WU polyomavirus infection among children in South China

This study aimed at investigating the prevalence and clinical characteristics of children with respiratory infection by WU polyomavirus (WUPyV) in Southern China. Nasopharyngeal aspirate samples were collected from 771 children with acute respiratory tract infection admitted to hospital and 82 samples from healthy subjects for routine examination at the outpatient service at the Second Affiliated Hospital of Shantou University, Medical College from July 2008 to June 2009. WUPyV was detected by the polymerase chain reaction (PCR) and DNA sequencing. All WUPyV-positive specimens were characterized further for nine viruses causing common respiratory infections, including influenza A and B, respiratory syncytial virus (RSV), parainfluenza virus (PIV) 1 and 3, human metapneumovirus, human bocavirus, adenovirus, and rhinovirus by PCR or real time (RT)-PCR. Fifteen out of 771 specimens from patients with acute respiratory tract infection, but none from healthy subjects, were positive for WUPyV and the positivity rate was 2%. Patients with WUPyV infection were between 2 and 48 months of age, and nine of the patients were male while six female. Four out of 15 patients were co-infected with RSV, one with adenovirus or rhinovirus, respectively. Patients with WUPyV infection displayed predominantly cough, moderate fever, and wheezing, and were diagnosed with pneumonia (n = 8), bronchiolitis (n = 4), upper respiratory tract infections (n = 2) and bronchitis (n = 1). One patient developed encephalitis. Therefore, WUPyV infection can cause acute respiratory tract infection with atypical symptoms, including severe complications, in children.

WU and KI polyomavirus infections in pediatric hematology/oncology patients with acute respiratory tract illness

Background

WU and KI polyomaviruses (PyV) were discovered in 2007 in respiratory tract samples in adults and children. Other polyomaviruses (BKPyV and JCPyV) have been associated with illness in immunocompromised patients, and some studies suggest a higher prevalence of WUPyV and KIPyV in this population.

Objective

To determine whether a higher prevalence or viral load for WUPyV and KIPyV exists in immunocompromised children compared with immunocompetent children.

Study design

We measured the prevalence and viral load of WU and KI PyV by quantitative real-time PCR of viral DNA in respiratory tract specimens from pediatric hematology/oncology patients and immunocompetent controls with acute respiratory illnesses.

Results

The prevalence of WUPyV in the immunocompromised population was 5/161 (3%) versus 14/295 (5%) in the control population (P = 0.5), and 9/161 (5.6%) versus 7/295 (2.3%) respectively for KIPyV (P = 0.13). The mean viral load (in copies per cell or mL of sample) for KIPyV, was higher in the immunocompromised group compared to the control group (P = 0.019), but was not statistically different for WUPyV. A higher prevalence was seen in the hematopoietic stem cell transplant recipients compared with other immunocompromised patients (6/26 versus 3/43, P = 0.054). Viral persistence was demonstrated only in 1/25 (4%) of sequential samples for KIPyV, and no persistence was seen for WUPyV.

Conclusions

A higher prevalence of WUPyV or KIPyV in the immunocompromised population compared with the immunocompetent group was not demonstrated. Higher viral loads for KIPyV in the immunocompromised group may suggest an increased pathogenic potential in this population.

Prevalence of polyomaviruses BK, JC, SV40, KI, and WU in non-malignant tonsil specimens

AIM

The recently described polyomaviruses KI and WU have been detected in respiratory samples, stools, tonsils, and blood, particularly in immunocompromised conditions, although little is known about tissue tropism. Herein we investigated the occurrence of KIV and WUV in non-malignant tonsillar specimens by Real-time quantitative PCR; the presence of polyomaviruses BK, JC and SV40-DNA was also evaluated.

METHODS

Twenty-nine non-malignant tonsil specimens obtained from children and adults admitted for tonsillectomy were prospectively studied. Real-time quantitative TaqMan PCR for polyomaviruses KI, WU, BK, JC, and SV40 were performed.

RESULTS

KI-DNA was positive in 2/29 tonsillar specimens (6.9%), while BK- DNA, JC-DNA, SV-40 DNA, and WU-DNA sequences were not identified.

