Rotavirus genotypes in children under five years hospitalized with diarrhea in low and middle-income countries: Results from the WHO-coordinated Global Rotavirus Surveillance Network.

Rotavirus is the most common pathogen causing pediatric diarrhea and an important cause of morbidity and mortality in low- and middle-income countries. Previous evidence suggests that the introduction of rotavirus vaccines in national immunization schedules resulted in dramatic declines in disease burden but may also be changing the rotavirus genetic landscape and driving the emergence of new genotypes. We report genotype data of more than 16,000 rotavirus isolates from 40 countries participating in the Global Rotavirus Surveillance Network. Data from a convenience sample of children under five years of age hospitalized with acute watery diarrhea who tested positive for rotavirus were included. Country results were weighted by their estimated rotavirus disease burden to estimate regional genotype distributions. Globally, the most frequent genotypes identified after weighting were G1P[8] (31%), G1P[6] (8%) and G3P[8] (8%). Genotypes varied across WHO Regions and between countries that had and had not introduced rotavirus vaccine. G1P[8] was less frequent among African (36 vs 20%) and European (33 vs 8%) countries that had introduced rotavirus vaccines as compared to countries that had not introduced. Our results describe differences in the distribution of the most common rotavirus genotypes in children with diarrhea in low- and middle-income countries. G1P[8] was less frequent in countries that had introduced the rotavirus vaccine while different strains are emerging or re-emerging in different regions.

Evaluation of the World Health Organization Global Invasive Bacterial Vaccine-Preventable Disease (IB-VPD) Surveillance Network's Laboratory External Quality Assessment Programme, 2014-2019.

Introduction. In 2009, the World Health Organization (WHO) established the Global Invasive Bacterial Vaccine Preventable Disease (IB-VPD) Surveillance Network (GISN) to monitor the global burden and aetiology of bacterial meningitis, pneumonia and sepsis caused by Haemophilus influenzae (Hi), Neisseria meningitidis (Nm) and Streptococcus pneumoniae (Sp).Hypothesis/Gap Statement. The GISN established an external quality assessment (EQA) programme for the characterization of Hi, Nm and Sp by culture and diagnostic PCR.Aim. To assess the performance of sentinel site laboratories (SSLs), national laboratories (NLs) and regional reference laboratories (RRLs) between 2014 and 2019 in the EQA programme.Methodology. Test samples consisted of bacterial smears for Gram-staining, viable isolates for identification and serotyping or serogrouping (ST/SG), plus simulated cerebrospinal fluid (CSF) samples for species detection and ST/SG by PCR. SSLs and NLs were only required to analyse the slides for Gram staining and identify the species of the live isolates. RRLs, and any SLs and NLs that had the additional laboratory capacity, were also required to ST/SG the viable isolates and analyse the simulated CSF samples.Results. Across the period, 69-112 SS/NL labs and eight or nine RRLs participated in the EQA exercise. Most participants correctly identified Nm and Sp in Gram-stained smears but were less successful with Hi and other species. SSLs/NLs identified the Hi, Nm and Sp cultures well and also submitted up to 56 % of Hi, 62 % of Nm and 33 % of Sp optional ST/SG results each year. There was an increasing trend in the proportion of correct results submitted over the 6 years for Nm and Sp. Some SSLs/NLs also performed the optional detection and ST/SG of the three organisms by PCR in simulated CSF from 2015 onwards; 89-100 % of the CSF samples were correctly identified and 76-93 % of Hi-, 90-100 % of Nm- and 75-100 % of Sp-positive samples were also correctly ST/SG across the distributions. The RRLs performed all parts of the EQA to a very high standard, with very few errors across all aspects of the EQA.Conclusion. The EQA has been an important tool in maintaining high standards of laboratory testing and building of laboratory capacity in the GISN.

Risk Factors for Mortality Among Children Younger Than Age 5 Years With Severe Diarrhea in Low- and Middle-income Countries: Findings From the World Health Organization-coordinated Global Rotavirus and Pediatric Diarrhea Surveillance Networks.

