Severe fever with thrombocytopenia syndrome (SFTS) was firstly discovered in China in 2010, followed by several reports from many other countries worldwide. SFTS virus (SFTSV) has been identified as the causative agent of the disease and has been recognized as a public health threat. This novel Bunyavirus belongs to the Phlebovirus genus in the family Bunyaviridae. This review also describes the different aspects of virology, pathogenesis, epidemiology, and clinical symptoms on the basis of the published article surveillance data and phylogenetic analyses of viral sequences of large, medium, and small segments retrieved from database using mega 5.05, simplot 3.5.1, network 4.611, and epi information system 3.5.3 software. SFTS presents with fever, thrombocytopenia, leukocytopenia, and considerable changes in several serum biomarkers. The disease has 10 ∼ 15% mortality rate, commonly because of multiorgan dysfunction. SFTSV is mainly reported in the rural areas of Central and North-Eastern China, with seasonal occurrence from May to September, mainly targeting those of ≥50 years of age. A wide range of domesticated animals, including sheep, goats, cattle, pigs, dogs, and chickens have been proven seropositive for SFTSV. Ticks, especially Haemaphysalis longicornis, are suspected to be the potential vector, which have a broad animal host range in the world. More studies are needed to elucidate the vector–animal–human ecological cycle, the pathogenic mechanisms in high level animal models and vaccine development. © 2013 The Authors. Reviews in Medical Virology published by John Wiley & Sons, Ltd.

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Zoonotic infections by avian influenza viruses occur at the human–poultry interface, but the modes of transmission have not been fully investigated. We assessed the potential for airborne and fomite transmission at live poultry markets in Guangzhou city and in Hong Kong Special Administrative Region (SAR), China, during 2014 and 2015. Viral genome and infectious avian influenza A viruses of H5N6, H7N9, and H9N2 subtypes were detected predominantly from particles larger or equal to 1 μm in diameter in the air sampled with cyclone-based bioaerosol samplers at the live poultry markets in Guangzhou. Influenza A(H9N2) viruses were ubiquitously isolated every month during the study period from air and environmental swabs, and different lineages of H9N2 virus were isolated from markets where chickens and minor land-based poultry were sold. The use of de-feathering devices increased the quantity of virus-laden airborne particles while market closure reduced the amount of such particles. The results highlight the possibility of airborne transmission of avian influenza viruses among poultry or from poultry to humans within such settings. This may explain epidemiological observations in which some patients with H7N9 infection reported being in markets but no direct contact with live poultry or poultry stalls.

Millions of incidents of hand, foot and mouth disease occur annually in China, with EVA71 and CVA16 as two major causative pathogens. A provincial surveillance system has been implemented in Guangdong for almost 5 years to analyze the aetiological spectrum and epidemic changes. An unusual enterovirus type, CVA6, was identified as the predominant serotype associated with an HFMD epidemic from late 2012 to 2013. In contrast to virus strains isolated before, all CVA6/CHN/2012-2013 strains segregated into one major genetic cluster. This study suggested that one cluster of circulating CVA6 strain had emerged as a new and major cause during a continuing HFMD epidemic in Guangdong, China.

Our results provide new insights into GII.17 norovirus evolution and transmission and highlight the potential for a rare norovirus genotype to rapidly replace existing strains and cause local epidemics.

ObjectivesFrequent outbreaks of dengue are considered to be associated with an increased risk for endemicity of the disease. The occurrence of a large number of indigenous dengue cases in consecutive years indicates the possibility of a changing dengue epidemic pattern in Guangdong, China.MethodsTo have a clear understanding of the current dengue epidemic, a retrospective study of epidemiological profile, serological response, and virological features of dengue infections from 2005–2011 was conducted. Case data were collected from the National Notifiable Infectious Diseases Reporting Network. Serum samples were collected and prepared for serological verification and etiological confirmation. Incidence, temporal and spatial distribution, and the clinical manifestation of dengue infections were analyzed. Pearson's Chi-Square test was used to compare incidences between different age groups. A seroprevalence survey was implemented in local healthy inhabitants to obtain the overall positive rate for the specific immunoglobulin (Ig) G antibody against dengue virus (DENV).ResultsThe overall annual incidence rate was 1.87/100000. A significant difference was found in age-specific incidence (Pearson's Chi-Square value 498.008, P<0.001). Children under 5 years of age had the lowest incidence of 0.28/100000. The vast majority of cases presented with a mild manifestation typical to dengue fever. The overall seroprevalence of dengue IgG antibody in local populations was 2.43% (range 0.28%–5.42%). DENV-1 was the predominant serotype in circulation through the years, while all 4 serotypes were identified in indigenous patients from different outbreak localities since 2009.ConclusionsA gradual change in the epidemic pattern of dengue infection has been observed in recent years in Guangdong. With the endemic nature of dengue infections, the transition from a monotypic to a multitypic circulation of dengue virus in the last several years will have an important bearing on the prevention and control of dengue in the province and in the neighboring districts.

