2001至2005年上海部分地区腹泻住院患儿诺若病毒分子临床流行病学研究

目的通过对上海地区腹泻住院患儿进行诺若病毒检测,对其流行株进行基因序列的测定,以了解诺若病毒在上海地区的流行特征,为该病原体所致腹泻的防治提供基础数据和理论依据。方法收集2001至2005年复旦大学附属儿科医院5岁以下腹泻住院患儿的粪便标本。首先进行轮状病毒的检测,在轮状病毒抗原阴性标本中,每隔8个标本按编号顺序行机械随机抽样,建立RT-PCR方法进行诺若病毒的检测。对PCR产物进行双向测序,测序结果通过Clustal W和Mega 4.1软件进行分析。结果研究期间共收集腹泻患儿粪便标本5534份,轮状病毒抗原阴性4084份,机械随机抽得484份用于诺若病毒检测,45/484份(9.3%)检测到诺若病毒。对诺若病毒感染季节分布和患儿年龄特点的分析表明,除4月和7月份未检测到诺若病毒外,其余各月份均检测到诺若病毒,其高发的月份是8至11月。5~6月也呈一个小高峰。77.8%(35/45)的患儿<2岁,其中6~11个月的患儿所占比例最高,达35.6%(16/45),<6个月的婴儿占20%(9/45)。GⅡ-4型是这5年间尤其是2003年之后的主要流行型别,2001至2002年尚存在其他的流行型别GⅡ-3和GⅡ-7...     

Gastrointestinal tract and viral pathogens

Viral gastroenteritis is the most common viral illness that affects the gastrointestinal (GI) tract, causing inflammation and irritation of the lining of the stomach and intestines. Common signs and symptoms associated with this condition include abdominal pain, diarrhea, and dehydration. The infections commonly involved in viral gastroenteritis are rotavirus, norovirus, and adenovirus, which spread through the fecal-oral and contact routes and cause non-bloody diarrhea. These infections can affect both immunocompetent and immunocompromised individuals. Since the pandemic in 2019, coronavirus gastroenteritis has increased in incidence and prevalence. Morbidity and mortality rates from viral gastroenteritis have declined significantly over the years due to early recognition, treatment with oral rehydration salts, and prompt vaccination. Improved sanitation measures have also played a key role in reducing the transmission of infection. In addition to viral hepatitis causing liver disease, herpes virus, and cytomegalovirus are responsible for ulcerative GI disease. They are associated with bloody diarrhea and commonly occur in im-munocompromised individuals. Hepatitis viruses, Epstein-Barr virus, herpesvirus 8, and human papillomavirus have been involved in benign and malignant diseases. This mini review aims to list different viruses affecting the GI tract. It will cover common symptoms aiding in diagnosis and various important aspects of each viral infection that can aid diagnosis and management. This will help primary care physicians and hospitalists diagnose and treat patients more easily.     

Diagnosis of viral gastroenteritis in children: interpretation of real-time PCR results and relation to clinical symptoms

Molecular methods such as real-time polymerase chain reaction (PCR) are rapidly replacing traditional tests to detect fecal viral pathogens in childhood diarrhea. This technique has now increased the analytical sensitivity so drastically that positive results are found in asymptomatic children, leading to complex interpretation of real-time PCR results and difficult distinction between asymptomatic shedding and etiological cause of disease. We performed a review of the literature including pediatric studies using real-time PCR and a minimal inclusion period of one year to exclude bias by seasonality. We searched for studies on rotavirus, norovirus, adenovirus, astrovirus, and sapovirus, known to be the most common viruses to cause gastroenteritis in the pediatric population. For these viruses, we summarized the detection rates in hospitalized and community-based children with clinical symptoms of gastroenteritis, as well as subjects with asymptomatic viral shedding. Moreover, insight is given into the different viral sero- and genotypes causing pediatric gastroenteritis. We also discuss the scoring systems for severity of disease and their clinical value. A few published proposals have been made to improve the clinical interpretation of real-time PCR results, which we recapitulate and discuss in this review. We propose using the semi-quantitative measure of real-time PCR, as a surrogate for viral load, in relation to the severity score to distinguish asymptomatic viral shedding from clinically relevant disease. Overall, this review provides a better understanding of the scope of childhood gastroenteritis, discusses a method to enhance the interpretation of real-time PCR results, and proposes conditions for future research to enhance clinical implementation.     

