and seroconversion rates up to 30 years after vaccination were predicted.@*Results@#A total of 375 participants who completed the two-dose vaccination were included in the analysis. Both models predicted that, over a life-long period, participants vaccinated with Healive would have close but slightly higher antibody titers than those of participants vaccinated with Havrix. Additionally, consistent with previous studies, more than 90% of participants were predicted to maintain seroconversion for at least 30 years. Moreover, the modified power-law model predicted that the antibody titers would reach a plateau level after nearly 15 years post-vaccination.@*Conclusions@#Based on the results of our modeling, Healive may adequately induce long-term immune responses following a 0, 6 months vaccination schedule in children induction of memory B cells to provide stable and durable immune protection.

Adolescent , Child , Child, Preschool , China , Female , Hepatitis A , Allergy and Immunology , Hepatitis A Antibodies , Blood , Hepatitis A Vaccines , Humans , Immunity, Active , Infant , Male , Models, Statistical , Vaccination
Article in English | WPRIM | ID: wpr-765073


Until 1995, the incidence of symptomatic acute hepatitis A was minimal and there were no cases of national outbreak in Korea. However, there was a nationwide outbreak of hepatitis A that peaked in 2009. In 2019, a total of 10,083 cases of acute hepatitis A were reported for seven months of the year according to the Korea Center for Disease Control and Prevention. This may be attributed to the proportion of susceptible subjects in the Korean population, as about 10 years have passed since herd immunity was induced by the epidemic occurring during the late 2000s. Recent studies have shown that the rate of seropositivity for anti-hepatitis A virus antibodies (anti-HAV) is the lowest in adults in their 20s and has not changed much over the past 10 years, and seropositivity of anti-HAV in adults in their 30s has continued to decline from 69.6% in 2005 to 32.4% in 2014. Most young adults who have not yet experienced hepatitis A and are not vaccinated are vulnerable to hepatitis A infection. This year's epidemic of hepatitis A is a predictable outcome for vulnerable populations. Therefore, effective acute hepatitis A control and prevention strategies are needed, particularly for those in their 20s and 30s.

Adult , Antibodies , Hepatitis A Antibodies , Hepatitis A , Hepatitis , Humans , Immunity, Herd , Incidence , Korea , Prevalence , Vulnerable Populations , Young Adult
Braz. j. infect. dis ; 22(3): 166-170, May-June 2018. tab
Article in English | LILACS | ID: biblio-974214


ABSTRACT Vaccination against the hepatitis A virus (HAV) administered in two doses has been used effectively in universal child immunization programs in several countries. A single-dose vaccination was adopted in some low-income countries in an attempt to reduce costs without losing effectiveness. In 2014, single-dose universal vaccination was introduced in Brazil for children aged two years. Since such strategy is still not universally accepted, its efficacy should be compared to the two-dose strategy. To assess the humoral response after the single-dose HAV vaccination schedule, a cross-sectional study was conducted in Primavera do Leste, in Mato Grosso state, Central Brazil, including 265 children vaccinated through the National Immunization Program. Blood was collected by using a digital puncture and further applied to filter paper cards. Anti-HAV was detected in 218 out of 265 dried blood spots (DBS). Blood venous samples were collected from 34 out of 47 children who were not anti-HAV positive in DBS samples. Eighteen of them tested positive for anti-HAV, giving a final score of 93.6% (236/252) of seropositivity. In conclusion, this study demonstrated a high rate of anti-HAV positivity in the short term after single-dose hepatitis A vaccination in the population investigated. Moreover, the DBS was shown to be a reliable tool for detecting anti-HAV antibodies.

Humans , Male , Female , Child , Mass Vaccination/methods , Hepatitis A Vaccines/administration & dosage , Hepatitis A Antibodies/blood , Hepatitis A/prevention & control , Brazil/epidemiology , Program Evaluation , Logistic Models , Seroepidemiologic Studies , Retrospective Studies , Immunoenzyme Techniques , Immunization Schedule , Hepatitis A Virus, Human/immunology , Hepatitis A Vaccines/immunology , Dried Blood Spot Testing , Hepatitis A/epidemiology
Article in English | LILACS | ID: lil-774574


Nonhuman primates are considered as the natural hosts of Hepatitis A virus (HAV), as well as other pathogens, and can serve as natural sentinels to investigate epizootics and endemic diseases that are of public health importance. During this study, blood samples were collected from 112 Neotropical primates (NTPs) (Sapajus nigritus and S. cay, n = 75; Alouatta caraya, n = 37) trap-captured at the Paraná River basin, Brazil, located between the States of Paraná and Mato Grosso do Sul. Anti-HAV IgG antibodies were detected in 4.5% (5/112) of NTPs, specifically in 6.7% (5/75) of Sapajus spp. and 0% (0/37) of A. caraya. In addition, all samples were negative for the presence of IgM anti-HAV antibodies. These results suggest that free-ranging NTPs were exposed to HAV within the geographical regions evaluated.

