RESUMO
BACKGROUND: Enteric hepatitis A virus (HAV) infections during childhood are often asymptomatic but may cause severe illness in adults. To improve public health surveillance we assessed the applicability of sewage monitoring during an HAV outbreak at a primary school. METHODS: Between October 19 and December 27, 2022, five symptomatic HAV cases were notified to the Public Health Service Amsterdam; all attended the same primary school. Passive samplers, small absorbent tools, were deployed in sewage near the school from November 14, 2022, to March 22, 2023. The absorbents were subjected to RNA extraction, HAV PCR testing, and, if positive, sequencing. PCR and sequencing were also performed on plasma and feces samples of HAV cases. RESULTS: In 22 out of 88 (25%) of sewage samples, HAV RNA was detected. All HAV-RNA-positive sewage samples until 8 February 2023 were subgenotype IB, matching the strain detected in all cases. Another strain of HAV (subgenotype IA) was detected in sewage from 15 February 2023 onwards, without associated cases. CONCLUSIONS: Passive sampler-based sewage monitoring is an effective method to rapidly detect HAV shedding linked to diagnosed cases. It detects unnoticed viral infections and allows monitoring of outbreaks. This suggests that passive sampler-based monitoring is a promising tool supporting the public health response during HAV and other outbreaks.
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Surtos de Doenças , Hepatite A , RNA Viral , Instituições Acadêmicas , Esgotos , Humanos , Hepatite A/epidemiologia , Hepatite A/virologia , Hepatite A/diagnóstico , Países Baixos/epidemiologia , Esgotos/virologia , RNA Viral/genética , RNA Viral/análise , Criança , Vírus da Hepatite A/isolamento & purificação , Vírus da Hepatite A/genética , Fezes/virologia , Masculino , Feminino , Genótipo , AdolescenteRESUMO
Among the risk factors and underlying etiology of acute portal vein thrombosis, viral hepatitis is an extremely rare cause. We report a case of a young healthy 40-year-old male who was diagnosed with acute hepatitis A virus infection and presented with acute portal vein thrombosis. This article describes the possible pathophysiological mechanisms, clinical symptoms, and treatment of acute portal vein thrombosis in this patient. Based on this patient's history and treatment, we encourage testing for hepatitis A serological markers in the emergency department in a population with recent hepatitis A exposure risk factors and concurrent unexplained acute portal thrombosis.
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Hepatite A , Veia Porta , Trombose Venosa , Humanos , Masculino , Veia Porta/diagnóstico por imagem , Adulto , Trombose Venosa/tratamento farmacológico , Trombose Venosa/diagnóstico , Hepatite A/complicações , Hepatite A/diagnóstico , Anticoagulantes/uso terapêutico , Resultado do Tratamento , Doença AgudaRESUMO
BACKGROUND: Acute hepatitis A infection is common among children in developing nations. The clinical presentation in children is usually asymptomatic and anicteric, and it is a self-limiting infection. Rarely, it can be associated with extrahepatic complications such as pleural effusion, acalculous cholecystitis, and ascites. CASE PRESENTATION: An 8-year-old middle eastern child presented with abdominal pain, jaundice in the sclera, yellowish color of urine, and poor appetite. In the last two days, abdominal distension developed. After conducting diagnostic investigations, the child was diagnosed with HAV hepatitis associated with bilateral pleural effusion, acalculous cholecystitis, and ascites. He was managed conservatively with vitamin K supplementation and supportive parenteral fluids. After 4 days, clinical improvement was observed. CONCLUSION: Hepatitis A infections presented with extrahepatic manifestations like pleural effusion, acalculous cholecystitis, and ascites are very rare, especially in children. There have been some reports of these manifestations occurring in isolation, but for them to co-exist to our knowledge, this has only been reported in two cases in the literature, and this is the third case with all these three rare complications being presented simultaneously in a single child. Although HAV infection is an asymptomatic and self-limiting viral disease in childhood, it can manifest with rare extrahepatic complications, so pediatricians should be aware of this rare association to avoid unnecessary investigations.