Effect of rotavirus vaccine implementation on the prevalence of coinfections with enteric viruses in Norway

Acute gastroenteritis (AGE) is a common illness in both adults and children worldwide and is caused by several microorganisms including viruses, bacteria, and parasites. Rotavirus (RV), which is the main cause of AGE, can occur as a mixed infection with other viruses. The aim of this study is to assess the molecular epidemiology of viral enteric viruses and assess RV coinfections with other enteric viruses and their influence on disease severity before and after RV vaccine introduction in children under 5 years of age. A total of 600 samples collected from children hospitalized for AGE in five large hospitals in Norway, and were analyzed for viral gastroenteritis agents by enzyme immunoassay and quantitative real-time polymerase chain reaction (qRT-PCR). Positive results confirmed either by Sanger sequencing or genotyped by multiplex semi-nested RT-PCR. In total, 243 of the 300 (81%) samples, collected from the prevaccine cohort, were positive for at least one of the four viruses tested in this study. RV was most frequently identified in 82.6% of the samples. In the postvaccine cohort, 114 of the 300 (38%) samples were positive for at least one of the viruses tested. RV found in 36.5% of the samples. Coinfections found less frequently in the postvaccine cohort. Among circulating enteric viruses in Norway, RV is the most important cause of viral gastrointestinal infection. As expected, there were fewer RV positive and fewer coinfections after RV vaccine implementation. The results provide valuable data that can aid in further evaluation of the vaccine impact.     

Etiology of Acute Gastroenteritis in Hospitalized Children in Melbourne, Australia, from April 1980 to March 1993

Acute infectious diarrhea is common in children. Control requires knowledge of causes. Few comprehensive long-term studies of etiology have been undertaken in developed countries. This report is of a 13-year survey of 4,637 children from 0 to 14 years of age, admitted to a large children’s hospital for treatment of gastroenteritis, in which viruses, bacteria, and parasites were sought. A recognized enteric pathogen was identified in 56.6% of children. Group A rotaviruses occurred in 39.6% of children overall and in 55% of children 12 to 23 months of age. They were a frequent cause (18.7%) of acute gastroenteritis in children under 6 months and in those aged 5 to 13 years (16%). Rotaviruses were almost entirely responsible for winter admission peaks. Enteric adenovirus types 40 and 41 (6% overall) were more frequent in children under 12 months (9.4%). Salmonella spp. (5.8%) and Campylobacter jejuni (3.4%) were more common in children over 5 years (13.1% and 6.7%, respectively). The 43.5% of cases (60% in children under 6 months) where no enteric pathogen was identified are cause for concern. The involvement of small viruses (including caliciviruses and astroviruses) may be clarified when molecular biology techniques are utilized to address this gap in our knowledge. This comprehensive 13-year study of the cause of acute infectious diarrhea in children in developed countries reinforces the importance of rotavirus and highlights a large group for whom the etiology remains unknown, an issue of particular concern with babies under 6 months of age. New techniques have the potential to identify old and new pathogens causing disease in these vulnerable infants.     

Detection and molecular characterization of cosavirus in adults with diarrhea, Thailand

Human cosavirus (HCoSV) is a newly discovered virus in Picornaviridae family. At present it is not clear whether HCoSV is associated with diseases, including gastroenteritis in humans, as epidemiological data is limited. Epidemiological surveillance of HCoSV was conducted on 150 fecal specimens collected from children and 150 samples from adults with diarrhea in Thailand by RT-PCR screening. HCoSV was found in a single adult specimen and not in any of the fecal specimens from children. This represents the first report of HCoSV infection in patients with diarrhea in Thailand. Extensive epidemiological surveillance of novel viruses associated with diarrhea in other populations may provide a better understanding of the distribution, genetic diversity, and association of the viral agents associated with acute gastroenteritis in humans.     

