Acute encephalitis and encephalopathy associated with human parvovirus B19 infection in children

Square the Circle: Diversity of Viral Pathogens Causing Neuro-Infectious Diseases

Neuroinfections rank among the top ten leading causes of child mortality globally, even in high-income countries. The crucial determinants for successful treatment lie in the timing and swiftness of diagnosis. Although viruses constitute the majority of infectious neuropathologies, diagnosing and treating viral neuroinfections remains challenging. Despite technological advancements, the etiology of the disease remains undetermined in over half of cases. The identification of the pathogen becomes more difficult when the infection is caused by atypical pathogens or multiple pathogens simultaneously. Furthermore, the modern surge in global passenger traffic has led to an increase in cases of infections caused by pathogens not endemic to local areas. This review aims to systematize and summarize information on neuroinvasive viral pathogens, encompassing their geographic distribution and transmission routes. Emphasis is placed on rare pathogens and cases involving atypical pathogens, aiming to offer a comprehensive and structured catalog of viral agents with neurovirulence potential.

Rubella virus chronic inflammatory disease and other unusual viral phenotypes in inborn errors of immunity

Infectious susceptibility is a component of many inborn errors of immunity. Nevertheless, antibiotic use is often used as a surrogate in history taking for infectious susceptibility, thereby disadvantaging patients who present with viral infections as their phenotype. Further complicating clinical evaluations are unusual manifestations of viral infections which may be less familiar that the typical respiratory viral infections. This review covers several unusual viral phenotypes arising in patients with inborn errors of immunity and other settings of immune compromise. In some cases, chronic infections lead to oncogenesis or tumor-like growths and the conditions and mechanisms of viral-induced oncogenesis will be described. This review covers enterovirus, rubella, measles, papillomavirus, and parvovirus B19. It does not cover EBV and hemophagocytic lymphohistiocytosis nor lymphomagenesis related to EBV. EBV susceptibility has been recently reviewed. Our goal is to increase awareness of the unusual manifestations of viral infections in patients with IEI and to describe treatment modalities utilized in this setting. Coincidentally, each of the discussed viral infections can have a cutaneous component and figures will serve as a reminder of the physical features of these viruses. Given the high morbidity and mortality, early recognition can only improve outcomes.

Vasconcelos D, Côrtes MF, Costa SF, Mendoza TRT, Gomes HR, Witkin SS, Mendes-Correa MC. Encephalopathy Caused by Human Parvovirus B19 Genotype 1 Associated with Haemophilus influenzae Meningitis in a Newborn

Parvovirus B19 infection is associated with a wide range of clinical manifestations, from asymptomatic to severe neurological disorders. Its major clinical symptoms, fever and rash, are common to multiple viruses, and laboratory tests to detect B19 are frequently not available. Thus, the impact of B19 on public health remains unclear. We report the case of a 38-day old girl admitted to São Paulo Clinical Hospital, Brazil, with an initial diagnosis of bacterial meningitis, seizures, and acute hydrocephalus. Antibiotic therapy was maintained for one week after admission and discontinued after negative laboratory results were obtained. Nine days after symptoms onset, a cerebral spinal fluid (CSF) sample revealed persistent pleocytosis. The complete B19 complete genome was subsequently identified in her CSF by a metagenomic next-generation sequencing approach. This report highlights the possible involvement of B19 in the occurrence of acute neurological manifestations and emphasizes that its possible involvement might be better revealed by the use of metagenomic technology to detect viral agents in clinical situations of unknown or uncertain etiology.

Human parvovirus B19 infection in hospitalized patients suspected of infection with pathogenic microorganism

Background

Human parvovirus B19 (HPV B19) is a single-stranded DNA virus. The detection rate of HPV B19 in the blood of healthy blood donors using PCR technology was reported to be 6.323/100000. However, that among hospitalized patients suspected of being infected with a pathogenic microorganism is unknown.

Methods

A retrospective analysis was conducted on 2,182 high-throughput NGS results for 1,484 inpatients admitted to the First Affiliated Hospital of Zhengzhou University from January 2020 to October 2021 who were suspected of being infected with a pathogenic microorganism, as well as on clinical data of some HPV B19-positive patients.