Animals , Female , Male , Hepatitis A Antibodies/blood , Hepatitis A virus/isolation & purification , Hepatitis A/veterinary , Monkey Diseases/virology , Brazil/epidemiology , Hepatitis A/diagnosis , Hepatitis A/epidemiology , Monkey Diseases/diagnosis , Monkey Diseases/epidemiology
Cad. Saúde Pública (Online) ; 32(11): e00175614, 2016. tab, graf
Article in English | LILACS | ID: biblio-828385


Abstract: This cross-sectional study was carried out between August 2011 and July 2012 in the city of Campos dos Goytacazes in Rio de Janeiro State, Brazil. Dried blood spot samples were collected on filter paper from 919 individuals between the ages of 1 and 19 and were tested for antibodies against the hepatitis A virus (anti-HAV). The total prevalence was 20.7%, while 94.7% of children under the age of 5 were found to be susceptible to HAV infection. The prevalence of anti-HAV increased with age, reaching 33.3% among individuals aged between 15 and 19, thereby indicating that this municipality has a low level of endemicity for hepatitis A. Age, non-white skin color, accustomed to swimming in the river and more than five people living at home were the factors that were associated with an increase in the chance of a positive anti-HAV result. Mother's education level (secondary or tertiary) was considered a protective factor for HAV infection. The data obtained showed that a large proportion of the children from Campos dos Goytacazes were at risk of HAV infection, which should be minimized with the introduction of the vaccination program against hepatitis A that was launched in the municipality in 2011.

Resumo: Estudo do corte transversal, realizado entre agosto de 2011 e julho de 2012 em Campos dos Goytacazes, Rio de Janeiro, Brasil. Amostras de sangue capilar em papel de filtro foram coletadas de 919 indivíduos com idade entre 1 e 19 anos e testadas para anticorpos para o vírus da hepatite A (anti-HAV). A prevalência total foi de 20,7% e 94,7% das crianças abaixo de 5 anos foi suscetível a infecção pelo HAV. A prevalência de anti-HAV aumentou com a idade, alcançando 33,3% entre indivíduos com 15 a 19 anos, caracterizando este município com um nível baixo de endemicidade para hepatite A. Idade, cor da pele não-branca, hábito de nadar no rio e número de moradores na residência acima de 5 foram associados com o aumento de chance de ser positivo para anti-HAV. O nível educacional materno (médio ou superior) foi considerado como fator de proteção para a infecção pelo HAV. Os dados obtidos mostraram que uma grande parte das crianças de Campos dos Goytacazes estava sob risco de infecção pelo HAV, o que deve ser minimizado com o programa de vacinação contra hepatite A implantado em 2011 no município.

Resumen: Estudio de corte transversal, realizado entre agosto de 2011 y julio de 2012 en Campos dos Goytacazes, Río de Janeiro, Brasil. Se recogieron muestras de sangre capilar en papel de filtro de 919 individuos con una edad entre 1 y 19 años y testadas para anticuerpos del virus de la hepatitis A (anti-HAV). La prevalencia total fue de un 20,7% y un 94,7% de los niños por debajo de los 5 años fue susceptible a la infección por el HAV. La prevalencia de anti-HAV aumentó con la edad, alcanzando un 33,3% entre individuos con 15 a 19 años, caracterizando este municipio con un nivel bajo de endemicidad para la hepatitis A. Edad, color de piel no-blanca, hábito de nadar en el río y un número de ocupantes en la residencia de más de 5 se asociaron con el aumento de oportunidad de ser positivo para anti-HAV. El nivel educacional materno (medio o superior) se consideró como un factor de protección para la infección por el HAV. Los datos obtenidos mostraron que una gran parte de los niños de Campos dos Goytacazes estaba bajo riesgo de infección por el HAV, lo que debe ser minimizado con el programa de vacunación contra la hepatitis A implantado en 2011 en el municipio.

Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , Young Adult , Hepatitis A Virus, Human/immunology , Hepatitis A Vaccines/administration & dosage , Hepatitis A Antibodies/blood , Hepatitis A/epidemiology , Socioeconomic Factors , Brazil/epidemiology , Seroepidemiologic Studies , Prevalence , Cross-Sectional Studies , Hepatitis A/prevention & control
Article in English | WPRIM | ID: wpr-218587


Although the overall incidence of hepatitis A in Korea has been decreasing, adolescents remain highly vulnerable to its outbreaks. This study was conducted to compare the immunogenicity and safety of three hepatitis A vaccines in Korean adolescents. Healthy anti-hepatitis A virus seronegative subjects aged 13 to 19 yr were randomized in three equal groups to receive two doses of Avaxim(TM), Epaxal(R), or Havrix(R), 6 to 12 months apart. Seroconversion rates one month after the first dose were 98%, 95%, and 93% for Avaxim(TM), Epaxal(R), and Havrix(R), respectively. Seroconversion rates reached 100% for all vaccine groups one month after the second dose. Anti-HAV geometric mean concentrations (GMCs) were 7,207.7 mIU/mL (95% CI, 6023.1-8684.7), 1,750.5 mIU/mL (95% CI, 1362.9-2248.3), and 1,953.5 mIU/mL (95% CI, 1459.4-2614.7) after two doses of Avaxim(TM), Epaxal(R), and Havrix(R) respectively. Avaxim(TM) was significantly more immunogenic than Epaxal(R) and Havrix(R), whereas there were no significant differences in antibody responses between Epaxal(R) and Havrix(R). Local and systemic solicited adverse events (AEs) were mostly of mild-to-moderate intensity and resolved within 5 days. No serious AEs were reported. In conclusion, all three vaccines are highly immunogenic and well-tolerated in Korean adolescents. (Clinical Trial Registry NCT00483470)

Adolescent , Antibody Formation , Female , Hepatitis A/immunology , Hepatitis A Antibodies/blood , Hepatitis A Vaccines/adverse effects , Humans , Male , Republic of Korea , Vaccines, Inactivated/adverse effects , Young Adult
Article in Korean | WPRIM | ID: wpr-32297


BACKGROUND: Nursing students may be exposed to patients with infectious diseases such as hepatitis B and hepatitis A through needle stick injuries or close contact during their clinical practice. This study surveyed the presence of antihepatitis B virus (anti-HBV), anti-hepatitis A virus (anti-HAV), and anti-varicella zoster virus antibodies in nursing students before the initiation of their clinical practice to help prevent subsequent infections. METHODS: From 2009 to 2013, the junior students of a nursing college in Jeollabuk-do were tested for antibodies against the hepatitis B, hepatitis A, and varicella zoster viruses before the initiation of their clinical practice. RESULTS: The students tested positive for anti-HBV (46.2-57.1%), anti-HAV (0-10.5%), and anti-varicella zoster antibodies (80.2-90.2%). No significant differences in the positivity rates were observed with respect to the year of their enrollment. CONCLUSION: This study was a survey of the seroprevalence of anti-HBV, anti-HAV, and anti-varicella zoster antibodies in nursing students before they started their clinical practice. The positivity rate of anti-HAV was lower than 10%. In order to prevent infection, it is necessary to test nursing students for the presence of antibodies against hepatitis B, hepatitis A, varicella, measles, mumps, and rubella, and check their vaccination history as recommended in the adult immunization schedule. Vaccination must be recommended for students who test negative for the respective antibodies.

Adult , Antibodies , Chickenpox , Communicable Diseases , Hepatitis A , Hepatitis A Antibodies , Hepatitis B , Hepatitis B Antibodies , Herpes Zoster , Herpesvirus 1, Cercopithecine , Herpesvirus 3, Human , Humans , Immunization Schedule , Measles , Mumps , Needlestick Injuries , Nursing , Rubella , Seroepidemiologic Studies , Students, Nursing , Vaccination
Article in English | WPRIM | ID: wpr-24789


