Quantitation of human parvovirus B19 DNA in erythema infectiosum and aplastic crisis

Parvovirus B19 Outbreak in Israel: Retrospective Molecular Analysis from 2010 to 2023

This study presents an analysis of the epidemiological trends of parvovirus B19 (B19V) in Israel from 2010 to 2023, with particular emphasis on the outbreak in 2023. The analysis utilized molecular diagnostic data from individual patients obtained at the Central Virology Laboratory. Between 2010 and 2022, 8.5% of PCR-tested samples were positive for B19V, whereas in 2023, this percentage surged to 31% of PCR-tested samples. Throughout the study period, annual cycles consistently peaked in early spring/summer, with the most recent prominent outbreak occurring in 2016. Predominantly, diagnoses were made in children and women aged 20-39. Despite the notable surge in 2023, over 80% of positive cases continued to be observed in children and young women, with a decrease in cases during winter months. Furthermore, genotype 1a of the virus remained the predominant strain circulating during the outbreak. In light of these circumstances, consideration should be given to implementing screening measures, particularly among high-risk groups such as pregnant women.

Parvovirus B19 Infection and Pregnancy: Review of the Current Knowledge

Parvovirus B19, a member of the Parvoviridae family, is a human pathogenic virus. It can be transmitted by respiratory secretions, hand-to-mouth contact, blood transfusion, or transplacental transmission. Most patients are asymptomatic or present with mild symptoms such as erythema infectiosum, especially in children. In rare cases, moderate-to-severe symptoms may occur, affecting blood cells and other systems, resulting in anemia, thrombocytopenia, and neutropenia. Non-immune pregnant women are at risk for fetal infection by parvovirus B19, with greater complications if transmission occurs in the first or second trimester. Infected fetuses may not show any abnormalities in most cases, but in more severe cases, there may be severe fetal anemia, hydrops, and even pregnancy loss. Maternal diagnosis of intrauterine parvovirus B19 infection includes IgG and IgM antibody testing. For fetal diagnosis, PCR is performed through amniocentesis. In addition to diagnosing the infection, it is important to monitor the peak of systolic velocity of the middle cerebral artery (PVS-MCA) Doppler to assess the presence of fetal anemia. There is no vaccine for parvovirus B19, and fetal management focuses on detecting moderate/severe anemia by fetal PVS-MCA Doppler, which, if diagnosed, should be treated with intrauterine transfusion by cordocentesis. Prevention focuses on reducing exposure in high-risk populations, particularly pregnant women.

Valproic acid induced aplastic crisis and Stevens-Johnson syndrome in a single pediatric patient

Valproic acid (VPA) is a commonly used antiepileptic drug (AED). Aplastic crisis is defined as acute arrest of hematopoiesis. Stevens-Johnson syndrome (SJS) is a fatal cutaneous adverse drug reaction. We herein report a rare case of aplastic crisis and SJS in a single pediatric patient that were probably caused by VPA. A 2-year-old girl was involved in a car accident. She was diagnosed with skull fractures, cerebral contusions, pulmonary contusions, and fractures of the left iliac bone by computed tomography. VPA was administered as prophylaxis for post-traumatic epilepsy. From day 13, she developed repeated high fevers, and multiple antibiotics were ineffective; she was then transferred to our pediatric intensive care unit. After transfer, she developed liver function impairment, decreased peripheral blood cell counts, and skin damage. After withdrawal of the VPA and administration of prednisone, intravenous immunoglobulin, local skin care, and nutritional support, her body temperature normalized and her hematopoietic function and skin lesions successively resolved. She was transferred out of the pediatric intensive care unit on day 56 and discharged on day 70. At the 6-month follow-up, a blood examination was normal, and repeat computed tomography revealed multiple softening foci of the bilateral brain and less subdural effusion than before. To our knowledge, no report to date has described aplastic crisis and SJS in a single patient. The purpose of this paper is to increase clinicians' knowledge in the treatment of adverse drug reactions (ADRs) and emphasize the importance of standardized application and strict monitoring of VPA in patients with post-traumatic brain trauma.

Use of oral fluid samples for the investigation of outbreaks of human parvovirus B19 infection

The use of oral fluid (OF) samples for serological diagnosis of parvovirus B19 infection during outbreaks of erythema infectiosum had already been demonstrated, but the feasibility of using OF for the characterization of B19 genotypes circulating during outbreaks has not been described. The aim of this study was to assess the use of "in-house" PCR-based assays as a powerful tool for a rapid diagnosis and molecular characterization of B19 strains in OF samples during outbreaks. Paired serum and OF samples collected from anti-B19 IgM-positive patients, during two outbreaks of ertythema infectiosum (1999-2000 and 2004-2005), were tested by conventional (cPCR) and quantitative PCR (qPCR). qPCR was more sensitive than cPCR for detecting B19-DNA in both OF and serum. Overall, OF presented lower viral load (9.97 × 106 UI/mL) than serum (2.42 × 1010 UI/mL) and this difference was statistically significant. All OF samples obtained from patients in the age group < 14 years presented low viral load (< 104 IU/mL). No correlation was found between viral load and the number of days of onset of rash. Sequence analysis from PCR positive OF samples confirmed the circulation of subgenotype 1a (G1a) during these outbreaks. Our findings indicate that PCR-based assays may fail to detect B19-DNA in approximately 50% of OF compared to serum samples. Nevertheless, our study has shown for the first time that the genome sequence of the amplicon from non-invasive clinical sample is useful for molecular genotyping and may be a tool to clarify the genetic diversity of B19 strains circulating in distinct outbreaks.

