RESUMO
BACKGROUND: Single-dose hepatitis A virus (HAV) vaccination was implemented in all Argentinean children aged 12 months in 2005. Between 2005 and 2011, a dramatic decline was observed in HAV infection rates, fulminant hepatitis, and liver transplantation. This study assessed current viral circulation and estimated protective antibody persistence 4 years after vaccination. METHODS: Prevalence of prevaccination anti-HAV antibodies in 12-month-old children was evaluated as an indirect estimation of viral circulation (Group A). Seroprevalence was also measured in 5-year-old children who received 1 dose of HAV vaccine at 1 year of age (Group B). Blood samples were tested for immunoglobulin (Ig)G anti-HAV antibodies (seroprotection = ≥10 mIU/mL). All Group A-positive samples were tested for IgM anti-HAV antibodies to identify recent infections. Logistic regression analysis was done to evaluate associations between demographic and socioeconomic variables and seroprotection. RESULTS: Of 433 children from Group A, 29.5% (95% confidence interval [CI], 25.2-33.8) were positive for IgG anti-HAV antibodies with a geometric mean concentration (GMC) of 6.17 mIU/mL (95% CI, 5.33-7.15 mIU/mL); all IgM anti-HAV were negative. From 1139 in Group B, 93% (95% CI, 91.7-94.6) maintained seroprotection with a GMC of 97.96 mIU/mL (95% CI, 89.21-107.57 mIU/mL). Kindergarten attendance was associated with seroprotection in Group B (odds ratio [OR], 2.0; 95% CI, 1.26-3.3). In contrast, high maternal educational level was associated with a lack of seroprotection in this group (OR, .26; 95% CI, .09-.8). CONCLUSIONS: Single-dose, universal hepatitis A immunization in infants resulted in low HAV circulation and persistent immunologic protection up to 4 years in Argentina. Variables associated with presence or absence of seroprotection in vaccinated children could be related to differences in hygiene habits in settings with residual viral circulation.
Assuntos
Anticorpos Anti-Hepatite A/sangue , Vacinas contra Hepatite A/uso terapêutico , Hepatite A/prevenção & controle , Argentina/epidemiologia , Pré-Escolar , Feminino , Hepatite A/epidemiologia , Humanos , Esquemas de Imunização , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Lactente , Masculino , Estudos SoroepidemiológicosRESUMO
BACKGROUND: Vaccination against hepatitis A (HA) was carried out only as part of a limited outbreak control strategy in Argentina until June 2005, when universal immunization in infants was introduced into the national immunization calendar. A single-dose strategy was chosen instead of the standard two-dose schedule used elsewhere. This study aimed to estimate preventive, medical, and non-medical costs related to HA and to compare these costs in the periods before and after mass vaccination. METHODS: A retrospective analysis estimated treatment costs of HA and unspecified hepatitis cases reported to the National Health Surveillance System from 2000 to 2010. Costs related to immunization, fulminant hepatitis (FH), liver transplantation, and death were projected as well. Using a social perspective and a healthcare system perspective, costs in two 5-year periods were compared: 2000-2004 versus 2006-2010. Finally, we evaluated the impact of different discount rates, FH risk, and exclusion of unspecified hepatitis cases in the sensitivity analysis. RESULTS: Total HA and unspecified hepatitis cases decreased from 157,871 in 2000-2004 to 17,784 in 2006-2010. Medical and non-medical costs decreased from US$11,811,600 and US$30,118,222 to US$1,252,694 and US$4,995,895 in those periods, respectively. Immunization costs increased from US$6,506,711 to US$40,912,132. Total preventive, medical, and non-medical costs decreased from US$48,436,534 to US$47,160,721, representing a 2.6% reduction in total costs between the two periods. When a healthcare system perspective was considered or unspecified hepatitis cases were excluded, total costs were 130.2% and 30.8% higher in 2006-2010 than in the previous period, respectively. CONCLUSION: After implementation of the universal single-dose vaccination against HA in infants in Argentina, an impressive decline was observed in HA cases, with a decrease in medical and non-medical costs in the first 5 years. The single-dose strategy, which is simpler and less expensive than the standard two-dose scheme, can be a good alternative for future vaccination policies in other countries where HA is endemic.
