Acute Gastroenteritis Morbidity and Mortality Trends Following Universal Rotavirus Vaccination in Children in Peru: Ecological Database Study with Time-Trend Analysis

Trends and spatial distribution of the burden of vaccine-preventable diseases in children under five in Brazil from 2000 to 2019

OBJECTIVE

To analyze mortality burden and spatial distribution of vaccine-preventable diseases in children under five in Brazil from 2000 to 2019.

STUDY DESIGN

Ecological study.

METHODS

Study using vaccination coverage data from 2000 to 2019 across 5570 Brazilian municipalities, and mortality estimates from the Global Burden of Disease 2019. Spatial analyses were conducted to identify statistically significant clusters (p < 0.05) and spatial autocorrelation.

RESULTS

There was a reduction in mortality from vaccine-preventable diseases in Brazil between 2000 and 2019. The North and Northeast regions showed high mortality rates and lower vaccination coverage compared to other regions.

CONCLUSIONS

Infant mortality in Brazil decreased significantly, especially after improvements in vaccination coverage. However, this reduction was not uniform, with the North and Northeast regions showing clusters of high mortality.

The prevalence of rotavirus infection among Congolese children younger than 5 years hospitalized for gastroenteritis 10 years after introduction of rotavirus vaccination

Objectives

Rotavirus A (RVA) remains the primary cause of acute severe gastroenteritis associated with high rates of childhood hospitalization and mortality worldwide. The prevalence of RVA infection varies within low-income countries. In addition, its genetic diversity may vary among regions and may affect its prevalence. To control the emergence of new strains of RVA circulating in the Republic of Congo, it is essential to know the diversity of both G and P genotypes, which could render the vaccine less effective. Therefore, this study aimed to determine the prevalence and genotype diversity of RVA strains in children who were hospitalized, whether vaccinated or not. Moreover, the potential risk factors of disease severity are identified.

Methods

The study was conducted from April 2022 to March 2023. Stool samples were collected from children younger than 5 years, hospitalized in a pediatric ward for acute gastroenteritis, and a commercial enzyme-linked immunosorbent assay (ELISA) was used to detect RVA cases. In parallel, a multiplex reverse transcription-polymerization chain reaction (RT-PCR) was performed for RVA detection and genotyping. All samples with ambiguous multiplex RT-PCR results were subjected to sequencing.

Results

A total of 227 children hospitalized were enrolled and tested for RVA infection. Using ELISA and PCR, 59 (26%) and 131 (57.7%) individuals were found to be infected with RVA, respectively. All individuals with a positive ELISA test result were confirmed as RVA-positive by PCR. Of the 98 children with documented histories of RVA vaccination, 60% presented with RVA infection. The occurrence of vomiting on more than three occasions within a 24-hour period and the time between vaccination and sample collection were found to be associated with RVA infection. RVA genotyping revealed six P types (P[4]; P[6]; P[8]; P[9]; P[10]; and P[11]). The predominant genotypes were (P[4] 15.3%; P[6] 13.7%; P[8] 22.1%; P[9] 14.5%). Among the eight G types, the most prevalent were G3 (13.7%), G4 (12.2%), and G1 (6.9%). No specific genotype distribution was discernible as a function of vaccination history.

Conclusions

Compared with the findings of our study before the implementation of rotavirus vaccination, in this report, we observed a roughly 20% decreased prevalence of RVA infection in children hospitalized. The results suggest that in Brazzaville at least, 10 years of rotavirus vaccination in the Republic of Congo have had a substantial effect, despite the reported reduced efficacy of the vaccines in low- and middle-income countries. The findings thus support enhanced efforts to increase coverage through national vaccination programs.

Etiologies of Mild and Moderate Diarrheal Illness among Children in Consuelo, Dominican Republic

Since the rotavirus vaccine was included in the Dominican Republic's national immunization schedule in 2012, the microbiologic etiologies of acute gastroenteritis have not been described. This study aimed to determine the contribution of rotavirus as an etiology of acute gastroenteritis over a 12-month period in children under 5 years of age in both an inpatient and an outpatient setting in Consuelo, Dominican Republic. All children who were seen at Niños Primeros en Salud clinic or admitted to Hospital Municipal Dr. Angel Ponce Pinedo for acute gastroenteritis during January 2021-April 2022 were enrolled in the study. Stools were evaluated for rotavirus, enteric parasites, and pathogenic bacteria. Pathogen detection was compared between outpatients and inpatients and on the basis of child's vaccination status. From 181 children enrolled, 170 stool samples were collected, 28 (16.5%) from inpatients and 142 (83.5%) from outpatients. Rotavirus was the most commonly detected pathogen and was proportionately more common among hospitalized children, with nine (32.1%) cases among hospitalized children and 16 (11.3%) among outpatient children. (Pearson χ2 = 8.1, P = 0.004). Among patients with a positive rotavirus result, vaccination rate was lower among moderate (hospitalized) (three of six; 50%) compared with mild (outpatient) diarrhea patients (12 of 15; 80%). Giardia lamblia (10%) was the next most prevalent pathogen detected in both inpatients and outpatients using standard laboratory measures. Despite the availability of rotavirus vaccination, rotavirus remains a common cause of gastrointestinal illness among children under 5 years of age in our cohort. Incomplete vaccination status was associated with hospitalization for gastrointestinal illness.

Impact of rotavirus vaccination on diarrheal disease burden of children in South America

INTRODUCTION

Rotavirus is a leading cause of severe diarrheal disease and death in children under five years of age worldwide. Vaccination is one of the most important public health interventions to reduce this significant burden.

AREAS COVERED

This literature review examined vaccination coverage, hospitalization rate, mortality, genotypic distribution, immunogenicity, cost-effectiveness, and risk versus benefit of rotavirus vaccination in children in South America. Nine out of twelve countries in South America currently include a rotavirus vaccine in their national immunization program with coverage rates in 2022 above 90%.

EXPERT OPINION

Introduction of the rotavirus vaccination has led to a marked reduction in hospitalizations and deaths from diarrheal diseases in children under 5 years, particularly infants under 1 year, in several South American countries. In Brazil, hospitalizations decreased by 59% and deaths by 21% (30-38% in infants). In Peru, hospitalizations in infants fell by 46% and deaths by 37% (56% in infants). Overall, data suggest that rotavirus vaccination has reduced rotavirus deaths by 15-50% in various South American countries. There is some evidence that immunity wanes after the age of 1-year old. Ongoing surveillance of vaccine coverage and changes in morbidity and mortality is important to maximize protection against this disease.