Clinical and molecular epidemiology of norovirus infection in adults with acute gastroenteritis in Ji’nan, China

Acute gastroenteritis caused by human noroviruses (NoVs) has become an important public health problem worldwide. This study was carried out to investigate the rates of NoV infections and the genetic characteristics of NoVs in adult outpatients with acute gastroenteritis in Ji’nan, a large eastern city in China. A total of 480 fecal samples were collected from outpatients at the Shandong University Qilu Hospital between June 2010 and May 2011. Of the collected samples, 42 (42/480, 8.75 %) were positive for NoVs by RT-PCR, and seven different genotypes were identified: GI-1, GI-4, GII-1, GII-3, GII-4, GII-6 and GII-13, of which GII-4 was the most prevalent (29/42, 69.0 %). Phylogenetic and Simplot analyses showed that three recombinant strains were detected: two GII-4 polymerase/GII-3 capsid recombinants and one GII-6 polymerase/GII-4 capsid recombinant. This study indicated that NoV was a common causative agent of sporadic acute gastroenteritis in adults in Ji’nan, China, and that NoV GII-4 was the predominant strain during this period. Three recombinant strains were identified in which GII-6 polymerase/GII-4 capsid was detected for the first time in China.     

Molecular epidemiology of noroviruses in children under 5 years of age with acute gastroenteritis in Yaoundé, Cameroon

Norovirus is a common cause of acute gastroenteritis (AGE) among children in developing countries. Limited data on the prevalence and genetic variability of norovirus are available in Cameroon, where early childhood mortality due to AGE is common. We tested 902 fecal specimens from children younger than 5 years of age hospitalized with AGE between January 2010 and December 2013. Overall, 76 (8.4%) samples tested positive for norovirus, of which 83% (63/76) were among children below 12 months old. Most of the noroviruses detected were in children infected between July and December of each year. All norovirus-positive specimens were genotyped, with 80% (61/76) being GII.4 (three variants detected). Genotypes GI.2, GI.6, GII.1, GII.2, GII.3, GII.6, GII.16, GII.17, and GII.21 were also detected. Interestingly, GII.4 Sydney and GII.17 Kawasaki viruses were found as early as 2010, years before their emergence globally. This study suggests norovirus is a significant cause of moderate to severe gastroenteritis among young children in Cameroon. The results are important to highlight appropriate prevention and control strategies for reducing the burden of norovirus disease.     

Genetic diversity of noroviruses from outbreaks,sporadic cases and wastewater in Luxembourg 2008–2009

The genetic diversity of norovirus strains obtained from gastroenteritis outbreaks, sporadic case surveillance and wastewater plants was compared in Luxembourg from October 2008 until June 2009. Except for GI.6 and GIV.1 strains detected exclusively in wastewater, all other genotypes were also found in human samples. Of the nine NoV genotypes detected, only three (GII.4, GIIb/II.3 and GIIc/II.12) were associated with institutional outbreaks. The majority of sequences from all sources belonged to genotype GII.4, including two potentially new subvariants. Strains collected in the context of outbreaks may significantly under-represent the overall genetic diversity of NoVs circulating in a country.     

Molecular evolution of GII.P17-GII.17 norovirus associated with sporadic acute gastroenteritis cases during 2013–2018 in Zhoushan Islands,China

Virus Genes - In this study, we investigated the molecular characteristics and spatio-temporal dynamics of GII.P17-GII.17 norovirus in Zhoushan Islands during 2013–2018. We collected 1849...     

Prevalence and factors associated with late diagnosis among older adults living with HIV in liuzhou,China: 2010−2020

This paper aimed to quantify and characterize the prevalence and associated factors for late diagnosis in older adults living with human immunodeficiency virus (HIV) in Liuzhou, China, from 2010 to 2020. The characteristics of older adults living with HIV were described separately in time, space and population. Multivariate logistic regression analysis evaluates the factors influencing late diagnosis in HIV-positive adults ≥ 50 years of age. The majority of older adults living with HIV were over 60 years old, male, and with CD4 counts < 200 cells/μl at diagnosis, with most late diagnoses being more likely to report heterosexual transmission. These two factors may potentially provide a positive influence on late diagnosis: older and CD4 counts < 500 cells/μl. In contrast, females and those with homosexual or other transmission provide a negative. These results suggest that late diagnosis of HIV-positive adults ≥ 50 years of age remains a severe and growing epidemiological issue.     