Assuntos
Vacinas contra Hepatite A/economia , Vacinas contra Hepatite A/imunologia , Hepatite A/economia , Hepatite A/prevenção & controle , Vacinação/economia , Argentina/epidemiologia , Política de Saúde , Hepatite A/epidemiologia , Vacinas contra Hepatite A/administração & dosagem , Humanos , Programas de Imunização , Modelos Estatísticos , Estudos Retrospectivos , Vacinação/métodosRESUMO
OBJECTIVES: To study the aetiology, outcome and prognostic indicators in children with acute liver failure (ALF). STUDY DESIGN: Retrospective chart review of 210 patients (107 males/103 females; median age: 5.33 years, range: 1-17.4). Patients were followed until discharge (group 1), death (group 2) or liver transplantation (LT; group 3). Data from group 1 were compared to data from the other two groups and King's College criteria were also assessed. RESULTS: Final diagnoses were: 128 (61%) hepatitis A, 68 (32%) indeterminate and 14 (7%) others. The characteristics of patients who survived (n = 59), died (n = 61) and underwent LT (n = 90) were analysed. In multivariate analysis, prothrombin time and encephalopathy III/IV were the most significant parameters suggesting a high likelihood of death. When King's College criteria were applied on admission in patients with and without transplantation, the positive predictive values were 96% and 95%, and the negative predictive values were 82% and 82%, respectively. CONCLUSIONS: Hepatitis A is the main cause of ALF in children in Argentina. Advanced encephalopathy and prolonged prothrombin time were significantly associated with death or need for LT. King's College criteria for predicting the outcome of ALF are applicable in children, including those with ALF due to hepatitis A infection.
Assuntos
Falência Hepática Aguda/mortalidade , Adolescente , Argentina/epidemiologia , Bilirrubina/sangue , Criança , Pré-Escolar , Feminino , Encefalopatia Hepática/classificação , Encefalopatia Hepática/mortalidade , Hepatite A/complicações , Humanos , Lactente , Coeficiente Internacional Normatizado , Falência Hepática Aguda/etiologia , Falência Hepática Aguda/cirurgia , Transplante de Fígado , Masculino , Análise Multivariada , Valor Preditivo dos Testes , Prognóstico , Tempo de Protrombina , Estudos RetrospectivosRESUMO
The aim of this study was to compare major histocompatibility complex (MHC) class II susceptibility to type 1 autoimmune hepatitis (AH) between children and adults of the same ethnic group. HLA-DRB1, HLA-DRB3, HLA-DQA1, and HLA-DQB1 gene subtypes were examined by high resolution oligonucleotide typing in 122 pediatric (PAH) and 84 adult (AAH) patients and in 208 controls. In children, HLA-DRB1*1301 was the primary susceptibility allele (66.4% patients vs. 10.6% controls, relative risk [RR] = 16.3, Pc < 10(-24)) whereas HLA-DRB1*1302, which differs from HLA-DRB1*1301 by only 1 amino acid, appeared to be protective. The exclusion of individuals with HLA-DRB1*1301 from control and pediatric patients allowed us to find a secondary association of PAH with HLA-DRB1*0301. Possession of HLA-DRB1*1301, however, was associated with a lower therapeutic response rate. Analysis of peptide binding pocket residues indicated that Tyr 10, Ser 11, Ser 13, and Val 86 in the class II beta chain were present in 85% of patients compared with 37% of controls, suggesting that a high proportion of AH susceptibility is attributable to these residues (etiologic fraction [EF] = 76%). In contrast to the class II associations in children, AAH was associated with HLA-DRB1*0405 (RR = 10.4, Pc <.005) but not with HLA-DRB1*1301 or HLA-DRB1*0301. In addition, HLA-DR4 with the class I gene, HLA-A11, appeared synergistic in predisposing AAH patients to develop extra-hepatic autoimmune (AI) manifestations (odds ratio [OR] = 104.9, Pc < 10(-4)). Concomitant differences in autoantibody profiles were also observed in PAH versus AAH: smooth muscle antibodies (SMA) were most prevalent in PAH but antinuclear antibodies were most prevalent in AAH (P =.003). This study therefore reveals that different HLA-DRB1 allotypes confer susceptibility to AH in children and adults and raises the possibility that PAH and AAH may be triggered by different factors.
Assuntos
Genes MHC da Classe II , Predisposição Genética para Doença/genética , Hepatite Autoimune/genética , Hepatite Autoimune/imunologia , Adulto , Idade de Início , Alelos , Motivos de Aminoácidos , Argentina , Autoanticorpos/imunologia , Criança , Etnicidade/genética , Antígenos HLA-DQ/genética , Antígenos HLA-DQ/imunologia , Antígenos HLA-DR/química , Antígenos HLA-DR/genética , Antígenos HLA-DR/imunologia , Haplótipos , Hepatite Autoimune/fisiopatologia , Hepatite Autoimune/terapia , Humanos , Desequilíbrio de Ligação/genética , Recidiva , Taxa de Sobrevida , Resultado do TratamentoAssuntos
Hepatite C/epidemiologia , Criança , Hepatite C/transmissão , Humanos , Reação TransfusionalRESUMO
The association of HLA antigens and type I or "lupoid" CAH-C was investigated in a population of 52 Argentinian Caucasoid patients. When compared with a population of normal individuals of the same ethnic group (n = 197), a significant increase of HLA-DR6 was observed (68.6% in patients vs 17.3% in controls; RR = 12.3, chi 2 = 52.4, pc = 0.00001). DNA typing showed that the HLA-DRB1*1301 allele was present in 32 out of 33 HLA-DR6 patients (66.6% of all the C-CAH patients vs 10.5% in controls; RR = 16.2, chi 2 = 111.3, pc = 0.00001). Analysis of HLA-DQB1 alleles also showed a significant increase of DQB1*0603 (RR = 15.4, chi 2 = 106.5, pc = 0.00001), an allele found in strong linkage disequilibrium with DRB1*1301. The association of CAH-C with this particular HLA-DR6 haplotype has not been previously described for the adult onset CAH. This different HLA predisposition, together with the fact that extrahepatic autoimmune diseases occur frequently only in the adult form of the disease, suggest that the immunopathogenic mechanisms involved in the development of these diseases may be different.
