Epidemiology of rotavirus infection in Thailand

Rotavirus is a major cause of acute severe diarrhea in children worldwide and an important cause of death among young children in developing countries. Group A rotaviruses are antigenically complex and multiple serotypes infect humans. Reassortant rotavirus vaccines are now available which offer protection against severe illness caused by rotavirus serotypes G1-4. Before vaccines are introduced into target populations, it is necessary to establish the baseline data of the epidemiology of rotavirus infection in those countries. The purpose of the present study is to provide information related to the epidemiology of rotavirus infection in Thailand. All rotavirus studies performed in Thailand were found through Medline and Thai Index Medicus searches. A total of 26 of the most relevant studies published in international and national journals are reviewed. Most studies reported that the prevalence of rotavirus infection in Thailand was 27-34%, although a few studies have reported a prevalence above this range. The peak seasonal distribution of rotavirus infection among children hospitalized with diarrhea in Thailand was seen in the dry cool seasons: October to February. The prevalence of rotavirus infection was most frequently found in children aged 6-11 months up to 2 years. G1 was the most prevalent serotype in Thailand, followed by G2, G4 and G3, respectively. At least three G serotypes, mostly G1, G2 and G4, are seen to coexist in Thailand each epidemic year and in some studies all four G-serotypes were reported in the same epidemics. In a 1996-1997 study, G9 was the third prevailing serotype after G1 and G2, respectively. These results indicate that rotavirus epidemics occur in Thailand every year and children are the most affected population. In Thailand, although G1-G4 have been reported, G1 is the most prevalent serotype in each epidemic and G9 is becoming increasingly common.     

Overview of rotavirus infections in Korea

Rotavirus is the most common cause of acute watery diarrhea in young Korean children. Rotavirus vaccine will soon be available, and information is urgently required about the serotype distribution of recent epidemics and clinical characteristics of rotavirus infection in Korean children before the implementation of a vaccination program against rotavirus. We reviewed published studies of the past 20 years, carried out on Korean children with rotavirus gastroenteritis. Rotavirus was estimated to be responsible for 46% of 4668 hospitalized Korean children with acute gastroenteritis. Rotavirus gastroenteritis was most prevalent among children aged 6-24 months, which accounted for 84% of all cases. Asymptomatic rotavirus infection was common. Rotavirus was one of the most commonly identified enteric pathogens in nosocomial diarrhea. Vomiting, respiratory symptoms and fever were prominent symptoms in rotavirus gastroenteritis. Transient elevation of liver enzymes, pulmonic infiltration and rarely afebrile convulsion were also observed. The epidemic peak, which occurred in November of the last 15 years, has been moving toward late winter and early spring in recent years. No apparent cause has been found to explain this alteration of peak seasonality. All serotyping studies in Korea for the past 10 years until 1997 revealed that G1 was most prevalent (45-81%). Interestingly, the predominant G serotype of the recent outbreaks in 1998 and 1999 was not G1 but G4. Approximately 95% of rotavirus isolates in recent outbreaks belonged to serotype G1, 2, 3 or 4.     

上海地区婴幼儿腹泻的轮状病毒分子流行病学研究

目的 了解上海地区婴幼儿腹泻轮状病毒感染的分子流行病学特点。方法 收集复旦大学儿科医院1999年11月-2001年12月,住院的腹泻病儿童粪便标本1230份。采用聚丙烯酰胺凝胶电泳法检测轮状病毒基因组,用核酸杂交确定轮状病毒G血清型别。采用Kruskal-Wallis非参数统计法对不同G血清型别的临床变量作分析。结果 1230份标本中轮状病毒基因阳性493份(40．1％),其中RNA长型397份(80．5％),短型55份(11．2％),混合型18份(3．7％),未能分型23份(4．7％)。328份含有足量RNA的标本行RT-PCR扩增VP7全基因,254份标本(77．4％)获得阳性产物,进一步作杂交分型显示G1血清型141例(55．5％),占第一位;G3血清型70例(27．6％),占第二位;G2血清型24例(9．4％),占第三位;混合感染血清型16例(6．3％),占第四位;仅发现1例G4型(0．4％),未分型2例(0．8％)。所有G2型均为电泳短型,而G1、G3、G4均为电泳长型。四种型别轮状病毒感染患儿的平均发病年龄以及发热峰值、热程、每天腹泻峰次数、腹泻天数、呕吐天数差异无显著意义。结论 A组轮状病毒是目前上海地区腹泻儿童的主要致病原。在不同的3年中,轮状病毒的电泳型均以长型为主,流行血清型为G1-G3型,G4型很少见。未发现轮状病毒感染的临床特征与不同G血清型有关。     

