Sentinel surveillance for rotavirus in children <5 years of age admitted for Diarrheal illness to Yangon Children's Hospital, Myanmar, 2009-2014

Recent Molecular Characterization of Porcine Rotaviruses Detected in China and Their Phylogenetic Relationships with Human Rotaviruses

Porcine rotavirus A (PoRVA) is an enteric pathogen capable of causing severe diarrhea in suckling piglets. Investigating the prevalence and molecular characteristics of PoRVA in the world, including China, is of significance for disease prevention. In 2022, a total of 25,768 samples were collected from 230 farms across China, undergoing porcine RVA positivity testing. The results showed that 86.52% of the pig farms tested positive for porcine RVA, with an overall positive rate of 51.15%. Through the genetic evolution analysis of VP7, VP4 and VP6 genes, it was revealed that G9 is the predominant genotype within the VP7 segment, constituting 56.55%. VP4 genotypes were identified as P[13] (42.22%), P[23] (25.56%) and P[7] (22.22%). VP6 exhibited only two genotypes, namely I5 (88.81%) and I1 (11.19%). The prevailing genotype combination for RVA was determined as G9P[23]I5. Additionally, some RVA strains demonstrated significant homology between VP7, VP4 and VP6 genes and human RV strains, indicating the potential for human RV infection in pigs. Based on complete genome sequencing analysis, a special PoRVA strain, CHN/SD/LYXH2/2022/G4P[6]I1, had high homology with human RV strains, revealing genetic reassortment between human and porcine RV strains in vivo. Our data indicate the high prevalence, major genotypes, and cross-species transmission of porcine RVA in China. Therefore, the continuous monitoring of porcine RVA prevalence is essential, providing valuable insights for virus prevention and control, and supporting the development of candidate vaccines against porcine RVA.

Clinical Epidemiology Features and Risk Factors for Acute Diarrhea Caused by Rotavirus A in Vietnamese Children

Introduction

Acute diarrhea caused by group A rotavirus (RVA) is a leading cause of morbidity and mortality globally in children less than 5 years old. Acute diarrhea caused by RVA is often manifested by loose/watery stool leading to different degrees of dehydration. The detection of risk factors, diagnosis, and prompt treatment of acute diarrhea caused by RVA is critical. We aimed to describe clinical epidemiological features of acute diarrhea caused by RVA and its associated risk factors. Subjects and Method. We conducted a cross-sectional study that included 321 children under 5 years old with acute diarrhea at Haiphong Children's Hospital, Vietnam, from 1 August 2019 to 31 July 2020.

Results

Among the 321 children included in our analysis, 221 (68.8%) children were positive for RVA. Males represented 61.1% of cases, 41.2% of children were in the 12-<24-month age group, and the majority of cases were among children in suburban areas (71.5%). Clinical manifestations included loose and watery stool (100%), vomiting-fever-loose/watery stool (57.9%), vomiting-loose/watery stool (83.2%), fever-loose/watery stool (58.8%), dehydration (30%), hyponatremia (22.1%), hypernatremia (1.4%), and hypokalemia (15%). Risk factors for acute diarrhea caused by RVA included history of diarrhea, not exclusive breastfeeding in the first 6 months, living area, maternal education, and income.

Conclusions

Acute diarrhea due to RVA was very prevalent in children under 5 years old. Clinical manifestations included a high prevalence of loose/watery stools/day and dehydration with electrolyte disorder. Mothers should exclusively breastfeed their children for the first 6 months to avoid the risk of acute diarrhea caused by RVA.

