Molecular and epidemiological features of gastroenteritis outbreaks involving genogroup I norovirus in Victoria, Australia, 2002-2010

GI noroviruses are relatively rare and systematic studies of the molecular epidemiology of GI norovirus outbreaks are lacking. The current study examined the molecular virology of GI norovirus outbreaks in Victoria, Australia (2002–2010). Of 1,617 norovirus outbreaks identified, 69 (4.3%) were associated with GI norovirus alone, 1,540 (95.2%) with GII norovirus alone and 8 (0.5%) with GI + GII. Some differences between GI and GII outbreak epidemiology were found. GI outbreaks peaked in the 2‐month period November/December whereas GII outbreaks peaked in the 2‐month period September/October and GI norovirus outbreaks were significantly more common in non‐healthcare settings (37.7%) than GII outbreaks (9.5%). ORF 1/ORF 2 genotypes found in the 69 outbreaks involving GI norovirus alone were: GI.2/GI.2, 7 outbreaks; GI.2/GI.6, 18 outbreaks; GI.3b/GI.3, 14 outbreaks; GI.4/GI.4, 21 outbreaks; GI.8/GI.8, one outbreak; GI.d/GI.3, four outbreaks; and GI.e/GI.13, one outbreak. The current study appears to be the first to have identified the recombinant form, GI.2/GI.6. Whereas GI.2/GI.6 and GI.3b/GI.3 outbreaks occurred with equal frequency in both healthcare and non‐healthcare settings, GI.4/GI.4 occurred predominantly in healthcare settings. GI ORF 1/ORF 2 genotypes found in the eight outbreaks involving GI + GII norovirus were GI.2/GI.6, GI.3b/GI.3, and GI.4/GI.4, indicating GI genotypes in GI + GII outbreaks were similar to those found in outbreaks involving GI alone. Apparent differences in the evolution of different GI genotypes were noted. GI.2/GI.2, GI.2/GI.6, and GI.4/GI.4 strains tended to undergo periodic shifts in nucleotide sequence whereas various GI.3b/GI.3 strains tended to circulate simultaneously. J. Med. Virol. 84:1437–1448, 2012. © 2012 Wiley Periodicals, Inc.     

天津市2019年住院散发急性胃肠炎患儿中诺如病毒感染分子流行病学特征分析

目的:了解天津市2019年散发急性胃肠炎患儿中诺如病毒(Norovirus, NoV)感染的分子流行病学特征。方法:收集2019年1—12月就诊于天津市儿童医院住院散发急性胃肠炎患儿的粪便标本3 116份,收集患儿临床资料和个人信息,采用实时荧光定量PCR方法对NoV进行初筛,应用反转录PCR方法对初筛阳性标本的聚合酶...     

Growth and health status of street children in Dhaka, Bangladesh.

The purpose of this study was to assess the effect of street life on the growth and health status of poor children who live and work full-time on the streets of Dhaka, Bangladesh (street children), independent of the effects of poverty. This was accomplished by comparing 142 street children with 150 poor children who live and work on the streets of Dhaka but who return to their families at night (slum children). Children between 7-14 years old were recruited at locales where street and slum children are typically found. Weight and upper arm circumference did not differ significantly between street and slum children (P > 0.05), but energy reserves, as assessed by skinfolds, were significantly larger in street than in slum children (P < 0.05). There was no wasting in either street or slum children. Although the majority of children in both groups were stunted and underweight, there were no significant differences between groups (P > 0.05). The prevalence of disease symptoms tended to be slightly higher in street children than in slum children, but few of the differences were statistically significant (P < 0.05). These data do not support the contention that street children are a particularly high-risk group. The greater-than-expected growth and health status of street children, compared to other poor children, may be due to biologically fitter children being more likely to permanently move to the streets and/or to remain on the streets once the move has been made.     

Molecular epidemiology of norovirus gastroenteritis in children in Jiangmen, China, 2005-2007

Human noroviruses (NoVs) are an important cause of epidemic acute gastroenteritis. Their role in sporadic cases, however, is less clear. In this study, we performed a two-year surveillance (September 2005 to August 2007) of NoV gastroenteritis in outpatient clinics in a southern city of China, Jiangmen City. NoVs were detected in 115 patients (115/881, 13.1%) with 30 (26.1%) co-infections with rotaviruses. Sequence analysis showed that all 115 NoVs belonged to genogroup II, with GII.4 being the most predominant (87.8%). NoV-associated infection can be seen year-around, with autumn and winter peaks. This study provides basic information on sporadic cases of major NoV gastroenteritis in children in different seasons, which is valuable for future disease control and prevention.     