BACKGROUND: Diarrhea is the second leading cause of death in children younger than 5 years of age globally. The burden of diarrheal mortality is concentrated in low-resource settings. Little is known about the risk factors for childhood death from diarrheal disease in low- and middle-income countries. METHODS: Data from the World Health Organization (WHO)-coordinated Global Rotavirus and Pediatric Diarrhea Surveillance Networks, which are composed of active, sentinel, hospital-based surveillance sites, were analyzed to assess mortality in children <5 years of age who were hospitalized with diarrhea between 2008 and 2018. Case fatality risks were calculated, and multivariable logistic regression was performed to identify risk factors for mortality. RESULTS: This analysis comprises 234 781 cases, including 1219 deaths, across 57 countries. The overall case fatality risk was found to be 0.5%. Risk factors for death in the multivariable analysis included younger age (for <6 months compared with older ages, odds ratio [OR] = 3.54; 95% confidence interval [CI], 2.81-4.50), female sex (OR = 1.18; 95% CI, 1.06-1.81), presenting with persistent diarrhea (OR = 1.91; 95% CI, 1.01-3.25), no vomiting (OR = 1.13; 95% CI, .98-1.30), severe dehydration (OR = 3.79; 95% CI, 3.01-4.83), and being negative for rotavirus on an enzyme-linked immunosorbent assay test (OR = 2.29; 95% CI, 1.92-2.74). Cases from the African Region had the highest odds of death compared with other WHO regions (OR = 130.62 comparing the African Region with the European Region; 95% CI, 55.72-422.73), whereas cases from the European Region had the lowest odds of death. CONCLUSIONS: Our findings support known risk factors for childhood diarrheal mortality and highlight the need for interventions to address dehydration and rotavirus-negative diarrheal infections.

Impact and effectiveness of monovalent rotavirus vaccine in Tajik children.

BACKGROUND: In 2015, Tajikistan became the second country in Central Asia to introduce rotavirus vaccine into its national immunization program. Before vaccine introduction, rotavirus was estimated to cause > 40% of pediatric diarrhea hospitalizations in Tajikistan. We aimed to assess the impact of rotavirus vaccine introduction on rotavirus disease burden and estimate rotavirus vaccine effectiveness (VE). METHODS: Using surveillance data from 2013 through 2019, we examined trends in monthly hospital admissions among children < 5 years old, before and after rotavirus vaccine introduction. Poisson regression was used to quantify decreases. VE was estimated using a test-negative case control design, with data from admissions during 2017 - 2019. Immunization records were obtained from clinics. RESULTS: Among enrolled children, rotavirus positivity declined from 42% to 25% in the post-vaccine introduction period, a decrease of 41% (95% Confidence Interval [CI]: 36 - 45%). Declines were greatest in children < 12 months of age. Estimated VE of a complete course of rotavirus vaccine was 55% (95% CI: 21 - 73%) among children 5 - 59 months of age and 64% (95% CI: 36 - 80%) among children 5 - 23 months of age. VE point estimates were higher among children receiving both doses of rotavirus vaccine non-concurrently with OPV and among children receiving their first dose of rotavirus vaccine at 4 - 11 months of age, but CIs were wide and overlapping. CONCLUSIONS: Our data demonstrate that rotavirus vaccine introduction was associated with a substantial reduction in pediatric rotavirus hospitalization burden in Tajikistan, and that rotavirus vaccination is effective in Tajik children.

Aetiology and incidence of diarrhoea requiring hospitalisation in children under 5 years of age in 28 low-income and middle-income countries: findings from the Global Pediatric Diarrhea Surveillance network.