Determinants of Pathogen Contamination of the Environment in the Greater Yangon Area, Myanmar

Recent results from water, sanitation, and hygiene interventions highlight the need to better understand environmental influences on enteropathogen transmission. We quantified a range of viral, bacterial, and protozoal pathogens and one indicator, Enterococcus faecalis in soil and water from urban and rural sites in and around Yangon, Myanmar. We found that environmental characteristics associated with contamination differed by pathogens and substrates. In soil, bacterial pathogen gene counts were associated with elevation and drainage ditches (compared to stagnant water) (RR = 0.96, 95% CI 0.93, 0.99 and RR = 1.70, 95% CI 1.18, 2.45, respectively), while viral gene counts were associated with the presence of sanitation facilities within 50 m of the collection point (RR = 3.99, 95% CI 1.12, 14.24). In water, E. faecalis, total pathogen, and bacterial pathogen gene counts were associated with drainage ditches (RR = 1.86, 95% CI 1.27, 2.72, RR = 1.38 95% CI 1.09, 1.74, and RR = 1.38 95% CI 1.07, 1.77, respectively). E. faecalis, total pathogen, bacterial pathogen, and viral gene counts were associated with the presence of uncollected garbage within 50 m of the collection point (RR = 1.57, 95% CI 1.00, 2.47, RR = 1.52, 95% CI 1.16, 2.00, RR = 1.52, 95% CI 1.13, 2.06, and RR = 1.75, 95% CI 1.17, 2.61 respectively). Measuring the environment provides added specificity toward identifying important environmental pathways that require mitigation.

Rotavirus infection among children under five years of age hospitalized with acute gastroenteritis in Myanmar during 2018-2020 - Multicentre surveillance before rotavirus vaccine introduction

BACKGROUND

Rotavirus gastroenteritis (RVGE) is a leading cause of severe diarrhea in children under-five worldwide, with the majority of mortality in lower -income countries. This study aimed to provide baseline information on epidemiology of rotavirus and circulating strains before rotavirus vaccine introduction in Myanmar.

METHODS

Hospital-based, prospective surveillance was conducted from May 2018 to January 2020 at four sentinel sites; two hospitals in Lower Myanmar, one hospital each in Middle Myanmar and East Myanmar. Children under five years of age hospitalized for acute gastroenteritis were enrolled; demographic and clinical data were collected. Stool samples were screened by ELISA (ProSpecT™ Rotavirus, OXOID-UK) for rotavirus antigen and a subset of ELISA positive samples were genotyped by reverse transcription polymerase chain reaction.

RESULTS

Rotavirus was detected in 45.7% (799/1750) of cases enrolled at three sites in May 2018-April 2019 and 42.5% (521/1227) at four sites in May 2019-January 2020. RVGE cases were predominantly male (58.7%; 775/1320) and 92.6% (1223/1320) of RVGE cases occurred in <2 years old. Rotavirus detection was higher in the cold and dry season (November-April). RVGE compared to non-RVGE cases had more frequent vomiting (78.3% Vs 68.1%, p < 0.01), fever (65.8% Vs 61.3%, p = 0.01), severe dehydration (3.6% Vs 2.1%, p < 0.01) and requirement of treatment by IV fluid (58.3% Vs 53.1%, p < 0.01). The most prevalent genotypes identified were G1P[6] (113/359, 31.5%), G1P[8] (94/359, 26.2%) and G2P[4] (33/359, 9.2%).

CONCLUSIONS

This study confirms the persistent high prevalence of RVGE among children under-five admitted to hospitals in different parts of Myanmar and the diversity of rotavirus strains over time prior to vaccine introduction. The rotavirus vaccine was introduced nationwide in February 2020 in Myanmar and these data will be important baseline data for post-vaccination monitoring of vaccine impact and circulating strains.

Viral etiology of acute gastroenteritis among Forcibly Displaced Myanmar Nationals and adjacent host population in Bangladesh

Background

Since August 2017, Myanmar nationals from Rakhine state have crossed the border into Bangladesh and settled in Cox’s Bazar, the World’s largest refugee camp. Due to overcrowding, poor sanitation, and hygienic practices they have been under significant health risks including diarrheal diseases. The objective of this study is to determine the viral etiology of acute gastroenteritis (AGE) among forcibly displaced Myanmar nationals (FDMN) and adjacent Bangladeshi local host population (AHP).

Methods

From April 2018 to April 2019, we collected stool specimens from 764 FDMN and 1159 AHP of all ages. We tested 100 randomly selected specimens from each group for the most common AGE viruses.

Results

Among 200 diarrhea patients, 55% and 64% of FDMN and AHP patients, respectively, had viral infections; the most common viruses were rotavirus (29% vs 44%), adenovirus (24% vs 31%), and norovirus (14% vs 10%). In both populations, viral infections were significantly higher in children less than 5 years of age, compared with bacterial infections that were higher in patients older than 5 years of age (P ≤ .05).

