1012. Clinical epidemiological analysis of co-infection at acute diarrheal disease accelerates the controversy of underlining bacteria infection or histo-blood group antigens (HBGAs) leading to viral infection susceptibility
Session: Poster Abstract Session: Enteric Infection
Friday, October 9, 2015
Room: Poster Hall
Background: There have been many reports that some people have genetically determined receptor, they presents some susceptibility to Norovirus (NV). Histo-blood group antigens (HBGAs) is supposed to play a role of NV receptor and leads to susceptibility of NV. We start this study formulating a hypothesis that co-infection in the gastrointestinal tract could be related to the mechanism except genetics.

Methods: We recruited total 261 cases of acute gastroenteritis who all presented diarrhea symptom since Jan 2011, aged from 14 to 83 years. A male/ female ratio 148:113. Patients’ stool sample were collected and examined for antigens of Norovirus (NV), Rotavirus (RV), and Adenovirus (AV) by the commercialized kits. At the same time, stool culture for pathogenic bacteria got started using same stool sample. Single infection (each bacteria, each virus), co-infection between virus and virus, and co-infection between virus and bacteria were statistically analyzed.

Results: Fifty six per 261 subjects (21.5 %) were positive for only virus, 75/261(28.7 %) were positive for only bacteria. Both of bacteria and virus were found in 33/261(12.6 %). Detected bacteria were pathogenic Escherichia coli (Ec) species, Campylobacter species (Cp), Salmonella specie (Sa) etc, and Ec species were most frequently detected 61/261 (15.8%). Mean ages of infected patients were 50±24.6, 36.3±15.8, 38.6±18.3, respectively. RV infection 80/261 (30.7%, co-infection 28.8%), AV infection 78/261 (29.1%, co-infection 29.4%), and NV infection 51/261(19.5%, co-infection 25.4%) were observed. NV co-infection with bacteria were 10/51 (19.6%) with Ec, 5/51(9.8%) with Ca. Statistical analysis revealed co-infection of bacteria and NV is not significant. Referring to ABO histo-blood group type and NV infection, frequency was not significantly increased although the cumulated number of O group patients was largest among ABO blood groups.

Conclusion: The co-infection of bacteria and virus occurred frequently at gastrointestinal tract, and this result suggests that there could be another pathway leading to an infectious diarrheal disease except a correlation between a person’s genetically determined HBGAs expression and their susceptibility to enteric viruses, especially NV.

Tadashi Maeda, MD1, Hitoshi Nakajima, MD, PhD2, Taito Miyazaki, MD1, Yoshihisa Urita, MD, PhD1, Toshiyasu Watanabe, MD, PhD1 and Hiroaki Zai, MD, PhD1, (1)Toho University, Tokyo, Japan, (2)Geneneral Medicine, Toho University, Tokyo143-8541, Japan


T. Maeda, None

H. Nakajima, None

T. Miyazaki, None

Y. Urita, None

T. Watanabe, None

H. Zai, None

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