Temporal Changes in Pediatric Gastroenteritis after Rotavirus Vaccination in Quebec

Epidemiology and molecular evolution of GI.1 sapovirus in the recent era

Sapovirus (SaV) infection is increasing worldwide. Herein, we provided evidence of a significant increase in SaV infection in Japan during 2010-2022, primarily due to the considerable (p = 0.0003) rise of the GI.1 genotype. Furthermore, we found that all major and minor SaV outbreaks in Japan, including the largest SaV outbreak in 2021-2022, were caused by the GI.1 genotype. Therefore, to get insight into the underlying molecular mechanism behind this rising trend of the SaV GI.1 type, we selected 15 SaV GI.1 outbreak strains for complete genome analysis through next-generation sequencing. Phylogenetically, our strains remained clustered in different branches in lineages I and II among the GI.1 genotype. We showed all amino acid (aa) substitutions in different open reading frames (ORFs) in these strains. Importantly, we have demonstrated that the strains involved in the largest SaV outbreak in Japan in 2021-2022 belonged to lineage II and possessed the third ORF. We have identified some unique aa mutations in these major outbreak strains in the NS1 and NS6-NS7 regions that are thought to be associated with viral pathogenicity, cell tropism, and epidemiological competence. Thus, in addition to enriching the database of SaV's complete sequences, this study provides insights into its important mutations.

Implementing a multiplex-PCR test for the diagnosis of acute gastroenteritis in hospitalized children: Are all enteric viruses the same?

BACKGROUND

Multiplex-PCR is a valuable tool for diagnosing viral acute gastroenteritis (AGE), enabling the detection of multiple pathogens. However, distinguishing between active disease and shedding poses challenges. This study aimed to evaluate viral AGE epidemiology and compare clinical characteristics among the five most common viruses.

METHODS

Rotavirus vaccine was introduced in 2010, with 70% coverage achieved in southern Israel in two years. All rectal swabs for multiplex-PCR targeting rotavirus, norovirus, adenovirus, astrovirus and sapovirus from hospitalized diarrheic children <5 years were included, from December 2017 through March 2022. Detection of the same virus within two months was considered a single episode. Clinical analysis included episodes with single-virus detection and negative bacterial PCR.

RESULTS

Among 5,879 rectal swabs, 2,662 (45.3%) tested positive for at least one virus, with 245 (9.2%) showing multiple virus detection. Rotavirus was the most prevalent. While rotavirus exhibited typical winter-spring seasonality in 2018-19, an unusual off-season surge was observed during the second year of the COVID-19 pandemic. Among negative bacterial PCR episodes, 34.6% had mucus stool, 5.9% had bloody stool, and 29.3% received antibiotics. Astrovirus or sapovirus infections were associated with higher rates of hospital-acquired AGE and immunodeficiency (P<0.05), whereas rotavirus infections had higher rates of dehydration severity and acute kidney injury (P<0.05).

DISCUSSION

Enteric viruses were detected in 45.3% of rectal swabs from hospitalized children with diarrhea. Despite vaccination efforts, rotavirus remained prevalent and caused more severe disease. Continuous surveillance using multiplex-PCR is crucial for accurate management and future prevention strategies for viral AGE.

Rotavirus infections and their genotype distribution in Rwanda before and after the introduction of rotavirus vaccination

Rotavirus vaccination has reduced mortality and hospital admissions due to rotavirus diarrhoea, but its effect on rotavirus infections and the impact of rotavirus genotypes are still unclear. Real-time PCR was used to detect rotavirus and other pathogens in faeces samples from children below five years of age with acute diarrhoea, collected before (n = 827) and after (n = 807, 92% vaccinated) the introduction of vaccination in Rwanda in 2012. Rotavirus was genotyped by targeting VP7 to identify G1, G2, G3, G4, G9 and G12 and VP4 to identify P[4], P[6] and P[8]. In vaccinated children, rotavirus infections were rarer (34% vs. 47%) below 12 months of age, severe dehydration was less frequent, and rotavirus was more often found as a co-infecting agent. (79% vs 67%, p = 0.004). Norovirus genogroup II, astrovirus, and sapovirus were significantly more often detected in vaccinated children. The predominant rotavirus genotypes were G2P[4] and G12P[6] in 2009-2010 (50% and 12%), G9P[8] and G1P[8] in 2011-2012 (51% and 22%), and G12P[8] in 2014-2015 (63%). Rotavirus vaccination in Rwanda has reduced the severity of rotavirus gastroenteritis and rotavirus infection frequency during the first year of life. Rotavirus infections were frequent in vaccinated children with diarrhoea, often as co-pathogen. Rotavirus genotype changes might be unrelated to vaccination because shifts were observed also before its introduction.

