High prevalence of hepatitis B virus and low vaccine response in children and adolescents in Northeastern Brazil

Could Herpesviridae be the cause of severe acute hepatitis of unknown origin in children?

INTRODUCTION

Severe acute hepatitis (SAH) is defined by a severe inflammation of hepatocytes in the liver parenchyma which can lead to an acute liver failure, a clinical condition with high mortality rate that can be triggered by several factors but is usually associated to hepatotropic viruses' infection. In 2022, cases of children with severe acute hepatitis of unknown origin hospitalized in Glasgow, Scotland, were reported. Possible causes of this condition include, but are not limited to, undiagnosed viral (and non-viral) infections, autoimmune hepatitis, drug and/or chemical toxicity, mitochondrial chain respiratory and metabolic disorders.

AREAS COVERED

Herpesviruses can cause severe acute hepatitis, but little is known about the role and the mechanisms of herpesviruses as a causative agent of this type of hepatitis. We review the role of herpesviruses as causative agent of SAH in children and other possible mechanisms involved in this disease.

EXPERT OPINION

Differential diagnosis for herpesvirus in SAH should be implemented in all settings. Alternative fluids, such as saliva and dried blood, could be used in the diagnosis to overwhelm the availability of biological specimens at sufficient volume. In the future, genetic studies could also be added to increase the knowledge about severe acute hepatitis in children.

Indicators of the National Immunization Program for children under one year old: time trend in Maranhão, Brazil, 2010 to 2021

We aimed to analyze the trend of indicators of the National Immunization Program (acronym in Portuguese. PNI) in children under one-year-old and classify municipalities regarding the risk of transmission of vaccine-preventable diseases (RTVPD) in Maranhão from 2010 to 2021. This ecological time series study was based on secondary data on vaccination coverage (VC). vaccination coverage homogeneity (VCH). proportion of abandonment (PA). and RTVPD. with state coverage for vaccines in the national children's calendar. Prais-Winsten regression estimated trends (α=5%) and the indicators' annual percentage change (APC). We identified fluctuating and discrepant VC between vaccines. with a decreasing trend (p < 0.01). except those against Hepatitis B (p = 0.709) and oral human rotavirus (p = 0.143). The sharpest falls were for Yellow Fever (APC = 12.24%) and BCG (APC = 12.25%) vaccines. All VCH rates were lower than expected. with a drop from 2014 and APC between 5.75% (Pneumococcal 10; p = 0.033) and 14.02% (Poliomyelitis; p < 0.01). We observed an increasing trend in PA for Pentavalent (APC = 4.91%; p < 0.01) and Poliomyelitis (APC = 3.55%; p < 0.01). We identified an increase of 52.54% in the proportion of municipalities in Maranhão from 2015 to 2021. with extremely high (p = 0.025) and high (p = 0.028) RTVPD. The PNI indicators deteriorated. reaffirming the susceptibility to the emergence of vaccine-preventable diseases.