[Epidemiology of rotavirus gastroenteritis among children under 5 years of age in Tunisia - results of sentinel hospital surveillance 2009 to 2011]

Genetic Profile of Rotavirus Type A in Children under 5 Years Old in Africa: A Systematic Review of Prevalence

Human type A rotavirus (RV-A) is world-recognized as the major pathogen causing viral gastroenteritis in children under 5 years of age. The literature indicates a substantial increase in the diversity of rotavirus strains across continents, especially in Africa, which can pose significant challenges including an increase of disease burden and a reduction of vaccines' effectiveness. However, few studies have mapped the variety of circulating virus strains in different regions, which may hamper decisions on epidemiological surveillance and preventive public health measures. Thus, our aim was to compile the most updated available evidence on the genetic profile of RV-A among children in Africa and determine the prevalence of different genotypes according to the geographical regions by means of a broad systematic review. Systematic searches were performed in PubMed, Scopus, Web of Science, and Scielo without language, time limits, or geographical restrictions within the African continent. We selected full-text peer-reviewed articles assessing the genetic profile (i.e., genotyping) of RV-A in children up to 5 years old in Africa. Overall, 682 records were retrieved, resulting in 75 studies included for evidence synthesis. These studies were published between 1999 and 2022, were conducted in 28 countries from the five African regions, and 48% of the studies were carried out for 24 months or more. Most studies (n = 55; 73.3%) evaluated RV-A cases before the introduction of the vaccines, while around 20% of studies (n = 13) presented data after the vaccine approval in each country. Only seven (9.3%) studies compared evidence from both periods (pre- and post-vaccine introduction). Genotyping methods to assess RV-A varied between RT-PCR, nested or multiplex RT-PCR, testing only the most common P and G-types. We observed G1 and P[8] to be the most prevalent strains in Africa, with values around 31% and 43%, respectively. Yet if all the genotypes with the following highest prevalence were added ((G1 + G2, G3, G9) and (P[8] + P[6], P[4])), these figures would represent 80% and 99% of the total prevalence. The combination G1P[8] was the most reported in the studies (around 22%). This review study demonstrated an increased strain diversity in the past two decades, which could represent a challenge to the efficacy of the current vaccine.

Global Estimates of Rotavirus Hospitalizations Among Children Below 5 Years in 2019 and Current and Projected Impacts of Rotavirus Vaccination

BACKGROUND

Rotavirus vaccine impact on rotavirus hospitalizations is not well documented globally. We performed a systematic review to estimate the number of rotavirus hospitalizations that (1) occur annually, (2) are currently prevented by rotavirus vaccines, and (3) could be prevented with improved vaccine coverage and universal vaccine introduction.

METHODS

We systematically reviewed articles indexed in the PubMed database published from January 1, 2000, to December 31, 2019. We included all primary peer-reviewed studies with rotavirus hospitalization rates for children below 5 years that reported data prior to vaccine introduction, utilized at least one continuous year of data collection, and collected hospitalization data after 2000 using active surveillance. We grouped pre-vaccine country estimates by childhood mortality strata and calculated the median rate among each group. We then assigned the mortality stratum-specific hospitalization rates to each country and calculated the number of rotavirus hospitalizations by country, mortality strata, and World Health Organization region.

RESULTS

Our search strategy identified 4590 manuscripts, of which 32 were included in the final dataset. In 2019, an estimated 1 760 113 (interquartile range [IQR]: 1 422 645-2 925 372) rotavirus hospitalizations occurred globally, with 524 871 (IQR: 415 987-814 835) prevented by rotavirus vaccination. With universal introduction of rotavirus vaccines and increased vaccine coverage, we estimate that an additional 751 609 (IQR: 607 671-1 318 807) rotavirus hospitalizations can be prevented annually.