The emergence of recombinant norovirus GII.12[P16] and predominance of GII.3[P12] strains in pediatric patients with acute gastroenteritis in Thailand, 2019-2020

Norovirus (NoV) and sapovirus (SaV) are important pathogens that cause acute gastroenteritis (AGE) in all age groups, commonly in children worldwide. Recently, a number of studies have reported a wide variety of NoV recombinant strains. This study aimed to investigate the distribution of NoV and SaV recombinant strains circulating in Chiang Mai, Thailand, during 2019-2020. One hundred and twenty-four NoV and seven SaV strains detected in children admitted to the hospital with AGE were included in this study. The partial RNA-dependent RNA-polymerase (RdRp)/VP1 regions of these NoV and SaV strains were analyzed by phylogenetic analysis, Simplot, and RDP software. Overall, eight recombination patterns of NoV were detected. NoV GII.4[P16] was the most common strain detected (39.1%), followed by GII.3[P12] (25.0%), GII.4[P31] (17.2%), and other recombinant strains were detected at a lower rate. NoV GII.12[P16] strains were detected for the first time in Thailand. For SaV, none of the recombinant strains was detected. All SaV strains, GI.1/GI.1, GI.2/GI.2, and GII.5/GII.5, exhibited VP1 genotype corresponded to RdRp genotype. In conclusion, this study demonstrates the distribution and diversity of NoV and SaV recombinant strains circulating in pediatric patients with AGE in Chiang Mai, during 2019-2020 with the emergence of NoV GII.3[P12] and GII.12[P16].

Molecular epidemiology and characterization of norovirus and sapovirus in pediatric patients with acute diarrhea in Thailand, 2019-2020

BACKGROUND

Human enteric pathogens in the family Caliciviridae including norovirus (NoV) and sapovirus (SaV) are associated with acute diarrheal disease globally and are considered as one of the viruses with high genetic diversity.

METHODS

In order to investigate the epidemiology of NoV and SaV in pediatric patients with acute diarrhea in Chiang Mai, Thailand from January 2019 to December 2020, a total of 675 stool specimens were collected and examined for the presence of NoV and SaV by RT-multiplex PCR.

RESULTS

126 (18.7 %) and 6 (0.9 %) stool samples were positive for NoV and SaV, respectively. Mixed infection of NoV and SaV was detected in one patient (0.2 %). Among 10 different NoV strains detected in this study, NoV genogroup II genotype 4 (GII.4) Sydney 2012 was the most predominant genotype (51.2 %) followed by GII.3, GII.2, GII.6, GII.12, GII.7, GII.17, GI.4, GII.14, and GI.3. Interestingly, monthly distribution of NoV genotypes revealed that NoV GII.3 increased dramatically in August 2019, suggesting an outbreak of NoV GII.3 might occur in the community. In addition, 3 genotypes of SaV were detected in this study with SaV GI.1 being the most common genotype (71.4 %) followed by GI.2 and GII.5 (each at 14.3 %).

CONCLUSIONS

This study demonstrates the prevalence and genetic diversity of NoV and SaV circulating in pediatric patients with acute gastroenteritis in Chiang Mai, Thailand during 2019-2020 and shows an emergence of NoV GII.3 infection in 2019.

Recombinant Noroviruses Circulating in Spain from 2016 to 2020 and Proposal of Two Novel Genotypes within Genogroup I