Rotavirus gastroenteritis among children under five years of age in Izmir, Turkey

Little is known about the epidemiology of rotavirus infection in Turkey. The aim of the study was to determine the incidence and clinical significance of rotavirus gastroenteritis, in view of the potentially available prevention by rotavirus vaccination. The study also sought to determine possible risk factors for rotavirus gastroenteritis. Therefore, 920 children under five years of age with acute gastroenteritis admitted to three pediatric hospitals in Izmir were studied. Rotavirus was identified in 39.8% of the children. Most children with rotavirus gastroenteritis (80.7%) were younger than two years of age. Marked seasonality of rotavirus gastroenteritis was observed, with a peak incidence from January to March. A total of 91% of rotavirus strains that were typed were of serotypes G 1-4. There was no significant difference among rotavirus-positive and rotavirus-negative patients with regard to family income. Compared with children who were exclusively breast-fed, those who were not exclusively breast-fed were at a two-fold greater risk of rotavirus diarrhea. Rotavirus gastroenteritis was significantly more severe than non-rotavirus gastroenteritis; 69% of children with rotavirus infection had severe gastroenteritis (score > or = 11). In conclusion, rotavirus is the most common cause of severe gastroenteritis among children under five years of age in Izmir. A new potent rotavirus vaccine, when available, will provide effective protection against severe rotavirus infection. Promotion of breast-feeding would augment the impact of rotavirus vaccines in preventing severe childhood diarrhea.     

马鞍山、苏州地区5岁以下腹泻儿童轮状病毒G、P分型研究

目的 研究马鞍山和苏州地区5岁以下腹泻儿童轮状病毒G型和P型的分型。方法 对马鞍山和苏州地区5岁以下急性腹泻儿童粪便标本1267份，采用酶联免疫吸附试验和巢式-聚合酶链式反应检测轮状病毒感染和血清型。结果 轮状病毒阳性标本378份，主要来自2岁以下婴幼儿；血清型G型是优势株共250株，其中G1100株，G28株，G3111株，G43株，G93株，混合感染4株，未能分型21株(8．40％)；马鞍山以G1型为主(58．54％)，苏州以G3型为优势株(47．85％)；P基因型两地区流行株为P[4]和P[8]，分别占52．33％和47．67％，G1P[4]成为仅次于G1P[8]的GP组合。结论 在苏州和马鞍山地区5岁以下儿童轮状病毒腹泻中，流行的血清型分别为G3和G1，P基因型流行株为P[4]和P[8]。     

Enteric adenovirus infection and childhood diarrhea: an epidemiologic study in three clinical settings

During a 2-year prospective study of gastroenteritis in children less than 2 years of age, the role of enteric adenovirus as a cause of infantile diarrhea was examined in three clinical settings in a case-control fashion. Using a monoclonal antibody-based enzyme-linked immunosorbent assay with specificity for adenovirus serotypes 40 and 41, enteric adenovirus was identified in 10 of 246 episodes of diarrhea in outpatients (4.1%), 13 of 211 children admitted to the hospital with diarrhea (6.2%), and 5 of 81 children in whom nosocomial diarrhea developed (6.2%), making this agent the third most commonly identified etiologic agent of diarrheal disease. Asymptomatic infections were uncommon (5 of 372 control subjects, or 1.3%) and were seen most frequently in the nosocomial setting. Cases occurred in every calendar month except March and April of each year. A syndrome of watery diarrhea of longer duration compared with other patients with diarrhea (mean 5.4 vs 3.8 days, P = .01), associated with vomiting and dehydration, was present in most cases. Compared with patients with rotavirus, patients were as likely to experience fever and dehydration and more likely to vomit. Household contact with gastroenteritis, often with a child 2 to 5 years of age, was a predisposing factor. It was concluded that enteric adenovirus is an important cause of infantile diarrhea in Baltimore children. Although far less common than rotavirus, this agent was associated with diarrheal illnesses that were at least as severe as those seen with rotavirus.     

