Human parvovirus B19: a review of clinical and epidemiological aspects in Brazil

Surveillance of Erythrovirus B19 (B19V) in patients with acute febrile illness suspected of arboviruses in Mato Grosso do Sul state, Brazil

Introduction

Human Erythrovirus (parvovirus) B19 infection can produce symptoms similar to those produced by Dengue, Chikungunya, and Zika viruses, making clinical diagnosis difficult. The importance of erythrovirus B19 in human pathology has been increased and reported in numerous studies published globally.

Methods

The B19V infection was investigated by real-time PCR in sera samples from patients with signs and symptoms related to classic arboviral symptoms. This study was conducted to provide information on the genetic diversity of Human Erythrovirus B19 (B19V) circulating in the state of Mato Grosso do Sul, Midwest region of Brazil, from 2017 to 2022. A total of 773 sera samples of patients with negative diagnostic results for Dengue, Chikungunya, and Zika, during the study period were analyzed.

Results

Erythrovirus DNA was found in 10.6% (82/773) of patients, among them 10 were pregnant women. Four samples were completely sequenced, and the other five partially, to genotype by phylogenetic reconstruction. All samples belong to worldwide dispersed genotype 1, subgenotype 1a.

Discussion

The findings of the study demonstrate the importance of including B19V in differential laboratory diagnosis for epidemiological purposes and appropriate patient management. The diagnosis for B19V should be performed, particularly among pregnant women, immunocompromised patients, and individuals with hemolytic diseases, given that the infection is more severe in these cases.

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.

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.

Metagenomic next-generation sequencing for the diagnosis of Pneumocystis jirovecii Pneumonia in critically pediatric patients

OBJECTIVE

The aim of this study was to evaluate the effectiveness of metagenomic next-generation sequencing (mNGS) for the diagnosis of Pneumocystis jirovecii Pneumonia (PCP) in critically pediatric patients.

METHODS

Seventeen critically pediatric patients with PCP and sixty patients diagnosed with non-PCP pneumonia who were admitted in pediatric intensive care unit between June 2018 and July 2021 were enrolled. Conventional methods and mNGS for detecting Pneumocystis jirovecii (P. jirovecii) were compared. The patients' demographics, comorbidities, laboratory test results, antibiotic treatment response and 30 day mortality were analyzed.

RESULT

The mNGS showed a satisfying diagnostic performance with a sensitivity of 100% in detecting P. jirovecii compared with Gomori methenamine silver staining (5.9%), serum (1,3)-β-D-glucan (86.7%) and and LDH (55.6%). The diagnostic specificity of mNGS for PCP was higher than that of serum BDG (56.7%) and LDH (71.4%). In PCP group, over one thirds' cases had mixed infections. Compared with survivors, non-survivors had higher stringently mapped read numbers (SMRNs) in bronchoalveolar lavage fluid (BALF) sample (P < 0.05), suggesting SMRNs were closely associated with the severity of response. The detection for P. jirovecii by mNGS both in BALF and blood samples reached a concordance rate of 100%, and the SMRNs in the BALF were remarkably higher than that in blood samples. Initial antimicrobial treatment was modified in 88.2% of PCP patients based on the mNGS results.

CONCLUSION

The mNGS is a potential and efficient technology in diagnosing PCP and shows a satisfying performance in the detection of co-pathogens. Both blood and BALF samples for mNGS are suggested for the presumptive diagnosis of PCP.

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.

Screening of febrile patients with suspected malaria from the Brazilian Amazon for virus infection

Arthropod-borne viruses (arboviruses) are a significant public health threat, especially in tropical and subtropical regions. More than 150 arboviruses can cause febrile illness following infection in humans. The Brazilian Amazon region has the highest number of arboviruses detected worldwide. In addition to arboviruses, malaria, caused by Plasmodium vivax, is endemic in the Amazon. Patients with malaria and arboviral disease frequently show similar clinical presentation and laboratory findings, making the diagnosis of the cause of the infection challenging. The aim of this study was to evaluate the potential for viral infections in patients with suspected malaria but without Plasmodium infection in the Brazilian Amazon. We recruited 200 subjects with suspected malaria in Manaus, Brazil. First, we tested for arboviruses in serum samples from 124 of the 200 participants using an arbovirus DNA microarray platform, which did not detect any virus. Then, we mixed the serum samples of the other 76 participants in 10 pools and subjected them to next-generation sequencing. Analysis of the sequencing data revealed the presence of only one arbovirus (Zika virus) in one sample pool. This analysis also detected the presence of primate erythroparvovirus 1 and pegivirus C. These results suggest that arboviruses are not the most frequent viral infections in patients with suspected malaria but without Plasmodium infection in the metropolitan region of Manaus. Implementation of specific viral surveillance tests will help in the early detection of viruses with epidemic potential.

Environmental Monitoring of Parvovirus B19 in the Kidney Transplantation Ward of a Chinese Teaching Hospital

Purpose

Parvovirus B19 (B19V) infection is a viral threat after kidney transplantation. It is mainly transmitted by close-contact inhalation of aerosolized viral particles. The risk of nosocomial spread of B19V in the transplantation ward is quite high. This study aimed to evaluate the quality of routine disinfection and the effectiveness of isolation measures in the wards of B19V-infected kidney transplant recipients.