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Colecistite Acalculosa , Ascite , Hepatite A , Derrame Pleural , Humanos , Colecistite Acalculosa/diagnóstico , Colecistite Acalculosa/virologia , Hepatite A/complicações , Hepatite A/diagnóstico , Ascite/etiologia , Criança , Derrame Pleural/etiologia , Masculino , Vitamina K/uso terapêutico , Dor Abdominal/etiologiaRESUMO
Viral hepatitis during pregnancy is common globally. In this review, we focus on the antenatal screen for hepatitis A, B, C and E, the prevention of mother-to-child transmission (MTCT) of hepatitis B and C, and the management of hepatitis A, B, C and E during pregnancy. Neonatal timely administration of hepatitis B immunoglobulin and hepatitis B vaccine is the cornerstone for preventing MTCT of hepatitis B virus (HBV), and perinatal antiviral prophylaxis with tenofovir disoproxil fumarate in mothers with positive HBeAg or HBV DNA >2 × 105 IU/ml also plays important roles in further reducing MTCT. Avoidance of risk practices in managing labor and delivery process of women with HCV infection may be useful to reduce MTCT of HCV. Early recognition of severe hepatic injury or liver failure associated with hepatitis viruses by regular liver function tests is critical to prevent maternal mortality associated with hepatitis.
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Hepatite Viral Humana , Transmissão Vertical de Doenças Infecciosas , Complicações Infecciosas na Gravidez , Humanos , Gravidez , Feminino , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/prevenção & controle , Hepatite Viral Humana/diagnóstico , Hepatite Viral Humana/prevenção & controle , Antivirais/uso terapêutico , Hepatite B/prevenção & controle , Hepatite B/diagnóstico , Hepatite B/transmissão , Portador Sadio/diagnóstico , Programas de Rastreamento/métodos , Recém-Nascido , Hepatite A/prevenção & controle , Hepatite A/diagnóstico , Hepatite A/transmissão , Vacinas contra Hepatite B/administração & dosagem , Vacinas contra Hepatite B/uso terapêutico , Hepatite C/diagnóstico , Hepatite C/prevenção & controle , Hepatite C/transmissãoRESUMO
Computer-aided vibrational spectroscopy detection technology has achieved promising results in the field of early disease diagnosis. Yet limited by factors such as the number of actual samples and the cost of spectral acquisition in clinical medicine, the data available for model training are insufficient, and the amount of data varies greatly between different diseases, which constrain the performance optimization and enhancement of the diagnostic model. In this study, vibrational spectroscopy data of three common diseases are selected as research objects, and experimental research is conducted around the class imbalance situation that exists in medical data. When dealing with the challenge of class imbalance in medical vibrational spectroscopy research, it no longer relies on some kind of independent and single method, but considers the combined effect of multiple strategies. SVM, K-Nearest Neighbor (KNN), and Decision Tree (DT) are used as baseline comparison models on Raman spectroscopy medical datasets with different imbalance rates. The performance of the three strategies, Ensemble Learning, Feature Extraction, and Resampling, is verified on the class imbalance dataset by G-mean and AUC metrics, respectively. The results show that all the above three methods mitigate the negative impact caused by unbalanced learning. Based on this, we propose a hybrid ensemble classifier (HEC) that integrates resampling, feature extraction, and ensemble learning to verify the effectiveness of the hybrid learning strategy in solving the class imbalance problem. The G-mean and AUC values of the HEC method are 82.7 % and 83.12 % for the HBV dataset, is 2.02 % and 1.98 % higher than the optimal strategy; 83.62 % and 83.76 % for the HCV dataset, is 9.79 % and 8.47 % higher than the optimal strategy; while for the thyroid dysfunction dataset are 77.56 % and 77.85 %, is 6.92 % and 6.36 % higher than that of the optimal strategy, respectively. The experimental results show that the G-mean and AUC metrics of the HEC method are higher than those of the baseline classifier as well as the optimal combination using separate strategies. It can be seen that the HEC method can effectively counteract the unfavorable effects of imbalance learning and is expected to be applied to a wider range of imbalance scenarios.