The worldwide seroprevalence of hepatitis A virus (HAV) and hepatitis B virus (HBV) has changed over the last two decades, indicating a declining incidence of HAV and HBV infections. Therefore, vaccinations against HAV and HBV are recommended for unimmunized people before traveling to an endemic area. Unfortunately, primary antibody deficiency (PAD) patients can only obtain humoral immunity through intravenous immunoglobulin G (IVIG) replacement and not from vaccination because of a defect in antibody production. However, few studies have analyzed the titers of antibodies against HAV or HBV in IVIG products. In this study, the titers of anti-HAV and anti-HBs antibodies were measured in nineteen lots of IVIG products from five manufacturers from three countries (A, B from Korea; C, D from Japan; and E from the USA), and trough titers in plasma were estimated. Concentrations of anti-HAV antibody ranged from 1,888–8,927 mIU/mL and estimated trough titers exceeded the minimal protective value in all evaluated IVIG products. Concentrations of anti-HBs antibody ranged from 438–965 mIU/mL in products A and B and were 157, 123, and 1,945 mIU/mL in products C, D, and E, respectively. Estimated trough titers in products A, B, and E exceeded the minimal protective value but those in products C and D did not reach this threshold. These data demonstrated that available IVIG products generally provide sufficient antibodies against HAV and HBV to protect patients with PAD, although the trough concentrations of anti-HBs antibody in two IVIG products did not reach the minimum protective value.

Antibodies , Antibody Formation , Hepatitis A Antibodies , Hepatitis A virus , Hepatitis A , Hepatitis B virus , Hepatitis B , Hepatitis , Humans , Immunity, Humoral , Immunoglobulin G , Immunoglobulins , Immunoglobulins, Intravenous , Incidence , Japan , Korea , Plasma , Seroepidemiologic Studies , Vaccination
Mem. Inst. Oswaldo Cruz ; 110(4): 577-579, 09/06/2015. graf
Article in English | LILACS | ID: lil-748866


An increasing amount of research has been conducted on immunoglobulin Y (IgY) because the use of IgY offers several advantages with respect to diagnostic testing, including its easy accessibility, low cost and translatability to large-scale production, in addition to the fact that it can be ethically produced. In a previous work, immunoglobulin was produced and purified from egg yolks (IgY) reactive to hepatitis A virus (HAV) antigens. In the present work, this anti-HAV-specific IgY was used in an indirect immunofluorescence assay to detect viral antigens in liver biopsies that were obtained from experimentally infected cynomolgus monkeys. Fields that were positive for HAV antigen were detected in liver sections using confocal microscopy. In conclusion, egg yolks from immunised hens may be a reliable source for antibody production, which can be employed for immunological studies.

Animals , Hepatitis A virus/immunology , Hepatitis A/diagnosis , Immunoglobulins/analysis , Liver/virology , Disease Models, Animal , Fluorescent Antibody Technique, Indirect , Hepatitis A Antibodies/immunology , Hepatitis A Antigens/immunology , Hepatitis A/immunology , Macaca fascicularis , Sensitivity and Specificity
Córdoba; s.n; 2015. 43 p. ilus.
Thesis in Spanish | LILACS | ID: biblio-971342


Argentina es considerada un país de endemicidad intermedia para el virus de la hepatitis A (VHA). Debido a la introducción de la vacuna al calendario nacional (2005), es notable la reducción de notificaciones de casos clínicos por este virus. Sin embargo, en los últimos años el Ministerio de Salud de la Nación reportó un desplazamiento de la incidencia de casos, siendo los más afectados los adolescentes y adultos jóvenes. Como en Córdoba no existían datos actualizados de la prevalencia de anticuerpos en la población general adulta, el objetivo del trabajo fue proveer información actualizada sobre el estado inmunitario específico para VHA en individuos adultos de la ciudad de Córdoba después de cuatro años de la presentación oficial de la vacuna. Para ello, se realizó un estudio retrospectivo de seroprevalencia en muestras de sueros de 416 individuos adultos sanos residentes en Córdoba capital, sin antecedentes previos de vacunación y que fueron atendidos en centros de atención de salud durante septiembre de 2009 y septiembre 2010. Las muestras se clasificaron por grupos etarios y condiciones socio-económicas. La asociación de la prevalencia con la edad y la variable socioeconómica se determinó mediante modelos de regresión spline, en el marco de los modelos aditivos generalizados. La prevalencia global de anti-VHA fue del 73,5 %...