CONCLUSION

Few studies have investigated the prevalence of polyomaviruses in tonsil specimens, with varying results, and data are particularly scant as regards the newly discovered KIV and WUV. Two major questions remain to be definitely answered at this regard: the possibility that human tonsils represent the initial site of infection and/or a latency site and the biological and clinical meaning of KIV and WUV in different contexts and groups of patients, in that it is not clear whether they are simple bystanders or play a role in tonsil disease.

Absence of merkel cell polyoma virus in cutaneous melanoma

Recently, merkel cell polyoma virus (MCPyV) has been described in 80% of merkel cell carcinomas (MCC). Similar to MCC, melanoma incidence is increased in immuno-suppressed patients. We hypothesized that MCPyV may play a role in melanoma development as well. We selected 95 archival, paraffin-embedded primary melanomas. DNA was obtained from micro-dissected tissue and amplified with PCR primer sets specific for the MCPyV T-antigen locus (LT1 and LT3) and for the VP1 gene. None of the 95 melanoma samples did show LT1, LT3, or VP1 fragment amplification. In conclusion, there is no evidence that MCPyV infection plays a role in cutaneous melanoma development.

[Genomic characterization of WU polyomavirus identified from pediatric patients with acute respiratory infections in Beijing, China]

To characterize the genomic sequence and arrangement of WU polyomavirus (WU virus) identified in clinical specimens collected from children with acute respiratory infections in Beijing, China, the sequences of capsid proteins VP1, VP2, and the large tumor antigen (LTAg), as well as the 5'-terminal sequence of WU virus, were amplified from the clinical specimen with ID number of BJF5276 which was determined as WU virus positive by PCR amplification. The PCR amplicons were sequenced, and genomic sequence analysis was performed by using the software DNAStar. In addition, VP2 coding-region sequences were amplified from other 21 clinical specimens identified as WU virus positive to investigate the gene diversity of WU virus. The genomic sequence of WU virus BJF5276 with accession number of HQ218321 in GenBank was 5,229 base pairs in length with 3 major coding domain sequences (CDS) sited on one strand coding for capsid proteins VP2, VP3 and VP1, and two CDS sited on the complementary strand coding for small tumor antigen (STAg) and LTAg; These 22 VP2 CDS sequences including 5 sequences submitted to GenBank were compared with 64 corresponding sequences downloaded from GenBank by MegAlign of DNAStar software, indicated that these sequences coming from children in Beijing shared high homology (over 98.8%) with those from GenBank. Phylogenetic analysis of these VP2 CDS by using Neighbor-joining (NJ) analyses with 2,000 bootstraps (Mega 4.0) showed that 20 sequences out of 22 belonged to clade Ia, and other 2 of them belonged to clade III, including 1 clustered in IIIa and 1 in a novel cluster proposed as IIIc. In conclusion, the genomic sequence of WU polyomavirus detected from clinical specimens from children in Beijing is closely related to other WU polyomaviruses in the feature of genomic coding region arrangement. Overall variation of VP2 CDS was very low, and there were different clades circulating in Beijing with a dominant clade Ia, which is different from dominated Ib circulating in other parts of the world reported previously, and a novel clade IIIc was proposed.

Prevalence and clinical impact of polyomaviruses KI and WU in lung transplant recipients

The newly discovered polyomaviruses KI and WU (KIV and WUV) were isolated from secretions of patients with respiratory symptoms as well as in blood, spleen, lymphoid tissues, and stools, especially in immunocompromised conditions. The aim of this work was to evaluate the prevalence of KIV and WUV in bronchoalveolar lavage (BAL) from lung transplant recipients. We also examined potential correlations between these viruses and occurrences of pneumonia, acute respiratory insufficiency, or other acute respiratory conditions and acute rejection episodes. Discharge diagnosis was based on the International Classification of Diseases-Italian version 2002, based on the 9th-revision clinical modification. A rejection episode was diagnosed by transbronchial lung biopsy in accordance with the 2007 International Society for Heart and Lung Transplantation Working Formulation. Overall, we analyzed 53 BALs obtained from 24 transplant recipients. Positive polymerase chain reaction results were observed in 6 samples (11.3%) from 6 patients (25%), versus 7 samples (13.2%) from 7 patients (29.2%) for KIV and WUV, respectively. Regarding the diagnosis of pneumonia, the prevalence was 22.2% and 33.3% for KIV and WUV, respectively. In cases of acute respiratory insufficiency or other acute respiratory conditions, 2 out of 9 samples were positive for KIV (22.2%) and 4 out of 9 for WUV (44.4%). An Acute rejection episode (ARE) was diagnosed in 7 instances among 6 lung transplant patients: The corresponding BAL specimens showed positive results for KIV in 3 out of 7 (42.8%) cases with ARE vs 3 out of 46 (6.5%) without an ARE (P < .05), and for WUV in 3 out of 7 (42.8%) vs 4 out of 46 (8.7%) (P < .05), respectively. Although the small number of specimens limits the statistical analysis, our results showed a higher prevalence of WUV compared with KIV. The compromised pulmonary environment in the lung allograft may cause reactivation of these viruses. Their roles in this context need to be further evaluated.