Molecular epidemiologic analysis of group A rotaviruses in adults and children with diarrhea in Wuhan city,China, 2000–2006

Summary To compare epidemiologic features and genetic characteristics of group A rotaviruses causing diarrhea in children and adults, a survey was conducted in Wuhan, China, during the period of Dec. 2000–May 2006. A total of 3839 stool specimens from diarrheal patients from eight hospitals were analyzed. Winter seasonality was observed for rotavirus diarrhea in both adults and children, showing overall rotavirus-positive rates of 9.0 and 23.9%, respectively. Throughout the study period, G3 was the most frequent G serotype in both adults and children (detection rates 86.2 and 87.8%, respectively), and was mostly associated with VP4 genotype P[8], VP 6 genotype II (subgroup II), and NSP4 genotype B. G3 rotaviruses were differentiated into eight electropherotypes, among which seven types were found in specimens from both adults and children. VP7 gene sequences of G3 rotaviruses from adults and children (6 and 4 strains, respectively), detected in different years and different hospitals, showed extremely high sequence identities (99–100%) to each other and to a few G3 rotavirus strains reported in Asia. However, lower sequence identities (82–96%) were observed to most of the human and animal G3 rotaviruses reported so far, including some Chinese strains. These findings indicate that in Wuhan, China, epidemic and genetic features of rotaviruses are similar in adults and children, and it has been suggested that G3 rotaviruses that might have originated from the same rotavirus were circulating among children and adults as prevailing viruses. In this study, two rotavirus strains, G9P[8] strain L169, derived from an adult, and G4P[6] strain R479, derived from a child, were isolated and genetically analyzed. The VP7 gene of L169 belongs to a major lineage of G9 rotaviruses that are globally widespread, but is distinct from G9 rotaviruses reported previously in China. The strain R479 had a VP7 gene which was divergent from most G4 human rotaviruses and showed an unusual dual subgroup specificity, I + II. The R479 VP6 gene does not belong to the main clusters of subgroup I and II rotaviruses phylogenetically, but is related to those of the porcine rotaviruses and some unusual human rotaviruses represented by the RMC321 strain isolated in eastern India.     

Monitoring progress toward measles elimination by genetic diversity analysis of measles viruses in China 2009–2010

With the achievement of high coverage for routine immunization and supplementary immunization activities (SIAs), measles incidence in mainland China reached its lowest level in 2010. The proportion of measles cases in the vaccination-targeted population decreased during 2007–2010 after the SIAs. More than 60% of measles cases were in adults or infants, especially in the coastal and eastern provinces during 2009 and 2010. A total 567 isolates of measles virus were obtained from clinical specimens from 27 of 31 provinces in mainland China during 2009 and 2010. Except for two vaccine-associated cases, one genotype D4 strain, two genotype D9 strains, and four genotype D11 strains, the other 558 strains were genotype H1 cluster H1a. Genotype H1 has been the only endemic genotype detected in China since surveillance began in 1993. Only genotype H1 was found in mainland China during 1993–2008, except for one detection of genotype H2. More recently, multiple genotypes of imported measles were detected even with the background of endemic genetotype H1 viruses. Analysis of the 450-nucleotide sequencing window of the measles virus N gene showed that the overall genetic diversity of the recent geneotype H1 strains decreased between 2008 and 2010. The lower genetic diversity of H1 strains suggested that enhanced vaccination may have reduced the co-circulating lineages of endemic genotype H1 strains in mainland China.     

High prevalence of torque teno sus virus in China and genetic diversity of the 5’ non-coding region

Members of the family Anelloviridae are emerging circular DNA viruses infecting many species of vertebrates including pigs. To date, members of two distinct genera, Iotatorquevirus, including torque teno sus virus 1a and torque teno sus virus 1b (TTSuV1a and TTSuV1b), and Kappatorquevirus, including torque teno sus virus k2a and torque teno sus virus k2b (TTSuVk2a and TTSuVk2b), have been identified in domestic pigs and wild boars. The goal of this study was to evaluate the prevalence and genetic diversity of these viruses based on 5’ non-coding genes in Chinese swine herds experiencing clinical symptoms. One hundred eighty-five clinical samples from 11 different regions, collected during 2008-2009, were analyzed using a PCR method, and the results revealed a high TTSuV-positive rate of 78.9 % (146/185) in pigs. Moreover, we detected co-infection with multiple TTSuV strains in the same pig. Nucleotide sequencing results revealed greater genetic diversity within the genus Kappatorquevirus than within the genus Iotatorquevirus. In addition, TTSuVk2b, a novel virus discovered in New Zealand in 2012, was also identified in this study. In summary, the present work helps us obtain more knowledge about the epidemiology and genetic diversity of TTSuVs.     