马鞍山、苏州地区婴幼儿轮状病毒腹泻临床特征和G血清型研究

目的　研究马鞍山和苏州地区婴幼儿轮状病毒 (RV)腹泻的临床特征和G血清型。方法　收集马鞍山和苏州地区5岁以下儿童急性腹泻粪便标本 1 2 67份 ,采用酶联免疫吸附试验和巢式 聚合酶链反应检测RV感染和血清型。结果　 1 2 67份标本中RV阳性 378份 ,血清型G型是优势株共 2 50株 ,其中G1 1 0 0株 ,G3 1 1 1株 ,G2 8株 ,G4、G9各 3株 ,混合感染 4株 ,未能分型2 1株 (8.40 % )。马鞍山地区以G1型为主 (58.54 % ) ,苏州地区以G3型为优势株 (47.85 % )。结论　RV是导致马鞍山和苏州地区婴幼儿腹泻的主要病原 ,流行的血清型分别为G1和G3型。     

Molecular epidemic features and variation of rotavirus among children with diarrhea in Lanzhou,China, 2001–2006

Background  Human rotavirus (HRV) is the most common pathogen causing severe diarrhea among infants and young children worldwide. This study aims to understand rotavirus epidemiology and its variation in the period of 2001–2006 in Lanzhou, Gansu Province, China, and to provide an epidemiological basis for the development of rotavirus vaccine. Methods  A total of 1019 stool specimens were collected from patients with acute diarrhea admitted to the First Hospital of Lanzhou University from 2001 to 2006, who were younger than 5 years old. Dako IDEIATM kits were used for detection of rotavirus, and RT-PCR was performed for determination of G serotype and P genotype of the rotavirus. Results  Rotavirus was present in 51.6% (526) of the 1019 specimens. G serotype identified G3 at 40.9%, G2 14.6%, G1 22.2% and G9 1.9%. Mixed-G infection was observed in 4.4% and non-typeable infection 16.0%. P genotype was observed in 372 samples, of which P[8] accounted for 186 cases (50.0%), P[4] 72 cases (19.4%), mixed-P infection 2 cases (0.5%), and non-typeable cases 112 (30.1%). G3 was the most prevalent G serotype found in this study from 2001 to 2004, G2 was the most prevalent G serotype (34.4%) from 2004 to 2005, and G1 (61.5%) was the most prevalent strain from 2005 to 2006. G9 was detected in 10 cases (1.9%) and G4 was not detected during this 5-year period. P[8] was the most prevalent P genotype found over the 5 consecutive years of this study, although there was a significant transition of P genotype from 2004 to 2005 with P[4] (45%) identified as the predominant P genotype, followed by P[8] (22.1%). The predominant G-P combination was P[8]G1 (33.6%), followed by P[8]G3 (32.1%) and P[4]G2 (17.2%). Rotavirus diarrhea admissions peaked between October and December. Continuous surveillance showed that the incidence rate of rotavirus was the highest in infants aged 6–23 months, averaging 11.0–11.9 months. Conclusions  Five years of continuous surveillance showed that rotavirus remains the most significant viral agent causing diarrhea hospitalization among children under 5 years old in Lanzhou, China although the predominant strain of rotavirus varies between years. Mixed-G serotype infection also appears to occur at a relatively high rate in Lanzhou.     