Patients and Methods

Throat swab samples of 19 kidney transplant recipients admitted to the isolation ward and three healthcare workers (HCWs) were collected for viral DNA detection. Routine disinfection procedures were performed twice a day in general and B19V isolation wards. Environmental surface and air samples were collected for viral DNA detection before and after disinfection.

Results

A total of four patients were diagnosed with B19V infection and transferred to the B19V isolation ward, of which only two had positive throat swab samples. The other 15 patients and all HCWs tested negative for B19V. A total of 88 environmental surface and air samples were collected. Eight of the environmental samples collected in the B19V isolation ward before disinfection tested positive for B19V, while one sample tested positive after disinfection. In the general wards, all environmental samples collected before disinfection tested negative for B19V. All 24 samples collected from ambient air, whether in B19V isolation or general wards, before or after disinfection, tested negative for B19V.

Conclusion

Existing methods of routine or terminal disinfection for air and object surfaces were effective in eliminating B19V from object surfaces and ambient air in the isolation and general wards. Material surfaces that are exposed to high frequency and easily contaminated by blood, body fluids, and indoor air were the focus of cleaning and disinfection. Nosocomial cross-infection of other immunocompromised patients and HCWs can be avoided if appropriate prevention and control measures are taken.

High Prevalence of Common Human Viruses in Thyroid Tissue

INTRODUCTION

Evidence points to viral infections as possible triggers of autoimmune thyroid disease (AITD), but little is known about the prevalence of common viruses in the thyroid gland. Using a novel approach based on virus enrichment in multiple cell lines followed by detection of the viral genome and visualization of viral proteins, we investigated the presence of multiple human viruses in thyroid tissue from AITD patients and controls.

METHODS

Thyroid tissue was collected by core needle biopsy or during thyroid surgery from 35 patients with AITD (20 Graves' disease and 15 Hashimoto's thyroiditis). Eighteen thyroid tissue specimens from patients undergoing neck surgery for reasons other than thyroid autoimmunity served as controls. Specimens were tested for the presence of ten different viruses. Enteroviruses and human herpesvirus 6 were enriched in cell culture before detection by PCR and immunofluorescence, while the remaining viruses were detected by PCR of biopsied tissue.

RESULTS

Forty of 53 cases (75%) carried an infectious virus. Notably, 43% of all cases had a single virus, whereas 32% were coinfected by two or more virus types. An enterovirus was found in 27/53 cases (51%), human herpesvirus 6 in 16/53 cases (30%) and parvovirus B19 in 12/53 cases (22%). Epstein-Barr virus and cytomegalovirus were found in a few cases only. Of five gastroenteric virus groups examined, only one was detected in a single specimen. Virus distribution was not statistically different between AITD cases and controls.

CONCLUSION

Common human viruses are highly prevalent in the thyroid gland. This is the first study in which multiple viral agents have been explored in thyroid. It remains to be established whether the detected viruses represent causal agents, possible cofactors or simple bystanders.

Disseminated Human Parvovirus B19 Infection Induced Multiple Organ Dysfunction Syndrome in an Adult Patient With Alcoholic Hepatitis Complicated by Hemolytic Anemia: A Case Report and Literature Review

Background

Human parvovirus B19 (B19) can cause acute hepatitis and is attributed to the high mortality of alcoholic hepatitis (AH). B19 infection is generally self-healing in previously healthy people, but it can cause fatal effects in some high-risk groups and increase its virulence and infectivity. Disseminated B19 infection-induced multiple organ dysfunction syndrome (MODS) in patients with AH has not been reported yet. Here, we described B19 viremia in an adult patient with AH accompanied by hemolytic anemia (HA), leading to disseminated infection and secondary MODS, as well as self-limiting B19 infections in seven nurses caring for him. Meanwhile, we reviewed the literature on AH and B19 infection.

Case Presentation

A 43-year-old male patient with AH accompanied by HA was transferred to the Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China, on March 31, 2021. After supportive treatment, his transaminase and bilirubin levels were reduced, but his anemia worsened. He received a red blood cell (RBC) infusion on April 9 for hemoglobin (Hb) lower than 6 g/dl. On April 13, he suddenly had a high fever. Under empirical anti-infection, his high fever dropped and maintained at a low fever level; however, his anemia worsened. On April 25, he was transferred to the medical intensive care unit (MICU) due to severe pneumonia, acute respiratory distress syndrome (ARDS), acute aplastic crisis (AAC), and hemophagocytic syndrome (HPS), which were subsequently confirmed to be related to B19 infection. After methylprednisolone, intravenous immunoglobulin (IVIG), empirical anti-infection, and supportive treatment, the lung infection improved, but hematopoietic and liver abnormalities aggravated, and systemic B19 infection occurred. Finally, the patient developed a refractory arrhythmia, heart failure, and shock and was referred to a local hospital by his family on May 8, 2021. Unfortunately, he died the next day. Fourteen days after he was transferred to MICU, seven nurses caring for him in his first two days in the MICU developed self-limiting erythema infectiosum (EI).

Conclusions

B19 infection is self-limiting in healthy people, with low virulence and infectivity; however, in AH patients with HA, it can lead to fatal consequences and high contagion.