Conclusions

Disparities in viral and bacterial prevalence among various age groups warrant careful antibiotic usage, especially in children less than 5 years of age.

Rotavirus gastroenteritis in Pakistan, 2018: updated disease burden

Objective

Rotavirus A (RVA) is a significant cause of severe diarrheal illness and one of the common causes of death in children under the age of five. This study was aimed at detecting the prevalence of RVA in Pakistan after rotavirus vaccines were introduced. Fecal samples were obtained from 813 children from different hospitals in Rawalpindi and Islamabad, Pakistan, from January 2018 to December 2018. To obtain additional information from the parents / guardians of the children, a standard questionnaire was used.

Results

Using an enzyme-linked immunosorbent assay kit (ELISA), rotavirus antigen was detected and ELISA positive samples were subjected to reverse transcription PCR (RT-PCR). The findings showed 22% prevalence of RVA in children with acute gastroenteritis (AGE) via ELISA and 21% prevalence via RT-PCR in children with AGE. There was no statistically significant difference between gender, age and RVA infections. The winter, spring and fall/autumn seasons were statistically significant for RVA prevalence.

Conclusion

The present study will provide post vaccine prevalence data for the health policy makers. The implementation of rotavirus vaccines, along with adequate nutrition for babies, clean water supply and maternal hygienic activities during infant feeding, is recommended. Furthermore, continuous surveillance is mandatory in the whole country to calculate the disease burden caused by RVA.

Epidemiology of intussusception among children less than 2 years of age; findings from baseline surveillance before rotavirus vaccine introduction in Myanmar

BACKGROUND

Rotavirus vaccine was planned to be introduced in the National Immunization Program of Myanmar in 2020. Reported potential association of a small increased risk of intussusception after rotavirus vaccination in some countries is a major safety concern and it is mandatory to collect baseline information before vaccine introduction.

METHODS

Retrospective study reviewed medical records of intussusception cases for past 3 years (2015-2018) and prospective, active study was conducted from August 2018 to January 2020 at three tertiary children hospitals where pediatric surgical facility is present. Brighton Level 1 Criteria was used for confirmation of intussusception among children <2 years of age admitted to surgical wards. Demographic, clinical, diagnostic and treatment practices data were collected and descriptive data analysis was performed.

RESULTS

A total of 697 (421 in retrospective and 276 in prospective) confirmed intussusception cases were identified. Majority of intussusception cases (550/697, 78.9%) were observed in the first year of life and most frequent between 5-7 months of age (292/697, 41.9%) with a peak at 6 months (114/697, 16.4%). The most common clinical presentations were vomiting and bloody diarrhea accounting 82.1% and 77.5% respectively. Regarding diagnosis and treatment, 458/697 (65.7%) required surgical intervention either manual reduction or intestinal resection and 34.4% by either air or barium enema. Overall mortality was 0.7% (5/697) and four out of five children died needed intestinal resection. Late arrival to hospital (>3days after onset) is significantly associated with requirement of surgery (61/85, 71.8%), which in turn is significantly associated with longer hospital stay (296/452, 65.5%) (p < 0.05).

CONCLUSIONS

Intussusception occurrence is most frequent between 5-7 months age group which is old enough to be vaccinated under the schedule that has now been introduced in Myanmar. More than half of the cases were treated by surgery and late arrival to hospital enhances requirement of surgery and poor outcome. Findings of this baseline surveillance provide important facts for public health officials in balancing risks and benefits of rotavirus vaccine introduction, defining targeted age and dosage scheduling and facilitate monitoring system in post-vaccination.

Rotavirus genotype trends from 2013 to 2018 and vaccine effectiveness in southern Vietnam

OBJECTIVES

Rotavirus (RV) genotypes vary geographically, and this can affect vaccine effectiveness (VE). This study investigated the genotype distribution of RV and explored VE before introducing the RV vaccine to the national immunization programme in Vietnam.

