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.

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.

Rotavirus hospitalizations among children <5 years of age-Tajikistan, 2013-2014.

BACKGROUND: In January 2015, Tajikistan introduced the monovalent rotavirus vaccine into the national immunization program. Our objective was to estimate pre-vaccine burden of rotavirus-associated hospitalizations in children <5 years of age in Tajikistan. METHODS: During January 2013-December 2014, active surveillance for acute gastroenteritis (AGE)-associated hospitalizations in children <5 years of age was conducted by sentinel surveillance site staff. Patients' demographic and clinical data were summarized and a stool sample was collected. An Enzyme Linked Immunosorbent Assay was used for diagnosis of rotavirus infection and subset of the specimens was sent for polymerase chain reaction (PCR) genotyping. RESULTS: Of 2860 eligible children enrolled and tested, 1207 (42%) were positive for rotavirus. An increase in the number and proportion of rotavirus cases attributed to rotavirus season, with positivity rates >40%, was annually observed during June-September. The median age of rotavirus patients was 9 months and 939/1207 (78%) rotavirus patients were aged 6-23 months. Most (1097/1203; 91%) rotavirus patients were treated with intravenous fluids. G1P[8] was the predominant genotype during both years of surveillance, accounting for 133/222 (60%) of genotyped cases. CONCLUSION: Rotavirus is a major cause of hospitalization due to severe AGE in children <5 years of age in Tajikistan, accounting for >40% of cases. Continued, enhanced rotavirus surveillance may allow documentation of changes in rotavirus disease burden following vaccine introduction and assessment of vaccine effectiveness.

Rotavirus gastroenteritis surveillance in Azerbaijan, 2011-2016.

INTRODUCTION: Rotavirus is a leading cause of acute gastroenteritis and mortality among children worldwide but data describing rotavirus disease in Azerbaijan are lacking. This analysis describes the rotavirus disease burden in Baku, the largest city in Azerbaijan. METHODS: We conducted active, prospective, sentinel hospital surveillance with laboratory confirmation for rotavirus among children under 5 years of age hospitalized at a large pediatric hospital in Baku during 2011-2016. Children with bloody diarrhea, or prior use of antibiotics or intravenous fluids were excluded. The guardians of enrolled children completed a questionnaire documenting clinical and demographic information. A stool specimen was collected from each enrolled child. We report the number and proportion of rotavirus positive hospitalizations during the surveillance period and a clinical description of rotavirus-positive and rotavirus-negative children. RESULTS: From July 2011 through June 2016, 3139 children <5 years of age were enrolled into the surveillance system. Of these, 523 (17%) were positive for rotavirus, varying from 13% to 21% by surveillance year, with a median of 16% over the surveillance period. Increase in rotavirus detections occurred during December-May. Most rotavirus infections (303/523; 58%) occurred in children aged 6-23 months. CONCLUSION: Rotavirus is responsible for approximately 16% of annual hospital admissions for acute gastroenteritis in children <5 years of age in Baku. This is lower than regional estimates. Exclusion of children with a history of antibiotic use or intravenous fluids may be accounting for this lower prevalence, and expansion of surveillance to include these groups could provide a more comprehensive picture of acute rotavirus gastroenteritis in Baku.

Observations on the epidemiology of rotavirus infection among hospitalized children younger than 5 years in 2 Ukrainian hospitals, 2007-2015.

BACKGROUND: Acute gastroenteritis remains a burden among children under 5 years of age. Ukraine joined the World Health Organization's Global Rotavirus Surveillance Network in 2006, with a goal of providing accurate rotavirus burden data to aid policy makers in planning for rotavirus vaccine introduction. This analysis describes rotavirus epidemiology among Ukrainian children enrolled in Kyiv and Odesa, two large Ukrainian cities. METHODS: Children 0-59 months of age hospitalized for acute gastroenteritis at 2 sentinel sites in Kyiv and Odesa were enrolled into the active, prospective surveillance program. In Odesa, the surveillance period was during 2007-2015 and in Kyiv, it was during 2011-2015. Acute gastroenteritis was defined as 3 or more episodes of diarrhea per day during a 24 h period, with symptom duration before hospitalization not exceeding 7 days. Guardians of enrolled children completed a questionnaire including demographic, clinical and treatment information. Each child provided a stool specimen within 2 days of hospitalization. Stools were tested for rotavirus using ProSpecT™ Rotavirus Kit (Oxoid Ltd., Great Britain), and positive specimens were genotyped. Descriptive data are reported, as well as comparison of demographic, clinical and treatment data among rotavirus positive and negative children. RESULTS: During July 2007-June 2015, 12,350 children were enrolled in the surveillance programs and had stool specimens collected and tested for rotavirus. Overall, rotavirus infection was diagnosed in 5412/12350 (44%) of children, 929/1734 (54%) of those in Kyiv and 4483/10616 (42%) in Odesa. Rotavirus infections peaked during the winter months. Children with rotavirus acute gastroenteritis displayed more severe clinical symptoms than those without rotavirus. Predominant genotypes identified included G1P[8], G2P[4], G3 P[8], G4 P[8] and G9 P[8]. CONCLUSION: Active surveillance of acute gastroenteritis in hospitalized children younger 5 years in two large Ukrainian cities reveals a significant burden of rotavirus infection. These data provide scientific justification for incorporating rotavirus vaccines into the Ukrainian national immunization schedule.