Noroviruses are the leading cause of sporadic cases and outbreaks of viral gastroenteritis. For more than 20 years, most norovirus infections have been caused by the pandemic genotype GII.4, yet recent studies have reported the emergence of recombinant strains in many countries. In the present study, 4,950 stool samples collected between January 2016 and April 2020 in Valencia, Spain, from patients with acute gastroenteritis were analyzed to investigate the etiological agent. Norovirus was the most frequently detected enteric virus, with a positivity rate of 9.5% (471/4,950). Among 224 norovirus strains characterized, 175 belonged to genogroup II (GII) and 49 belonged to GI. Using dual genotyping based on sequencing of the open reading frame 1 (ORF1)/ORF2 junction region, we detected 25 different capsid-polymerase-type associations. The most common GII capsid genotype was GII.4 Sydney 2012, followed by GII.2, GII.3, GII.6, and GII.17. A high prevalence of recombinant strains (90.4%) was observed among GII infections between 2018 and 2020. GII.4 Sydney[P16] was the predominant genotype from 2019 to 2020. In addition, GII.P16 polymerase was found harbored within six different capsid genes. GI.4 and GI.3 were the predominant genotypes in genogroup I, in which recombinant strains were also found, such as GI.3[P10], GI.3[P13], and GI.5[P4]. Interestingly, applying the criterion of 2 times the standard deviation, we found that 12 sequences initially classified as GI.3 may represent two new tentative genotypes in genogroup I, designated GI.10 and GI.11. This study shows the extensive diversity of recombinant noroviruses circulating in Spain and highlights the role of recombination events in the spread of noroviruses. IMPORTANCE Human noroviruses are the most common cause of viral diarrhea. There are no approved vaccines to prevent their infections yet, which would be very useful to protect infants, small children, and the elderly in residential institutions. These viruses are extremely contagious and can be transmitted by contaminated food and water as well as directly from person to person. Molecular surveillance and epidemiology of norovirus infections allow the identification of the most common viral strains in different geographical areas over time. Noroviruses show wide genetic variability due to a high rate of mutations but also due to genomic recombinations, as we demonstrate in this study. We have detected 25 different viral capsid-polymerase gene associations among 224 norovirus strains characterized in Spain between January 2016 and April 2020, including two tentative new capsid genotypes in genogroup I.

Pooled prevalence and genetic diversity of norovirus in Africa: a systematic review and meta-analysis

Background

Noroviruses are the leading cause of acute gastroenteritis in all age groups globally. The problem is magnified in developing countries including Africa. These viruses are highly prevalent with high genetic diversity and fast evolution rates. With this dynamicity, there are no recent review in the past five years in Africa. Therefore, this review and meta-analysis aimed to assess the prevalence and genetic diversity of noroviruses in Africa and tried to address the change in the prevalence and genetic diverisity the virus has been observed in Africa and in the world.

Methods

Twenty-one studies for the pooled prevalence, and 11 out of the 21 studies for genetic characterization of norovirus were included. Studies conducted since 2006, among symptomatic cases of all age groups in Africa, conducted with any study design, used molecular diagnostic methods and reported since 2015, were included and considered for the main meta-analysis. PubMed, Cochrane Library, and Google Scholar were searched to obtain the studies. The quality the studies was assessed using the JBI assessment tool. Data from studies reporting both asymptomatic and symptomatic cases, that did not meet the inclusion criteria were reviewed and included as discussion points. Data was entered to excel and imported to STATA 2011 to compute the prevalence and genetic diversity. Heterogeneity was checked using I² test statistics followed by subgroup and sensitivity analysis. Publication bias was assessed using a funnel plot and eggers test that was followed by trim and fill analysis.

Result

The pooled prevalence of norovirus was 20.2% (95% CI: 15.91, 24.4). The highest (36.3%) prevalence was reported in Ghana. Genogroup II noroviruses were dominant and reported as 89.5% (95% CI: 87.8, 96). The highest and lowest prevalence of this genogroup were reported in Ethiopia (98.3%), and in Burkina Faso (72.4%), respectively. Diversified genotypes had been identified with an overall prevalence of GII. 4 NoV (50.8%) which was followed by GII.6, GII.17, GI.3 and GII.2 with a pooled prevalence of 7.7, 5.1, 4.6, and 4.2%, respectively.

Conclusion

The overall pooled prevalence of norovirus was high in Africa with the dominance of genogroup II and GII.4 genotype. This prevalence is comparable with some reviews done in the same time frame around the world. However, in Africa, an in increasing trained of pooled prevalence had been reported through time. Likewise, a variable distribution of non-GII.4 norovirus genotypes were reported as compared to those studies done in the world of the same time frame, and those previous reviews done in Africa. Therefore, continuous surveillance is required in Africa to support future interventions and vaccine programs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-022-01835-w.

Use of multiplex PCR in diagnosis of childhood acute viral diarrhoea caused by rotavirus, norovirus, astrovirus and adenovirus in Upper Egypt

Background

Diarrhoea is still a major public health issue in developing countries, and it is one of the leading causes of morbidity and mortality in children. We aimed to assess the use of a multiplex reverse transcription polymerase chain reaction (RT-PCR) assay for the detection of five viruses, including rotavirus, norovirus (genogroups 1 and 2), astrovirus, and adenovirus, responsible for gastroenteritis in children under 5 years old in primary care centres in Upper Egypt.

