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Research Interests: Biology and Gut Microbes
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Objective: To learn the epidemiologic characteristics of rotavirus diarrhea in three hospitals under sentinel surveillance from August 2001 to July 2004 and to provide background information for developing and implementing rotavirus... more
Objective: To learn the epidemiologic characteristics of rotavirus diarrhea in three hospitals under sentinel surveillance from August 2001 to July 2004 and to provide background information for developing and implementing rotavirus vaccine. Methods: Data from hospital-based rotavirus surveillance among children < 5 years old hospitalized with acute diarrhea was used. Patients' clinic information and feces specimens were collected. Specimens were tested and typed for rotavirus. Results: Totally, 3121 specimens were tested and the detection rate of rotavirus was 51%. Among all the children with rotavirus diarrhea, 94% were < 2 years old. G3 (69.9%) was the most prevalent serotype followed by G1 (6.6%) and G2 (2.9%). P[8] was the most common genotype of rotavirus. The most common G-P combination identified in this study was P[8] G3 (64.0%). Seveal other combinations of minor frequency were also identified. Conclusion: Rotavirus infection was most commonly seen among children < 5 years old hospitalized with acute diarrhea in the three hospitals. It is important to develop and implement rotavirus vaccine to prevent and control severe rotavirus infection. Because of the diversity of rotavirus strains, it is necessary to perform rotavirus strain surveillance to understand the dynamic nature of viral transmission.
Research Interests: Pediatrics, China, Medicine, Hospitals, Diarrhea, and 11 moreHumans, Female, Pubmed, Male, Infant, Newborn Infant, Rotavirus, Feces, Serotype, Child preschool, and Sentinel surveillance
*Correspondence to: Baoming Jiang; Email: bxj4@cdc.gov In June 2009, the Strategic Advisory Group of Experts (SAGE) of the World Health Organization (WHO) issued a recommendation for global use of the two currently licensed live oral... more
*Correspondence to: Baoming Jiang; Email: bxj4@cdc.gov In June 2009, the Strategic Advisory Group of Experts (SAGE) of the World Health Organization (WHO) issued a recommendation for global use of the two currently licensed live oral rotavirus vaccines, a pentavalent human-bovine reassortant RotaTeq developed by Merck and a monovalent attenuated human strain RotarixTM from GlaxoSmithKline. This represented an expansion of an initial SAGE recommendation in 2007 that vaccines be used in the Americas and Europe where vaccine efficacy had been established in pivotal pre-licensure trials. The expansion was based, in large part, on efficacy data from recently completed clinical trials that established the efficacy of RotarixTM in Malawi and South Africa and effectiveness results from postlicensure studies of the two vaccines in El Salvador and Nicaragua. The global recommendation for rotavirus vaccination is welcome news for millions of young children throughout the world. Each year, rotavirus is estimated to cause more than 125 million diarrhea illnesses, 24 million outpatient visits, 2 million hospitalizations, and approximately 527,000 deaths in children <5 years of age worldwide, with >85% of rotavirus deaths occurring in the low income countries of sub-Saharan Africa and Asia. Vaccination is thus likely to substantially reduce severe morbidity and mortality from rotavirus; early data from high and middle income countries in the Americas and Australia that have been using rotavirus vaccines in their routine immunization schedules for the past 2–3 years are quite encouraging. For example, in both the United States and Australia, the introduction of rotavirus vaccines has resulted in a dramatic decline in cases of rotavirus diarrhea, including possible indirect benefits of vaccination (i.e., herd immunity) leading to disease reduction in older unvaccinated children. Despite this early success, some issues and challenges remain and need to be addressed. First, data from recently completed clinical trials and post-licensure studies indicate that both vaccines are significantly less immunogenic and effective in low-income countries of Africa, Asia and Latin America where a highly effective vaccine is needed most. For example, the immunogenicity of RotarixTM ranged from >90% in Finland to ∼60% in Latin America and 40% to 50% in low-income countries of