Assuntos
Hepatite A , Hepatite B , Análise Espectral Raman , Análise Espectral Raman/métodos , Humanos , Hepatite B/diagnóstico , Hepatite B/sangue , Hepatite A/diagnóstico , Hepatite A/sangue , Doenças da Glândula Tireoide/diagnóstico , Doenças da Glândula Tireoide/sangue , Máquina de Vetores de Suporte , Algoritmos , Aprendizado de Máquina , Árvores de DecisõesRESUMO
BACKGROUND AND OBJECTIVES: Acute liver failure (ALF) is an uncommon but potentially dramatic syndrome characterized by massive hepatic necrosis and has a very high mortality rate of 50% to 75% without liver transplantation. This study is aimed at analyzing the etiological spectrum of ALF patients and compare these with ALF mimics such as malaria, dengue fever and other tropical infectious diseases. METHODS: The study population included patients who presented with ALF and ALF mimics in a tertiary care center over two years. We retrospectively analyzed the patient case files and a comparison was made concerning the baseline demographic details, clinical profile, laboratory values and outcomes. RESULTS: Sixty-three patients were assessed, with 32 in ALF and 31 in ALF mimics group. The most common cause for ALF was hepatitis A virus (25%), followed by hepatitis B virus (18.7%), drug-induced liver injury (12.7%), autoimmune hepatitis (12.5%), hepatitis E virus (9.3%) and Wilson's disease (6.25%). In the ALF mimics group, malaria (58.06%) was the most common cause, followed by dengue fever (16.1%), leptospirosis (12.9%) and scrub typhus (12.9%). Patients in the ALF mimics group had significantly higher incidence of fever (p = 0.001), hepatosplenomegaly (p = 0.01), anemia (p = 0.02) and shorter jaundice to encephalopathy duration (p = 0.032) as compared to the ALF group, while higher transaminase levels (p = 0.03), bilirubin (p = 0.01), prothrombin time (p = 0.01), serum ammonia (p = 0.02) and mortality (p = 0.02) were observed in ALF patients. CONCLUSIONS: The most common cause for ALF was hepatitis A virus, followed by hepatitis B virus, while in ALF mimics it was malaria followed by dengue fever, in our study. Patients of ALF mimics can have similar presentation, but a high index of suspicion and awareness is required to identify the common infectious ALF mimics for early diagnosis.
Assuntos
Dengue , Falência Hepática Aguda , Malária , Humanos , Falência Hepática Aguda/etiologia , Estudos Retrospectivos , Feminino , Masculino , Adulto , Malária/complicações , Diagnóstico Diferencial , Pessoa de Meia-Idade , Dengue/complicações , Dengue/diagnóstico , Hepatite A/complicações , Hepatite A/diagnóstico , Hepatite B/complicações , Hepatite Autoimune/complicações , Degeneração Hepatolenticular/complicações , Degeneração Hepatolenticular/diagnóstico , Hepatite E/complicações , Adulto Jovem , AdolescenteRESUMO
OBJECTIVES: Hepatitis A virus (HAV) is the commonest cause for pediatric acute liver failure (PALF) in India. The objective of the study was to identify the predictors of mortality and to evaluate the utility of Peds-HAV model in a cohort of non-LT HAV-PALF. METHODS: The study included HAV-related PALF from two non-transplant centers. The predictors of outcome were identified by univariate analysis followed by Cox regression analysis. The prognostic accuracy of Peds-HAV model, King's College Hospital (KCH) criteria and pediatric end-stage liver disease score (PELD) were evaluated. RESULTS: As many as 140 children with PALF were included, of whom 96 (68.6%) children had HAV-PALF. On Cox regression analysis, international normalized ratio (INR) (p < 0.001), jaundice to encephalopathy (JE) interval (p < 0.001) and hepatic encephalopathy (HE) grade 3/4 (p = 0.01) were independent predictors of mortality. The mortality rates were 0% (0/42), 14.3% (3/21), 60% (9/15) and 94.4% (17/18) when none, 1, 2 or 3 criteria of the Peds-HAV were met, respectively. Peds-HAV model at a listing cut-off of ≥ 2 criteria predicted death with 89.7% sensitivity and 89.6% specificity. In contrast, KCH criteria had a lower sensitivity of 62.1%. PELD score had a sensitivity of 89.7% and specificity of 85.1% at a cut-off of 30. The overall prognostic accuracy of Peds-HAV model (89.6%) was higher than those of KCH (83.3%) and PELD (86.5%). CONCLUSION: INR, HE grade and JE interval were independent predictors of mortality. The study provides an external validation of Peds-HAV model as a prognostic score in HAV-PALF. CLINICAL TRIAL REGISTRY NUMBER: Not applicable as this is a retrospective study.