Evidence of an epidemic of Blastocystis hominis infections in preschool children in northern Jordan.

Blastocystis hominis is now gaining acceptance as an agent of human intestinal disease. A case-control study of the cause of gastroenteritis in children less than 6 years old was conducted. A total of 500 stool specimens were examined by wet mount preparation, formalin-ether concentration, Sheather's sugar flotation technique, and permanent stains when necessary. B. hominis was found in 63 (25%) of 250 stool specimens of the cases examined; 38 (15%) of these specimens contained this parasite alone. The appearance of severe symptoms was associated with increased numbers of the parasite in the diarrheic specimens (more than five parasites per field at a magnification of x 400). The most common symptoms were abdominal pain, recurrent diarrhea, cramps, anorexia, and fatigue. Contaminated water was suspected to be the major source of infection, since several cases were associated with Giardia infection. These findings support the concept of B. hominis pathogenicity in children with gastroenteritis.     

New Kids on the Block Causing Gastroenteritis: Bugs You Need To Look For

Currently, there are over 30 recognized or reputed bacterial agents that are regarded as causes of gastroenteritis. Most clinical microbiology laboratories test for only the most common enteric pathogens. However, three newer bacterial agents, Providencia alcalifaciens, Escherichia albertii, and Klebsiella oxytoca, are worthy of attention and consideration because of their ability to cause diarrhea and outbreaks of infection. In addition, these three bacterial agents possess virulence factors that can produce severe disease. This review summarizes our present knowledge of each bacterial group.     

Molecular epidemiology of noroviruses in children under 5 years of age with acute gastroenteritis in Yaoundé, Cameroon

Norovirus is a common cause of acute gastroenteritis (AGE) among children in developing countries. Limited data on the prevalence and genetic variability of norovirus are available in Cameroon, where early childhood mortality due to AGE is common. We tested 902 fecal specimens from children younger than 5 years of age hospitalized with AGE between January 2010 and December 2013. Overall, 76 (8.4%) samples tested positive for norovirus, of which 83% (63/76) were among children below 12 months old. Most of the noroviruses detected were in children infected between July and December of each year. All norovirus-positive specimens were genotyped, with 80% (61/76) being GII.4 (three variants detected). Genotypes GI.2, GI.6, GII.1, GII.2, GII.3, GII.6, GII.16, GII.17, and GII.21 were also detected. Interestingly, GII.4 Sydney and GII.17 Kawasaki viruses were found as early as 2010, years before their emergence globally. This study suggests norovirus is a significant cause of moderate to severe gastroenteritis among young children in Cameroon. The results are important to highlight appropriate prevention and control strategies for reducing the burden of norovirus disease.     

Prevalence of group C rotavirus among children in Rhode Island, United States.

BACKGROUND: Group C rotavirus causes sporadic cases and outbreaks of acute diarrhea in humans but its burden as a cause of severe gastroenteritis in children remains unclear. OBJECTIVES: To investigate the epidemiology and burden of group C rotavirus gastroenteritis among children in Rhode Island, United States. STUDY DESIGN: Diarrhea stool specimens from 124 children < or =10 years of age were collected, screened for group C and A rotavirus by EIA specific for each group, and further examined by nested PCR and Southern hybridization using primers and probes specific to the VP7 gene of human group C rotavirus. Group C rotavirus-positive fecal specimens were also examined by EM. RESULTS: Rotavirus was detected in 73 (59.0%) of 124 fecal samples. These included 53 (42.7%) positive for group A, 5 (4.0%) for group C and 15 (12.1%) for both group A and C rotaviruses. Examination of group C-positive samples by EM revealed the presence of largely empty or damaged rotavirus-like particles. CONCLUSION: These findings indicate that group C rotavirus is an important cause or a contributing cause of diarrhea among infants and older children in Rhode Island, United States.     