Seasonality and diversity of Group A rotaviruses in Europe

Group A rotaviruses are a mojor cause of severe gastroenteritis in children under 4 y of age worldwide. Group A rotaviruses have been identified in many animal and bird species, they are antigenically complex, and multiple serotypes infect humans. Re-assortant rotavirus vaccines are now available which confer protection against severe illness due to rotavirus serotypes G1-4. Before vaccines are introduced it is necessary to establish the diversity of rotavirus in the target population to ensure efficacy and to establish a baselinefor future surveillance strategies. The purpose of this review is to describe our current knowledge of the diversity of rotaviruses accross Europe. Since multinatinal studies with standardized methodology have not been performed, this review is based on the available published studies. In Europe, more than 90% of Group A rotavirus strains that have been typed are of serotypes G1-4, with an average 8% of non-G1-4 Strains in published studies. The percentage of non-typeable strains may fluctuate from one year to another, and has been as high as 18% in one study in Great Britain, indicating the need for a more systematic study. Group A rotavirus infection typically occurs as a winter peak in the European countries studied. Comparison of seasonality data from national laboratory surveillance systems showed seasonal differences, with the annual rotavirus peak occuring first in Spain, usually in December, followed by France in February, and ending in Northern Europe in England and Wales in February or March, and the Netherlands and Finland in March. □ Europe, G-types, P-types, rotavirus, seasonality, serotypes.     

Lack of association between rotavirus infection and intussusception: implications for use of attenuated rotavirus vaccines

BACKGROUND: Withdrawal of the tetravalent rhesus-human rotavirus vaccine Rotashield because of its association with intussusception raised concerns about a potential link between natural rotavirus disease and intussusception. Our objective was to determine whether such an association exists. METHODS: In the Southern California Kaiser Permanente Health Care Plan, a large health maintenance organization, from October, 1992, to July, 1999, we retrospectively identified by computerized data and medical charts all children <3 years old with intussusception, and from 1997 to 1999 we independently identified by prospective clinical and laboratory evaluation children <3 years old with rotavirus diarrhea. We compared the epidemiologic characteristics of intussusception and rotavirus infection in our study population and evaluated for the presence of both diseases in individual patients. RESULTS: Using computerized data we identified 124 cases of intussusception, 101 (81%) of which were confirmed by medical chart and radiologic reviews. The incidences for infants <1 year old and for children <3 years old were 41 (95% confidence interval, 32 to 55) and 17 (95% confidence interval, 13 to 20) per 100,000 child years, respectively. Between November 1997 and July 1999, we identified 470 cases of rotavirus diarrhea and none had intussusception. Although rotavirus diarrhea had a distinct peak incidence between December and February, intussusception had no apparent seasonality. The age distributions overlapped, but intussusception occurred at an earlier age than rotavirus disease. CONCLUSIONS: We found no epidemiologic evidence for an association between intussusception and natural rotavirus infection, but our study was limited by an insufficient number of cases to definitively exclude a causal link. The dramatic winter peak of rotavirus disease had no discernable parallel in the incidence of intussusception. Our data suggest that the association between tetravalent rhesus-human rotavirus vaccine and intussusception may possibly result from the nonhuman rotavirus components of that vaccine.     

2001-2003年杭州地区婴幼儿腹泻轮状病毒VP7型别分析

目的研究杭州地区秋冬季婴幼儿腹泻轮状病毒（RV）的感染特点及RV分子流行病学特点。方法收集2001--2003年秋冬季来本院就诊拟诊为病毒性肠炎患儿的粪便共683份,采用乳胶凝集试验（LAT）检测A组RV,阳性者再用酶联免疫吸附试验（ELISA）分型检测RVVP7（G）血清型;将ELISA确定VP7（G）血清型的标本进一步做逆转录一聚合酶链反应（RT-PCR）扩增及RV基因测序,证实其VP7（G）血清型。结果683份标本中,RV阳性297份,检出率为43．5％（297／683）;ELISA分型：VP7（G）血清型以G1、G3型为主,其中G1型占36．7％（109／297）、G3型占30．9％（92／297）,其余G2、G4、混合型和未分型分别占4．O％（12／297）、7．1％（21／297）、11.8％（35／297）和9.4％（28／297）;每年流行的VP7（G）血清型的主流不同,2001年以G1型为主,占54．9％（45／82）、G3型占14.6％（12／82）,2003年以G3型为主,占43．2％（63／146）、G1型占29．5％（43／146）。RT-PCR扩增、基因序列测定和同源性分析证实了ELISA分型的可信性。结论2001--2003年杭州地区秋冬季婴幼儿腹泻RV VP7（G）血清型以G1、G3型为主,且每年流行的主流血清型不同。     