Subjects and methods

A total of 500 stool samples were collected. Fifty samples were randomly selected for viral examination using multiplex RT-PCR for the detection of rotavirus, norovirus (genogroups 1 and 2), astrovirus, and adenovirus, causing diarrhoea.

Results

Viruses were detected in 45 (90%) of the 50 stool samples. The most frequently identified virus was norovirus G2, followed by Group A rotavirus, astrovirus and adenovirus. Mixed infection by two and three viruses was observed in 7/50 cases (14%) and 2/50 cases (4%), respectively. Norovirus G1 was not detected in the samples examined.

Conclusion

Our study reveals that multiplex PCR allows for the detection of multiple viral targets in only one reaction, rendering the assay easier to perform compared to existing testing methodologies (RT-PCR and electron microscopy). Additionally, most of the viruses were detected in summer, and the highest prevalence was in the age group less than 1 year. Norovirus G2 and rotavirus were the most frequent agents and the most common coinfections responsible for gastroenteritis in children.

Global prevalence of norovirus in cases of acute gastroenteritis from 1997 to 2021: An updated systematic review and meta-analysis

BACKGROUND

The worldwide response towards the acute gastroenteritis epidemic was well known, but the absence of an updated systematic review of global norovirus epidemiology in cases of gastroenteritis existed. We aimed to conduct and update a systematic review and meta-analysis of studies assessing norovirus prevalence among gastroenteritis patients worldwide.

METHODS

Four databases (PubMed, EMBASE, Cochrane Library, and Web of Science) were searched for epidemiological papers from 2014 to 2021 which applied the PCR method to access the prevalence of norovirus in acute gastroenteritis patients more than a full year. Statistical analysis was conducted using R-4.0.0 software.

RESULTS

A total of 405 records with 842, 926 cases were included. The pooled prevalence of norovirus was 16% (95%CI 15, 17). Children under 5 years old were at a higher risk with norovirus. A higher prevalence was seen in South America (22%, 95% CI 18, 27), while other continents showed a similar result with the overall prevalence of norovirus. No association was found between national income level and norovirus prevalence. A gradient of decreasing prevalence was noticed from community (20%, 95% CI 16, 24) to outpatients (18%, 95% CI 16, 20) to hospital setting (included both in- and outpatients, 17%, 95% CI 16, 19) to inpatients (15%, 95% CI 13, 17).

CONCLUSION

Norovirus were associated with 16% acute gastroenteritis globally. To fully understand the prevalence of norovirus worldwide, the continual surveillance of norovirus epidemics was required.

Global molecular prevalence and genotype distribution of Sapovirus in children with gastrointestinal complications: A systematic review and meta-analysis

Sapovirus (SaV) is an emerging cause of children gastrointestinal complications such as acute gastroenteritis (AGE). The aim of the present systematic review and meta-analysis was to estimate the global prevalence of the SaV in children and association of infection with SaVs and AGE in children based on case-control studies. Four international databases (PubMed, Scopus, Web of Sciences and Google Scholar) were used to retrieve English-language studies published between January 2000 and December 2020. Comprehensive Meta-Analysis software was applied to estimate the overall prevalence, publication bias and heterogeneity index. The pooled prevalence of SaV infection among children with gastroenteritis was 3.4% [95% confidence interval (CI): 2.9%-3.9%] based on a random-effects meta-analysis. Genogroup I was the dominant genogroup of SaV in children with gastroenteritis [2.2% (95% CI: 1.6%-3.0%)], association analysis showed that SaV was associated with gastroenteritis [OR: 1.843 (95% CI: 1.27-2.66)]. Given the significant prevalence of the virus in children, it is necessary to pay more attention to this situation. Therefore, preventive health measures in children should be a priority.