ABSTRACT: Hepatitis A virus (HAV) has shown intermediate endemicity in Argentina, but notification of clinical cases has decreased since the introduction of the vaccine in 2005. However, in recent years the Ministry of Health of Argentina reported a shift in the incidence of cases, being the most affected adolescents and young adults. In Cordoba, no data updated on the prevalence of antibodies in general adult population. So the objective was to provide information on HAV immune status of the adult population of Córdoba city after four years of the official introduction of the vaccine. The prevalence of anti-HAV was determined by EIA in 416 serum samples of people (without prior vaccination) from Córdoba city (sept2009–sept2010). Spline regression models were estimated under generalized additive models. In Córdoba, the global prevalence of anti-HAV was 73.5%...

Male , Female , Humans , Adult , Hepatitis A Virus, Human , Hepatitis A virus , HIV Seroprevalence , Seroepidemiologic Studies , Adult , Hepatitis A Antibodies , Argentina/epidemiology
Rio de Janeiro; s.n; 2015. xxiv, 86 p. ilus, tab, graf.
Thesis in Portuguese | LILACS | ID: biblio-971496


O diagnóstico da infecção pelo vírus da hepatite A (HAV) através de testes de alta sensibilidade e especificidade pode levar um diagnóstico mais precoce e mais preciso,melhorando o prognóstico da doença. Deve também ser mencionado que um diagnóstico mais preciso pode tornar estudos epidemiológicos mais confiáveis e servir de base para a produção de programas de controle e erradicação mais efetivos. O objetivo deste estudo foi avaliar a utilização de um teste imunocromatográfico em surtos e estudos epidemiológicos de prevalência, triagem de candidatos para programas de vacinação e detecção de resposta imunológica pós-vacinação. Para este fim, 342 amostras provenientes de quatro grupos diferentes foram analisadas: (I) amostras de doadores de sangue (n= 96), (II) amostras de indivíduos vacinados contra a hepatite A (n= 46), amostras de surtos de hepatite A (III) (n=103) e (IV) amostras de casos esporádicos de hepatite A (n= 97). Estas amostras foram submetidas ao teste rápido SD BIOLINE HAV IgG/IgM e todos os resultados do teste rápido foram comparados com os resultados do ensaio imunoenzimático para HAV (EIA), que é o padrão ouro para detectar anticorpos contra o HAV...

The diagnosis of infection by the hepatitis A virus (HAV) through high sensitivity andspecificity tests can lead an earlier and more accurate diagnosis, improving the prognosis ofthe disease. It should also be mentioned that a more precise diagnosis can become morereliable epidemiological studies and as a basis for the production of more effective controland eradication programs. The aim of this study was to evaluate an immunochromatographictest in outbreaks and epidemiological studies of prevalence, screening candidates forvaccination and post-vaccination surveillance programs. For this purpose, 342 samples frompatients of four different groups were analyzed: (I) samples from blood donors (n=96), (II)samples from individuals vaccinated for hepatitis A (n=46), (III) samples from hepatitis Aoutbreaks (n=103) and (IV) samples from sporadic cases of hepatitis A (n=97). These sampleswere submitted to the rapid test SD BIOLINE HAV IgG/IgM and all results of the rapid testwere compared to the results of HAV enzyme immunoassay (EIA) that is the gold standard todetect antibodies against HAV. The results obtained for the group I showed that, 33.3%(32/96) were positive for anti-HAV IgG using the rapid test and 67.7% (65/96) were positivefor IgG anti-HAV by EIA. At group II, 71.7% (33/46) of the samples were positive for antiHAVIgG by EIA and none of them (0/33) was reactive by rapid test. Groups III and IV weretested for the presence of anti-HAV IgG and anti-HAV IgM antibodies...

Humans , Chromatography, Affinity , Hepatitis A Antibodies , Disease Outbreaks , Epidemiologic Studies
Chinese Journal of Epidemiology ; (12): 1127-1130, 2014.
Article in Chinese | WPRIM | ID: wpr-335273


