Shouyi Yu

Isolation and phylogenetic characterization of bat astroviruses in southern China.

Astroviruses are associated with acute gastroenteritis of human and many animal species. Recently, two studies have reported that novel astroviruses were found in bats. In order to extensively understand the genetic and phylogenetic characterization of bat astroviruses, we tested fecal samples of nine bat species that were collected at four natural habitats in three areas of southern China. The geographic distributions of the bats involved differed from previous reports. Three out of nine species of bats were observed to harbor astroviruses. These included Miniopterus schreibersii, Scotophilus kuhlii, and Rousettus leschenaultia. Phylogenetic analysis based on amino acid sequences of partial ORFs of astroviruses revealed that the bat astroviruses are not only divergent from previously described human and other animal astroviruses but also show remarkable diversity among themselves. However, five bat astroviruses were phylogenetically related to mink astrovirus, ovine astrovirus, and the recently discovered human astroviruses VA1, VA2, and VA3. The results indicate that astroviruses may have adapted to the Chiroptera, and bats may transmit astroviruses to humans and other animals, or vice versa.

Characterization of severe hand, foot, and mouth disease in Shenzhen, China, 2009–2013

Hand, foot, and mouth disease (HFMD) is caused by human enteroviruses, especially by enterovirus 71 (EV71) and coxsackievirus A16 (CA16). Patients infected with different enteroviruses show varied clinical symptoms. The aim of this study was to determine whether the etiological spectrum of mild and severe HFMD changed, and the association between pathogens and clinical features. From 2009 to 2013, a total of 2,299 stool or rectal specimens were collected with corresponding patient data. A dynamic view of the etiological spectrum of mild and severe HFMD in Shenzhen city of China was provided. EV71 accounted for the majority proportion of severe HFMD cases and fatalities during 2009–2013. CA16 and EV71 were gradually replaced by coxsackievirus A6 (CA6) as the most common serotype for mild HFMD since 2010. Myoclonic jerk and vomiting were the most frequent severe symptoms. Nervous system complications, including aseptic encephalitis and aseptic meningitis were observed mainly in patients infected by EV71. Among EV71, CA16, CA6, and CA10 infection, fever and pharyngalgia were more likely to develop, vesicles on the hand, foot, elbow, knee and buttock were less likely to develop in patients infected with CA10. Vesicles on the mouth more frequently occurred in the patients with CA6, but less in the patient with EV71. Associations between diverse enterovirus serotypes and various clinical features were discovered in the present study, which may offer further insight into early detection, diagnosis and treatment of HFMD. J. Med. Virol. 87:1471–1479, 2015.

A randomized controlled trial of low-dose recombinant human interferons α-2b nasal spray to prevent acute viral respiratory infections in military recruits.

Abstract The military population has a high disease burden of acute viral respiratory infections in China. To assess the efficacy and safety of a low-dose recombinant human interferon α-2b (rIFNα-2b) nasal spray in preventing acute viral respiratory infections in military population, we performed this randomized controlled trial. The results showed that application of the rIFNα-2b nasal spray had the benefits in prevention of infections caused by influenza A virus, influenza B virus parainfluenza viruses 1–3 and adenovirus species B. However, no benefit was seen in preventing respiratory syncytial virus. No severe adverse events were reported. Therefore, the rIFNα-2b nasal spray was effective and well tolerated for preventing common viral respiratory infections in the military recruits.

Molecular Phylogeny of Coxsackievirus A16 in Shenzhen, China, from 2005 to 2009

ABSTRACT Phylogenetic analysis of a Coxsackievirus A16 (CA16) sequence from Shenzhen, China, and other Chinese and international CA16 sequences revealed a pattern of endemic cocirculation of strains of clusters B2a and B2b within subtype B2 viruses. Amino acid evolution and nucleotide variation in the VP1 region were slight for 5 years.