Molecular epidemiology of norovirus infections in children with acute gastroenteritis in 2017-2019 in Tianjin, China

Norovirus (NoV) is the leading cause of acute gastroenteritis (AGE) worldwide. Globally, the GII.4 Sydney 2012 strain has predominated since 2012, although GII.4 variant strains have caused AGE outbreaks in China. Recent patterns of NoV genotype distributions in 6011 children with AGE in Tianjin, China were investigated. NoV was detected using real-time reverse-transcriptase polymerase chain reaction and sequencing of partial sequences of the viral capsid gene. NoV genotypes were determined, and phylogenetic analysis was conducted. Epidemiological and clinical data were compared between children infected with different NoV genotypes. NoV was detected in 27.6% of the specimens tested. GII.4 strains comprised 49.4% infections, followed by GII.3 at 39.9%. Genotypes GII.2, GII.13, GII.17, GII.1, GII.6, and GII.14 were also detected. NoV was detected during most of the year, with a peak season of cases in the winter. Diarrhea, vomiting, fever, abdominal pain, and dehydration were present in patients with NoV infection. The main genotypes were GII.4 and GII.3, with a slight increase in GII.2, beginning in March 2017. Among the GII.4 strains, GII.4 Sydney 2012 was the only epidemic strain in Tianjin. Patients with GII.4 genotypes were more likely to present with diarrhea and vomiting than those with GII.3. Children with GII. Others were prone to suffered from dehydration and abdominal pain than those with GII.3. NoV GII has become the main cause of viral AGE in Tianjin, China. The predominant genotypes of NoV were GII.4 and GII.3. Identification of emerging genotypes is crucial for the prevention and control of NoV-caused AGE.

Global distribution of sporadic sapovirus infections: A systematic review and meta-analysis

Acute gastroenteritis (AGE), characterized by diarrhea and vomiting, is an important cause of global mortality, accounting for 9% of all deaths in children under five years of age. Since the reduction of rotavirus in countries that have included rotavirus vaccines in their national immunization programs, other viruses such as norovirus and sapovirus have emerged as more common causes of AGE. Due to widespread use of real-time RT-PCR testing, sapovirus has been increasingly reported as the etiologic agent in both AGE outbreaks and sporadic AGE cases. We aimed to assess the role of sapovirus as a cause of endemic AGE worldwide by conducting a systematic review of published studies that used molecular diagnostics to assess the prevalence of sapovirus among individuals with AGE symptoms. Of 106 articles included, the pooled sapovirus prevalence was 3.4%, with highest prevalence among children <5 years of age (4.4%) and among individuals in community settings (7.1%). Compared to studies that used conventional RT-PCR, RT-qPCR assays had a higher pooled prevalence (5.6%). Among individuals without AGE symptoms, the pooled sapovirus prevalence was 2.7%. These results highlight the relative contribution of sapovirus to cases of AGE, especially in community settings and among children <5 years of age.

Molecular Epidemiology of Human Sapovirus Among Children with Acute Gastroenteritis in Western Canada

Objectives: Sapovirus is increasingly recognized as an important cause of acute gastroenteritis (AGE) worldwide, however studies of prevalence, genetic diversity and strain-specific clinical implications have been scarce. Methods: To fill this knowledge gap, we used reverse transcription real-time PCR and sequencing of the partial major capsid protein VP1 gene to analyze stool specimens and rectal swabs obtained from 3347 children with AGE and 1355 asymptomatic controls (all <18 years old) collected between December 2014 and August 2018 in Alberta, Canada. Results: Sapovirus was identified in 9.5% (317/3347) of the children with AGE and 2.9% of controls. GI.1 (36%) was the predominant genotype identified, followed by GI.2 (18%), GII.5 (8%) and GII.3 (6%). Rare genotypes GII.1, GII.2, GV.1, GII.4, GIV.1, GI.3 and GI.7 were also seen. Sapovirus was detected year-round, peaking during the winter months of November to January. The exception was the 2016-2017 season when GI.2 overtook GI.1 as the predominant strain with a high detection rate persisting into April. We did not observe significant difference in the severity of gastroenteritis by genogroup or genotype. Repeated infection by sapovirus of different genogroups occurred in three controls who developed AGE later. Conclusions: Our data suggests that sapovirus is a common cause of AGE in children with high genetic diversity.

Sapovirus: an emerging cause of childhood diarrhea

PURPOSE OF REVIEW

Sapovirus, a genus in the Caliciviridae family alongside norovirus, is increasingly recognized as an important cause of childhood diarrhea. Some challenges exist in our ability to better understand sapovirus infections, including the inability to grow sapovirus in cell culture, which has hindered diagnosis and studies of immunity. Another challenge is that individuals with sapovirus infection are commonly coinfected with other enteric pathogens, complicating our ability to attribute the diarrhea episode to a single pathogen.

