We report a severe acute respiratory syndrome coronavirus 2 superspreading event in the Netherlands after distancing rules were lifted in nightclubs, despite requiring a negative test or vaccination. ...This occurrence illustrates the potential for rapid dissemination of variants in largely unvaccinated populations under such conditions. We detected subsequent community transmission of this strain.
Parechoviruses (PeVs) are highly prevalent viruses worldwide. Over the last decades, several studies have been published on PeV epidemiology in Europe, Asia and North America, while information on ...other continents is lacking. The aim of this study was to describe PeV circulation in a cohort of children in Malawi, Africa. A total of 749 stool samples obtained from Malawian children aged 6 to 60 months were tested for the presence of PeV by real-time PCR. We performed typing by phylogenetic and Basic Local Alignment Search Tool (BLAST) analysis. PeV was found in 57% of stool samples. Age was significantly associated with PeV positivity (
p
= 0.01). Typing by phylogenetic analysis resulted in 15 different types, while BLAST typing resulted in 14 different types and several indeterminate strains. In total, six strains showed inconsistencies in typing between the two methods. One strain, P02-4058, remained untypable by all methods, but appeared to belong to the recently reclassified PeV-A19 genotype. PeV-A1, -A2 and -A3 were the most prevalent types (26.8%, 13.8% and 9.8%, respectively). Both the prevalence and genetic diversity found in our study were remarkably high. Our data provide an important contribution to the scarce data available on PeV epidemiology in Africa.
Enteroviruses (EVs) are among the most commonly detected viruses infecting humans worldwide. Although the prevalence of EVs is widely studied, the status of EV prevalence in sub-Saharan Africa ...remains largely unknown. The objective of our present study was therefore to increase our knowledge on EV circulation in sub-Saharan Africa. We obtained 749 fecal samples from a cross-sectional study conducted on Malawian children aged 6 to 60 months. We tested the samples for the presence of EVs using real time PCR, and typed the positive samples based on partial viral protein 1 (VP1) sequences. A large proportion of the samples was EV positive (89.9%). 12.9% of the typed samples belonged to EV species A (EV-A), 48.6% to species B (EV-B) and 38.5% to species C (EV-C). More than half of the EV-C strains (53%) belonged to subgroup C containing, among others, Poliovirus (PV) 1-3. The serotype most frequently isolated in our study was CVA-13, followed by EV-C99. The strains of CVA-13 showed a vast genetic diversity, possibly representing a new cluster, ‘F’. The majority of the EV-C99 strains grouped together as cluster B. In conclusion, this study showed a vast circulation of EVs among Malawian children, with an EV prevalence of 89.9%. Identification of prevalences for species EV-C comparable to our study (38.5%) have only previously been reported in sub-Saharan Africa, and EV-C is rarely found outside of this region. The data found in this study are an important contribution to our current knowledge of EV epidemiology within sub-Saharan Africa.
Abstract
Background
The majority of hepatitis C virus (HCV) infections are found in low- and middle-income countries, which harbor many region-specific HCV subtypes. Nevertheless, direct-acting ...antiviral (DAA) trials have almost exclusively been conducted in high-income countries, where mainly epidemically spread HCV subtypes are present. Recently, several studies have demonstrated suboptimal DAA efficacy for certain nonepidemic subtypes, which could hamper global HCV elimination. Therefore, we aimed to evaluate DAA efficacy in patients treated for a nonepidemic HCV genotype infection in the Netherlands.
Methods
We performed a nationwide retrospective study including patients treated with interferon-free DAAs for an HCV genotype other than 1a/1b/2a/2b/3a/4a/4d. The genotype was determined by NS5B region phylogenetic analysis. The primary end point was SVR-12. If stored samples were available, NS5A and NS5B sequences were obtained for resistance-associated substitutions (RAS) evaluation.
Results
We included 160 patients, mainly infected with nonepidemic genotype 2 (41%) and 4 (31%) subtypes. Most patients were from Africa (45%) or South America (24%); 51 (32%) were cirrhotic. SVR-12 was achieved in 92% (140/152) of patients with available SVR-12 data. Only 73% (8/11) genotype 3–infected patients achieved SVR-12, the majority being genotype 3b patients with 63% (5/8) SVR. Regardless of SVR, all genotype 3b patients had 30K and 31M RAS.
Conclusions
The DAA efficacy we observed in most nonepidemic genotypes in the Netherlands seems reassuring. However, the low SVR-12 rate in subtype 3b infections is alarming, especially as it is common in several HCV-endemic countries. Alongside earlier results, our results indicate that a remaining challenge for global HCV elimination is confirming and monitoring DAA efficacy in nonepidemic genotypes.
•Characterization of HCV NS3 variants by 454 and clonal sequencing was compared.•No significant differences were found in Shannon entropy/average pairwise distance.•Consensus sequences and ...phylogenetic tree topology were similar.•454 sequencing was superior in characterizing low frequency variants.•For intra-host diversity and population structure both methods were comparable.
We compared 454 amplicon sequencing with clonal sequencing for the characterization of intra-host hepatitis C virus (HCV) NS3 variants. Clonal and 454 sequences were obtained from 12 patients enrolled in a clinical phase I study for telaprevir, an NS3-4a protease inhibitor. Thirty-nine datasets were used to compare the consensus sequence, average pairwise distance, normalized Shannon entropy, phylogenetic tree topology and the number and frequency of variants derived from both sequencing techniques. In general, a good concordance was observed between both techniques for the majority of datasets. Discordant results were observed for 5 out of 39 clonal and 454 datasets, which could be attributed to primer-related selective amplification used for clonal sequencing. Both 454 and clonal datasets consisted of a few major variants and a large number of low-frequency variants. Telaprevir resistance-associated variants were observed in low frequencies and were detected more often by 454. We conclude that performance of 454 and clonal sequencing is comparable for the characterization of intra-host virus populations. Not surprisingly, 454 is superior for the detection of low frequency resistance-associated variants. However, despite the greater coverage, 454 failed to detect some low frequency variants detected by clonal sequencing.
INNO-LiPA HBV Genotyping (LiPA HBV GT) and INNO-LiPA HBV PreCore (LiPA HBV PC) are commercially available assays for hepatitis B virus (HBV) characterization. These assays are labor-intensive and may ...be prone to exogenous DNA contamination due to their use of nested PCR amplification procedures and lack of contamination control measures.
Standardized, single-round INNO-LiPA PCR amplification protocols incorporating uracil
N-glycosylase and automated sample processing by the MagNA Pure LC instrument were evaluated.
HBV standards containing 10,000, 1000, 100, 10, and 0
IU/mL were analyzed to determine the analytical sensitivity and reproducibility of these modified procedures. One hundred clinical serum specimens with viral titers ranging from 390 to 16,900,000
IU/mL were tested by modified LiPA HBV GT, while 34 specimens with viral titers ranging from 378 to 11,600,000
IU/mL were tested by modified LiPA HBV PC.
Modified LiPA HBV GT and LiPA HBV PC each yielded analytical sensitivities of 100% at an HBV DNA level of 1000
IU/mL and 90% at a level of 100
IU/mL. Among clinical specimens, success rates for both INNO-LiPA procedures were ≥94%.
Both modified INNO-LiPA procedures were sensitive and reproducible, with improved efficiency and suitability for routine laboratory use.
PDF