<p><b>OBJECTIVE</b>Hepatitis A immunization strategies were carried out in 2001 in Tianjin. We wanted to evaluate the effectiveness of the strategies related to hepatitis A control programs and to provide the basis for further modification of the strategies.</p><p><b>METHODS</b>Descriptive epidemiology study was used to analyze the hepatitis A epidemic situation in 2000-2011 in Tianjin and to evaluate the disease reporting system. Hepatitis A vaccine coverage of target population and serum epidemiological study were carried out in 1999, 2005 and 2010 to check on the hepatitis A antibody levels so as to evaluate the immuno-barrier condition in the normal population. Cox-Stuart test was used to analyze the epidemic trend of hepatitis A and other intestinal infectious diseases in Tianjin.</p><p><b>RESULTS</b>The incidence rate of hepatitis A decreased from 2.89/100 000 in 2000 to 0.12/100 000 in 2011, and the percentage of hepatitis A in all types of viral hepatitis decreased from 8.02% in 2000 to 0.48% in 2011 in Tianjin. The positive rates of hepatitis A antibody also increased in the residents.</p><p><b>CONCLUSION</b>The hepatitis A vaccination program was successful in the programs on prevention and control of hepatitis A in Tianjin, China.</p>

China , Epidemiology , Epidemics , Hepatitis A , Epidemiology , Hepatitis A Antibodies , Blood , Hepatitis A Vaccines , Humans
Article in English | WPRIM | ID: wpr-119488


BACKGROUND/AIMS: The incidence of symptomatic hepatitis A reportedly increased among 20- to 40-year-old Korean during the late 2000s. Vaccination against hepatitis A was commenced in the late 1990s and was extended to children aged <10 years. In the present study we analyzed the changes in the seroprevalence of IgG anti-hepatitis A virus (HAV) over the past 13 years. METHODS: Overall, 4903 subjects who visited our hospital between January 2001 and December 2013 were studied. The seroprevalence of IgG anti-HAV was analyzed according to age and sex. In addition, the seroprevalence of IgG anti-HAV was compared among 12 age groups and among the following time periods: early 2000s (2001-2003), mid-to-late 2000s (2006-2008), and early 2010s (2011-2013). The chi-square test for trend was used for statistical analysis. RESULTS: The seroprevalence of IgG anti-HAV did not differ significantly between the sexes. Furthermore, compared to the seroprevalence of IgG anti-HAV in the early 2000s and mid-to-late 2000s, that in the early 2010s was markedly increased among individuals aged 1-14 years and decreased among those aged 25-44 years (P<0.01). We also found that the seroprevalence of IgG anti-HAV in individuals aged 25-44 years in the early 2010s was lower than that in the early 2000s and mid-to-late 2000s. CONCLUSIONS: The number of symptomatic HAV infection cases in Korea is decreasing, but the seroprevalence of IgG anti-HAV is low in the active population.

Adolescent , Adult , Age Factors , Child , Child, Preschool , Female , Hepatitis A/diagnosis , Hepatitis A Antibodies/analysis , Hepatitis A virus/immunology , Humans , Immunoglobulin G/analysis , Infant , Infant, Newborn , Male , Middle Aged , Republic of Korea , Seroepidemiologic Studies , Sex Factors , Young Adult
Article in English | WPRIM | ID: wpr-159647


This study aimed to identify the risk factors associated with acute hepatitis A virus (HAV) infection in the Korean population. Participants were recruited from five referral hospitals across the country in 2007 and from 11 hospitals in 2009. Patients with positive anti-HAV IgM antibody tests became the case group, while patients treated for non-contagious diseases at the same hospitals were recruited as controls. A total of 222 and 548 case-control pairs were studied in the 2007 and 2009 surveys, respectively. Data from the surveys were analyzed jointly. In a multivariate analysis, sharing the household with HAV-infected family members (OR, 6.32; 95% CI, 1.4-29.6), contact with other HAV-infected individuals (OR, 4.73; 95% CI, 2.4-9.4), overseas travel in 2007 (OR, 19.93; 95% CI, 2.3-174.4), consumption of raw shellfish (OR, 2.51; 95% CI, 1.8-3.5), drinking bottled water (OR, 1.64; 95% CI, 1.3-8.4), and occupation that involve handling food (OR, 3.30; 95% CI, 1.3-8.4) increased the risk of HAV infection. Avoiding contact with HAV-infected individuals and avoiding raw foods eating could help minimize the risk of hepatitis A infection. Immunization must be beneficial to individuals who handle food ingredients occupationally or travel overseas to HAV-endemic areas.