北京市6岁以下门诊和住院腹泻患儿腺病毒检出率及流行特征

目的 了解北京单中心门诊和住院腹泻患儿腺病毒（Ad）检出情况及流行特征。方法 收集2010年1月至2013年12月首都儿科研究所6岁以下门诊腹泻、因腹泻住院和在住院期间出现腹泻症状患儿的粪便标本,采用PCR法检测Ad基因组DNA,分析流行特征。结果 进入本文分析腹泻患儿3 357例,门诊和住院腹泻患儿分别为862和2 495例。①3 357例腹泻患儿粪便标本中Ad检测阳性341例（10.2%）,门诊和住院腹泻患儿Ad检出率分别为8.1%（70/862）和10.9%（271/2 495）;门诊腹泻患儿肠道Ad（EAd）40例,包括Ad41和40型别,非肠道Ad（NEAd）30例（42.9%）,包括Ad31和Ad2等5种型别; 住院腹泻患儿EAd 271例,包括Ad41和Ad40型别,NEAd 157例（57.9%）,包括Ad31和Ad7等11种型别;门诊和住院腹泻患儿Ad和NEAd检出率差异均有统计学意义（P分别为0.022和0.002）。②Ad在门诊腹泻男女患儿中的检出率分别为9.0%和6.5%,在住院腹泻男女患儿中的检出率分别为11.7%和9.5%,差异均无统计学意义(P分别为0.206和0.086)。男女患儿Ad检出率在住院和门诊腹泻患儿间差异均无统计学意义(P分别为0.080和0.112)。③门诊腹泻患儿~6月龄、~1岁、~2岁和~6岁的Ad检出率分别为4.4%、7.7%、11.6%和12.3%,各年龄段Ad检出率差异有统计学意义（P=0.017）。住院腹泻患儿<28 d、~6月龄、~1岁、~2岁和~6岁的Ad检出率分别为4.4%、9.4%、13.2%、12.3%和13.4%,各年龄段Ad检出率差异有统计学意义(P=0.001）。④无论是门诊亦或住院腹泻患儿,全年各月均可见Ad检出。⑤Ad合并轮状病毒感染门诊腹泻患儿8/70例(11.4%),住院腹泻患儿29/271例(10.7%),差异无统计学意义（P=0.862）。结论 北京单中心门诊和住院腹泻患儿中Ad检出率为10.2%,以EAd41型占优势,NEAd31型在儿童腹泻中的作用也不容忽视。     

Rotavirus in Ireland: national estimates of disease burden, 1997 to 1998

BACKGROUND: We estimated the disease burden caused by rotavirus hospitalizations in the Republic of Ireland by using national data on the number of hospitalizations for diarrhea in children and laboratory surveillance of confirmed rotavirus detections. METHODS: We examined trends in diarrheal hospitalizations among children <5 years old as coded by ICD-9-CM for the period January, 1997, to December, 1998. We collated data on laboratory-confirmed rotavirus detections nationally for the same period among children <2 years old. We calculated the overall contribution of rotavirus to laboratory-confirmed intestinal disease in children <5 years old from INFOSCAN, a disease bulletin for one-third of the population. We compared data from all sources and estimated the proportion of diarrheal hospitalizations that are likely the result of rotavirus in children <5 years old. RESULTS: In children <5 years old, 9% of all hospitalizations are for diarrheal illness. In this age group 1 in 8 are hospitalized for a diarrheal illness, and 1 in 17 are hospitalized for rotavirus by 5 years of age. In hospitalized children <2 years old, 1 in 38 have a laboratory confirmed rotavirus infection. CONCLUSIONS: The disease burden of rotavirus hospitalizations is higher than in other industrialized countries. Access to comprehensive national databases may have contributed to the high hospitalization rates, as well as a greater tendency to hospitalize children with diarrhea in Ireland.     

