ABSTRACT
Hepatitis B virus (HBV) infection is a major public health problem in the world. Approximately 296 million people are chronically infected. In endemic areas, vertical transmission is a common route of transmission. There are several strategies for the prevention of HBV vertical transmission, such as antiviral treatment during the third trimester of pregnancy and immunoprophylaxis to newborns that includes the administration of hepatitis B immune globulin (HBIG) and an HBV vaccine. Despite this, immunoprophylaxis failure can occur in up to 30% of infants born to HBeAg-positive mothers and/or with high viral load. Therefore, management and prevention of HBV vertical transmission is of paramount significance. In this article, we provided a review of the epidemiology, mechanisms of pathogenesis and risk factors of vertical transmission, as well as the strategies implemented to prevent the infection.
ABSTRACT
El virus de la hepatitis delta (VHD) es un virus satélite del virus de la hepatitis B (VHB), dado que requiere el antígeno de superficie del VHB (HBsAg) para la producción de partículas virales infecciosas. Se han caracterizado ocho genotipos del VHD, con una distribución geográfica relacionada con la prevalencia de la infección por VHB. Se estima que aproximadamente el 5% de los pacientes con infección crónica por VHB también están infectados con VHD. Se han descrito dos tipos de infección: la coinfección simultánea por VHB y VHD, y la superinfección con VHD en un paciente previamente infectado por VHB, esta última asociada a una mayor morbilidad y mortalidad por falla hepática aguda. La infección se diagnostica en nuestro medio con la determinación de IgM contra el VHD, acompañada idealmente de la carga viral. Aunque el tratamiento de elección es la terapia con interferón alfa pegilado, en el momento se están evaluando otros medicamentos antivirales en ensayos clínicos, con resultados alentadores, teniendo en cuenta el efecto observado en la carga viral del VHD y/o del VHB en los pacientes. La presente revisión tiene como objetivo incluir temas como la biología del virus, la epidemiología, las características clínicas, el diagnóstico y el tratamiento en la infección por VHD.
Hepatitis delta virus (HDV) is a satellite virus of hepatitis B virus (HBV), as it requires the HBV surface antigen (HBsAg) for the production of infectious viral particles. Eight HDV genotypes have been characterized with a geographic distribution associated with the prevalence of HBV infection. It is estimated that approximately 5% of patients with chronic HBV infection are also infected with HDV. Two types of infection have been described: coinfection, by simultaneously contracting HBV and HDV infection, and superinfection, by contracting HDV when chronically infected with HBV, the latter associated with increased morbidity and mortality from acute liver failure. Anti-HDV IgM is used to diagnose the infection, ideally together with the detection of HDV-RNA. Although the treatment of choice is pegylated interferon alpha, other antiviral drugs are currently being evaluated in clinical trials, with encouraging results, in terms of their effect on HDV and/or HBV viral load in patients. This review aims to include topics such as virus biology, epidemiology, clinical manifestations, diagnosis, and treatment in HDV infection.
Subject(s)
Humans , Hepatitis Delta Virus , Hepatitis B virus , Epidemiology , Diagnosis , Drug TherapyABSTRACT
BACKGROUND: In Colombia, cases of Hepatitis D virus (HDV) infection have been officially described since 1985 mainly in Amerindian population from Sierra Nevada de Santa Marta (North Caribbean Coast), Uraba (North West), and Amazon (South East). The last official report of a clinical case of HDV infection in Colombia was registered in 2005. OBJECTIVES: The aims of this study were to identify cases of HDV and/or Hepatitis B virus (HBV) infection in asymptomatic Amerindians from Amazonas state, South East Colombia, and to describe the circulating viral genotypes in this population. STUDY DESIGN: The study population was recruited in 19 Amerindian communities in the Amazonas state. Individuals over 18 years old were screened by rapid test for Hepatitis B surface Antigen (HBsAg). Blood samples obtained from individuals positives for HBsAg in the rapid-test assay were analyzed for HBsAg, anti-HBc, anti-HDV IgM/IgG by ELISA. The detection of HBV DNA and HDV RNA was performed by PCR amplification. The viral genotype was determined by sequencing and phylogenetic analysis. RESULTS: A total of 23/861 individuals were positive for HBsAg detection by rapid test. Serological and/or molecular markers of HDV infection were demonstrated in 43.5 % (10/23) of samples from Amerindians. The phylogenetic analysis demonstrated the exclusive circulation of HBV subgenotype F1b of and HDV 3 in this population. CONCLUSIONS: A high frequency of HBV/HDV infection was found in Amerindian population from Amazonas State, Colombia (43.5 %, 10/23). Nine cases were identified in a population of 861 asymptomatic Amerindian individuals; one symptomatic case (with diagnosis of end-stage hepatic disease) was also identified in the study. The circulation of HDV 3 and HBV subgenotype F1b suggests a constant flow of these viral genotypes as a result of the interaction of the Amerindian populations from Amazon basin. Further studies are necessary to confirm whether HBV subgenotype F1b is the prevalent in the population from South East region in Colombia.