Diagnosis of Peripheral Facial Palsy Associated with Parvovirus B19 Infection by Polymerase Chain Reaction

Human parvovirus B19 (PVB19) infection causes neurological manifestations, including encephalitis, meningitis, and neuropathy, but facial nerve palsy is rare. Moreover, no case of facial nerve palsy related to PVB19 infection that was diagnosed by PCR and serology has been reported. A 19-month-old boy without the medical history developed facial nerve palsy and was treated with prednisolone and valacyclovir. On the 19th day, erythema appeared on his body, and the PVB19-specific IgM and PVB19 DNA were detected in the serum, leading to the diagnosis of infectious erythema associated with PVB19 infection. This case indicates that PVB19 may be one of the causative agents of facial nerve palsy.

Human parvovirus B19 infection in patients with or without underlying diseases

BACKGROUND/PURPOSE

The clinical presentations of parvovirus B19 in patients with underlying diseases have greater diversity than previously healthy patients. We retrospectively identified patients with polymerase chain reaction (PCR)-confirmed parvovirus B19 infection in attempt to describe its clinical features especially in these populations.

METHODS

From 2009 to 2018, patients with real-time PCR-confirmed parvovirus B19 infection were collected. Comparisons were done between previously healthy patients and patients with preexisting diseases, as well as patients with high (>5.5 × 10⁵ copies/mL sera) and low viral loads.

RESULTS

Parvovirus B19 DNA was detected in 31 patients. Fourteen (45%) patients had underlying diseases, including six (19%) with immunologic diseases, five (16%) with hematologic diseases, and three (10%) with cardiopulmonary diseases. Only seven (23%) patients received an initial impression of erythema infectiosum prior to positive PCR. A higher proportion of patients with underlying diseases presented with fatigue and pallor, and suffered from tachycardia and hepatosplenomegaly compared to previously healthy patients. Among patients with a high viral load, a substantial proportion were of older age, suffered fatigue, and anemia. There was a trend of patients with immunologic comorbidity having a higher viral load.

CONCLUSION

The classical parvovirus B19 manifestations were less frequently observed in patients with a preexisting disease compared with previously healthy patients. Depending on host factors, the symptoms of parvovirus B19 infection can be multifaceted.

Parvovirus B19: A Cause of Sepsislike Syndrome in an Infant

Parvovirus B19 (PB19) is an important human pathogen that results in a wide spectrum of clinical outcomes, from mild, self-limiting erythema infectiosum in immunocompetent children and arthralgia in adults to lethal cytopenia in immunocompromised patients and intrauterine fetal death. However, there have been few reports of PB19 infection in neonates or young infants (aged 28-90 days), and no previous reports contained descriptions of PB19 infection as a cause of sepsislike syndrome in this age group. We report a case of sepsislike syndrome caused by PB19 infection in a 56-day-old infant whose mother had polyarthralgia at the time of his admission. PB19 infection was diagnosed on the basis of positive polymerase chain reaction results for PB19 DNA in the serum and cerebrospinal fluid. Positive immunoglobulin M and negative immunoglobulin G for PB19 suggested acute infection. He was admitted to the ICU because of poor peripheral circulation, but fully recovered without antibiotic administration. After excluding other possible pathogens, PB19 should be suspected as a cause of sepsislike syndrome in young infants, especially those who have close contact with PB19-infected individuals.

Parvovirus B19 integration into human CD36+ erythroid progenitor cells

The pathogenic autonomous human parvovirus B19 (B19V) productively infects erythroid progenitor cells (EPCs). Functional similarities between B19V nonstructural protein (NS1), a DNA binding endonuclease, and the Rep proteins of Adeno-Associated Virus (AAV) led us to hypothesize that NS1 may facilitate targeted nicking of the human genome and B19 vDNA integration. We adapted an integration capture sequencing protocol (IC-Seq) to screen B19V infected human CD36+ EPCs for viral integrants, and discovered 40,000 unique B19V integration events distributed throughout the human genome. Computational analysis of integration patterns revealed strong correlations with gene intronic regions, H3K9me3 sites, and the identification of 41 base pair consensus sequence with an octanucleotide core motif. The octanucleotide core has homology to a single region of B19V, adjacent to the P6 promoter TATA box. We present the first direct evidence that B19V infection of erythroid progenitor cells disrupts the human genome and facilitates viral DNA integration.

Genotype 1 of human parvovirus B19 in clinical cases

Summary Introduction: Virus surveillance strategies and genetic characterization of human parvovirus B19 (B19V) are important tools for regional and global control of viral outbreak. In São Paulo, Brazil, we performed a study of B19V by monitoring the spread of this virus, which is an infectious agent and could be mistakenly reported as a rash and other types of infection. Method: Serum samples were subjected to enzyme immunoassay, real time polymerase chain reaction, and sequencing. Results: From the 462 patients with suspected cases of exanthematic infections, the results of the 164 serum samples were positive for B19V immunoglobulin M. Among these cases, there were 38 patients with erythema infections and B19-associated with other infections such as encephalitis, hydrops fetalis, chronic anemia, hematological malignancies. These samples were sequenced and identified as genotype 1. Conclusion: This study showed patients with infections caused by B19V and sequencing genotype 1. Continuous monitoring is necessary to detect all known genotypes, and the emergence of new genotypes of these viruses for case management in public health control activities.