Epizootic occurrence of haemorrhagic nephritis enteritis virus infection of geese

Recent outbreaks of haemorrhagic nephritis enteritis in geese flocks of 3 to 10 weeks in age in Hungary were investigated. Mortality varied between 4% and 67%. Affected birds generally died suddenly. Occasional clinical signs included tremors of the head and neck, subcutaneous haemorrhages and excretion of faeces containing partly digested blood. At necropsy the most frequent findings were a turgid wall and reddish mucosa of the intestines and reddish discolouration of the swollen kidneys, but oedema and haemorrhages of the subcutaneous connective tissue, hydropericardium and ascites were also seen. In subacute cases, visceral gout was frequently observed. Histological examination revealed zonal necrosis of the tubular epithelial cells with haemorrhages in the kidney. Other histological findings were serous hepatitis with fatty infiltration, necrotizing haemorrhagic enteritis and haemorrhages in the different organs including the brain. Experimental geese infected parenterally with crude liver and spleen homogenates prepared from diseased birds died after 8 to 20 days without premonitory signs, and had typical gross and histological lesions. Attempts to isolate cytopathic virus on different tissue cultures failed. The presence of polyomavirus was proven by polymerase chain reaction. Five isolates were further investigated by analysing their complete VP1 gene sequence. All tested strains were very closely related to each other on the basis of the nucleotide sequence, and they were identical at the deduced amino acid level.

Polyomavirus infection in a free-ranging California sea lion (Zalophus californianus) with intestinal T-cell lymphoma

An adult female California sea lion (Zalophus californianus) that stranded in central California was found to have a small glossal polypoid mass on gross necropsy. Histologically, the mass was consistent with a fibropapilloma, and intranuclear inclusions were found within endothelial cells lining small arterioles within the mass. Electron microscopy revealed 40-nm virions within endothelial intranuclear inclusions. Rolling circle amplification was used to obtain a partial viral genomic sequence. Sequence analysis identified the virus as a novel polyomavirus, tentatively named California sea lion polyomavirus 1. In addition, the sea lion had a severely thickened small intestine and swollen pale kidneys on gross examination. Severe renal amyloidosis with chronic interstitial nephritis was diagnosed histologically as well as T-cell intestinal lymphoma, which was confirmed via immunophenotyping and molecular clonality. The relationship, if any, between polyomavirus infection and the other disease processes in this sea lion is not known, but it is considered unlikely that the polyomavirus induced the lymphoma.

Discovery of a new human polyomavirus associated with trichodysplasia spinulosa in an immunocompromized patient

The Polyomaviridae constitute a family of small DNA viruses infecting a variety of hosts. In humans, polyomaviruses can cause infections of the central nervous system, urinary tract, skin, and possibly the respiratory tract. Here we report the identification of a new human polyomavirus in plucked facial spines of a heart transplant patient with trichodysplasia spinulosa, a rare skin disease exclusively seen in immunocompromized patients. The trichodysplasia spinulosa-associated polyomavirus (TSV) genome was amplified through rolling-circle amplification and consists of a 5232-nucleotide circular DNA organized similarly to known polyomaviruses. Two putative “early” (small and large T antigen) and three putative “late” (VP1, VP2, VP3) genes were identified. The TSV large T antigen contains several domains (e.g. J-domain) and motifs (e.g. HPDKGG, pRb family-binding, zinc finger) described for other polyomaviruses and potentially involved in cellular transformation. Phylogenetic analysis revealed a close relationship of TSV with the Bornean orangutan polyomavirus and, more distantly, the Merkel cell polyomavirus that is found integrated in Merkel cell carcinomas of the skin. The presence of TSV in the affected patient's skin was confirmed by newly designed quantitative TSV-specific PCR, indicative of a viral load of 10⁵ copies per cell. After topical cidofovir treatment, the lesions largely resolved coinciding with a reduction in TSV load. PCR screening demonstrated a 4% prevalence of TSV in an unrelated group of immunosuppressed transplant recipients without apparent disease. In conclusion, a new human polyomavirus was discovered and identified as the possible cause of trichodysplasia spinulosa in immunocompromized patients. The presence of TSV also in clinically unaffected individuals suggests frequent virus transmission causing subclinical, probably latent infections. Further studies have to reveal the impact of TSV infection in relation to other populations and diseases.