INTRODUCTION: Diarrhoea remains a leading cause of child morbidity and mortality. Systematically collected and analysed data on the aetiology of hospitalised diarrhoea in low-income and middle-income countries are needed to prioritise interventions. METHODS: We established the Global Pediatric Diarrhea Surveillance network, in which children under 5 years hospitalised with diarrhoea were enrolled at 33 sentinel surveillance hospitals in 28 low-income and middle-income countries. Randomly selected stool specimens were tested by quantitative PCR for 16 causes of diarrhoea. We estimated pathogen-specific attributable burdens of diarrhoeal hospitalisations and deaths. We incorporated country-level incidence to estimate the number of pathogen-specific deaths on a global scale. RESULTS: During 2017-2018, 29 502 diarrhoea hospitalisations were enrolled, of which 5465 were randomly selected and tested. Rotavirus was the leading cause of diarrhoea requiring hospitalisation (attributable fraction (AF) 33.3%; 95% CI 27.7 to 40.3), followed by Shigella (9.7%; 95% CI 7.7 to 11.6), norovirus (6.5%; 95% CI 5.4 to 7.6) and adenovirus 40/41 (5.5%; 95% CI 4.4 to 6.7). Rotavirus was the leading cause of hospitalised diarrhoea in all regions except the Americas, where the leading aetiologies were Shigella (19.2%; 95% CI 11.4 to 28.1) and norovirus (22.2%; 95% CI 17.5 to 27.9) in Central and South America, respectively. The proportion of hospitalisations attributable to rotavirus was approximately 50% lower in sites that had introduced rotavirus vaccine (AF 20.8%; 95% CI 18.0 to 24.1) compared with sites that had not (42.1%; 95% CI 33.2 to 53.4). Globally, we estimated 208 009 annual rotavirus-attributable deaths (95% CI 169 561 to 259 216), 62 853 Shigella-attributable deaths (95% CI 48 656 to 78 805), 36 922 adenovirus 40/41-attributable deaths (95% CI 28 469 to 46 672) and 35 914 norovirus-attributable deaths (95% CI 27 258 to 46 516). CONCLUSIONS: Despite the substantial impact of rotavirus vaccine introduction, rotavirus remained the leading cause of paediatric diarrhoea hospitalisations. Improving the efficacy and coverage of rotavirus vaccination and prioritising interventions against Shigella, norovirus and adenovirus could further reduce diarrhoea morbidity and mortality.

The Global Landscape of Pediatric Bacterial Meningitis Data Reported to the World Health Organization-Coordinated Invasive Bacterial Vaccine-Preventable Disease Surveillance Network, 2014-2019.

BACKGROUND: The World Health Organization (WHO) coordinates the Global Invasive Bacterial Vaccine-Preventable Diseases (IB-VPD) Surveillance Network to support vaccine introduction decisions and use. The network was established to strengthen surveillance and laboratory confirmation of meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis. METHODS: Sentinel hospitals report cases of children <5 years of age hospitalized for suspected meningitis. Laboratories report confirmatory testing results and strain characterization tested by polymerase chain reaction. In 2019, the network included 123 laboratories that follow validated, standardized testing and reporting strategies. RESULTS: From 2014 through 2019, >137 000 suspected meningitis cases were reported by 58 participating countries, with 44.6% (n = 61 386) reported from countries in the WHO African Region. More than half (56.6%, n = 77 873) were among children <1 year of age, and 4.0% (n = 4010) died among those with reported disease outcome. Among suspected meningitis cases, 8.6% (n = 11 798) were classified as probable bacterial meningitis. One of 3 bacterial pathogens was identified in 30.3% (n = 3576) of these cases, namely S. pneumoniae (n = 2177 [60.9%]), H. influenzae (n = 633 [17.7%]), and N. meningitidis (n = 766 [21.4%]). Among confirmed bacterial meningitis cases with outcome reported, 11.0% died; case fatality ratio varied by pathogen (S. pneumoniae, 12.2%; H. influenzae, 6.1%; N. meningitidis, 11.0%). Among the 277 children who died with confirmed bacterial meningitis, 189 (68.2%) had confirmed S. pneumoniae. The proportion of pneumococcal cases with pneumococcal conjugate vaccine (PCV) serotypes decreased as the number of countries implementing PCV increased, from 77.8% (n = 273) to 47.5% (n = 248). Of 397 H. influenzae specimens serotyped, 49.1% (n = 195) were type b. Predominant N. meningitidis serogroups varied by region. CONCLUSIONS: This multitier, global surveillance network has supported countries in detecting and serotyping the 3 principal invasive bacterial pathogens that cause pediatric meningitis. Streptococcus pneumoniae was the most common bacterial pathogen detected globally despite the growing number of countries that have nationally introduced PCV. The large proportions of deaths due to S. pneumoniae reflect the high proportion of meningitis cases caused by this pathogen. This global network demonstrated a strong correlation between PCV introduction status and reduction in the proportion of pneumococcal meningitis infections caused by vaccine serotypes. Maintaining case-based, active surveillance with laboratory confirmation for prioritized vaccine-preventable diseases remains a critical component of the global agenda in public health.The World Health Organization (WHO)-coordinated Invasive Bacterial Vaccine-Preventable Disease (IB-VPD) Surveillance Network reported data from 2014 to 2019, contributing to the estimates of the disease burden and serotypes of pediatric meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis.