Africa and Asia. Similarly, efficacy of RotarixTM against severe rotavirus disease ranged from >90% in Europe to 85% in Latin America to 76% in South Africa and only 49% in Malawi. Clinical trials of RotaTeq recently completed in Africa and Asia have yielded similar results. Thus, the gradient in immune response and protective efficacy appears to be directly related to the socio-economic status of the population. These findings are not unexpected because live oral rotavirus vaccines previously tested in the 1980s and 1990s were also less effective in developing countries and other live oral vaccines against polio (OPV) and cholera have also shown diminished performance in resource-limited settings. While even a moderately effective rotavirus vaccine will have a substantial impact in developing country settings with high disease burden, room for improving vaccine performance remains. Rotavirus vaccines for global use
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Research Interests: Acute gastroenteritis, Biology, Medicine, Molecular Epidemiology, Phylogeny, and 15 moreHumans, Child, Hospitalization, Clinical, Gastroenteritis, Infant, Clinical microbiology and infection control, Clinical Sciences, Republic of Korea, Rotavirus, Genotype, Feces, Outbreak, Molecular Sequence Data, and Child preschool
In August 1993, an outbreak of group C rotavirus-associated gastroenteritis occurred among children attending a day-care centre in Belém, Brazil. Of the 64 children, 21 (33%) became ill. Group C rotavirus was identified in faecal... more
In August 1993, an outbreak of group C rotavirus-associated gastroenteritis occurred among children attending a day-care centre in Belém, Brazil. Of the 64 children, 21 (33%) became ill. Group C rotavirus was identified in faecal specimens from 8 (38%) children with diarrhoea by electron microscopy (EM) and an enzyme immunoassay (EIA), using antibodies specific to the Cowden strain of porcine group C rotavirus. By polyacrylamide gel electrophoresis (PAGE), a pattern similar to that of group C rotavirus was observed in 5 (62.5%) of the 8 EM- and EIA-positive samples. These 5 faecal samples were confirmed to be positive for group C rotavirus by reverse transcriptase-polymerase chain reaction, using specific VP6 and VP7 primers. This is the first report of an outbreak of diarrhoea in North Brazil associated with group C rotavirus. These findings suggest that group C rotavirus may be an important aetiological agent of diarrhoea in this region, which requires further study.
Research Interests: Demography, Nutrition and Dietetics, Electron Microscopy, Brazil, Medicine, and 15 moreDiarrhea, Disease Outbreaks, Humans, Female, Pubmed, Male, Gastroenteritis, Disease Outbreak, Feces, Polyacrylamide Gel Electrophoresis, Outbreak, Diarrhoeal Diseases, Child preschool, Enzyme Immunoassay, and reverse transcriptase polymerase chain reaction
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Introduction:Numerous studies have shown that the oral rotavirus vaccines are less effective in infants born in low income countries compared to those born in developed countries. Identifying the specific factors in developing countries... more
Introduction:Numerous studies have shown that the oral rotavirus vaccines are less effective in infants born in low income countries compared to those born in developed countries. Identifying the specific factors in developing countries that decrease and/or compromise the protection that rotavirus vaccines offer, could lead to a path for designing new strategies for the vaccines’ improvement.Areas covered:We accessed PubMed to identify rotavirus vaccine performance studies (i.e., efficacy, effectiveness and immunogenicity) and correlated performance with several risk factors. Here, we review the factors that might contribute to the low vaccine efficacy, including passive transfer of maternal rotavirus antibodies, rotavirus seasonality, oral polio vaccine (OPV) administered concurrently, microbiome composition and concomitant enteric pathogens, malnutrition, environmental enteropathy, HIV, and histo blood group antigens.Expert commentary:We highlight two major factors that compromise rotavirus vaccines’ efficacy: the passive transfer of rotavirus IgG antibodies to infants and the co-administration of rotavirus vaccines with OPV. We also identify other potential risk factors that require further research because the data about their interference with the efficacy of rotavirus vaccines are inconclusive and at times conflicting.