Diseases that occur exclusively in immunocompromized patients are often of an infectious nature. Trichodysplasia spinulosa (TS) is such a disease characterized by development of papules, spines and alopecia in the face. Fortunately this disease is rare, because facial features can change dramatically, as in the case of an adolescent TS patient who was on immunosuppressive drugs because of heart-transplantation. A viral cause of TS was suspected already for some time because virus particles had been seen in TS lesions. In pursuit of this unknown virus, we isolated DNA from collected TS spines and could detect a unique small circular DNA suggestive of a polyomavirus genome. Additional experiments confirmed the presence in these samples of a new polyomavirus that we tentatively called TS-associated polyomavirus (TSPyV or TSV). TSV shares several properties with other polyomaviruses, such as genome organization and proteome composition, association with disease in immunosuppressed patients and occurence in individuals without overt disease. The latter indicates that TSV circulates in the human population. Future studies have to show how this newly identified polyomavirus spreads, how it causes disease and if it is related to other (skin) conditions as well.

Mycobacterium genavenseand avian polyomavirus co-infection in a European Goldfinch (Carduelis carduelis)

Systemic mycobacteriosis associated with avian polyomavirus infection was diagnosed histologically in an 8-year-old, captive European goldfinch with a history of nervous signs. Severe mycobacterial lesions were observed in the central nervous system, lungs, cervical air sacs and adrenal glands, without involvement of the gastrointestinal tract. In addition to mycobacteriosis, intranuclear inclusions, typical of polyomavirus, were identified in the adrenal glands. Polymerase chain reaction assays were used to identify Mycobacterium genavense and finch polyomavirus as the causative agents. The absence of involvement of the gastrointestinal tract and the severity of the lesions in the respiratory tract suggested that inhalation may have been the primary route of infection with M. genavense.

Real-time PCR detection of adenoviruses, polyomaviruses, and torque teno viruses in river water in Japan

The prevalence of DNA viruses in water from the Tamagawa River, Japan was quantitatively surveyed for 6months, from April to September 2003. A total of 18 river water samples were subjected to virus concentration method using an electronegative membrane, followed by DNA extraction and direct quantitative real-time polymerase chain reaction (qPCR) for DNA viruses. Adenoviruses of serotypes 40 and 41 were detected most frequently in the river water samples tested (61.1%), at a concentration ranging from 3.16x10(3) to 1.38x10(5) copies/l, followed by JC polyomaviruses (11.1%) and torque teno viruses (5.6%). No sample was positive for BK polyomaviruses. In addition, for selective detection of virus particles, adenoviruses 40 and 41 were tested with qPCR combined with an immunomagnetic separation technique; they were detected in only 16.7% of the samples, showing a concentration ranging from 7.42x10(2) to 4.24x10(4) copies/l. This study is significant since it is the first study to demonstrate the prevalence of polyomaviruses in water samples in Japan and to use immunomagnetic separation qPCR to detect adenovirus particles in aquatic environments.

[Detection and clinical characterization of WU polyomavirus in acute respiratory tract infection in children]

OBJECTIVE

WU polyomavirus (WUPyV), a new member of the genus Polyomavirus in the family Polyomaviridae, has been found to be associated with respiratory tract infections recently. But the role of the WUPyV as agents of human disease remains uncertain. We sought to describe the detection and clinical characterization of WUPyV in acute respiratory tract infection in children.

