Tina Uršič

Human bocavirus as the cause of a life-threatening infection.

ABSTRACT Human bocavirus is a recently described respiratory pathogen. A case of a life-threatening human bocavirus infection of a previously healthy pediatric patient is described. An initial clinical presentation of acute bronchiolitis developed into an extremely severe course of disease characterized by pneumothorax, pneumomediastinum, and acute respiratory failure with pronounced air-leak syndrome.

Coronavirus infections in hospitalized pediatric patients with acute respiratory tract disease

BackgroundAcute viral respiratory infections are an important cause of morbidity and mortality in humans worldwide. The etiological backgrounds of these infections remain unconfirmed in most clinical cases. The aim of this study was to estimate the prevalence of human coronavirus infections in a series of children hospitalized with symptoms of acute respiratory tract disease in a one-year period in Slovenia.MethodsThe 664 specimens from 592 children under six years of age hospitalized at the University Children’s Hospital in Ljubljana were sent for the routine laboratory detection of respiratory viruses. Respiratory viruses were detected with a direct immunofluorescence assay and human coronaviruses were detected with a modified real-time RT–PCR.ResultsHCoV RNA was detected in 40 (6%, 95% CI: 4.3%–8.1%) of 664 samples. Of these specimens, 21/40 (52.5%) were identified as species HKU1, 7/40 (17.5%) as OC43, 6/40 (15%) as 229E, and 6/40 (15%) as NL63. Infection with HCoV occurred as a coinfection with one or more other viruses in most samples (70%). Of the HCoV-positive children, 70.3% had lower respiratory tract infections.ConclusionThe results of our study show that HCoV are frequently detected human pathogens, often associated with other respiratory viruses and acute respiratory tract infections in hospitalized children. An association between age and the viral load was found. The highest viral load was detected in children approximately 10 months of age.

Human bocavirus and other respiratory viral infections in a 2-year cohort of hospitalized children.

Human bocavirus (HBoV) infection is reported worldwide and may cause severe respiratory tract infections. The aim of the present study was to assess the prevalence of HBoV, and other respiratory viral pathogens, in a 2‐year retrospective study of children admitted to hospital, and to investigate whether viral loads of HBoV DNA were associated with severity of infection. Between April 2007 and March 2009, 891 respiratory samples from 760 children admitted to hospital with acute respiratory tract infection were tested for the presence of respiratory viruses by real‐time PCR or direct immunofluorescence testing. HBoV DNA was detected by using internally controlled real‐time quantitative PCR assay and 25 samples selected at random were sequenced. The virus detected most frequently was rhinovirus, followed by respiratory syncytial virus, HBoV, and human metapneumovirus. HBoV DNA was detected in 18.4% of children admitted to hospital. HBoV was the only viral pathogen detected in 66/164 (40.2%) of HBoV DNA‐positive children and in 7.4% of all 891 samples. Ninety‐seven percent (64/66) of children with an HBoV single infection were diagnosed as having lower respiratory tract infection. Median HBoV DNA viral load was significantly higher in children when HBoV was detected as a single pathogen. Higher HBoV DNA viral loads were associated with prematurity and age. HBoV seems to be an important and frequent pathogen in respiratory tract infections in children, and it is likely that the severity of illness is comparable to the severity of RSV illness. J. Med. Virol. 84:99–108, 2011.

Diagnosing cytomegalovirus in patients with inflammatory bowel disease—by immunohistochemistry or polymerase chain reaction?

Cytomegalovirus (CMV) reactivation is a common complication in patients with inflammatory bowel diseases (IBD), particularly in those with steroid-resistant ulcerative colitis. It is usually diagnosed by histopathologic and immunohistochemical examination of the colon biopsy. The introduction of quantitative, real-time polymerase chain reaction (qPCR) has been recommended to improve the sensitivity, but there is little consensus on how to use it. We compared the two methods in samples from resected bowel of patients with IBD. Twelve patients with IBD who had undergone bowel resection were analysed for CMV, using qPCR and immunohistochemistry. In all cases, tissue samples from the base and the edge of ulcers and from uninvolved mucosa were obtained. The highest densities of CMV-positive cells were found in samples from the base of ulcers (immunohistochemistry 0–0.47 positive cells/mm2; qPCR 10–3809 viral copies/mg) or the edge of ulcers (immunohistochemistry 0.06–0.32 positive cells/mm2; qPCR 35–1049 viral copies/mg). In samples of uninvolved mucosa, immunohistochemistry was negative, whereas qPCR was either negative or showed very low values (0–3 viral copies/mg). We conclude that both immunohistochemistry and qPCR can be successfully used for diagnosing CMV reactivation in patients with IBD. The base and the edge of ulcers are the optimal sites for endoscopic biopsies. The density of CMV-positive cells was low and their distribution within the colon uneven. It therefore seems that the number of sampled biopsies and/or the number of investigated levels is more important that the choice of diagnostic method.