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To understand virus and host interactions and host responses to rotavirus infection in children, we analysed by real-time polymerase chain reaction (PCR) the expression of mRNA for five Toll-like receptors (TLRs) (TLR2, TLR3, TLR4, TLR7... more
To understand virus and host interactions and host responses to rotavirus infection in children, we analysed by real-time polymerase chain reaction (PCR) the expression of mRNA for five Toll-like receptors (TLRs) (TLR2, TLR3, TLR4, TLR7 and TLR8) and four T helper (Th)1 and Th2 cytokines [interleukin (IL)-2, IL-12, interferon (IFN)-γ and IL-4) in peripheral blood mononuclear cells (PBMC) of children with acute rotavirus diarrhoea. We observed significantly higher expression of genes encoding TLR2, TLR3, TLR4, TLR7 and TLR8 in PBMC of 41% (31/75) patients within 3 days of illness onset than those in healthy children. After 3 days of illness onset, only TLR3 and TLR8 mRNA expressions were still significantly (P< 0·05) increased in 59% (44/75) children with diarrhoea. We also observed significantly (P< 0·05) elevated expression of IL-12p40 and IFN-γ in PBMC of patients during the entire period of illness and the first 3 days of illness, respectively. We further demonstrated a weak but significant association between elevated levels of gene expression of four TLRs (TLR2, TLR3, TLR4 and TLR8) and IFN-γ. Our results suggest that multiple TLRs may modulate the immune response in the acute phase of rotavirus infection and play a role in the activation of IFN-γ.
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Research Interests: Biology, Medicine, Cell Culture, Clinical Microbiology, Biological Sciences, and 15 morePrimates, Phylogeny, Humans, Animals, Clinical, Pan troglodytes, Feces, Rhesus macaques, Picornavirus, Macaca Mulatta, Human Disease, Capsid Protein, Enterovirus, reverse transcriptase polymerase chain reaction, and Medical and Health Sciences
BackgroundGroup C rotaviruses are recognized enteric pathogens of humans and animals. Human group C rotaviruses have been associated with sporadic episodes and large outbreaks of gastroenteritis in children and adults but their... more
BackgroundGroup C rotaviruses are recognized enteric pathogens of humans and animals. Human group C rotaviruses have been associated with sporadic episodes and large outbreaks of gastroenteritis in children and adults but their epidemiology and ecology are still unexplored.
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In a recent study, we used RT-PCR and partial genome sequencing to detect simian enteroviruses SV6, SV19 and SV46, as well as two new enterovirus types (EV92 and EV103) in fecal specimens from rhesus macaques (Macaca mulatta), pigtail... more
In a recent study, we used RT-PCR and partial genome sequencing to detect simian enteroviruses SV6, SV19 and SV46, as well as two new enterovirus types (EV92 and EV103) in fecal specimens from rhesus macaques (Macaca mulatta), pigtail macaques (M. nemestrina), and sooty mangabeys (Cercocebus atys) with diarrheal disease at a US primate center. The complete genome sequences of representative SV46, EV92, and EV103 strains, presented here, show that SV46 and EV92 are typical of the simian enteroviruses classified within the species Human enterovirus A, while EV103 appears to belong to an unclassified species that also contains SV6 and N125/N203.
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While a monovalent Rotarix® [RV1] and a pentavalent RotaTeq® [RV5] have been extensively tested and found generally safe and equally efficacious in clinical trials, the question still lingers about the evolving diversity of circulating... more
While a monovalent Rotarix® [RV1] and a pentavalent RotaTeq® [RV5] have been extensively tested and found generally safe and equally efficacious in clinical trials, the question still lingers about the evolving diversity of circulating rotavirus strains over time and their relationship with protective immunity induced by rotavirus vaccines. We reviewed data from clinical trials and observational studies that assessed the efficacy or field effectiveness of rotavirus vaccines against different rotavirus strains worldwide. RV1 provided broad clinical efficacy and field effectiveness against severe diarrhea due to all major circulating strains, including the homotypic G1P[8] and the fully heterotypic G2P[4] strains. Similarly, RV5 provided broad efficacy and effectiveness against RV5 and non-RV5 strains throughout different locations. Rotavirus vaccination provides broad heterotypic protection; however continuing surveillance is needed to track the change of circulating strains and monitor the effectiveness and safety of vaccines.