METHOD

From July 2008 through June 2009, nasopharyngeal aspirates were collected from 771 children who were hospitalized with acute respiratory tract infection in Second Affiliated Hospital of Shantou University Medical College, and from 82 asymptomatic children who visited the health checkup clinic. WUPyV was detected by using PCR technology and was identified by using DNA sequencing. All WUPyV-positive specimens were screened for 9 common viruses [influenza A and B, respiratory syncytial virus (RSV), parainfluenza virus (PIV) 1 and 3, human metapneumovirus, human bocavirus, adenovirus and rhinovirus] by using PCR or RT-PCR. The clinical data of WUPyV infection were collected and analyzed.

RESULT

In this study, fifteen of the 771 tested specimens with acute respiratory tract infection were positive for WUPyV, the positive rate was 1.95% and all of the asymptomatic children who visited the health checkup clinic were negative. Of the 15 cases who were positive for the virus, the age range was 2 to 48 (mean 18.8) months, 9 (60%) were male and 6 (40%) were female. WUPyV was the sole virus detected in 9 specimens (60%) from patients with acute respiratory tract infection. WUPyV was associated with the co-infection with another respiratory virus in 6 of 15 (40%) cases, most frequently with RSV (n = 4), followed by adenovirus (n = 1) and rhinovirus (n = 1). The most common clinical findings in the patients with WUPyV were cough, fever and wheezing. The most frequent diagnoses were pneumonia (n = 8), bronchiolitis (n = 4), upper respiratory tract infections (n = 2) and bronchitis (n = 1). A severe case was complicated with viral encephalitis.

CONCLUSION

WUPyV may be a respiratory pathogen because it was the sole virus detected in 9 specimens from patients with respiratory illness and all of the asymptomatic controls were negative. The most common clinical findings are cough and wheezing. Young children may be susceptible to infection with this virus and occasionally the infection with this virus may cause severe disease. More comprehensive and in-depth studies are required to prove the pathogenicity of these viruses.

Identification of WU polyomavirus from pediatric patients with acute respiratory infections in Beijing, China

A novel polyomavirus (WU virus) has been identified in pediatric patients with acute respiratory tract infections (ARI), but its role as a respiratory pathogen has not yet been demonstrated. To investigate if WU virus is related to acute respiratory infections in infants and children in Beijing, specimens collected from 674 pediatric patients with ARI from April 2007 to May 2008 and from 202 children without ARI were used for this investigation. Common respiratory viruses were tested by virus isolation and/or antigen detection by indirect immunofluorescent assay followed by RT-PCR or PCR for other viruses associated with respiratory infections in specimens collected from patients with ARI before WU virus DNA was detected. WU virus DNA was detected by initial screening and secondary confirmation PCR for all specimens. The region encoding the VP2 gene of the virus was amplified from 17 WU-virus-positive clinical specimens, and sequence analysis was performed. Thirty-eight of 674 (5.6%) specimens from patients with ARI and 3 of 202 (1.5%) specimens from children without ARI yielded PCR products with the predicted molecular weight, using either screening or confirmation primer sets, indicating that these specimens were WU virus positive. However, more than 60% of the 38 WU-virus-positive specimens from patients with ARI were also positive for one or more respiratory viruses. The nucleotide and deduced amino acid sequences of the region encoding the VP2 gene from 17 Beijing WU viruses shared high homology (>98.5%) with sequences from GenBank and among themselves. The data indicated that WU virus in Beijing occurred 3.7 times more frequently in pediatric patients with ARI than in those without ARI (p < 0.05).