Rotavirus vaccine effectiveness and impact in Uzbekistan, the first country to introduce in central Asia.

Uzbekistan, the most populous country in central Asia, was the first in the region to introduce rotavirus vaccine into its national immunization program. Rotarix (GlaxoSmithKline Biologicals, RV1) was introduced in June 2014, with doses recommended at age 2 and 3 months. To evaluate vaccine impact, active surveillance for rotavirus diarrhea was reestablished in 2014 at 2 hospitals in Tashkent and Bukhara which had also performed surveillance during the pre-vaccine period 2005-2009. Children aged <5 y admitted with acute diarrhea had stool specimens collected and tested for rotavirus by enzyme immunoassay. Proportions testing rotavirus-positive in post-vaccine years were compared with the pre-vaccine period. Vaccine records were obtained and effectiveness of 2 RV1 doses vs 0 doses was estimated using rotavirus-case and test-negative design among children enrolled from Bukhara city. In 2015 and 2016, 8%-15% of infants and 10%-16% of children aged<5 y hospitalized with acute diarrhea at the sites tested rotavirus-positive, compared with 26% of infants and 27% of children aged<5 y in pre-vaccine period (reductions in proportion positive of 42%-68%, p <.001). Vaccine effectiveness of 2 RV1 doses vs 0 doses in protecting against hospitalization for rotavirus disease among those aged ≥6 months was 51% (95% CI 2-75) and is based on cases predominantly of genotype G2P[4]. Vaccine effectiveness point estimates tended to be higher against cases with higher illness severity (e.g., clinical severity based on modified Vesikari score ≥11). Our data demonstrate that the monovalent rotavirus vaccine is effective in reducing the likelihood of hospitalization for rotavirus disease in young children in Uzbekistan.

Global impact of rotavirus vaccine introduction on rotavirus hospitalisations among children under 5 years of age, 2008-16: findings from the Global Rotavirus Surveillance Network.

BACKGROUND: Rotavirus vaccine use in national immunisation programmes has led to declines in hospital admissions for rotavirus gastroenteritis among children; however, the global impact of rotavirus vaccine introduction has not been described using primary data. We describe the impact of rotavirus vaccine introduction on admissions for acute rotavirus gastroenteritis in primarily low-income and middle-income countries, using 9 years of data from the WHO-coordinated Global Rotavirus Surveillance Network (GRSN). METHODS: Between Jan 1, 2008, and Dec 31, 2016, children younger than 5 years of age who were admitted to hospital with acute gastroenteritis were prospectively enrolled in GRSN sites. We included sites that enrolled children and collected stool specimens monthly and tested at least 100 specimens annually in the impact analysis, with a separate analysis taking into account site continuity. We compared proportions of acute gastroenteritis cases positive for rotavirus in the pre-vaccine and post-vaccine periods and calculated mean proportion changes for WHO regions, with 95% CIs; these findings were then compared with interrupted time series analyses. We did further sensitivity analyses to account for rotavirus vaccination coverage levels and sites that collected specimens for at least 11 months per year and tested at least 80 specimens per year. We also analysed the age distribution of rotavirus-positive cases before and after vaccine introduction. FINDINGS: 403 140 children younger than 5 years of age admitted to hospital with acute gastroenteritis from 349 sites in 82 countries were enrolled over the study period, of whom 132 736 (32·9%) were positive for rotavirus. We included 305 789 children from 198 sites in 69 countries in the impact analysis. In countries that had not introduced rotavirus vaccine in their national immunisation programmes, rotavirus was detected in 38·0% (95% CI 4·8-73·4) of admissions for acute gastroenteritis annually whereas in those that have introduced the vaccine, rotavirus was detected in 23·0% (0·7-57·7) of admissions for acute gastroenteritis, showing a 39·6% (35·4-43·8) relative decline following introduction. Interrupted time series analyses confirmed these findings. Reductions by WHO regions ranged from 26·4% (15·0-37·8) in the Eastern Mediterranean Region to 55·2% (43·0-67·4) in the European Region and were sustained in nine countries (contributing up to 31 sites) for 6-10 years. The age distribution of children with rotavirus gastroenteritis shifted towards older children after rotavirus vaccine introduction. INTERPRETATION: A significant and sustained reduction in the proportion of hospital admissions for acute gastroenteritis due to rotavirus was seen among children younger than 5 years in GRSN sites following rotavirus vaccine introduction. These findings highlight the need to incorporate rotavirus vaccines into immunisation programmes in countries that have not yet introduced them and underline the importance of high-quality surveillance. FUNDING: The GRSN receives funding from Gavi, the Vaccine Alliance and the US Centers for Disease Control and Prevention. No specific funding was provided for this Article.

