Characterization of the new GII.17 norovirus variant that emerged recently as the predominant strain in China.

Human noroviruses are the most important viral pathogens causing epidemic acute gastroenteritis, in which the GII.4 viruses have been predominant worldwide for the past decades. During 2014-2015 winter season, a new GII.17 variant emerged as the predominant virus in China surpassing the GII.4 virus in causing significantly increased acute gastroenteritis outbreaks. Genome sequences of the new GII.17 variant was determined and compared with other GII.17 noroviruses, revealing residue substitutions at specific locations, including the histo-blood group antigen-binding site and the putative antigenic epitopes. Further study of GII.17 outbreaks focusing on host susceptibility showed that the new GII.17 variant infected secretor individuals of A, B, O and Lewis types. Accordingly, the P particles of the new GII.17 variant bound secretor saliva samples of A, B, O and Lewis types with significantly higher binding signals than those of the P particles of the previous GII.17 variants. In addition, human sera collected from the outbreaks exhibited stronger blockade against the binding of the new GII.17 P particles to saliva samples than those against the binding between the P particles of previous GII.17 variants and saliva samples. Taken together, our data strongly suggested that the new GII.17 variant gained new histo-blood group antigen-binding ability and antigenic features, which may contribute to its predominance in causing human norovirus epidemics.

A Spatio-Temporal Modeling Framework for Surveillance Data of Multiple Infectious Pathogens with Small Laboratory Validation Sets.

Many surveillance systems of infectious diseases are syndrome-based, capturing patients by clinical manifestation. Only a fraction of patients, mostly severe cases, undergo laboratory validation to identify the underlying pathogen. Motivated by the need to understand transmission dynamics and associate risk factors of enteroviruses causing the hand, foot and mouth disease (HFMD) in China, we developed a Bayesian spatio-temporal modeling framework for surveillance data of infectious diseases with small validation sets. A novel approach was proposed to sample unobserved pathogen-specific patient counts over space and time and was compared to an existing sampling approach. The practical utility of this framework in identifying key parameters was assessed in simulations for a range of realistic sizes of the validation set. Several designs of sampling patients for laboratory validation were compared with and without aggregation of sparse validation data. The methodology was applied to the 2009 HFMD epidemic in southern China to evaluate transmissibility and the effects of climatic conditions for the leading pathogens of the disease, enterovirus 71 and Coxsackie A16.

[Evaluation on the highly active anti-retroviral therapy in 181 AIDS patients].

OBJECTIVE: To study the clinical effect under highly active anti-retroviral therapy (HAART) in AIDS patients and for improving the curative effect and prognosis. METHODS: Epidemiological method was used from five aspects to describe the post-treatment clinical symptoms of 181 AIDS patients in Suizhou, and to evaluate the change of virus load and immune function of 79 AIDS patients. Data was doubly recorded by Epi Data and database was set up by SPSS 13.0 for analysis. RESULTS: The effective powers of anomal-fever, cough, diarrhoea, lymphadenectasis, weight drop, erythra, mycotic infection were 81.39%, 85.00%, 84.62%, 81.89%, 82.86%, 66.07% and 45.45% respectively. CD4+ T lymphocyte count rose obviously after treatment, with an averag of 276 x 10(6) cells/ml (65 x 10(6)-824 x 10(6) cells/ml), an 129 x 10(6) cells/ml increase in three months and was 294 x 10(6) cells/ml (102 x 10(6)-750 x 10(6) cells/ml) in six months. The count change of CD4+ T lymphocyte between 3 months and 6 months did not show sigificant difference. The number of deaths among drug withdrawals was 14, with a case fatality rate as 29.79%; while the number of deaths among non-drug withdrawals was 3, with the case fatality rate as 2.24%. CONCLUSION: Results through this study showed that HAART could obviously improve the clinical symptom of AIDS patients, and to increase the number of virus load. Improving the compliance could also reduce the case fatality rate.