CONCLUSIONS

This analysis highlights the continued burden of rotavirus hospitalizations among children below 5 years. A large, preventable proportion of this burden could be eliminated by expanding introductions to new countries and increasing rotavirus vaccine coverage to levels seen with other childhood vaccinations.

Systematic review of the rotavirus infection burden in the WHO-EMRO region

Rotavirus gastroenteritis imposes a heavy burden on low- and middle-income countries. The World Health Organization defines the Eastern Mediterranean region (WHO-EMRO) as a diverse area in terms of socioeconomic status and health indicators. Rotavirus vaccination has been introduced, at least partially, in 19 out of the 22 EM countries; however, vaccine coverage remains low, and data on rotavirus disease burden is scarce.Available data on rotavirus prevalence, seasonality, vaccination status, and genotype evolution was systematically compiled following a literature review that identified 165 relevant WHO-EMRO epidemiology studies published between 1990 and 2017.Although the infectious agents responsible for acute gastroenteritis vary over time, rotavirus remained the leading cause of acute gastroenteritis in children, as seen in 76.3% of reviewed publications. Younger children (<2 years old) were at higher risk and thus increased vaccination coverage and surveillance systems are required to reduce the rotavirus gastroenteritis burden in WHO-EMRO countries.

Circulating rotavirus G and P strains post rotavirus vaccination in Eastern Mediterranean Region

OBJECTIVE

To detect changes in circulating strains of rotavirus in the Eastern Mediterranean Region post rotavirus immunization drive.

METHODS

We searched MEDLINE, PubMed, ScienceDirect, and the Cochrane Library and specific database website (Nutrition and Food Sciences) for relevant articles. Our search included websites of a number of relevant organizations in addition to gray literature search. Of the 2198 articles found, we included only 35 studies after excluding irrelevant, ineligible, duplicated, and very low-quality papers.

RESULTS

Thirty pre-vaccination studies reported frequent rotavirus strains among children below 5 years of age. G1P[8] has been identified as the most dominant type prior to vaccination in Eastern Mediterranean Region (EMR) countries. Five post-vaccination studies conducted in 3 countries (Saudi Arabia, Morocco, and Yemen) illustrated that G1P[8] is the most prevalent strain in Saudi Arabia, and the incidence of G2P[4] has increased from 21.6% to 33.3%. In Yemen, G1P[4] is the most prevalent strain (87.5%), followed by G9P[8] (57%) and G1P[8] (18.5%). Furthermore, in Yemen, G9P[8] were the most prevalent strains accounting to 57% and 14% in G9P[4], post vaccination. Finally, in Morocco, G1P[8] was not reported 3 years post vaccination; however, incidence of G9P[8] was reported at 67% and G2P[4] at 33%.

CONCLUSIONS

Rotavirus circulating strain prevalence in EMR countries has changed post vaccination, and G9P[8], G2P[4], and G9P[4] have become more dominant. Proportion of rotavirus strains in these countries after vaccination has significantly reduced. There is an increase in circulating strain G2P[4] in the post-vaccination period, which needs further monitoring.

Molecular Epidemiology of Rotavirus Strains in Under Five Children

OBJECTIVES

To determine the prevalence and genotype distribution of rotaviruses in children presenting to authors' hospital in Middle Black Sea region of Turkey. The results may supply important information about vaccine studies in Turkey.

METHODS

Rotavirus antigen was detected by latex agglutination test and rotavirus RNA was detected by RT-PCR test. On the other hand, rotavirus positive samples were genotyped by semi-nested multiplex polymerase chain reaction.

RESULTS

The highest rate of rotavirus positivity (46.9%) was observed among children in the 13 to 24 mo age group. All the positive-strains were in G1-4, G8-9, P [4], P [8], and P [9] genotypes. The most common G and P combination in present study was G9P[8] (n = 24, 28.9%).

CONCLUSIONS

The present results indicated that the most prevalent genotypes were G1, G9, P8, G9P[8] and G1P[8] in authors' region. Rotavirus vaccines used in this region must include mainly these genotypes.