RECENT FINDINGS

Development of molecular methods for sapovirus detection has increased our ability to measure disease prevalence. The prevalence of sapovirus varies between 1 and 17% of diarrhea episodes worldwide, with the highest burden in young children and older adults. Further, epidemiological studies have used novel approaches to account for the presence of coinfections with other enteric pathogens; one multisite cohort study of children under two years of age found that sapovirus had the second-highest attributable incidence among all diarrheal pathogens studied.

SUMMARY

Especially in settings where rotavirus vaccines have been introduced, efforts to reduce the overall burden of childhood diarrhea should focus on the reduction of sapovirus transmission and disease burden.

Paediatric viral gastroenteritis and regional predominant viral pathogens in the post-rotavirus vaccination year: prospective Irish regional study

Acute gastroenteritis harbours a significant global burden. Rotavirus is the primary cause of gastroenteritis in children worldwide. We aim to determine the predominant enteric viral pathogens detected in the post-rotavirus vaccine period (2016-2017) in our region in county Mayo (west of Ireland), United Kingdom. All children up to 3 years old, who presented to Mayo University Hospital with vomiting and diarrhoea, from November 18th, 2016, to November 18th, 2017, had their stools tested by real-time reverse transcription polymerase chain reaction for viral pathogens. A total of 150 stool samples were tested, and 90 (60%) tested positive for a single viral pathogen. Rotavirus was the leading cause of gastroenteritis (37 patients, 24.6%; including 6 rotavirus vaccinated infants), followed by human adenovirus F (19 patients, 13%), norovirus (18 patients, 12%), sapovirus (9 patients, 6%) and astrovirus (7 patients, 5%). Rotavirus remained the predominant cause of gastroenteritis in the first year post-rotavirus vaccination, similar to the national Irish data from the pre vaccination years (July 2014-June 2015).

Clinical manifestations associated with acute viral gastroenteritis pathogens among pediatric patients in Qatar

BACKGROUND

Acute gastroenteritis (AGE) remains a significant cause of diarrhea that affects children worldwide. It is usually caused by viral agents, including rotavirus (RV), norovirus (NoV), adenovirus (AdV), astrovirus (AstV), and sapovirus (SaV), and the disease severity varies accordingly. Here, we report the association of clinical severity among AGE-infected pediatrics caused by a single viral pathogen, coinfection (viral-viral), mixed infection (viral-bacterial), and AGE-negative samples.

METHODS

A total of 901 pediatric patients were admitted with AGE to the Pediatric Emergency Center of Hamad Medical Corporation in Qatar from June 2016 to June 2018. The age of the subjects ranged between 3 months and 14 years (median of 16 months). Virus antigens detection was performed by using Film Array Gastrointestinal (GI) Panel kit. AGE severity was assessed using the Vesikari Clinical Severity Scoring System. Multivariable multinomial logistic regression was used to model the five AGE viral agents' likelihood in relation to severity versus co-infection, mixed infection, and AGE-negative samples.

RESULTS

AGE was most common in pediatrics aged 1-3 years (median age = 1.25 years) and more frequent in males than females, with a ratio of 1:0.8. About 19.2% of the infections were caused by NoV, followed by RV (18.2%), AdV (6.5%), SaV (2.3%), and AstV (1.8%). The majority of viral agents were detected higher in mixed infection (32.1%) than coinfection (4.9%). Based on the Vesikari score system, severe clinical illness was recorded among pediatrics infected with RV (82.2%) and NoV (75.7%). Further on multivariable analysis, compared to testing negative, the odds of detecting RV was three times significantly higher in children with severe symptoms relative to those with moderate (adjusted-odds ratio [a-OR] = 3.10; 95% confidence interval [CI] = 1.82-5.28). Similar results were observed when considering RV relative to co-infection and mixed infection (a-OR = 2.59; 95% CI = 1.23-5.48 and a-OR = 2.06; 1.28-3.30, respectively). About one-third of the study sample were Qatari children with AGE (33%), whereas 35% and 32% were pediatrics from the Middle East and North Africa region, excluding Qatari and nonregions.

CONCLUSION

This study underlines the association of disease severity among AGE-infected pediatrics in Qatar. The overall Vesikari median score was significantly high, followed by more frequent hospitalization among RV-infected pediatrics compared to others. There was no reduction in the disease severity among RV-infected regardless of the vaccine dose.