Seroprevalence of Antibodies against Noroviruses among Students in a Chinese Military Medical University

ABSTRACT Noroviruses (NVs) are important causes of nonbacterial gastroenteritis in humans, but the role of NVs as a cause of diseases in the Chinese people, particularly in Chinese military personnel, remains unclear. This study investigated antibody prevalence and factors that associate with the prevalence of antibody to NVs among students attending a military medical university. Serum specimens were tested by an enzyme-linked immunosorbent assay for immunoglobulin G antibody to recombinant capsid antigens of three NVs (rNorwalk, rMxV, and rVA387). Of 588 serum samples tested, the antibody prevalence was 88.9, 54.1, or 90.0% for the three antigens, respectively. There were significant differences in the prevalence of antibody to rMxV between blood types (P < 0.05); the prevalence for type O was the highest (62.5%), and the prevalence for type B was the lowest (49.1%). The average optical density values for antibody to rNorwalk and rMxV were lowest among students with type B. The number of students who did not have antibody to any of the three antigens was the highest for blood type B (6.9%) compared to other blood types (0.8 to 3.4% [P < 0.006]). The antibody prevalence also varied with the hometown residencies of the students before joining the military, with the highest rates for students from rural areas, lower rates for students from small towns or villages, and the lowest rates for students from large cities. The numbers of students who did not have antibody to any of the three antigens were highest for students from the large cities, lower for students from small towns or villages, and lowest for students from rural areas. The distribution of ABO blood types did not differ among the three groups. These data suggest that NVs are prevalent in China and that both genetic and environmental factors play a role in NV infection.

Surveillance and risk factors of norovirus gastroenteritis among children in a southern city of China in the fall–winter seasons of 2003–2006

Aim:  Noroviruses (NoVs) are an important cause of acute gastroenteritis but knowledge on the disease burden and epidemiology in children in the developing countries remains limited. In this study, we performed a surveillance of NoV gastroenteritis in children of China to address some of the questions.

Diversity and recombination of human parechovirus in children with acute gastroenteritis in Guangzhou, China

Human parechovirus (HPeV), a member of Picornaviridae family, is a widespread pathogen causing a wide spectrum of diseases. Like other picornaviruses, HPeV genome recombination has been detected. A total of 322 fecal samples were collected from children outpatients in Guangzhou, China, including 42 (13.0%, 42/322) HPeV‐positive samples detected in most of the infected children less than two years old. Seven HPeV genotypes (HPeV1, HPeV3, HPeV4, HPeV5, HPeV6, HPeV8 and HPeV14) were detected, among which, HPeV14, a rare genotype, was reported for the first time in children with acute gastroenteritis in China. This study revealed recombination events in eight samples. Clinical profiles did not yield statistical significance between children with HPeV infection alone and cases without pathogens detected. In conclusion, this study demonstrated that HPeV circulated in Guangzhou, China is diverse genetically, which provided evidence of recombination in HPeV in China. J. Med. Virol. 87:296–302, 2015.

Molecular detection and phylogenetic analysis of human parechovirus in individuals with acute diarrhea and healthy controls in Guangzhou, China: CHEN et al.

Human parechoviruses (HPeVs) are prevalent in young children; however, their effects are incompletely understood. We investigated the prevalence, genotype distribution, and phylogeny of HPeVs in individuals with diarrhea (n = 430) and healthy controls (n = 93) by the analysis of stool specimens collected from July 2013 to December 2014; 51 (11.86%) and 6 (6.45%) specimens were HPeV positive, respectively. HPeV1A occurred in 28 (6.51%) and 6 (6.45%) individuals with diarrhea and controls, respectively, whereas HPeV1B (3.95%), HPeV3 (0.23%), HPeV4 (0.70%), and HPeV14 (a rare genotype, 0.47%) were only detected in individuals with diarrhea. There was no significant difference in the rate of HPeV detection between the 2 groups; however, the mean age of HPeV infection was significantly lower in males. We conclude that HPeVs may be opportunistic pathogens associated with acute diarrhea. Immunocompromised individuals, such as children aged under 2 years and the elderly, could be vulnerable to HPeV infections.