Results

Human parvovirus B19 was detected in 39 samples from 33 patients. The positivity rate was 2.22% among patients and 1.78% among samples. HPV B19 was detected in 20 cerebrospinal fluid samples, 13 blood samples, 3 alveolar lavage fluid samples, 2 tissue samples, and 1 throat swab. Based on clinical symptoms and NGS results, 16 patients were diagnosed with HPV B19 infection. The number of HPV B19 sequences in these patients was greater than 6, and the patients showed common symptoms such as fever (14 cases), anemia (11 cases), and severe nervous system symptoms such as meningoencephalitis (9 cases) and Guillain-Barré syndrome with peripheral motor and sensory nerve axon damage (4 cases). All 16 patients had experienced events likely to lead to decreased immunity (11 had a history of trauma/surgery/major disease, 4 had a history of precursor infection, and 3 had used immunosuppressants) and 7 had a history of blood transfusion during hospitalization. After treatment with antiviral drugs (12 cases) and intravenous human immunoglobulin (3 cases), of the 16 patients, 14 patients improved.

Conclusion

The HPV B19 infection rate in hospitalized patients suspected of microbial infection was 2.22%. Most patients with HPV B19 infection had a history of low immunity and blood transfusion. HPV B19 could be detected in various bodily fluids and tissues (especially cerebrospinal fluid) using NGS. Patients with severe HPV B19 infection may have nervous system damage such as Guillain-Barré syndrome and meningoencephalitis. Early diagnosis using NGS and treatment with antiviral drugs and immunoglobulin can improve prognosis.

Clinical features and imaging manifestations of acute necrotizing encephalopathy in children

PURPOSE

We summarized the clinical features of acute necrotizing encephalopathy (ANE) in children.

METHODS

Clinical data of 14 children with ANE at one center from January 2017 to January 2020 were retrospectively analyzed. ANE severity score (ANE-ss) was used to assess ANE severity, and the Glasgow Outcome Scale-Extended was used to assess functional outcomes.

RESULTS

Peak incidence was between 1 and 3 years of age (71%), and a large percentage of males were affected (79%). The main manifestations included fever (100%), seizure (86%), and impaired consciousness (100%). Seven patients (58%) developed status epilepticus. The etiology was identified in 10 patients (71%) and mainly included H1N1 (36%) and Epstein-Barr virus (29%).Complications included multiple organ failure (MOF), predominantly liver (36%), heart (21%) and kidney (7%) failure, gastrointestinal hemorrhage (21%), hypernatremia (7%), hematuria (7%), disseminated intravascular coagulation (7%), and shock (7%). Pleocytosis was observed in two patients, and increased cerebrospinal fluid protein was found in 11 patients. A missense mutation in RANBP2 (c.1754C>T: p.Thr585Met) was observed in one patient. Magnetic resonance imaging revealed increased T2 and T1 signal density in multifocal and symmetric brain lesions (bilateral thalami, 100%) in all patients during the acute phase. There were no deaths. Nine children retained neurological sequelae affecting movement, cognition, speech, vision, and/or seizure. Four children recovered almost completely. There was a significant correlation between risk classification and outcome by ANE-ss.

CONCLUSION

ANE is a group of clinical and imaging syndromes. Most patients have severe neurological sequelae, and ANE may have lower mortality. And ANE-ss can assess prognosis.

Parvovirus B19 infection during pregnancy

Parvovirus B19 (B19V) is a widespread pathogen causing infection that occurs mostly in children. Even though infection of B19V is mainly asymptomatic, it can bring about a few conditions that may require medical intervention, including erythema infectiosum (fifth disease), slapped cheek syndrome, papular-purpuric gloves and socks syndrome (PPGSS), as well as other disorders related to the hematological system. Despite the fact that the most common route of transmission is through the respiratory system, B19V can be also transmitted transplacentally from mother to foetus. Vertical transmission may lead to myocarditis, thrombocytopenia, neural manifestations, and foetal hydrops, which may be life-threatening conditions to both mother and foetus. Detection of B19V infection is based mostly on molecular and serological screening and it is performed after suspected exposure to pathogen or exhibition of symptoms. Currently, there is no specific medication against B19V infection, therefore, treatment is based on the elimination of symptoms. New therapies are, however, under development.