Molecular and epidemiological trends of human bocavirus and adenovirus in children with acute gastroenteritis in Bangladesh during 2015 to 2019

Virus associated diarrhea remains one of the leading causes of children morbidity and mortality in Bangladesh. Human bocavirus (HBoV) has been reported as a potential pathogen of children's diarrhea worldwide. However, due to its frequent association with other gastroenteric pathogens, its role as diarrhea causative agent remains to be defined. This study focuses to detect the incidence of HBoV and adenovirus (AdV) and to determine the molecular and epidemiological characteristics of HBoV and AdV. Between January 2015 to January 2019, 290 fecal specimens were collected from diarrheal children in Bangladesh. All fecal specimens were tested for HBoV and AdV by conventional polymerase chain reaction and sequencing methods. HBoV was detected in 7.24% (21 of 290) of the stool samples, as a sole virus in 71.42% (15 of 21) of the positive samples. AdV was detected in 4.82% (14 of 290) of the samples. The most common clinical symptoms of HBoV infected patients were diarrhea (100%) and vomiting (57%). All of the isolates of HBoV were from HBoV1 and AdV were from AdV41, AdV5, AdV7, and AdV8. To the best of our knowledge, this is the first epidemiological and molecular analysis report of HBoV from clinical specimens in Bangladesh. In the future, more studies are needed to clarify the role of HBoV as diarrheal pathogens.     

广东省暴发性胃肠炎中诺如病毒的分子流行病学特点分析

目的研究广东省暴发性胃肠炎中诺如病毒的分子流行病学特点。方法对2003年至2004年的13起急性胃肠炎患者的粪便和肛拭子标本,采用针对诺如病毒的特异引物和逆转录-聚合酶链反应(RT-PCR)技术进行检测,再经核苷酸序列测定分析病毒的基因型,同时收集患者相关流行病学资料。结果13起暴发性胃肠炎中有8起是由诺如病毒引起的,时间主要集中在每年的10月至12月,基因分析显示这些病毒都属基因Ⅱ组,但分属3个亚型,6株病毒属GⅡ-4型。结论诺如病毒是广东省暴发性非细菌性胃肠炎的重要病原体之一,具有分布广、流行时间集中在秋冬季的特点。引起暴发的病毒主要为基因Ⅱ组,在现阶段存在优势毒株。     

Molecular and epidemiological features of norovirus-associated gastroenteritis outbreaks in Victoria, Australia in 2001

Norovirus was identified in 30 of 59 gastroenteritis outbreaks occurring in the state of Victoria, Australia in 2001 by RT-PCR and/or electron microscopy (EM). Norovirus outbreaks occurred in hostels/nursing homes (27%), hospitals (13%), youth refuges (3%), social gatherings associated with food consumption (27%), school outings/camps (13%), and pre-school/child-minding centers (17%). Norovirus outbreaks tended to occur in the warmer months. Phylogenetic analysis identified six clusters, one within genogroup 1 (G1) and five within genogroup 2 (G2). Cluster 1, which incorporates the G2 Camberwell/Lordsdale strains, was the most common (39% of outbreaks). In 2 of 27 outbreaks, strains from two G2 clusters, 1 and 5, occurred. Norovirus G2 was more common in the young and very old than in those in intermediate years. Norovirus G2 detection rate was higher in females than in males for adults (>15 years) and the susceptibility of adult females to norovirus G2 infection relative to males increased with age. In one outbreak analyzed, some sequences had a single base substitution, but this did not result in an amino acid (aa) change. The two most common norovirus clusters (G2 clusters 1 and 4) occurred in the capital of Victoria, Melbourne, and regional Victoria, but the least common clusters (G2 clusters 2 and 3 and G1 cluster 8) only occurred in inner Melbourne. Norovirus was occasionally detected by EM but not by RT-PCR. The occurrence of norovirus outbreaks is modulated by a large group of factors, which will have to be considered in any epidemiological model.     

GII.17 norovirus infections in outbreaks of acute nonbacterial gastroenteritis in Osaka City,Japan during two decades

Norovirus (NoV) is a major cause of viral gastroenteritis, and GII.4 has been the predominant genotype worldwide since the mid-1990s. During the 2014 to 2015 winter, a rare genotype, NoV GII.17, emerged and became prevalent mainly in East Asia. Over the past two decades, NoV molecular surveillance in Osaka City, Japan, has revealed that NoV GII.17 was detected for the first time in February 2001 and that NoV GII.17-associated outbreaks remarkably increased during the 2014 to 2015 season, with higher incidence recorded in January to March 2015. Genetic analysis indicated that 28 GII.17 outbreak strains were closely related to the novel GII.P17-GII.17 variants represented by the Kawasaki308/2015/JP strain, similar to that in other regions. Statistical analysis showed that NoV GII.17 infections were more common in adults than GII.3 and GII.4 infections, suggesting that the affected adults most likely did not have antibodies against NoV GII.17 and the novel GII.17 variant had recently appeared. Regarding transmission, food was one of the most important factors involved in the spread of NoV GII.17 among adults; 61% of GII.17 outbreaks were foodborne, with oysters being the most common vehicle. Interplay between pathogens, hosts, and environmental factors was considered to be important in the 2014 to 2015 NoV GII.17 epidemic.     