Hospital-Wide Surveillance of Healthcare-Associated Infections as a Source of Information about Specific Hospital Needs. A 5-Year Observation in a Multiprofile Provincial Hospital in the South of Poland

Healthcare-associated infections (HAIs) are adverse complications of hospitalisation resulting in delayed recovery and increased costs. The aim of this study was an analysis of epidemiological factors obtained in the framework of constant, comprehensive (hospital-wide) infection registration, and identification of priorities and needs in infection control, both with regard to targeted surveillance, as well as preventative actions. The study was carried out according to the methodology recommended by the HAI-Net (Surveillance Network) coordinated by the European Centre for Disease Prevention and Control, in the multiprofile hospital in Southern Poland, between 2012 and 2016. A total of 159,028 patients were under observation and 2184 HAIs were detected. The incidence was 1.4/100 admissions (2.7/1000 patient-das of hospitalisation) and significantly differed depending on the type of the patient care: in intensive care units (ICU) 16.9%; in surgical units, 1.3%; non-surgical units, 1.0%; and paediatric units, 1.8%. The most common HAI was gastrointestinal infections (GIs, 28.9%), followed by surgical site infections (SSIs, 23.0%) and bloodstream infections (BSIs, 16.1%). The vast majority of GIs, BSIs, urinary tract infections, and incidents of pneumonia (PN) were detected in non-ICUs. As many as 33.2% of cases of HAI were not confirmed microbiologically. The most frequently detected etiologic agent of infections was Clostridium difficile-globally and in GI (49%). Comprehensive analysis of the results allowed to identify important elements of surveillance of infections, i.e., surveillance of GI, PN, and BSI not only in ICU, but also in non-ICU wards, indicating a need for implementing rapid actions to improve compliance with HAI prevention procedures.

Norovirus RNA in serum associated with increased fecal viral load in children: Detection, quantification and molecular analysis

Worldwide, norovirus (NoV) is a major cause of acute gastroenteritis (AGE) responsible for pandemics every ~3 years, and over 200,000 deaths per year, with the majority in children from developing countries. We investigate the incidence of NoV in children hospitalized with AGE from Belém, Pará, Brazil, and also correlated viral RNA levels in their blood and stool with clinical severity. For this purpose, paired stool and serum samples were collected from 445 pediatric patients, ≤9 years between March 2012 and June 2015. Enzyme-linked immunosorbent assay (EIA) was used to detect NoV in stool and reverse transcription quantitative PCR (RT-qPCR) used to quantify NoV RNA levels in sera (RNAemia) and in the positive stool. Positives samples were characterized by the partial ORF1/2 region sequence of viral genome. NoV antigen was detected in 24.3% (108/445) of stool samples, with RNAemia also present in 20.4% (22/108). RNAemia and a high stool viral load (>10⁷ genome copies/gram of faeces) were associated with longer hospitalizations. The prevalent genotypes were GII.4 Sydney_2012 (71.6%-58/81) and New Orleans_2009 (6.2%-5/81) variants. Eight other genotypes belonging to GII were detected and four of them were recombinant strains. All sera were characterized as GII.4 and shared 100% similarity with their stool. The results suggest that the dissemination of NoV to the blood stream is not uncommon and may be related to increased faecal viral loads and disease severity.

Determinants of under-immunization and cumulative time spent under-immunized in a Quebec cohort

BACKGROUND

Under-immunization refers to a state of sub-optimal protection against vaccine preventable diseases. Vaccine coverage for age may not capture intentional or non-intentional spacing of vaccines in the recommended provincial immunization guidelines. We aimed to identify factors associated with coverage and under-immunization and to determine the number of days during which children were under-immunized during their first 24months of life.

METHODS

Secondary analysis of children ≤3years recruited through active surveillance for gastroenteritis from three Quebec pediatric emergency departments from 2012 to 2014. Vaccination status for children at least 24months of age was determined using provincial immunization guidelines. Cumulative days under-immunized were calculated for DTaP-VPI-Hib, PCV, MMR, and Men-C-C. Factors associated with up-to-date (UTD) status at 24months of life and for under-immunization ≥6months were analyzed using logistic regression.

RESULTS

Of 246 eligible children, 180 (73%) were UTD by 24months of life. The mean cumulative days under-immunized for MMR was 107days, for PCV 209days, for Men-C-C 145days, and for DTaP-VPI-Hib 227days. Overall, 149 children (60%) experienced delay for at least 1 vaccine. Factors associated with both an UTD status at 24months and concurrently associated with being under-immunization ≥6months, included timely initiation of immunization (OR=5.85; 95% CI: 2.80-12.22) and (OR=0.13; 95% CI: 0.07-0.24), failure to co-administer 18-month vaccines (OR=0.15; 95% CI: 0.10-0.21) and (OR=3.29; 95% CI: 2.47-4.39), and having a household with ≥3 children under 18years ((OR=0.50; 0.28-0.86) and (OR=2.99; 1.45-6.22), respectively.