METHODS

This hospital-based surveillance study was conducted at Children's Hospital 1, Ho Chi Minh City in 2013-2018. Stool samples and relevant data, including vaccination history, were collected from children aged <5 years who were hospitalized with gastroenteritis. RV was detected using enzyme immunoassays and then genotyped. Children aged ≥6 months were included in the VE analysis.

RESULTS

Overall, 5176 children were included in this study. RV was detected in 2421 children (46.8%). RV positivity decreased over the study period and was associated with age, seasonality, location and previous vaccination. Among 1105 RV-positive samples, G3P[8] was the most prevalent genotype (43.1%), followed by G8P[8] (19.7%), G1P[8] (12.9%) and G2P[4] (12.9%). Overall VE was 69.7% [95% confidence interval (CI) 53.3-80.6%] in fully vaccinated children and 58.6% (95% CI 44.1-69.4%) in children who had received at least one dose of RV vaccine. VE was highest for G3P[8] (95% CI 75.1-84.5%) and lowest for G2P[4] (95% CI 32.4-57.2%).

CONCLUSIONS

RV remains a major cause of acute gastroenteritis requiring hospitalization in southern Vietnam. The RV vaccine is effective, but its effectiveness varies with RV genotype.

Rotavirus infection in children in Southeast Asia 2008-2018: disease burden, genotype distribution, seasonality, and vaccination

Background

Rotaviruses (RVs) are recognized as a major cause of acute gastroenteritis (AGE) in infants and young children worldwide. Here we summarize the virology, disease burden, prevalence, distribution of genotypes and seasonality of RVs, and the current status of RV vaccination in Southeast Asia (Cambodia, Indonesia, Lao People’s Democratic Republic, Malaysia, Myanmar, Philippines, Singapore, Thailand, and Vietnam) from 2008 to 2018.

Methods

Rotavirus infection in Children in Southeast Asia countries was assessed using data from Pubmed and Google Scholars. Most countries in Southeast Asia have not yet introduced national RV vaccination programs. We exclude Brunei Darussalam, and Timor Leste because there were no eligible studies identified during that time.

Results

According to the 2008–2018 RV surveillance data for Southeast Asia, 40.78% of all diarrheal disease in children were caused by RV infection, which is still a major cause of morbidity and mortality in children under 5 years old in Southeast Asia. Mortality was inversely related to socioeconomic status. The most predominant genotype distribution of RV changed from G1P[8] and G2P[4] into the rare and unusual genotypes G3P[8], G8P[8], and G9P[8]. Although the predominat strain has changed, but the seasonality of RV infection remains unchanged. One of the best strategies for decreasing the global burden of the disease is the development and implementation of effective vaccines.

Conclusions

The most predominant genotype distribution of RV was changed time by time. Rotavirus vaccine is highly cost effective in Southeast Asian countries because the ratio between cost per disability-adjusted life years (DALY) averted and gross domestic product (GDP) per capita is less than one. These data are important for healthcare practitioners and officials to make appropriate policies and recommendations about RV vaccination.

Molecular epidemiology of group A rotavirus in outpatient diarrhea infants and children in Chongqing, China, 2011-2015

Human group A rotavirus (RVA) is the leading cause of acute viral gastroenteritis in children under 5 years old worldwide. The aim of this study was to investigate the genotype distribution of RVA in the Midwest of China. Sentinel-based surveillance of acute diarrhea was conducted at Children's Hospital of Chongqing Medical University from 2011 to 2015. RVA was tested by using enzyme-linked immunosorbent assays. The partial VP4 genes and VP7 genes of rotavirus were amplified and sequenced, and genotyping and phylogenetic analyses were performed. Among the 2236 stool specimens collected from children with acute gastroenteritis, 681 (30.46%) were positive for RVA. The majority of children (89.28%) who tested positive for RVA were children aged ≤2 years. The seasonal peak of RVA was in the winter. As for genotype, four strain combinations, G9P[8], G3P[8], G1P[8], and G2P[4] contributed to 75.62% (515/681) of the RVA-associated diarrhea cases. After a marked increase in G9P[8] (30.77%) in 2013, G9P[8] became the predominant genotype in 2014 and 2015, whilst the prevalence of G1P[8] was decreased to 2.72% in 2015. Unusual G-P combinations (eg, G1P[4], G9P[4], G4P[6], G3P[4], G2P[8]) were also detected sporadically over the study period. Phylogenetic tree analysis results showed that the VP7 sequences of G9 strains were clustered into two main lineages, and 77.34% of them were clustered into lineage VI, with the highest nucleotide similarity to the strain JS12-17(China). VP4 gene sequences of P[8] strains were almost P[8]-lineage 3. Substantial temporal variation in the circulation of various genotypes of rotavirus in Chongqing was observed during 2011-2015, and highlights the need for continuous surveillance of RVA infection for better understanding and control of RVA infection.