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BACKGROUND Rotavirus A (RVA) are a group of diverse viruses causing acute gastroenteritis (AGE) in humans and animals. Zoonotic transmission is an important mechanism for rotavirus evolution and strain diversity in humans, but the extent... more
BACKGROUND Rotavirus A (RVA) are a group of diverse viruses causing acute gastroenteritis (AGE) in humans and animals. Zoonotic transmission is an important mechanism for rotavirus evolution and strain diversity in humans, but the extent of pigs as a major reservoir for human infection is not clear. METHODS AND FINDINGS We have surveyed 153 pig farms across Taiwan with a total of 4588 porcine stool samples from three age groups from 2014 to 2017. Nursing piglets (less than one month of age) had higher detection rate for rotavirus than older age groups. Five VP7 (G) genotypes and 5 VP4 (P) genotypes were found in a total of 14 different G/P genotype combinations. In addition, porcine RVA strains had 2 NSP4 (E) genotypes and 3 VP6 (I) genotypes. A P[3]-like genotype was also discovered among strains collected in 2016 and 2017. CONCLUSIONS Most of the genes from Taiwanese porcine strains clustered with each other and the lineages formed by these strains were distinct from the sequences of numerous regional variants or globally circulating porcine strains, suggesting an independent evolutionary history for Taiwanese rotavirus genotypes. The close relationship among porcine RVA strains and some unique porcine-like genotypes detected sporadically among human children in swine farms illustrates that pigs might serve as a reservoir for potential zoonotic transmission and novel genotype evolution in Taiwan's insular environment.
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Rotavirus live-attenuated vaccines generate broadly heterotypic protection, and B-cells isolated from adults encode antibodies that are broadly protective in mice. Determining the structural and mechanistic basis of broad protection can... more
Rotavirus live-attenuated vaccines generate broadly heterotypic protection, and B-cells isolated from adults encode antibodies that are broadly protective in mice. Determining the structural and mechanistic basis of broad protection can contribute to understanding the current limitations of vaccine efficacy in developing countries.
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In August 1993, an outbreak of group C rotavirus-associated gastroenteritis occurred among children attending a day-care centre in Belém, Brazil. Of the 64 children, 21 (33%) became ill. Group C rotavirus was identified in faecal... more
In August 1993, an outbreak of group C rotavirus-associated gastroenteritis occurred among children attending a day-care centre in Belém, Brazil. Of the 64 children, 21 (33%) became ill. Group C rotavirus was identified in faecal specimens from 8 (38%) children with diarrhoea by electron microscopy (EM) and an enzyme immunoassay (EIA), using antibodies specific to the Cowden strain of porcine group C rotavirus. By polyacrylamide gel electrophoresis (PAGE), a pattern similar to that of group C rotavirus was observed in 5 (62.5%) of the 8 EM- and EIA-positive samples. These 5 faecal samples were confirmed to be positive for group C rotavirus by reverse transcriptase-polymerase chain reaction, using specific VP6 and VP7 primers. This is the first report of an outbreak of diarrhoea in North Brazil associated with group C rotavirus. These findings suggest that group C rotavirus may be an important aetiological agent of diarrhoea in this region, which requires further study.
OBJECTIVE To learn the relationship between severity of rotavirus diarrhea and serotype G and genotype P. METHOD The clinical information and fecal specimens of hospitalized children less than 5 years of age with acute diarrhea in four... more
OBJECTIVE To learn the relationship between severity of rotavirus diarrhea and serotype G and genotype P. METHOD The clinical information and fecal specimens of hospitalized children less than 5 years of age with acute diarrhea in four sentinel hospitals were collected from Aug 2001 to July 2003. Specimens were tested and typed for rotavirus. Each child with rotavirus infection was assessed for severity of diarrhea according to the 20-points scoring system of Vesikari. RESULTS When combined with P[8], the severity scores for rotavirus diarrhea of P[8]G1 and P[8]G3 were 13 and 12 points, respectively, and the durations of diarrhea were 6 days and 5 days, respectively. The percentage of fever in patients with diarrhea caused by P[8]G1 was higher than that in those with diarrheas caused by P[8]G3 (97 percent vs. 73 percent). And the highest temperature in the cases with diarrheas caused by G1 and G3 was 39 degrees C and 38.6 degrees C, respectively. When combined with G3, the differenc...