Comparison of molecular markers to detect fresh sewage in environmental waters

Human-specific Bacteroides HF183 (HS-HF183), human-specific Enterococci faecium esp (HS-esp), human-specific adenoviruses (HS-AVs) and human-specific polyomaviruses (HS-PVs) assays were evaluated in freshwater, seawater and distilled water to detect fresh sewage. The sewage spiked water samples were also tested for the concentrations of traditional fecal indicators (i.e., Escherichia coli, enterococci and Clostridium perfringens) and enteric viruses such as enteroviruses (EVs), sapoviruses (SVs), and torquetenoviruses (TVs). The overall host-specificity of the HS-HF183 marker to differentiate between humans and other animals was 98%. However, the HS-esp, HS-AVs and HS-PVs showed 100% host-specificity. All the human-specific markers showed >97% sensitivity to detect human fecal pollution. E. coli, enterococci and, C. perfringens were detected up to dilutions of sewage 10(-5), 10(-4) and 10(-3) respectively. HS-esp, HS-AVs, HS-PVs, SVs and TVs were detected up to dilution of sewage 10(-4) whilst EVs were detected up to dilution 10(-5). The ability of the HS-HF183 marker to detect fresh sewage was 3-4 orders of magnitude higher than that of the HS-esp and viral markers. The ability to detect fresh sewage in freshwater, seawater and distilled water matrices was similar for human-specific bacterial and viral marker. Based on our data, it appears that human-specific molecular markers are sensitive measures of fresh sewage pollution, and the HS-HF183 marker appears to be the most sensitive among these markers in terms of detecting fresh sewage. However, the presence of the HS-HF183 marker in environmental waters may not necessarily indicate the presence of enteric viruses due to their high abundance in sewage compared to enteric viruses. More research is required on the persistency of these markers in environmental water samples in relation to traditional fecal indicators and enteric pathogens.

Merkel cell carcinoma: recent progress and current priorities on etiology, pathogenesis, and clinical management

PURPOSE

To expedite improved understanding, diagnosis, treatment, and prevention of Merkel cell carcinoma (MCC), a rare malignancy of cutaneous neuroendocrine cells that has a 28% 2-year mortality rate.

METHODS

This article summarizes a workshop that discussed the state-of-the-art research and priorities for research on MCC and on a new human polyomavirus (ie, MCPyV) recently discovered in 80% of MCC tumors.

RESULTS

Normal Merkel cells are widely distributed in the epidermis near the end of nerve axons and may function as mechanoreceptors or chemoreceptors. Malignant MCC cells typically stain for cytokeratin 20 as well as for other epithelial and neuroendocrine markers. MCC subtypes, which are based on histology, on cell line growth properties, and on gene expression profiles, have been reported but have not been linked to prognosis. Clinical management has been empiric. MCPyV is clonally integrated at various sites in the human genome of MCC tumors, with truncating mutations in the viral, large T antigen gene that interrupt viral replication. MCPyV seroprevalence may be high, as with previously known human polyomaviruses. MCC risk is increased 11-fold with AIDS and with other cell-mediated immune deficiencies, B-cell neoplasms, and ultraviolet radiation exposure.

CONCLUSION

Development and validation of a range quantitative polymerase chain reaction and serologic assays for detection of MCPyV, as well as an infectious clone of the virus, would clarify the fundamental biology, natural history, and epidemiology of the virus, of MCC, and of other diseases. Contingent on standardized histologic diagnosis and staging of MCC, consortia are needed to clarify the risks and benefits of sentinel lymph node biopsy, adjuvant radiation therapy, and salvage therapies; consortia are needed also for epidemiologic studies of MCC etiology.

Detection of human viruses in rivers of a densly-populated area in Germany using a virus adsorption elution method optimized for PCR analyses

Transmission of viruses via surface water is a major public health concern. To determine the viral concentration in rivers of a densely-populated area in Germany, the virus adsorption elution (VIRADEL) method was optimized for downstream PCR applications. Using a high-salt alkaline phosphate buffer for elution, the median recovery efficiency from spiked 1l water samples ranged from 21.3% to 100% for JC polyomavirus, human adenovirus type 5, Echovirus 11, and norovirus genogroup I. Analyses of 41 water samples collected during the winter 2007/08 from the rivers Ruhr and Rhine yielded detection rates 97.5% for adenoviruses and human polyomavirus (JC, BK), and 90% for group A rotaviruses. Noroviruses genogroup II were detected in 31.7% of the samples and only one sample was positive for enteroviruses. Virus concentrations ranged from 9.4 to 2.3x10(4) gen.equ./l. However, the genome equivalents/liter determined for the RNA viruses and their detection frequency are only lower limits, since the concentration procedure leads to carry-over of inhibitors of the reverse transcription step. Sequence analyses of the PCR products revealed that the adenovirus and rotavirus PCRs used could cross-react with animal viruses from the respective virus families. These results suggest that detection of human polyomavirus genomes is the most sensitive and specific marker for contamination of surface water with viruses from human sewage. Although we could routinely detect nucleic acids of viral pathogens in river water by the PCR-optimized VIRADEL method, threshold levels of viral nucleic acids above which there is a risk of infection with viruses derived from human remain to be determined.