Acute Disease , Adolescent , Adult , Case-Control Studies , Child , Child, Preschool , Female , Food Handling , Hepatitis A/diagnosis , Hepatitis A Antibodies/blood , Humans , Immunoglobulin M/blood , Infant , Infant, Newborn , Interviews as Topic , Male , Middle Aged , Multivariate Analysis , Odds Ratio , Referral and Consultation , Risk Factors , Seafood , Travel , Vaccination , Young Adult
Mem. Inst. Oswaldo Cruz ; 107(7): 960-963, Nov. 2012. ilus, tab
Article in English | LILACS | ID: lil-656052


The detection of anti-hepatitis A virus (HAV) antibody levels by diagnostic kits in the convalescent period of disease generally use immunoglobulin G (IgG), which is expensive. An alternative to IgG is immunoglobulin Y (IgY), an immunoglobulin antibody encountered in birds and reptiles. The aim of this study was to develop a competitive immunoenzymatic assay to measure total anti-HAV antibody levels using anti-HAV IgY as the capture and conjugated immunoglobulins. For this purpose, anti-HAV IgY was conjugated to horseradish peroxidase (HRP) and the optimal dilution of HRP-conjugated antibodies was evaluated to establish the competitive immuneenzymatic assay. The results obtained from our "in-house" assay were plotted on a receiver operator curve, which showed a sensitivity of 95% and a specificity of 98.8%, demonstrating that a competitive anti-HAV IgY immunoenzymatic assay developed "in house" could be used as an alternative to commercial assays that utilise IgG.

Humans , Hepatitis A Antibodies/blood , Hepatitis A virus/immunology , Hepatitis A/diagnosis , Immunoglobulins , Immunoenzyme Techniques/methods , Sensitivity and Specificity
Mem. Inst. Oswaldo Cruz ; 107(5): 652-658, Aug. 2012. ilus, tab
Article in English | LILACS | ID: lil-643751


Age-related seroprevalence studies that have been conducted in Brazil have indicated a transition from a high to a medium endemicity of hepatitis A virus (HAV) infection in the population. However, most of these studies have focused on urban populations that experience lower incidence rates of HAV infection. In the current study, the prevalence of anti-HAV antibodies was investigated in children with a low socioeconomic status (SES) that live on the periphery of three capital cities in Brazil. A total of 1,162 dried blood spot samples were collected from individuals whose ages ranged from one-18 years and tested for anti-HAV antibodies. A large number of children under five years old (74.1-90%) were identified to be susceptible to HAV infection. The anti-HAV antibody prevalence reached ≥ 50% among those that were 10-14 years of age or older. The anti-HAV prevalence rates observed were characteristics of regions with intermediate level of hepatitis A endemicity. These data indicated that a large proportion of children with a low SES that live at the periphery of urban cities might be at risk of contracting an HAV infection. The hepatitis A vaccine that is currently offered in Brazil is only available for high-risk groups or at private clinics and is unaffordable for individuals with a lower SES. The results from this study suggest that the hepatitis A vaccine should be included in the Brazilian National Program for Immunisation.

Adolescent , Child , Child, Preschool , Female , Humans , Infant , Male , Hepatitis A Vaccines , Hepatitis A Antibodies/blood , Hepatitis A Virus, Human/immunology , Hepatitis A/epidemiology , Age Distribution , Brazil/epidemiology , Cross-Sectional Studies , Hepatitis A/prevention & control , Prevalence , Seroepidemiologic Studies , Socioeconomic Factors , Urban Population
Article in English | WPRIM | ID: wpr-725422


PURPOSE: To determine the association of gallbladder (GB) abnormalities on ultrasonography (US) of patients with acute hepatitis A with demographic, clinical, and biochemical factors, and with other US findings. MATERIALS AND METHODS: This retrospective study was approved by our institutional review board, which waived the requirement for informed consent. We retrospectively evaluated 152 consecutive patients with acute hepatitis A who underwent US. The diagnosis of acute hepatitis A was made during acute illness by demonstrating anti-HAV of the IgM class. US images were reviewed simultaneously by two abdominal radiologists and a consensus was reached for GB wall thickening, GB collapse, lymphadenopathy, and hepatic echogenicity. The associations between demographic, clinical, biochemical, and US findings and GB wall thickening or collapse were then assessed. RESULTS: GB wall thickening was present in 123 (81%) and GB collapse in 96 (63%) of the 152 patients. Total bilirubin level and GB collapse differed significantly (p < 0.05) between patients with and without GB wall thickening. Gender ratio, total and peak total bilirubin level, and GB wall thickness differed significantly (p < 0.05) between patients with and without GB collapse. Multivariate analysis showed that GB wall thickening was associated with GB collapse and vice versa. CONCLUSION: GB wall thickening and GB collapse are common US abnormalities associated with each other in patients with acute hepatitis A. However, GB wall thickening or collapse is not associated with any demographic, clinical, or biochemical factors, or with other US findings, in patients with acute hepatitis A.

