Diagnosing atopic dermatitis in infancy using established diagnostic criteria: a cohort study.

BACKGROUND: Diagnosing atopic dermatitis (AD) in infants is challenging. OBJECTIVES: To determine the incidence and persistence of eczema and AD in infants using the UK Working Party (UKWP) and Hanifin and Rajka (H&R) criteria. METHODS: A cohort of 1834 infants was examined clinically at 3, 6 and 12 months of age. AD was diagnosed by UKWP (3, 6 and 12 months) and H&R (12 months) criteria. Logistic regression models were used to assess the relationship between AD and eczema. RESULTS: Eczema was observed in 628 (34·2%) infants (n = 240, n = 359 and n = 329 at 3, 6 and 12 months, respectively), with AD diagnosed in 212 (33·7%) infants with any eczema and in 64/78 (82%) infants with eczema at all three visits. The odds of AD were lower with first presentation of eczema at 6 [odds ratio (OR) 0·33, 95% confidence interval (CI) 0·22-0·48] or 12 months (OR 0·49, 95% CI 0·32-0·74) than at 3 months, and higher in infants with eczema at three (OR 23·1, 95% CI 12·3-43·6) or two (OR 6·5, 95% CI 4·3-9·9) visits vs. one visit only. At 12 months, 156/329 (47·4%) fulfilled the UKWP and/or H&R criteria; 27 (8%) fulfilled the UKWP criteria only and 65 (20%) only the H&R criteria. Of the 129 infants who fulfilled the H&R criteria, 44 (34·1%) did not meet the itch criterion. CONCLUSIONS: Used in combination and at multiple timepoints, the UKWP and H&R criteria for AD may be useful in clinical research but may have limited value in most other clinical settings.

JAK2 V617F mutation can be reliably detected in serum using droplet digital PCR.

INTRODUCTION: Detection of the JAK2 V617F mutation is a key step in the diagnosis of myeloproliferative neoplasms (MPN). Sensitive real-time quantitative PCR (qPCR) detection on peripheral blood (PB) is the most widely used method. The main objective of this study was to determine whether serum, the most common material available in archival biobanks, is a good liquid biopsy for detecting and quantifying the JAK2 V617F mutation using droplet digital PCR (ddPCR). METHODS: Paired PB and serum samples from 66 patients with MPN were used. Serum samples were frozen at -25°C before analysis. DNA was extracted from 200 µL PB and 400 µL serum, and ddPCR analysis was performed. RESULTS: Among the 47 patients with detectable mutation in their PB samples, the overall sensitivity for the detection of JAK2 mutation in serum was of 96% (45 of 47); V617F was detected in all cases where mutation load was above 1%. Our results showed very strong correlation between PB and serum (Spearman r: 0.989, P < .0001). Significantly higher allele burden was detected in serum compared to PB (Wilcoxon signed ranks test, Z = -5.672, P < .0001). CONCLUSION: In our study, JAK2 V617F mutation load as low as 1% was reliably detected in serum using ddPCR.

HPV genotype profile in a Norwegian cohort with ASC-US and LSIL cytology with three year cumulative risk of high grade cervical neoplasia.

OBJECTIVE: To explore the HPVgenotype profile in Norwegian women with ASC-US/LSIL cytology and the subsequent risk of high-grade cervical neoplasia (CIN 3+). METHODS: In this observational study delayed triage of ASC-US/LSIL of 6058 women were included from 2005 to 2010. High-risk HPV detection with Hybrid Capture 2 (HC2) was used and the HC2+ cases were genotyped with in-house nmPCR. Women were followed-up for histologically confirmed CIN3+ within three years of index HPV test by linkage to the screening databases at the Cancer Registry of Norway. RESULTS: HC2 was positive in 45% (2756/6058) of the women. Within 3years CIN3+ was diagnosed in 26% of women<34year and in 15%≥34year. HC2 was positive at index in 94% of CIN3+ cases and negative in 64 cases including three women with cervical carcinomas. Women<34years with single infections of HPV 16, 35, 58 or 33 or multiple infections including HPV 16, 52, 33 or 31 were associated with highest proportions of CIN 3+. Older women with single infection with HPV 16, 33, 31 or 35 or multiple infections including HPV 16, 33, 31 or 18/39 were more likely to develop CIN 3+. CONCLUSIONS: HPV 16 and HPV 33 at baseline both as single or multiple infections, were associated with the highest risk for CIN3+. Among older women, all 13 high-risk genotypes as single infection were associated with >20% risk of CIN3+. Further studies are necessary to risk stratify the individual genotypes to reduce the number of colposcopies in Norway.

Use of molecular epidemiology to trace transmission pathways for infectious salmon anaemia virus (ISAV) in Norwegian salmon farming.

