Viral gastroenteritis is one of the most common illnesses in humans worldwide and it has a great impact on people. The mortality among children due to acute gastroenteritis is greater in developing than in developed countries. 275-V Three RT-multiplex PCR assays with specific primers and protocols for the detection of three groups of diarrheal viruses were developed. The first group includes viruses group A, B and C rotaviruses and adenovirus; the second group includes astrovirus, norovirus (GI, GII) and sapovirus; and the third group includes enteroviruses, hepatitis A and E viruses and influenza A virus. These assays demonstrated as potential, simple, sensitive, specific and cost-effective methods in the detection of many target viruses. V-326 Among different kinds of diarrheal viruses, rotavirus is also considered to be significant global enteropathogen of acute gastroenteritis. Group A rotavirus had been demonstrated to undergo constant genetic variation and the emergence of strains might not be typed by current methods. Therefore, a PCR-ELISA assay was developed and demonstrated to be i) sensitive and specific, ii) easy to perform without use of any expensive and sophisticated equipment and iii) advantageous over the multiplex PCR. V-318 The epidemiological patterns of rotavirus causing diarrhea in children throughout Australia from 1997 to 2004 was done. G1 was the most prevalent type, being dominant in 6 of the 8 years. G9 emerged as predominant type in 2002 and 2003. Interestingly, G3 was common in 2003-2004. V-332 In Japan, rotavirus is still an important agent causing diarrhea among pediatric population. It is noteworthy to point out the first prevalence pattern of rotavirus serotype with an increase of G2, G3 as well as G9 and a decrease of G1 during the 20 year-survey of rotavirus infection in Japan. 262-V Rotavirus had been long known to infect terminally differentiated mature enterocytes in small intestinal villi. However, recent evidence suggests that infection may not be confined to the intestine. The findings of Indian researchers were that antigenemia is common in children with rotavirus diarrhea among several factors examined (age, clinical severity, G-type, medical history), infection with G1 strains and lack of prior exposure to rotavirus infection were important covariates of rotavirus antigenemia. V-324 The rotavirus nonstructural protein 4 (NSP4) has been shown to play a crucial role in rotavirus-induced diarrhea, acting as a viral enterotoxin. According to research in Spain, NSP4 can elicit an IgG antibody response in humans after natural rotavirus infections. The prevalence of IgG antibodies against NSP4 is very low among non-convalescent healthy children below 5 years of age, as well as in adults supposed to be protected from rotavirus disease upon re-infections. V-308 Diarrhea in HIV-infected African adults causes significant morbidity and mortality; however, few studies have examined the etiologic role of viral agents in this population. It was found that rotavirus was strongly associated with diarrhea in adults with HIV in Western Kenya and norovirus was the next most frequently detected viral pathogen. V-314 Group C rotavirus was found associated with sporadic cases or outbreaks of diarrhea worldwide. Diarrheal samples collected from children from 1997 to 2003 in Buenos Aires, Argentina were investigated for group C rotavirus by EIA and a subset by EM, RT-PCR, nested PCR and Southern hybridization. Positive EIA but negative PCR or hybridization results were obtained more frequently in samples with poorly preserved virus particles as seen by EM. Particle intrinsic instability could make IEA more adequate than molecular methods for group C rotavirus. V-117 A part from rotavirus as an important enteropathogen, norovirus is recognized a global agent of acute gastroenteritis. The sensitive real time immuno-PCR (rtI-PCR) method for the detection of norovirus in food samples was developed. The viral antigens were captured and detected with two polyclonal antisera against recombinant Norwalk-like viral partical (rNLVP). Then a real time PCR method was used to perform a quantitative analysis of norovirus in spiked food samples. It was found that the sensitivity of rtI-PCR was >1000 fold higher than the standard ELISA and about 10 times higher than RT-PCR in detection of norovirus in food samples. V-135 Based on the Australia research group, norovirus was identified as the major cause of a sharp increase in gastroenteritis illness in New South Wales in 2004. Norovirus was determined as the cause of 44.2% of gastroenteritis outbreaks between 2000 and 2004. Reported norovirus GII gastroenteritis increased from 17 outbreaks in 2000 to 179 outbreaks in 2004, the majority of which were in aged care facilities and hospitals. V-121 Up to date, the cell culture for human norovirus is not available. This limits the development of immunological methods to detect this virus. Recently, VLPs have been produced to make immune antisera. The Ridascreen ELISA kit (R-Biopharm) was used to detect norovirus. This assay could react with 4 VLPs of GI and 11 VLPs of GII produced. V-119 Moreover, a Japanese group successfully obtained norovirus specific Mabs which could detected norovirus GII/1-6, 8 and 12 genotypes from stool samples by Sandwich-ELISA. This demonstrated as potential to develop broadly reactive IC.