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Hepatite A , Falência Hepática Aguda , Humanos , Prognóstico , Hepatite A/complicações , Hepatite A/diagnóstico , Hepatite A/mortalidade , Falência Hepática Aguda/mortalidade , Falência Hepática Aguda/etiologia , Falência Hepática Aguda/diagnóstico , Feminino , Masculino , Criança , Pré-Escolar , Lactente , Coeficiente Internacional Normatizado , Encefalopatia Hepática/etiologia , Encefalopatia Hepática/diagnóstico , Estudos de Coortes , Adolescente , Biomarcadores/sangue , Índia/epidemiologia , Icterícia/etiologia , Valor Preditivo dos TestesRESUMO
Studies reporting the expression of hepatitis A virus (HAV) structural proteins, specifically recombinant VP1-2A containing an immunogenic activity, use the Escherichia coli system. Recombinant HAV proteins may represent a source of less expensive antigens for application in different diagnostic platforms. However, the formation of insoluble aggregates is an obstacle to obtaining large amounts of HAV proteins in their native form. To overcome this obstacle, some approaches were applied in this study to improve purification, solubility, and protein expression levels. Critical properties were evaluated. The introduction of another insertion codon to increase the protein concentration and vector activity was observed and verified by SDS-PAGE. The expression was established with 0.4 mM IPTG for 4 h at 37 °C. The VP1 protein was partially soluble at an isoeletric point (pI) of 6.45. The majority of HAV VP1-2A proteins measured 45.19 kDa in size and had a homogeneity of 53.58%. Multi-antigen print immunoassay (MAPIA) showed antigenicity at different HAV VP1-2A concentrations, and microsphere-based immunoassays showed a specificity of 100% and a sensitivity of 84%. HAV VP1-2A was characterized using different sensitivity methods to prove its biological activity, indicating its use as a tool for the diagnosis of Hepatitis A virus infection.
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Vírus da Hepatite A , Hepatite A , Humanos , Vírus da Hepatite A/genética , Proteínas Recombinantes , Hepatite A/diagnósticoRESUMO
Hepatitis A is a common cause of acute infectious hepatitis in children, transmitted through the faeco-oral route. Although mostly self-limiting, cholestasis is a rare but known complication of acute hepatitis A in children. This report presents an adolescent girl who developed cholestatic features following hepatitis A infection and successful treatment with oral steroid therapy. Prolonged cholestasis jaundice (PCJ) is a known manifestation of hepatitis A infection, characterised by prolonged fever, pruritus and jaundice. While the exact mechanisms causing PCJ are not fully understood, immunological-mediated responses could play a role. Treatment options for PCJ are limited, and there is no currently accepted standard of care. Steroids have shown promise in treating PCJ, as observed in this case and a few other reported cases. When other therapies fail to alleviate symptoms, corticosteroids should be considered as a potential treatment option. However, further studies are required to conclusively establish their efficacy.
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Colestase , Hepatite A , Hepatite , Icterícia Obstrutiva , Icterícia , Adolescente , Feminino , Humanos , Colestase/etiologia , Colestase/complicações , Hepatite/complicações , Hepatite A/complicações , Hepatite A/tratamento farmacológico , Hepatite A/diagnóstico , EsteroidesRESUMO
Hepatitis A is one of the most common causes of acute viral hepatitis in children. Immunological manifestations involving the nervous system are rare with hepatitis A infection. We report a case of a toddler who presented with acute liver failure secondary to hepatitis A infection. The child showed clinical and laboratory improvement initially with conservative management. However, after the initial improvement, she developed acute-onset ptosis along with areflexia. Serological and neurophysiological tests revealed the occurrence of ocular variant Guillain-Barré syndrome and ocular myasthenia gravis, which was only partially responsive to treatment (intravenous immunoglobulin and pyridostigmine). A sudden clinical deterioration was noted after the onset of ptosis. She succumbed on day 40 of hospitalisation due to hospital-acquired infection along with the primary hepatic pathology. This is a rare coincidental presentation of acute viral hepatitis A infection with autoimmune manifestations.
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Blefaroptose , Síndrome de Guillain-Barré , Vírus da Hepatite A , Hepatite A , Falência Hepática Aguda , Miastenia Gravis , Feminino , Humanos , Síndrome de Guillain-Barré/complicações , Síndrome de Guillain-Barré/diagnóstico , Hepatite A/complicações , Hepatite A/diagnóstico , Miastenia Gravis/complicações , Miastenia Gravis/diagnóstico , Miastenia Gravis/tratamento farmacológico , Blefaroptose/complicações , Doença Aguda , Falência Hepática Aguda/complicaçõesRESUMO
Picornavirus hepatitis A virus (HAV) is a common cause of hepatitis worldwide. It is spread primarily through contaminated food and water or person-to-person contact. HAV I has been identified as the most common type of human HAV infection. Here, we have developed a cell-free toehold switch sensor for HAV I detection. We screened 10 suitable toehold switch sequences using NUPACK software, and the VP1 gene was used as the target gene. The optimal toehold switch sequence was selected by in vivo expression. The best toehold switch concentration was further found to be 20 nM in a cell-free system. 5 nM trigger RNA activated the toehold switch to generate visible green fluorescence. The minimum detection concentration decreased to 1 pM once combined with NASBA. HAV I trigger RNA could be detected accurately with excellent specificity. In addition, the cell-free toehold switch sensor was verified in HAV I entities. The successful construction of the cell-free toehold switch sensor provided a convenient, rapid, and accurate method for HAV I on-site detection, especially in developing countries, without the involvement of expensive facilities and additional professional operators.