Epidemiologic features of rotavirus infection in Taiwan: A review

Group A rotaviruses are a major cause of severe gastroenteritis in children under 4 years of age worldwide. Group A rotaviruses have been identified in many animal and bird species; they are antigenically complex, and multiple serotypes infect humans. Reassortant rotavirus vaccines are now available that confer protection against severe illness due to rotavirus serotypes G1-4. Before vaccines are introduced, it is necessary to establish their efficacy and to establish a baseline for future surveillance strategies. The purpose of the present review is to describe current knowledge of the diversity of rotavirus in Taiwan. The present review is based on the available published studies and data from China Medical College Hospital (Taiwan). In Taiwan, rotavirus has been detected year-round, with the epidemic peak swinging from November-December in 1984 to January-March in 1988-95 and then back to December-March in 1996-99. Most affected patients are under 2 years of age. Only group A rotavirus has been found. Neither group B nor group C rotavirus have been identified. G1 strains have been the predominant strains except for the year 1992-93, when G2 strains were prevalent. There has been no G4 strain detected in published studies. The electropherotype 'baba' has been observed every year. Five other electropherotypes have been sporadically found. Half of the strains that have been studied were genotype P[8] and their VP7 serotype was G1 or G3. All genotype P[4] strains have shown serotype G2. It is expected that the reassortant rotavirus vaccine will be effective in prevention of severe illness caused by rotavirus in Taiwan.     

2009-2010年南京地区5岁以下儿童轮状病毒性腹泻临床特点及分子流行病学研究

目的 了解2009年7月-2010年6月南京地区轮状病毒性腹泻的流行病学情况及病毒的血清及基因分型特点,为轮状病毒感染性腹泻的防治提供科学依据.方法 收集2009年7月-2010年6月本科随机留取水样泻患儿粪便标本300份,标本采集后立即保存于- 20℃冰箱,集中进行病毒检测和数据分析.使用ELISA法检测A组人类轮状病毒(HRV),应用Trizol法提取HRV RNA,反转录合成病毒cDNA,采用巢式反转录PCR法对HRV标本进行G血清型和P基因型分型.结果 300份患儿粪便标本中113份标本检测出A组HRV,阳性率为37.67％.G血清型最常见的为G3型[44份(38.94％)],其次为G2型[10份(8.85％)],G1型、G2+G3型各2份(1.77％),G9型1份(0.88％),未能分型54份(47.79％);P基因型最常见的为P[8]型[38份(33.63％)],其次为P[4]型[19份(16.81％)],未能分型56份(49.56％),未发现P[6]、P[9]、P[10]型.G血清型和P基因型组合以G3P[8]为主(18/113例,15.93％).南京地区HRV腹泻季节高峰在10月份-次年1月份,95.58％的腹泻儿童在2岁以前感染过HRV,HRV组发热率、腹泻次数、出现呕吐和脱水症状的概率与HRV阴性组比较差异均有统计学意义(Pa＜0.05).结论 HRV是引起南京地区婴幼儿水样泻的最主要的病原体,以G3P[8]为主要优势株.     

2001至2005年上海1 450份住院患儿A组轮状病毒分子流行病学研究

目的 对2001至2005年上海地区住院患儿A组轮状病毒分子流行病学进行研究，为今后轮状病毒疫苗的研制和应用提供基础数据和理论依据。方法 从复旦大学附属儿科医院2001至2005年住院的腹泻婴幼儿1450份轮状病毒抗原阳性粪便标本中用机械抽样的方法随机抽取363份，建立套式RT-PCR的方法，从粪便中检测轮状病毒基因并进行G和P型别的分型。结果 轮状病毒腹泻的主要流行季节是10~12月份，2岁以内的患儿占全部患儿总数的79.9%（290/363）。G1型所占比例在2001年最多为28.8%（25/87），以后逐年下降至2004年的1.7%（1/60），但2005年又回升至7.0%（4/57）。G3型在5年间均是最主要的流行型别。存在但少见的流行型别是G2和G4型，2001和2002年分别为14.9%（13/87）和5.0%（5/100）。每年的主要流行株均为P［8］，不同年份尚流行少量的P［4］和P［6］型。G3 P［8］成为2001至2005年上海地区的主要轮状病毒流行株，其次的流行型别包括2001和2003年份的G1 P［8］，2002年的G3、P混合型，2004至2005年的G3、P未知型。结论 2001至2005年上海地区轮状病毒流行型别显示了一定的变化规律，G3、P［8］ 及其组合G3 P［8］是5年间上海地区的主要轮状病毒流行株，不同年份尚有一些其他已知和未知型别的流行。     