Global invasive bacterial vaccine-preventable diseases surveillance--2008-2014.

Meningitis and pneumonia are leading causes of morbidity and mortality in children globally infected with Streptococcus pneumoniae (pneumococcus), Neisseria meningitidis, and Haemophilus influenzae causing a large proportion of disease. Vaccines are available to prevent many of the common types of these infections. S. pneumoniae was estimated to have caused 11% of deaths in children aged <5 years globally in the pre-pneumococcal conjugate vaccine (PCV) era. Since 2007, the World Health Organization (WHO) has recommended inclusion of PCV in childhood immunization programs worldwide, especially in countries with high child mortality. As of November 26, 2014, a total of 112 (58%) of all 194 WHO member states and 44 (58%) of the 76 member states ever eligible for support from Gavi, the Vaccine Alliance (Gavi), have introduced PCV. Invasive pneumococcal disease (IPD) surveillance that includes data on serotypes, along with meningitis and pneumonia syndromic surveillance, provides important data to guide decisions to introduce PCV and monitor its impact.

Viral gastroenteritis in rotavirus negative hospitalized children <5 years of age from the independent states of the former Soviet Union.

PURPOSE: Rotavirus causes nearly 40% of all hospitalizations for AGE among children <5 years of age in the NIS of the former Soviet Union. The etiologic role of other established gastroenteritis viruses in this age group is unknown. METHODS: Laboratory-confirmed rotavirus negative fecal specimens (N=495) collected between January and December 2009 from children in 6 NIS (Armenia, Azerbaijan, Belarus, Georgia, Republic of Moldova and Ukraine) were tested for norovirus, sapovirus, enteric adenovirus and astrovirus by real-time RT-PCR. Genotyping was carried out by sequencing and phylogenetic analysis. RESULTS: Norovirus, enteric adenovirus, sapovirus and astrovirus were detected in 21.8%, 4.0%, 3.2%, and 1.4% of the rotavirus negative specimens, respectively. Mixed infections were identified in 4.1% of the specimens. Phylogenetic analysis showed co-circulation of several different genotypes with GII.4 Den Haag (2006b) norovirus, GI.2 sapovirus, adenovirus type 41, and astrovirus type 1 causing majority of the infections. CONCLUSION: Norovirus, enteric adenovirus, sapovirus and astrovirus account for a significant proportion (30.5%) of AGE in hospitalized children <5 years of age in 6 NIS.

Rotavirus genotypes in Belarus, 2008-2012.

This study describes group A rotavirus (RVA) genotype prevalence in Belarus from 2008 to 2012. In 2008, data from 3 sites in Belarus (Brest, Mogilev, Minsk) indicated that G4P[8] was the predominant genotype. Data from Minsk (2008-2012) showed that G4P[8] was the predominant RVA genotype in all years except in 2011 when G3P[8] was most frequently detected. Other RVA genotypes common in Europe (G1P[8], G2P[4]) were detected each year of the study. This study reveals the dominance of genotype G4P[8] in Belarus and helps to establish the baseline genotype prevalence prior to RVA vaccine introduction in the country.