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Vírus da Hepatite A , Hepatite A , Humanos , Vírus da Hepatite A/genética , Hepatite A/diagnóstico , Vírus da Hepatite A Humana/genética , RNARESUMO
BACKGROUND: We evaluated the proportion, clinical features, and outcomes of previously healthy children presenting to a large Canadian quaternary pediatric center with severe acute hepatitis of unknown etiology. METHODS: All patients with serum alanine aminotransferase (ALT) > 500 U/L or aspartate aminotransferase (AST) > 500 U/L between June 1, 2018, and May 31, 2022, at The Hospital for Sick Children, were identified. Subjects with only AST > 500 U/L were excluded. Clinical characteristics, investigations, and outcomes for patients without clear etiology for ALT > 500 U/L (severe acute hepatitis of unknown etiology) for our study period and from October 1 to May 31 of each year 2018-2021 were reviewed. RESULTS: Of 977 patients with ALT/AST> 500 U/L, 720 had only ALT > 500 U/L. We excluded age below 6 months (n = 99) or above 16 years (n = 66), known pre-existing liver conditions (n = 66), and ALT > 500 U/L in already admitted patients (n = 151). Among the remaining 338 children with ALT > 500 U/L at presentation, an etiology was identified in 303 subjects. 33 (9.8%) children [median age 6.1 y (range 0.5-15.5); 61% male] were confirmed as severe acute hepatitis of unknown etiology. Twenty patients (60.6%) were tested for blood adenovirus by PCR, and 1 (5%) was positive (serotype B7). Liver tissue specimens from 18 patients revealed no evidence of viral inclusions or adenovirus. Twelve (36.3%) presented with pediatric acute liver failure, with 8 (24.2%) requiring liver transplantation. There were no deaths. Hepatitis-associated aplastic anemia occurred in 5 (15%) patients. CONCLUSIONS: Of children presenting with severe acute hepatitis to a quaternary children's hospital over a 48-month period, 9.8% had unknown etiology with no change over time. Liver transplantation remains an important treatment strategy for those presenting with pediatric acute liver failure phenotype. The frequency of cases associated with human adenovirus infection was noncontributory.
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Hepatite A , Hepatite , Falência Hepática Aguda , Humanos , Criança , Masculino , Lactente , Feminino , Canadá/epidemiologia , Hepatite/etiologia , Hepatite A/complicações , Hepatite A/diagnóstico , Hepatite A/epidemiologia , Doença Aguda , Falência Hepática Aguda/diagnóstico , Falência Hepática Aguda/epidemiologia , Falência Hepática Aguda/etiologiaRESUMO
High-throughput sequencing is a robust tool used for identifying and tracking pathogen outbreaks. Whole-genome sequencing of hepatitis A virus (HAV) remains poor due to ultra-low viral loads, limitations of next-generation sequencing technology, and its high costs in clinical applications. This study evaluated multiplex polymerase chain reaction (PCR)-based nanopore sequencing to obtain whole-genome sequences of HAV. The HAV genomes were obtained directly from patient specimens for a rapid molecular diagnosis of viral genotypes. Serum and stool samples were collected from six patients with hepatitis A infection. Amplicon-based nanopore sequencing was performed from the clinical specimens to identify HAV genotypes by acquiring nearly complete-genome sequences. TaqMan-based quantitative PCR (qPCR) was conducted to detect and quantify multiple HAV genes. Singleplex-based nanopore sequencing demonstrated high genome coverage rates (90.4-99.5%) of HAV within 8 h, at viral RNA loads of 10 to 105 copies/µL. TaqMan qPCR showed multiplex quantification of HAV genes namely, VP0, VP3, and 3C. This study provides useful insights into rapid molecular diagnosis during hepatitis A outbreaks and may ultimately augment public health disease surveillance in the hospital and epidemiology field.