Identification and Genomic Characterization of Parvovirus B19V Genotype 3 Viruses from Cases of Meningoencephalitis in West Bengal, India

Brain infections are a major public health problem in India and other parts of the world, causing both mortality and lifelong disability. Even after a thorough investigation, many cases remain without an etiological diagnosis. Primate erythroparvovirus 1 (B19V) has been identified as a pathogen associated with undiagnosed meningoencephalitis in other settings, including the United Kingdom, France, and Latvia. Here, we reported 13/403 (3.2%) B19V PCR positive cases of meningoencephalitis in West Bengal, India. The positive samples were mostly from children (10/13, 76.92%) and presented as a spectrum consisting of acute encephalitis (7/13), acute meningoencephalitis (3/13), and meningitis (3/13). Of the 13 cases, 8/13 (61.5%) had no known etiology and 5/13 (38.5%) had a previous etiological diagnosis. The cases did not cluster in time or by location, suggesting sporadic occurrence rather than outbreaks. We were able to retrieve the complete B19V genomes from cerebrospinal fluid (CSF) in 12/13 cases. The sequences clustered into genotype 3b with complete genomes from Brazil, Ghana, and France, and partial genomes from India and Kyrgyzstan. This is the first report of B19V in cases of neurological infections from India. It highlights the need to evaluate the causal relationship between B19V with meningoencephalitis in the country. These were also the first complete genomes of genotype 3b from CSF and will be critical in the evaluation of the relationship between genotypes and disease. IMPORTANCE Cases of meningoencephalitis with no known etiology remain a major challenge to clinical management of brain infections across the world. In this study, we detected and characterized the whole-genome of primate erythroparvovirus 1 (B19V) in cases of meningoencephalitis in India. Our work highlighted the association between B19V and brain infections which has been reported in other countries. Our work also emphasized the need to examine the role of B19V in meningoencephalitis, specifically whether it caused or contributed to the disease together with other pathogens in India. Our study provided the first 12 genomes of B19V from cerebrospinal fluid. These genomes will contribute to an understanding of how the virus is changing across different locations and over time.

GABAA receptor encephalitis associated with human parvovirus B19 virus infection: Case report

RATIONALE

Human parvovirus B19 (B19) infection can produce a spectrum of clinical syndromes, including neurological manifestations, most notably encephalitis. Although symptoms suggestive of autoimmune disease in patients with B19 infection have been previously described, a clear association of autoimmune encephalitis with B19 infection has yet to be established.

PATIENT CONCERNS

We describe the case of a 6-year-old boy who was hospitalized due to status epilepticus, which evolved to super-refractory status epilepticus that was only mildly responsive to anticonvulsant drugs.

DIAGNOSIS

A cerebrospinal fluid study identified slight pleocytosis and B19 positivity. A subsequent autoimmunity cerebrospinal fluid study revealed the presence of anti-γ-aminobutyric acid type A (GABAA) receptor antibodies.

INTERVENTIONS

After pulse therapy with methylprednisolone and continuous therapy with prednisolone with cyclosporine, the patient experiencing seizure persistence with disordered motor function manifestations and only minor improvement in consciousness, and so, plasmapheresis was performed. With continued immunosuppressive treatments with cyclosporine and prednisolone, the patient's clinical picture showed progressive improvement, with good control of seizures. Although the patient tolerated withdrawal of the anticonvulsant drugs well, he developed seizures when corticosteroid therapy withdrawal was attempted, so was started on azathioprine.

OUTCOMES

After immunosuppressive therapy, the patient evolved with complete remission of symptoms, normal neurological examination and age-appropriate neuropsychomotor development.

LESSONS

The present case characteristics, together with previous findings, support the hypothesis that autoimmunity may be triggered by extensive antigen release due to degeneration of infected neurons. This case highlights the importance of early clinical suspicion and treatment.