BACKGROUND: Infectious Salmon Anaemia (ISA) is a disease affecting farmed Atlantic salmon, and most salmon producing countries have experienced ISA outbreaks. The aim of the present study was to use epidemiological and viral sequence information to trace transmission pathways for ISA virus (ISAV) in Norwegian salmon farming. METHODS: The study covers a period from January 2007 to July 2009 with a relatively high rate of ISA outbreaks, including a large cluster of outbreaks that emerged in Northern Norway (the North-cluster). Farms with ISA outbreaks and neighbouring salmon farms (At-risk-sites) were tested for the presence of ISAV, and epidemiological information was collected. ISAV hemagglutinin-esterase (HE) and fusion (F) protein genes were sequenced and phylogenetic analyses were performed. Associations between sequence similarities and salmon population data were analysed to substantiate possible transmission pathways. RESULTS: There was a high degree of genetic similarity between ISAV isolates within the North-cluster. ISAV was detected in 12 of 28 At-risk-sites, and a high proportion of the viruses were identified as putative low virulent genotypes harbouring the full length highly polymorphic region (HPR); HPR0 of the HE protein and the amino acid glutamine (Q) in the F protein at position 266. The sequences from HPR0/F (Q(266)) genotypes revealed larger genetic variation, lower viral loads and lower prevalence of infection than HPR-deleted genotypes. Seaway distance between salmon farms was the only robust explanatory variable to explain genetic similarity between ISAV isolates. DISCUSSION: We suggest that a single HPR-deleted genotype of ISAV has spread between salmon farms in the North-cluster. Furthermore, we find that HPR0/F (Q(266)) genotypes are frequently present in farmed populations of Atlantic salmon. From this, we anticipate a population dynamics of ISAV portrayed by low virulent genotypes occasionally transitioning into virulent genotypes, causing solitary outbreaks or local epidemics through local transmission.

Epidemiological investigation of infectious salmon anaemia (ISA) outbreaks in Norway 2003-2005.

Epidemiological information was summarized from 32 outbreaks of infectious salmon anaemia (ISA) on salmon farming sites in Norway in 2003-2005. Virus isolates from the outbreak sites were genotyped, and the genotyping was used to assess possible associations between outbreak sites due to adjacent location, sharing fish farming authorisation, sharing smolt suppliers or sharing broodfish origin of the fish. The ISA outbreaks were distributed along most of the Norwegian coast and showed a variable clinical picture. The virus genotypes clustered into three genogroups. Pairs of outbreak sites matched for adjacent location or registered under the same authorisation, all shared genogroup, which was a significantly higher number of corresponding genogroups than expected by chance. For outbreak sites sharing smolt suppliers, corresponding genogroups appeared in 7 out of 12 matched pairs, which was not significant. An evaluation of broodfish origin associated with genogroups did not support transmission linked to broodfish origin. In conclusion, genotyping of virus isolates from ISA outbreaks supports associations between adjacent outbreaks. This is consistent with horizontal transmission. The present study failed to find evidence for vertical transmission (patterns of genogroups related to smolt suppliers or broodfish companies were not identified).

Two cases of severe obstructive pneumonia associated with an HKU1-like coronavirus.

BACKGROUND: During the last few years a number of previously undescribed viruses, including human metapneumovirus, coronaviruses SARS, NL63 and HKU1, and bocavirus, were identified in nasopharyngeal samples from patients with signs of respiratory infections. These viruses may cause mild to life-threatening infections. OBJECTIVES: Nasopharyngeal samples from hospitalized pediatric patients with respiratory disease were analysed for the presence of coronaviruses and other well known and newly identified respiratory viruses. RESULTS: Two clinical cases of a severe obstructive pneumonia, which were associated with the presence of RNA of a novel variant (subtype) of HKU1 coronavirus in the nasopharyngeal aspirates, were identified. DISCUSSION: The detection of a HKU1-like coronavirus in pediatric patients in the current study complement the most recent independent finding of similar or closely related coronaviruses in patients with respiratory diseases in France (Vabret et al. 2006) and Norway (Jonassen et al., see accompanying manuscript). These observations indicate a wide dissemination of HKU1-like coronaviruses in Europe.

Molecular epidemiology of viral infections. How sequence information helps us understand the evolution and dissemination of viruses.

Viruses evolve much faster than cellular organisms. Together with recent advances in nucleic acid sequencing and biocomputing, this allows us to distinguish between related strains of viruses, and to deduce the relationships between viruses from different outbreaks or individual patients. Databases of nucleotide sequences contain a large number of viral sequences with which novel sequences from local outbreaks can be compared. In this way the dissemination of viruses can be followed both locally and globally. We here review the biological and technological background to the use of virus nucleic acid sequences in epidemiological studies, and provide examples of how this information can be used to monitor human viruses. Molecular studies are particularly valuable for understanding the dissemination and evolution of viruses. The knowledge obtained is useful in epidemiological reconstructions, in real-time surveillance, and may even enable us to make predictions about the future developments of viral diseases.

A common RNA motif in the 3' end of the genomes of astroviruses, avian infectious bronchitis virus and an equine rhinovirus.

In the 3' non-coding region of the genomes of infectious bronchitis virus, an avian coronavirus and the picornavirus equine rhinovirus serotype 2, there is a motif with remarkable similarity, both in sequence and folding, to the second RNA stem-loop from the 3' end of the genomes of human astroviruses. This motif was also found in astroviruses of sheep, pig and turkey, suggesting that it is a common feature of all astroviruses. The conserved nature of the motif indicates that there has been strong selection for its preservation. There is significant homology between the regions flanking this motif in infectious bronchitis virus and a continuous RNA sequence at the same distance from the 3' poly(A) tail in some related mammalian coronaviruses. These observations suggest that the presence of the motif in these three viral families is the result of at least two separate RNA recombination events.