Assuntos
Vírus da Hepatite A , Hepatite A , Sequenciamento por Nanoporos , Humanos , Hepatite A/diagnóstico , Hepatite A/epidemiologia , Vírus da Hepatite A/genética , Surtos de Doenças , GenótipoRESUMO
Background and Objectives: Chronic viral hepatitis such as hepatitis B or hepatitis C is frequently related to nephropathies, yet acute hepatitis A virus (HAV) infection is an exception. Materials and Methods: A 43-year-old male presented with jaundice accompanied by nausea and vomiting. The patient was diagnosed with acute HAV infection. Although the liver function improved after conservative treatment, various symptoms such as proteinuria, hypoalbuminemia, generalized edema and pleural effusion persisted. Due to nephrotic syndrome, the patient was referred to the clinic of the nephrology department and a renal biopsy was performed. Results: The result of the renal biopsy was focal segmental glomerulosclerosis (FSGS) based on histology, electron microscopy and immunohistochemistry. Therefore, based on the clinical history and biopsy results, the patient was diagnosed as having FSGS aggravated by acute HAV infection. Proteinuria, hypoalbuminemia and generalized edema were improved after prednisolone treatment. Conclusions: Although less common, acute HAV infection can also present with an extrahepatic manifestation, for example, FSGS. Hence, clinical attention is required if proteinuria or hypoalbuminemia persists in patients with acute HAV infection.
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Glomerulosclerose Segmentar e Focal , Hepatite A , Hipoalbuminemia , Síndrome Nefrótica , Masculino , Humanos , Adulto , Glomerulosclerose Segmentar e Focal/complicações , Glomerulosclerose Segmentar e Focal/tratamento farmacológico , Hepatite A/complicações , Hepatite A/diagnóstico , Hipoalbuminemia/complicações , Síndrome Nefrótica/complicações , ProteinúriaRESUMO
Hepatitis A diagnosis relies on serology and occasionally on hepatitis A virus (HAV) RNA detection. For timely diagnosis and the avoidance of drawing additional blood, molecular testing is often performed as reflex testing by using blood specimens that were initially sent for anti-HAV serology. Reflex molecular testing is preferably performed from different sample aliquots, but, for limited sample quantities, it uses samples that have been preprocessed in an immunoassay analyzer. In 2012, we first observed sporadic HAV RNA-positive cases that were inconsistent with patients' serological profiles and/or medical histories, suggesting that occasional laboratory contamination was causing false-positive PCR results. Multiple external quality assurance (EQA) and laboratory surface contamination checks were performed, questionable specimens were tested with various HAV RNA tests, and follow-up serum/stool samples were collected. All contamination-check samples and samples from healthy individuals tested HAV RNA-negative, and the laboratory successfully passed all EQAs. The HAV RNA-positive results were reproducible with various HAV RNA assays. No patients seroconverted, and their follow-up samples were consistently HAV RNA-negative. Finally, a detailed review of testing protocols revealed a correlation between HAV RNA false positivity and preceding anti-HAV testing with the Cobas-e411 automated immunoassay analyzer. HAV RNA was detected in the Cobas-e411 anti-HAV reagents, with the HAV sequences matching those from the false-positive samples. Preceding anti-HAV testing using two other immunoassay analyzers did not result in subsequent HAV RNA false positivity during reflex testing. The Cobas-e411 pipetting procedure with a single pipette tip collecting samples and anti-HAV reagents contaminated the original sample with the HAV RNA that was present in the immunoassay's reagents, thereby resulting in HAV RNA false positivity during the reflex testing. IMPORTANCE We present the first report of sporadic HAV PCR false-positive results that have been observed during the reflex testing of serum samples that have previously been tested for anti-HAV antibodies and have been caused by contamination with HAV RNA that is present in the reagents of the commercial anti-HAV immunoassay, with potentially serious clinical consequences. Although HAV RNA was consistently detected in the anti-HAV reagents of all three automated immunoassay analyzers that were in use in our laboratory, only the use of one analyzer and the corresponding commercial anti-HAV immunoassay reagents resulted in contamination that led to false positive HAV RNA results, and this was due to a peculiar pipetting mode of action in which the analyzer uses a single pipette tip to collect both anti-HAV reagents and a sample, which consequently causes the permanent contamination of the original sample with HAV RNA. Manufacturers should strongly consider the occasional need for reflex molecular testing from preprocessed samples and design their analyzers in a way that prevents contamination.