Bilirubin , Consensus , Ethics Committees, Research , Gallbladder , Hepatitis , Hepatitis A , Hepatitis A Antibodies , Humans , Immunoglobulin M , Informed Consent , Lymphatic Diseases , Multivariate Analysis , Retrospective Studies
São Paulo; s.n; 2012. [165] p. tab, graf.
Thesis in Portuguese | LILACS | ID: lil-664732


As hepatites virais continuam sendo uma preocupação em nível de saúde pública no Brasil e no Mundo, tanto pelo número de indivíduos atingidos, como pela possibilidade de complicação das formas agudas e crônicas. Segundo a Organização Mundial de Saúde (OMS), 170 milhões de pessoas são portadoras crônicas de hepatite C e 350 milhões portadoras crônicas de hepatite B. No Brasil, a estimativa de portadores de hepatite B crônica é de aproximadamente 600 mil pessoas e de hepatite C crônica, 1,5 milhão. Quanto à hepatite aguda A foram confirmados no país, em 2010, 5943 casos. O objetivo deste estudo foi conhecer a prevalência de marcadores sorológicos dos vírus das hepatites A, B e C em crianças e adolescentes matriculados em creches e escolas de ensino infantil e fundamental da rede municipal na cidade de Santos; conhecer os aspectos moleculares dos vírus das hepatites B e C, identificando o genótipo dos dois agentes e estudar modo de aquisição nos casos com sorologias positivas. Tratou-se de um estudo transversal realizado no período de 28 de Junho a 14 de Dezembro de 2007 onde foram coletadas 4680 amostras de sangue colhidas através de punção capilar e ao mesmo tempo aplicado um questionário nos familiares das crianças e adolescentes. Os exames sorológicos foram realizados utilizando a técnica de ELISA. O estudo molecular foi realizado pela técnica de reação em cadeia de polimerase "in House". A idade da população estudada variou de 7 meses a 18 anos e 1 m. A prevalência geral do anti-HVA IgG reagente foi de 9,7% e desses 74,6% foi anti-HVA IgM reagente. A prevalência de anti-HVA IgG foi maior entre as crianças mais velhas, meninas, aquelas que brincavam em córregos, sem esgoto em sua moradia, de pais com baixa instrução, de baixa renda familiar e aquelas que não eram moradoras da Orla...

Viral hepatitis are still a concern in the public health level in Brazil and around the Word, due both to the number of affected subjects and the possibility of complication in the acute and chronic forms. According to the World Health organization (WHO), 170 million people are chronic carriers of hepatitis C and 350 million chronic carriers of hepatitis B. In Brasil, the estimate of people with chronic hepatitis B is approximately 600 thousand people and chronic hepatitis C, 1,5 million. It has been confirmed in the country, in 2010, 5943 cases of acute hepatitis A. The The aim of this study was to learn the prevalence of serological markers of hepatitis A, B and C virus in children and teenagers enrolled at the municipal education network in the city of Santos, to learn molecular aspects of hepatitis B and C, identifying the genotype of the two agents and to study the acquisition mode in cases with positive serology. Cross-sectional study carried out over the period from June 28 to December 14, 2007, in which 4680 fingerprick blood samples were collected; at the same time, a survey questionnaire was applied to the family members of the children and teenagers. The serological tests were performed using the ELISA technique. The molecular analysis was performed using the technique of polymerase chain reaction "in House". Age of the population studied ranged from 7 months to 18 years and 1 month. . The general prevalence of serological markers anti-HAV IgG reagent was 9.7% and between them 74,7% was anti-HAV IgM reagent. There was higher prevalence among older children, females, those who used to play in streams near their home, the absence of a sewage system in home, parents with low education, low household income and among those who did not live in the seashore. The prevalence of anti-HAV IgM was not different between the categories, except for the age (peak in the early years and subsequent fall) and lower on the Hills and Northweast Zone. ...

Humans , Child , Adolescent , Child , Epidemiology , Hepatitis A Antibodies , Hepatitis B Antibodies , Hepatitis C , Prevalence , Child Day Care Centers/education