Assuntos
Doenças Autoimunes/genética , Antígenos HLA-DR/genética , Haplótipos/genética , Hepatite Crônica/genética , Adolescente , Doenças Autoimunes/imunologia , Criança , Pré-Escolar , DNA/análise , Feminino , Antígeno HLA-DR6/genética , Cadeias HLA-DRB1 , Hepatite Crônica/imunologia , Humanos , MasculinoRESUMO
Fourteen patients between the ages of 9 months and 5 years with chronic diarrhea and giardiasis were studied. Ten were eutrophic and 4 undernourished. The parasitological diagnosis was based on stool examination, a trophozoite search in duodenal aspiration, mucus adhered to mucosa and parasite identification in the intestinal biopsy material. Functional intestinal absorption studies, IgA determination in intestinal secretions and immunofluorescence studies were made. After the tests, tinidazole in suspension was administered at 60-70 mg/kg in one single oral dose. Patients were clinically re-evaluated and tests were done again after 30 days. The purpose of this paper was to evaluate the changes in the functional morphologic and immunologic studies and the therapeutic efficacy of the drug in a single dose. Nine patients had good clinical results, 2 fair and 3 were not evaluated due to celiac disease. All had negative results on the parasitological tests after treatment. There was no relationship between the number of parasites and the severity of symptoms. There was no significant difference between stool fat and d-xylose at the time of diagnosis and 30 days after the administration of tinidazole. The lactose tolerance test presented a significant difference (p less than 0.05) in the disaccharide absorption after treatment. The secretory IgA revealed significantly lower value (p less than 0.01) with respect to the normal values. The immunofluorescence showed productive IgA cells in all cases. The histologic changes were: mild enteropathy (grade I) in 6 patients; moderate (grade II) in 5; and severe (grade III-IV) in 3. Improvement of the mucosa was seen in 6 patients.
Assuntos
Diarreia/parasitologia , Giardíase/tratamento farmacológico , Nitroimidazóis/administração & dosagem , Tinidazol/administração & dosagem , Administração Oral , Pré-Escolar , Ensaios Clínicos como Assunto , Diarreia/fisiopatologia , Diarreia Infantil/parasitologia , Feminino , Giardíase/fisiopatologia , Humanos , Imunoglobulina A Secretora/análise , Lactente , Absorção Intestinal , Secreções Intestinais/análise , Intestino Delgado/patologia , Lactose/metabolismo , Masculino , Estado NutricionalAssuntos
Hepatite Viral Humana/microbiologia , Doença Aguda , Adolescente , Criança , Pré-Escolar , Feminino , Anticorpos Anti-Hepatite B/análise , Antígenos de Superfície da Hepatite B/análise , Vírus de Hepatite/imunologia , Hepatite Viral Humana/imunologia , Hepatite Viral Humana/patologia , Humanos , Lactente , Fígado/patologia , MasculinoRESUMO
Seven patients with diagnosis of biliary atresia (BA) and two patients with neonatal hepatitis were studied by electron microscopy. In all patients the diagnosis was done by clinical examinations, laboratory assays, histological studies by punch or surgical biopsies and or surgical examinations combined with intraoperatory cholangiography. The ultrastructural alterations found in both groups of patients were essentially similar to those described in other forms of cholestasis. In patients suffering from biliary atresia the main features found at hepatocytic livel were: Finely granular deposits of electron dense substance sometimes conforming lamellar structures; 2) Some increase and vesiculation of smooth endoplasmic reticulum membranes; 3) Reductions in number and length of sinusoidal microvilli; in some areas was also detected basal membrane and an increase in the amount of collagen fibers in the space of Disse; 4) Marked bile canaliculi dilatations with reduction of microvilli and thickening of the pericanalicular surrounding area, some canaliculi were constitued by several hepatocytes. Ductules were found in only 3 cases with the following alterations: 1) Intracytoplasmic electron dense deposits of granular material without limiting membranes; 2) A marked increase in the number of microfilaments mainly located in the apical portion of the cell or in the vicinity of the nuclei; 3) Inflammatory cells in the duct epithelium or in direct contact with the hepatocytes. The ultrastructural findings in the two cases of neonatal hepatitis (NH) resembled those described in the biliary atresia.(ABSTRACT TRUNCATED AT 250 WORDS)