CONCLUSION

Paired with an unexpected low level of coverage at 24months of life, the majority of our cohort also experienced a state of under-immunization for a least one vaccine. Estimates of coverage do not capture intentional or non-intentional gaps in protection from vaccine preventable illnesses. Timely preventive care should be prioritized.

Burden of acute gastroenteritis caused by norovirus in China: A systematic review

BACKGROUND

To understand the epidemiology and disease burden of norovirus (NoVs) gastroenteritis in China, a systematic review was conducted.

METHODS

Studies on acute gastroenteritis (AGE) caused by NoVs from mainland China, published before 2017 were searched. All retrieved articles were screened and reviewed by a standardized algorithm. NoVs detection rates as well as strain variations by ages, seasonal variations and geographic locations were analyzed using random-effects model.

RESULTS

A total of 225 articles were included in the final analysis. Similar detection rates at 21.0% and 19.8% were obtained from the North and the South, respectively. NoVs infection occurred year round, with a peak between October and January in the North and between August and November in the South. High detection rates (∼29%) of NoVs were found in adults and the elderly and in children aged 6-35 months (∼22%). The predominant strains were GII.4 (70.4%), followed by GII.3 (13.5%).

CONCLUSION

NoVs cause significant disease burden in China which warrants development of vaccines against NoVs, particularly for children and the elderly who are vulnerable to gastroenteritis diseases. To achieve a broad protection, continual monitoring NoV epidemics and strain variations for selection of proper vaccine strains is critical.

Epidemiology and Factors Related to Clinical Severity of Acute Gastroenteritis in Hospitalized Children after the Introduction of Rotavirus Vaccination

We aimed to investigate epidemiology and host- and pathogen-related factors associated with clinical severity of acute gastroenteritis (AGE) in children after rotavirus vaccination introduction. Factors assessed included age, co-infection with more than 2 viruses, and virus-toxigenic Clostridium difficile co-detection. Fecal samples and clinical information, including modified Vesikari scores, were collected from hospitalized children with AGE. The presence of enteric viruses and bacteria, including toxigenic C. difficile, was detected by polymerase chain reaction (PCR). Among the 415 children included, virus was detected in stool of 282 (68.0%) children. Co-infection with more than 2 viruses and toxigenic C. difficile were found in 24 (8.5%) and 26 (9.2%) children with viral AGE, respectively. Norovirus (n = 130) infection, including norovirus-associated co-infection, was the most frequent infection, especially in children aged < 24 months (P < 0.001). In the severity-related analysis, age < 24 months was associated with greater diarrheal severity (P < 0.001) and modified Vesikari score (P = 0.001), after adjustment for other severity-related factors including rotavirus status. Although the age at infection with rotavirus was higher than that for other viruses (P = 0.001), rotavirus detection was the most significant risk factor for all severity parameters, including modified Vesikari score (P < 0.001). Viral co-infection and toxigenic C. difficile co-detection were not associated with any severity-related parameter. This information will be helpful in the management of childhood AGE in this era of rotavirus vaccination and availability of molecular diagnostic tests, which often lead to the simultaneous detection of multiple pathogens.

Two Birds With One Stone: Estimating Population Vaccination Coverage From a Test-negative Vaccine Effectiveness Case-control Study

Vaccination program evaluation includes assessment of vaccine uptake and direct vaccine effectiveness (VE). Often examined separately, we propose a design to estimate rotavirus vaccination coverage using controls from a rotavirus VE test-negative case-control study and to examine coverage following implementation of the Quebec, Canada, rotavirus vaccination program. We present our assumptions for using these data as a proxy for coverage in the general population, explore effects of diagnostic accuracy on coverage estimates via simulations, and validate estimates with an external source. We found 79.0% (95% confidence interval, 74.3%, 83.0%) ≥2-dose rotavirus coverage among participants eligible for publicly funded vaccination. No differences were detected between study and external coverage estimates. Simulations revealed minimal bias in estimates with high diagnostic sensitivity and specificity. We conclude that controls from a VE case-control study may be a valuable resource of coverage information when reasonable assumptions can be made for estimate generalizability; high rotavirus coverage demonstrates success of the Quebec program.