Molecular epidemiology of norovirus gastroenteritis outbreaks in New Zealand from 2002-2009

Noroviruses are the most common cause of acute non-bacterial gastroenteritis outbreaks worldwide, including New Zealand. New Zealand has a population of 4.4 million, which allows for centralized outbreak surveillance and a Norovirus Reference Laboratory, which facilitates efficient diagnosis, surveillance, and tracking of norovirus outbreaks. Norovirus outbreak strains are identified, sequenced, and compared with international reference strains. Between January 2002 and December 2009, 1,206 laboratory-confirmed norovirus outbreaks were recorded. The predominant outbreak settings were healthcare institutions for the elderly and acute care patients. Other outbreak settings included catering establishments, cruise ships, homes, community events, school camps, child-related settings, and consumption of contaminated shellfish. Of the 1,206 outbreaks, 105 (8.7%) were caused by norovirus genogroup I (GI) strains, 1,085 (89.9%) were caused by genogroup II (GII) strains, and both GI and GII strains were detected in 9 (0.8%) outbreaks. The genogroup was not identified in 7 (0.6%) outbreaks. A range of norovirus genotypes, including GI genotypes 1-6, GII genotypes 2-8, and GII.12, were associated with these outbreaks. The predominant genotype was GII.4, which was identified in 825 (68.4%) outbreaks. Norovirus GII.4 variant strains, including 2002 (Farmington Hills), 2004 (Hunter), 2006a (Laurens, Yerseke), 2006b (Minerva), and 2010 (New Orleans) implicated in overseas outbreaks also occurred in New Zealand, providing evidence of global spread.     

Molecular epidemiology of norovirus gastroenteritis outbreaks in North Carolina, United States: 1995-2000

Noroviruses (NoVs) are the most common cause of acute non-bacterial gastroenteritis outbreaks in the US. We investigated 16 gastroenteritis outbreaks in North Carolina (NC), from 1995 to 2000, to further characterize the epidemiology of NoV using RT-PCR on stool and ELISA on sera. NoV were identified in 14 outbreaks by RT-PCR. Sequence analyses of the amplicons indicated the outbreak strains belonged to the following clusters: five GII/4, three GI/3, one GI/4, one GII/2, one GII/5, one GII/7, and one GII/13 (prototype strain). We detected NoV in stool samples from one outbreak but could not determine its specific cluster within the GII genogroup based on polymerase sequence analysis. The five GII/4 strains were classified as the "95/96 US common strain" and occurred throughout the 5-year period. In contrast to national trends, the majority (86%) of NoV outbreaks identified in North Carolina were foodborne. Of the 12 food-related NoV outbreaks, we were able to document transmission by food handlers in two outbreaks. Person-to-person transmission from primary cases was suggested in three outbreaks. Our results indicate that NoVs are important agents of viral gastroenteritis outbreaks in NC.     

Molecular detection and genetic diversity of norovirus in hospitalized young adults with acute gastroenteritis in Bahia,Brazil

The molecular epidemiology of a recent norovirus (NoV) outbreak in Brazil performed by comparative analysis with Genebank NoV sequences showed that the GII.4 strain was responsible for 72.5% of all NoV-positive cases (58/80). Other detected NoV strains included GII.3 (7/80; 8.8%) and GII.9 (8/80; 10%). This is the first outbreak reported in Bahia state, Brazil, during June-July of 2006, where NoV was identified as the principal etiologic agent in hospitalized young adults with acute gastroenteritis symptoms. These findings suggest that GII.4 is a predominant circulating genotype in NoV outbreaks in Brazil.     

Molecular and epidemiological features of GIIb norovirus outbreaks in Victoria,Australia, 2002–2005

The epidemiology of GIIb norovirus outbreaks and the characteristics of GIIb open reading frame (ORF) 2 recombinant forms are poorly understood and this study examined these questions using norovirus‐associated gastroenteritis outbreaks in Victoria, Australia, during 2002–2005. Twenty‐one GIIb outbreaks were detected and were the second most common ORF 1 norovirus outbreak genotype (5%) after GII.4 (90%). Both GIIb and GII.4 outbreaks peaked in warmer months of the year but their periodicity was different. ORF 2 sequencing analysis was carried out in the two regions previously designated C and D. RT‐PCR region D primers were less sensitive than region C primers. No evidence of recombination between regions C and D was found. ORF 2 genotypes for the 21 GIIb outbreaks were: GII.1 (10 outbreaks), GII.3 (10 outbreaks) and, apparently for the first time, GII.13 (1 outbreak). GIIb outbreaks could occur in a broad range of settings and there was no correlation between ORF 2 genotype and setting except that all 5 outbreaks involving mainly young children were associated with GIIb/GII.3. J. Med. Virol. 81:1652–1660, 2009. © 2009 Wiley‐Liss, Inc.