Epidemiology of norovirus gastroenteritis in hospitalized children under five years old in western China, 2015–2019

ObjectivesNorovirus is associated with one-fifth of all gastroenteritis cases, but basic epidemiological data is lacking, especially in developing countries. As long-term surveillance on norovirus gastroenteritis is scarce in western China, this study aims to update the epidemiological knowledge of norovirus gastroenteritis and to characterize the genotypes of norovirus strains.MethodsStool samples were collected from hospitalized children under 5 years old with gastroenteritis in Chengdu, China. All samples were tested for norovirus as well as rotavirus, sapovirus, enteric adenovirus, and astrovirus by real-time RT-PCR. RdRp and VP1 genes were sequenced in norovirus-positive samples to investigate viral phylogenies.ResultsOf the 1181 samples collected from 2015 to 2019, 242 (20.5%) were positive for norovirus.Among norovirus-positive cases, 65 cases had co-infection with another virus; norovirus/enteric adenovirus was most frequently detected (50.8%, 33/65). The highest positive rate was observed in children aged 13–18 months (23.7%, 68/287). Norovirus infection peaked in autumn (36.6%, 91/249), followed by summer (20.3%, 70/345). Pearson correlation analysis showed significant correlation between the norovirus-positive rate and humidity (r = 0.773, P < 0.05). GII.4 Sydney 2012 [P31] (48.5%, 79/163) and GII.3 [P12] (35.6%, 58/163) were the dominant norovirus strains.ConclusionsNorovirus has become one of the most common causes of viral gastroenteritis in children under 5 years old in western China. Continuous monitoring is imperative for predicting the emergence of new epidemic strains and for current vaccine development.     

Prevalence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis in 1–2-month-old highland yaks in Qinghai Province,China

Parasitology Research - Cryptosporidium and Giardia are ubiquitous parasites that infect humans and animals. Few reports are available on the prevalence of these two protozoan parasites in yaks...     

Treatment outcomes of multidrug-resistant tuberculosis patients in Zhejiang,China, 2009–2013

ObjectivesTo examine treatment outcomes and factors associated with poor outcome of multidrug-resistant (MDR) tuberculosis (TB) in China.MethodsWe conducted a prospective observational cohort study including consecutive patients with MDR-TB between 2009 and 2013 in six regions of Zhejiang province. Patients were prescribed treatments by infectious disease specialists, and treatment outcomes were recorded. Sociodemographic characteristics were obtained through a structured questionnaire. The primary endpoint was poor treatment outcomes, defined as treatment failure based on microbiologic persistence, default (lost to follow-up) or death at 24 months. We assessed risk factors for poor treatment outcomes using a Cox proportional hazards model.ResultsA total of 820 MDR-TB patients were observed, and 537 with known treatment outcomes were included in our study. Overall, the treatment success rate was 40.2 per 100 years (374/537 participants, 69.6%), while treatment failure, death and default rates were 10.0 per 100 years (101 participants, 18.8%), 3.4 per 100 years (36 participants, 6.7%) and 2.7 per 100 years (26 participants, 4.8%) respectively. Independent predictors of poor treatment outcomes included age >60 years (hazard ratio (HR) 2.3, 95% confidence interval (CI) 1.2–4.2), patients registered as experiencing relapse (HR 2.2, 95% CI 1.1–4.4), patients registered as receiving treatment after failure (HR 2.4, 95% CI 1.2–4.9), use of standardized MDR-TB regimens (HR 0.6, 95% CI 0.4–1.0), cavitary disease (HR 4.9, 95% CI 2.8–8.6) and adverse events (HR 2.5, 95% CI 1.2–5.5).ConclusionsUnder well-designed treatment and management scheme, high treatment success rates were achieved in a high-MDR-TB-burden country. Antimicrobial susceptibility testing for all second-line drugs should be conducted to further assist in the treatment of MDR-TB.     

The genetic and antigenic diversity of avian influenza viruses isolated from domestic ducks, muscovy ducks, and chickens in northern and southern Vietnam, 2010–2012

To estimate the prevalence of avian influenza virus infection in Vietnam, surveillance was conducted in domestic and wild birds from households, live-bird markets, slaughtering sites, and bird sanctuaries in Vietnam between October 2010 and October 2012. Of the 4,550 samples collected, 226 influenza A virus isolates were obtained from domestic ducks, muscovy ducks, and chickens. Of these, 25 and 22 H5N1 highly pathogenic avian influenza viruses (HPAIVs) were isolated from apparently healthy domestic ducks in live-bird markets and slaughtering sites in northern and southern Vietnam, respectively. The HA genes of H5 viruses isolated from birds in northern Vietnam phylogenetically belonged to the genetic clade 2.3.2.1 and those in southern Vietnam belonged to the genetic clade 1.1. In addition, 39 H3, 12 H4, 1 H5, 93 H6, 2 H7, 18 H9, 3 H10, and 11 H11 viruses were isolated. Phylogenetic and antigenic analyses of the H6 and H9 viruses revealed that they were closely related to the isolates obtained from domestic poultry in China. Phylogenetic analyses of internal gene segments of these isolates revealed that these viruses were circulating in both domestic and wild birds in Asia and reassortment events had occurred frequently. Therefore, it will be important to continue the surveillance and strict controls over the movement and trade of poultry and poultry products in order to eradicate H5N1 HPAIV from Asia.