A meta-analysis on association between viral infections and Kawasaki disease in children

Aim: To investigate the association between different viral infections and the development of Kawasaki disease (KD) in children. Materials & methods: Electronic databases were searched for relevant studies published from inception to May 2020. The pooled odds ratios (ORs) of the association of different viral pathogens with KD were estimated using a random-effects model weighted by the inverse variance method. Results: The strongest associations were found between KD and human parvovirus B19 viremia (OR = 41.05; 95% CI: 5.13–328.28; I-square = 0%), EBV IgM seropositivity (OR = 7.18; 95% CI: 3.65–14.12, I-square = 0%) and human herpesvirus-6 IgG seropositivity (OR = 5.83; 95% CI: 1.06–32.01). Conclusion: Human parvovirus B19, EBV and human herpesvirus-6 are highly suspected to be key contributors to the development of KD.

Viruses in unexplained encephalitis cases in American black bears (Ursus americanus)

Viral infections were investigated in American black bears (Ursus americanus) from Nevada and northern California with and without idiopathic encephalitis. Metagenomics analyses of tissue pools revealed novel viruses in the genera Circoviridae, Parvoviridae, Anelloviridae, Polyomaviridae, and Papillomaviridae. The circovirus and parvovirus were of particular interest due to their potential importance as pathogens. We characterized the genomes of these viruses and subsequently screened bears by PCR to determine their prevalence. The circovirus (Ursus americanus circovirus, UaCV) was detected at a high prevalence (10/16, 67%), and the chaphamaparvovirus (Ursus americanus parvovirus, UaPV) was found in a single bear. We showed that UaCV is present in liver, spleen/lymph node, and brain tissue of selected cases by in situ hybridization (ISH) and PCR. Infections were detected in cases of idiopathic encephalitis and in cases without inflammatory brain lesions. Infection status was not clearly correlated with disease, and the significance of these infections remains unclear. Given the known pathogenicity of a closely related mammalian circovirus, and the complex manifestations of circovirus-associated diseases, we suggest that UaCV warrants further study as a possible cause or contributor to disease in American black bears.

Parvovirus-induced encephalitis in a juvenile raccoon

A juvenile raccoon was euthanized because of severe neurologic signs. At postmortem examination, no significant gross lesions were present. Histologic evaluation demonstrated nonsuppurative encephalitis in thalamus, brainstem, and hippocampus, cerebellar Purkinje cell loss, as well as poliomyelitis and demyelination of the spinal cord. Parvovirus antigen-specific immunohistochemistry revealed immunopositive neurons in the brainstem, cerebral cortex, and hippocampus. A few Purkinje cells were also immunopositive. DNA extracted from formalin-fixed, paraffin-embedded brain tissue (thalamus, hippocampus, cerebral cortex) yielded a positive signal using PCR targeting both feline and canine parvovirus. Sequencing analyses from a fragment of the NS1 gene and a portion of the VP2 gene confirmed the presence of DNA of a recent canine parvovirus variant (CPV-2a-like virus) in the cerebellum. Our case provides evidence that a recent canine parvovirus (CPV) strain (Carnivore protoparvovirus 1) can infect cerebral and diencephalic neurons and cause encephalitis in an otherwise healthy raccoon. Parvovirus-induced encephalitis is a differential diagnosis of rabies and canine distemper in raccoons with neurologic signs.

Central Nervous System Virus Infection in African Children with Cerebral Malaria

We aimed to identify the contribution of central nervous system (CNS) viral coinfection to illness in African children with retinopathy-negative or retinopathy-positive cerebral malaria (CM). We collected cerebrospinal fluid (CSF) from 272 children with retinopathy-negative or retinopathy-positive CM and selected CSF from 111 of these children (38 retinopathy positive, 71 retinopathy negative, 2 retinopathy unknown) for analysis by metagenomic next-generation sequencing. We found CSF viral coinfections in 7/38 (18.4%) retinopathy-positive children and in 18/71 (25.4%) retinopathy-negative children. Excluding HIV-1, human herpesviruses (HHV) represented 61% of viruses identified. Excluding HIV-1, CNS viral coinfection was equally likely in children who were retinopathy positive and retinopathy negative (P = 0.1431). Neither mortality nor neurological morbidity was associated with the presence of virus (odds ratio [OR] = 0.276, 95% CI: 0.056-1.363). Retinopathy-negative children with a higher temperature, lower white blood cell count, or being dehydrated were more likely to have viral coinfection. Level of consciousness at admission was not associated with CNS viral coinfection in retinopathy-negative children. Viral CNS coinfection is unlikely to contribute to coma in children with CM. The herpesviruses other than herpes simplex virus may represent incidental bystanders in CM, reactivating during acute malaria infection.