Symptomatic and asymptomatic infections of rotavirus, norovirus, and adenovirus among hospitalized children in Xi'an, China

Rotavirus (RV), norovirus (NoV), and adenovirus (AdV) have been reported as the common viral pathogens of acute gastroenteritis in children. To determine the prevalence of RV, NoV, and AdV infections among hospitalized children with and without symptoms of acute gastroenteritis, fecal specimens, and data on clinical symptoms were collected from 201 children with diarrhea and 53 children without diarrhea admitted to the Xi'an Children's Hospital in Xi'an, China between March 2009 and May 2010. RV, NoV, and AdV were identified in 68.7% (138/201), 20.4% (41/201), and 5.0% (10/201), respectively, of children with diarrhea. These three viruses were also detected in 13.2% (7/53), 35.9% (19/53), and 9.4% (6/53), respectively, of children without diarrhea. Diarrheal children infected with RV alone showed the average severity score of 6.5, statistically significant higher than the average score of 5.3 in children with unidentifiable viruses. GII.3 and GII.4 were the only two NoV genotypes identified, and the GII.4 sequences were genetically close to GII.4 2006b cluster. These findings highlight the importance of NoV as a causative agent of pediatric diarrhea after RV based on the clinical and epidemiological characteristics of NoV infection, and particularly convey information of asymptomatic infections of enteric viruses in young children.     

世界范围内A组轮状病毒G1型毒株VP7基因及VP4基因高变区的分析

Ａ组轮状病毒的ＶＰ４和ＶＰ７多肽是刺激机体产生中和抗体的主要保护性抗原。我们总结了世界多个地区和国家Ｇ１型轮状病毒流行株ＶＰ４和ＶＰ７基因的分子流行病学调查结果，并根据ＶＰ７多肽序列绘制了分子系统分类树。结果表明，所有流行株ＶＰ４基因的高变区具有相似的氨基酸组成，而ＶＰ７多肽疏水区，特别是已知的抗原决定簇ＶＲ３，ＶＲ４及ＶＲ６的氨基酸组成有规律性变异，提示这些毒株间在抗原性上有微小差异。分子系统分类树将所有毒株分为三个与氨基酸组成相对应的亚组，各个亚组的成员构成反映出了世界范围内轮状病毒流行株的分布具有较明显的地域性。     

世界范围内A组轮状病毒G1型毒株VP7基因及VP4基因高变区…

Ａ组轮状病毒的ＶＰ４和ＶＰ７多肽是刺激机体产生中的抗体的主要保护性抗原。我们总结了世界多个地区和国家Ｇ１型轮状病毒流行株ＶＰ４和ＶＰ７基因的分子流行病学调查结果，并根据ＶＰ７多肽序列绘制了分子系统分类树。结果表明，所有流行株ＶＰ４基因的高变区具有相似的氨基酸组成，而ＶＰ７多肽疏水区，特别是已知的抗原决定簇ＶＲ３，ＶＲ４及ＶＲ６的氨基酸组成有规律性变异，提示这些毒株间在抗原性上有微小差异。分子系数分     

Emergence of a new norovirus GII.6 variant in Japan, 2008-2009

Norovirus (NoV) is recognized as one of the most common causative agents of diarrhea disease in young children. A total of 187 fecal specimens collected from non-hospitalized children with acute gastroenteritis in Shizuoka, Japan during July 2008 to June 2009 were investigated for the presence of diarrhea viruses by a multiplex RT-PCR. Diarrhea viruses were overall detected in 158 of 187 (84.5%). Of the viruses detected, NoV was the most prevalent (55.6%). Most of the NoV sequences belonged to GII.4 (53.8%). NoV GII.6 emerged as the second most common strain (40.4%). The full-length capsid sequences of five representative Shizuoka GII.6 strains were compared with all 12 GII.6 strains available in GenBank database between 1990 and 2009. At least three distinct GII.6 subclusters (a-c) appeared in different parts of the world. Shizuoka GII.6 strains formed their own subcluster c, distinct from other complete GII.6 reference sequences. The Shizuoka strains had significant amino acid divergence, particularly in the P2 domain up to 10.9-17.5% and contained eight unique mutations in the P domains, compared with subcluster a and b viruses. The homology model showed that the eight mutations were predicted to be located at the surface-exposed P1 and P2 domains. The data suggest the emergence of a new NoV GII.6 variant in Shizuoka, with a high level of genetic variation.     