Fatal human bocavirus infection in an 18-month-old child with chronic lung disease of prematurity.

A fatal case of human bocavirus 1 pulmonary infection in an 18-month-old prematurely born child is described. Despite conventional and oscillatory ventilatory support, intractable hyperinflation developed with bilateral pneumothorax and acute cardiac failure 3 days after the onset of respiratory symptoms.

Seroprevalence of human anaplasmosis in slovene forestry workers.

Abstract:  The aim of the present study was to establish the prevalence and incidence of symptomatic and asymptomatic infection with Anaplasma phagocytophilum during the period of tick activity and to compare the risk of infection for forestry workers and indoor workers in Slovenia.

Narrowing of the Diagnostic Gap of Acute Gastroenteritis in Children 0-6 Years of Age Using a Combination of Classical and Molecular Techniques, Delivers Challenges in Syndromic Approach Diagnostics.

Background: Twenty-five percent to 50% of acute gastroenteritis (AGE) cases remain etiologically undiagnosed. Our main aim was to determine the most appropriate list of enteric pathogens to be included in the daily diagnostics scheme of AGE, ensuring the lowest possible diagnostic gap. Methods: Two hundred ninety seven children ⩽6 years of age, admitted to hospital in Slovenia, October 2011 to October 2012, with AGE, and 88 ⩽6 years old healthy children were included in the study. A broad spectrum of enteric pathogens was targeted with molecular methods, including 8 viruses, 6 bacteria and 2 parasites. Results: At least one enteric pathogen was detected in 91.2% of cases with AGE and 27.3% of controls. Viruses were the most prevalent (82.5% and 15.9%), followed by bacteria (27.3% and 10.2%) and parasites (3.0% and 1.1%) in cases and controls, respectively. A high proportion (41.8%) of mixed infections was observed in the cases. For cases with undetermined etiology (8.8%), stool samples were analyzed with next generation sequencing, and a potential viral pathogen was detected in 17 additional samples (5.8%). Conclusions: Our study suggests that tests for rotaviruses, noroviruses genogroup II, adenoviruses 40/41, astroviruses, Campylobacter spp. and Salmonella sp. should be included in the initial diagnostic algorithm, which revealed the etiology in 83.5% of children tested. The use of molecular methods in diagnostics of gastroenteritis is preferable because of their high sensitivity, specificity, fast performance and the possibility of establishing the concentration of the target. The latter may be valuable for assessing the clinical significance of the detected enteric, particularly viral pathogens.

Human Herpesvirus 6 Infection Presenting as an Acute Febrile Illness Associated with Thrombocytopenia and Leukopenia.

We present an infant with acute fever, thrombocytopenia, and leukopenia, coming from an endemic region for tick-borne encephalitis, human granulocytic anaplasmosis, and hantavirus infection. The primary human herpesvirus 6 infection was diagnosed by seroconversion of specific IgM and IgG and by identification of viral DNA in the acute patients serum. The patient did not show skin rash suggestive of exanthema subitum during the course of illness.

Chapter 15 – Human Bocavirus

Human bocavirus 1 (HBoV1), family Parvoviridae, subfamily Parvovirinae, genus Bocavirus, is a recently described respiratory virus with a worldwide distribution. It is recognized as one of the most frequently detected respiratory viruses in hospitalized children below 5 years of age and mainly detected in children between 6 and 24 months of age. The severe clinical course of HBoV1 infection can be seen in prematurely born children or children, but rarely adults, with other underlying medical conditions. The seroepidemiological studies show that most of the children are infected with HBoV1 by the age of 6 and that the IgG antibodies remain for life. The routine laboratory diagnostics of HBoV1 infections is almost exclusively based on detection of HBoV1 DNA in respiratory samples by PCR. Due to frequent coinfections with other respiratory viruses, PCR of plasma samples and detection of specific IgM might aid in determining the etiology of infection.