Human Parvoviruses May Affect the Development and Clinical Course of Meningitis and Meningoencephalitis

Meningitis and meningoencephalitis are neurological inflammatory diseases, and although routine diagnostics include testing of a wide range of pathogens, still in many cases, no causative agent is detected. Human parvovirus B19 (B19V), human bocaviruses 1–4 (HBoV1–4), and human parvovirus 4 (hPARV4) are members of the Parvoviridae family and are associated with a wide range of clinical manifestations including neurological disorders. The main aim of this study was to determine whether human parvoviruses infection markers are present among patients with meningitis/meningoencephalitis in Latvia as well as to clarify the role of these viruses on the clinical course of the mentioned diseases. Our study revealed HBoV1–4 and B19V genomic sequences in 52.38% and 16.67% of patients, respectively. Furthermore, symptoms such as the presence of a headache and its severity, fatigue, disorientation, and difficulties to concentrate were significantly frequently present in patients with active parvovirus infection in comparison with parvoviruses negative patients, therefore we suggest that HBoV1–4 and B19V infection should be included in the diagnostics to reduce the number of meningitis/meningoencephalitis with unknown/unexplained etiology.

Prevalence of Human Parvovirus B19 in Neurological Patients: Findings from Region of Western Saudi Arabia

Human parvovirus (B19) infection causes Erythema infectiosum in persons with other hematological disorders like aplastic anemia and complications such as hydrops fetalis, spontaneous abortions. This study aimed to determine the prevalence of IgG and IgM antibodies in B19 infected neurological patients and to assess possible transmission related risk factors. This cross-sectional descriptive study comprised 140 neurological patients. Blood samples were screened for both IgG and IgM against B19 by ELISA and nested PCR. IgG and IgM accounted 6.4% and 3.5% prevalence in neurological patients. Both IgG and IgM revealed prevalence of 3.5% simultaneously in different age groups. IgG and IGM Nested PCR displayed 6.42% B19 viral DNA prevalence among samples analyzed. Among B19 risk associated factors, only history of blood transfusion (Odds Ratio=1.9:1, P=0.04) was significantly associated with B19 infection among neurological patients. Neurological patients showed very less prevalence of B19 infection and hence disclose no significant association on risk factors associated with its transmission.

Clinical impact & pathogenic mechanisms of human parvovirus B19: A multiorgan disease inflictor incognito

Human parvovirus B19 (B19V) causes myriads of clinical diseases; however, owing to lack of awareness and undetermined clinical impact, it has failed to become a virus pathogen of global concern. Cryptically, B19V causes significant morbidity and mortality. Half of the world population and 60 per cent of Indians are known to be serologically naive and are at risk of acquiring B19V infections. Cumulatively, our data showed 21.3 per cent B19V-infected patients with juvenile chronic arthropathy, recurrent abortions, multi-transfused thalassaemia and leukaemia. In addition, B19V-infected cases that ended fatally included patients with pure red cell aplasia, fulminant hepatitis and haemophagocytic syndrome. Novel clinical associations of B19V observed were amegakaryocytic thrombocytopaenia, myositis and non-occlusive ischaemic gangrene of bowel. B19V possesses multiple receptors which are distributed widely in human tissues. Vascular endothelial cell infection by B19V causes endothelialitis and vasculitic injuries besides antibody-dependent enhancement which empowered B19V to cause multiorgan diseases. Owing to lack of suitable animal model for B19V, true causal role remains to be determined, but numerous reports on B19V infections substantiate a causal role in multiorgan diseases. Hence, B19V infections need to be recognized, investigated and treated besides making efforts on vaccine developments.