Epidemiologic patterns of diarrheal disease in Argentina: estimation of rotavirus disease burden

BACKGROUND: Information on the burden of diarrheal diseases and rotavirus diarrheal diseases would help define strategies for management and prevention and clarify the potential benefits of candidate vaccines. This report of our study of the epidemiology of rotavirus diseases in Argentina analyzes the burden of rotavirus diarrhea, based on those studies and national statistics of diarrhea-associated medical visits, hospital discharges and deaths. METHODS: Information of diarrhea-associated medical visits, hospital discharges and deaths were provided by the Argentine Health Ministry. Estimation of rotavirus disease burden was performed using the percentage of rotavirus identification from previous reports.RESULTS: The incidence of diarrhea-associated medical visits (1999) was 14 times greater for ages 0 to 4 years than for ages of > or =5 years. Diarrhea-associated hospital discharges (0 to 4 years of age) decreased between 1981 and 1995 from 1.3 per 100 to 0.9 per 100 person-years) and diarrheal deaths (<2 years of age) decreased by a factor of 4 between 1985 and 1999 (64.7 per 100 000 to 16.1 per 100 000 person-years). Frequency of diarrheal deaths, hospital discharges and medical visits were highest in some of the northern Argentine provinces (26.2, 14.7 and 5.9 times greater, respectively, than in the lower risk areas of the country). We estimated that 1 in 2 children born in 1995 visited a public hospital, 1 in 12 required hospitalization, 1 in 1599 died of diarrheal diseases before their fifth year of life; 1 in 6, 1 in 35 and 1 in 4169 of those, respectively, died as a result of rotavirus diarrhea before their third year of life. CONCLUSIONS: The number of preventable diarrhea-associated and rotavirus-associated hospitalizations and deaths in Argentina is significant. The lack of rotavirus diagnostic capability in Argentine hospitals has resulted in underestimation of the disease burden of this virus. A rotavirus vaccine would have the potential to avoid thousands of hospitalizations and dozens of deaths, especially in the poor high risk Argentine provinces.     

Rotavirus infection among infants with diarrhea in Vietnam

Rotavirus was examined from diarrheal stool samples of 158 infants in rural area near Ho Chi Minh City, Vietnam, from 1994 to 1996. Group A rotavirus was detected in 50%. G1 and G4 were the predominant serotypes. G3 was not detected. The most predominant type changed from year to year. Rotavirus was found in all seasons, especially in winter and autumn. Infants younger than 2 years of age were those mostly infected and the virus was suspected to invade high concentration in this area.     

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目的通过分子流行病学调查研究兰州地区婴幼儿病毒性腹泻的病原学特点。方法采用酶联免疫吸附试验(ELISA)及逆转录聚合酶链反应(RTPCR),对2003年7月至2004年6月兰州地区收集的624例婴幼儿腹泻粪便标本随机抽取271例进行轮状病毒(RV)、杯状病毒(HuCV)及星状病毒(AstV)检测。结果在271例标本中共检出RV感染153例(56.46%),其中G394例(61.44%),G24例(2.61%),G93例(1.96%),未发现G1、G4型和混合感染;在随机抽取的69例G分型阳性标本中,检出P[8]型28例(40.58%);RV的感染对象主要为6～23月龄的婴幼儿,发病高峰在10、11月份(86.27%、73.81%)。在118例RVELISA阴性标本中检出HuCV感染13例(11.02%),其中诺如病毒(NLV)GⅡ型11例,札如病毒(SLV)2例,未检出NLVGⅡ型,发病年龄1～18个月(11.31±4.53个月);同时检出AstV感染7例(5.93%),发病年龄4～12个月(8.27±2.69)个月,其中有1例合并有SLV感染,另有1例为迁延性腹泻。HuCV和AstV感染均未表现出明显的季节性。结论RV是兰州婴幼儿病毒性腹泻的主要病原,其流行的主要血清型为G3型,HuCV和AstV亦是重要病原之一。