Occurrence of Viral Gastroenteritis in Children below 5 Years: A Hospital-based Study from Assam,India

Viral gastroenteritis is an important cause of mortality and morbidity in children under 5 years of age. Many a time, these cases go unnoticed causing immense scarcity of data on viral diarrhoea. The study aimed to determine the occurrence of viral gastroenteritis among children below 5 years and the aetiological viral agents. Stool samples were collected from patients suffering from acute gastroenteritis. Real-time polymerase chain reaction was done for detection of rotavirus, adenovirus, norovirus, astrovirus and sapovirus. Viruses were detected in 55% of children. Adenovirus was found to be the most common virus (33.7%), followed by rotavirus infection (28.7%).     

Human caliciviruses in Europe.

Caliciviruses are single-stranded RNA viruses, which are divided into four genera based on their morphology and genomic structure. Viruses from two genera, the Norwalk like viruses and Sapporo like viruses, are a common cause of acute, nonbacterial gastroenteritis in humans. Although the first human calicivirus discovered nearly 30 years ago, much of the epidemiological and biological character of these viruses is only now beginning to unfold. Investigation has been difficult due to a number of factors, the viruses cannot be amplified by in vitro cell culture or animal models and electron microscopy (EM) is often not sensitive enough to detect the viruses in stool samples. Recent advances in molecular diagnostic techniques and the advent of a baculovirus expression system have highlighted the clinical and public health importance of calicivirus in all age groups, their ability to cause infection via a number of transmission routes as well as their considerable genetic diversity. These characteristics, in conjunction with the inability of humans to develop long-term immunity make HuCV an important public health issue in Europe and worldwide.     

Adenovirus infection in children with diarrhea disease in Northwestern Nigeria

BACKGROUND: Adenoviruses, particularly enteric adenoviruses (EAds) type 40 (Ad40) and type 41(Ad41), can cause acute and severe diarrhea in young children worldwide. This study was conducted to delineate the epidemiological features of adenoviruses identified in children with gastroenteritis in Northwestern Nigeria. METHODS: All 282 specimens comprising 248 diarrheic and 34 non-diarrheic stools were randomly selected from 1063 stools previously analyzed for rotaviruses. These specimens were collected between July 2002 and July 2004 from children < 5 years of age. The specimens were screened for the presence of adenoviruses using monoclonal antibody-based Enzyme Immuno Assay (EIA), (Adenovirus RIDASCREEN r-Biopharm, UK) and the positive specimens were further examined for Ad40 and Ad41 using Premier Adenoclone -Type 40/41 EIA (Meridian Biosciences, USA). Negative staining electron microscopy was performed on selected specimens to confirm the presence of adenovirus particles. RESULTS: Adenovirus antigen was detected in 63/282 (23%) of the diarrheic diarrheic and in 6/34 (17.6%) of the non-diarrheic specimens. Adenoviruses were detected throughout the study period with most patients infected in the age group 25-36 months. The male-to-female ratio was 2.2:1 (43/20). Clinical features included fever (60%: 38/63), vomiting (56%: 35/63), mild dehydration (49%: 31/63), symptoms of upper respiratory tract infection (13%: 8/63) and abdominal pain (5%: 3/63). Analysis of stool specimen in adenovirus infected patients showed watery diarrhea in 87% (55/63), diarrhea with mucus in 19% (12/63) and diarrhea with mucus and blood in 3% (2/63). Ten (10) percent of the children were hospitalized due to gastroenteritis while 9 patients (14.3%) had co-infections with rotavirus. Human EAds were detected in 8% of specimens mainly in the dry season and among children older than 2 years. The principal symptoms were diarrhea (100%), dehydration (80%) and fever (80%). CONCLUSION: The findings of this study suggest that adenoviruses are important etiologic agents of gastroenteritis in Northwestern Nigerian children.