Health and immunisation services for the urban poor in selected countries of Asia

Background

Asia is a region that is rapidly urbanising. While overall urban health is above rural health standards, there are also pockets of deep health and social disadvantage within urban slum and peri-urban areas that represent increased public health risk. With a focus on vaccine preventable disease and immunisation coverage, this commentary describes and analyses strengths and weaknesses of existing urban health and immunisation strategy, with a view to recommending strategic directions for improving access to immunisation and related maternal and child health services in urban areas across the region. The themes discussed in this commentary are based on the findings of country case studies published by the United Nations Childrens Fund (UNICEF)  on the topic of immunisation and related health services for the urban poor in Cambodia, Indonesia, Mongolia, Myanmar, the Philippines, and Vietnam.

Main body

Although overall urban coverage is higher than rural coverage in selected countries of Asia, there are also wide disparities in coverage between socio economic groups within urban areas. Consistent with these coverage gaps, there is emerging evidence of outbreaks of vaccine preventable diseases in urban areas. In response to this elevated public health risk, there have been some promising innovations in operational strategy in urban settings, although most of these initiatives are project related and externally funded. Critical issues for attention for urban health services access include reaching consensus on accountability for management and resourcing of the strategy, and inclusion of an urban poor approach within the planning and budgeting procedures of Ministries of Health and local governments. Advancement of local partnership and community engagement strategies to inform operational approaches for socially marginalised populations are also urgently required. Such developments will be reliant on development of municipal models of primary health care that have clear delegations of authority, adequate resources and institutional capabilities to implement.

Conclusions

The development of urban health systems and immunisation strategy is required regionally and nationally, to respond to rapid demographic change, social transition, and increased epidemiological risk.

Electronic supplementary material

The online version of this article (10.1186/s40249-019-0538-4) contains supplementary material, which is available to authorized users.

Adenovirus associated with acute diarrhea: a case-control study

Background

Diarrhea is a major source of morbidity and mortality among young children in low-income and middle-income countries. Human adenoviruses (HAdV), particular HAdV species F (40, 41) has been recognized as important causal pathogens, however limited data exist on molecular epidemiology of other HAdV associated with acute gastroenteritis.

Methods

In the present preliminary study, we performed a case-control study involving 273 children who presented diarrheal disease and 361 healthy children matched control in Children’s hospital of Hebei Province (China) to investigate the relationship between non-enteric HAdV and diarrhea. HAdV were detected and quantified using quantitative real-time PCR (qPCR) and serotyped by sequencing and phylogenetic analysis. Odds ratio (OR) was used to assess the risk factor of HAdV.

Results

HAdV were detected in 79 (28.94%) of 273 children with diarrhea including 7 different serotypes (HAdV 40, 41, 3, 2,1,5 and 57) with serotypes 40, 41 and 3 being the most dominant and in 26 (7.20%) of 361 healthy children containing 9 serotypes (HAdV 40, 41, 3, 2,1,5,57,6 and 31). A majority (91.14%) of HAdV positives occurred in diarrhea children and 65.38% in controls< 3 years of age. No significant difference in the viral load was found between case and control groups or between Ad41-positive patients and healthy controls. In addition to HAdV 40 and 41, HAdV 3 was also associated with diarrhea (OR = 17.301, adjusted OR = 9.205, p < 0.001).

Conclusions

Our results demonstrate a high diversity of HAdV present among diarrhea and healthy children and implicate that non-enteric HAdV3 may lead to diarrhea.