Evidence of Human Parvovirus B19 Infection in the Post-Mortem Brain Tissue of the Elderly

After primary exposure, the human parvovirus B19 (B19V) genome may remain in the central nervous system (CNS), establishing a lifelong latency. The structural characteristics and functions of the infected cells are essential for the virus to complete its life cycle. Although B19V has been detected in the brain tissue by sequencing PCR products, little is known about its in vivo cell tropism and pathogenic potential in the CNS. To detect B19V and investigate the distribution of its target cells in the CNS, we studied brain autopsies of elderly subjects using molecular virology, and optical and electron microscopy methods. Our study detected B19V in brain tissue samples from both encephalopathy and control groups, suggesting virus persistence within the CNS throughout the host’s lifetime. It appears that within the CNS, the main target of B19V is oligodendrocytes. The greatest number of B19V-positive oligodendrocytes was found in the white matter of the frontal lobe. The number was significantly lower in the gray matter of the frontal lobe (p = 0.008) and the gray and white matter of the temporal lobes (p < 0.0001). The morphological changes observed in the encephalopathy group, propose a possible B19V involvement in the demyelination process.

Recent Advances in Replication and Infection of Human Parvovirus B19

Parvovirus B19 (B19V) is pathogenic to humans and causes bone marrow failure diseases and various other inflammatory disorders. B19V infection exhibits high tropism for human erythroid progenitor cells (EPCs) in the bone marrow and fetal liver. The exclusive restriction of B19V replication to erythroid lineage cells is partly due to the expression of receptor and co-receptor(s) on the cell surface of human EPCs and partly depends on the intracellular factors essential for virus replication. We first summarize the latest developments in the viral entry process and the host cellular factors or pathways critical for B19V replication. We discuss the role of hypoxia, erythropoietin signaling and STAT5 activation in the virus replication. The B19V infection-induced DNA damage response (DDR) and cell cycle arrest at late S-phase are two key events that promote B19V replication. Lately, the virus infection causes G2 arrest, followed by the extensive cell death of EPCs that leads to anemia. We provide the current understanding of how B19V exploits the cellular resources and manipulate pathways for efficient virus replication. B19V encodes a single precursor mRNA (pre-mRNA), which undergoes alternate splicing and alternative polyadenylation to generate at least 12 different species of mRNA transcripts. The post-transcriptional processing of B19V pre-mRNA is tightly regulated through cis-acting elements and trans-acting factors flanking the splice donor or acceptor sites. Overall, in this review, we focus on the recent advances in the molecular virology and pathogenesis of B19V infection.

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.

Human Parvoviruses

Parvovirus B19 (B19V) and human bocavirus 1 (HBoV1), members of the large Parvoviridae family, are human pathogens responsible for a variety of diseases. For B19V in particular, host features determine disease manifestations. These viruses are prevalent worldwide and are culturable in vitro, and serological and molecular assays are available but require careful interpretation of results. Additional human parvoviruses, including HBoV2 to -4, human parvovirus 4 (PARV4), and human bufavirus (BuV) are also reviewed. The full spectrum of parvovirus disease in humans has yet to be established. Candidate recombinant B19V vaccines have been developed but may not be commercially feasible. We review relevant features of the molecular and cellular biology of these viruses, and the human immune response that they elicit, which have allowed a deep understanding of pathophysiology.

Focal epilepsy as a long term sequela of Parvovirus B19 encephalitis

Human Parvovirus B19 (PVB19), the etiological agent of the fifth disease, is associated with a large spectrum of pathologies, among which is encephalitis. Since it has been detected from the central nervous system in children or in immunocompromised patients, its causative role in serious neurological manifestations is still unclear. Here we report the case of an 18-year-old healthy boy who developed encephalitis complicated by prolonged status epilepticus. The detection of PVB19 DNA in his serum and, subsequently, in his cerebrospinal fluid supports the hypothesis that this virus could potentially play a role in the pathogenesis of neurological complications. In addition, the detection of viral DNA and the presence of specific IgM and IgG antibodies in serum, together with clinical findings such as skin rash, support the presence of a disseminated viral infection. In the presence of neurological disorders, especially when there are no specific signs, but seizures and rash are present, it is important to search for PVB19 both in immunocompromised and immunocompetent patients. Moreover, the introduction of the PVB19 DNA test into diagnostic protocols of neuropathies, especially those undiagnosed, could clarify the etiological agent that otherwise could remain unrecognized.