On 30 March 2013, a novel avian influenza A H7N9 virus causing severe human respiratory infections was identified in China. Preliminary sequence analyses have shown that the virus is a reassortant of H7N9 and H9N2 avian influenza viruses. In this study, we conducted enhanced surveillance for H7N9 virus in Guangdong, China, from April to August 2013. We isolated two H7N9 viral strains from environmental samples associated with poultry markets and one from a clinical patient. Sequence analyses showed that the Guangdong H7N9 virus isolated from April to May shared high sequence similarity with other strains from eastern China. The A/Guangdong/1/2013 (H7N9) virus isolated from the Guangdong patient on 10 August 2013 was divergent from previously sequenced H7N9 viruses and more closely related to local circulating H9N2 viruses in the NS and NP genes. Phylogenetic analyses revealed that four internal genes of the A/Guangdong/1/2013 (H7N9) virus-the NS, NP, PB1, and PB2 genes-were in clusters different from those for H7N9 viruses identified previously in other provinces of China. The discovery presented here suggests that continuing reassortment led to the emergence of the A/Guangdong/1/2013 (H7N9) virus as a novel H7N9 virus in Guangdong, China, and that viral adaptation to avian and human hosts must be assessed. IMPORTANCEIn this study, we isolated and characterized the avian influenza A H7N9 virus in Guangdong, China, from April to August 2013. We show that the viruses isolated from Guangdong environmental samples and chickens from April to May 2013 were highly similar to other H7N9 strains found in eastern China. The H7N9 virus isolated from the clinical patient in Guangdong in August 2013 was divergent from previously identified H7N9 viruses, with the NS and NP genes originating from recent H9N2 viruses circulating in the province. This study provides direct evidence that continuing reassortment occurred and led to the emergence of a novel H7N9 influenza virus in Guangdong, China. These results also shed light on how the H7N9 virus evolved, which is critically important for future monitoring and tracing of viral transmission.

Abstract.Background: Epidemiological studies suggest that proxies of higher lifetime estrogen exposure are associated with better cognitive function in postmenopausal women, but this has not been found consistently. Objective: To determine whether reproductive history, an important modifier of estrogen exposure across the lifetime, is associated with risk of cognitive impairment in postmenopausal women. Methods: We analyzed the baseline data from Zhejiang Major Public Health Surveillance Program (ZPHS) including 4,796 postmenopausal women. Cognitive impairment was assessed through the application of Mini-Mental State Examination questionnaire. Logistic regression models, controlled for an extensive range of potential confounders, were generated to examine the associations between women's reproductive history and risk of cognitive impairment in their later life. Results: The length of reproductive period was inversely associated with risk of cognitive impairment (p = 0.001). Odds ratio (OR) of cognitive impairment were 1.316 (95% CI 1.095∼1.582) for women with 5 or more times of full-term pregnancies, compared with those with 1∼4 times of full-term pregnancies. Women without incomplete pregnancy had a significant higher risk of cognitive impairment (OR = 1.194, 95% CI 1.000∼1.429), compared with the reference (1∼2 times of incomplete pregnancies). Oral contraceptive use (OR = 0.489, 95% CI 0.263∼0.910) and intrauterine device (IUD) use (OR = 0.684, 95% CI 0.575∼0.815) were associated with significantly reduced risk of cognitive impairment. Conclusion: Our results indicated that shorter reproductive period, higher number of full-term pregnancies and no incomplete pregnancy history were associated with an increased risk of cognitive impairment. In contrast, oral contraceptive and IUD use corresponded to reduced risk of cognitive impairment.