Removal of Rotavirus and Bacteriophages by Membrane Bioreactor Technology from Sewage

Human enteric viruses constitute a public health concern due to their low infectious dose and their resistance to environmental factors and to inactivation processes. We aimed at assessing the performance of a laboratory scale Submerged membrane bioreactor (SMBR) treating abattoir wastewaters for Rotavirus (RV) and total coliphages removal. We also aimed at evaluating removal efficiency of enteric viruses through conventional activated sludge treatment by measuring concentrations of total coliphages, considered as fecal and viral contamination indicators, with double-layer agar technique. The Log10 reduction values of bacteriophages ranged from 1.06 to 1.47. Effluents were analyzed to investigate and quantify RV, hepatitis A virus (HAV), Hepatitis E virus (HEV), Noroviruses genogroup I (NoV GI) and genogroup II (NoVGII), and Enterovirus (EV) by real-time PCR, using standardized detection kits (ceeramTools detection kits(®)). All effluent samples were positive for RV; concentrations ranged from 5.2 × 10(5) to 1.3 × 10(7) genome copies/L. These results highlight the inefficiency of conventional biological process for viral removal. A complete removal of RV during Membrane Bioreactor treatment was obtained. To the best of our knowledge, this is the first study providing an evidence of removal of RV simultaneously with total coliphages by SMBR.

Rotavirus infection among Sudanese children younger than 5 years of age: a cross sectional hospital-based study

Introduction

In Sudan, rotavirus has been one of the important causative agents of diarrhea among children. Rotavirus A is well known as the leading cause of diarrhea in young children worldwide. It was estimated to account for 41% of hospitalized cases of acute gastroenteritis among children in Sub-Saharan Africa. This study aimed to determine the prevalence and the common clinical presentations of rotavirus A infection among Sudanese children with gastroenteritis seeking management in hospitals.

Methods

755 Sudanese children less than 5 years of age suffering from acute gastroenteritis in hospital settings were included. The positive stool specimens for rotavirus A was used for extract Ribonucleic acid (RNA) and the RNA product was loaded on formaldehyde agarose gel and visualized under UV illumination.

Results

Of the 755 children, 430(57%) were males while 325(43%) were female. The age of children ranged from 1 to 60 months. There were 631 (84%) children who were less than 24 months of age. Out of the 755 stool samples, 121(16%) were positive for rotavirus. Of the 121 infected children with rotavirus, 79(65.3%) were male and 42(34.7%) were female and the highest infection rate was seen among 91(75.2%) of children up to 12 months of age. Children of illiterate parents were more infected with rotavirus than children of educated parents. Severe dehydration present among 70% of infected children with rotavirus.

Conclusion

Since this study is hospital-based, the 16% prevalence rate may not reflect the true prevalence among Sudanese children, thus a community-based surveillance is needed.

Sequence and phylogenetic analyses of human rotavirus strains: comparison of VP7 and VP8(∗) antigenic epitopes between Tunisian and vaccine strains before national rotavirus vaccine introduction

Group A rotaviruses (RVA) are the leading cause of severe gastroenteritis in infants and young children worldwide. Due to their epidemiological complexity, it is important to compare the genetic characteristics of vaccine strains with the RVA strains circulating before the introduction of the vaccine in the Tunisian immunization program. In the present study, the nucleotide sequences of VP7 and VP8∗ (n=31), the main targets for neutralizing antibodies, were determined. Comparison of antigenic epitopes of 11 G1P[8], 12 G2P[4], 4 G3P[8], 2 G4P[8], 1 G6P[9] and 1 G12P[8] RVA strains circulating in Tunisia from 2006 to 2011 with the RVA strains present in licensed vaccines showed that multiple amino acid differences existed in or near putative neutralizing domains of VP7 and VP8∗. The Tunisian G3 RVA strains were found to possess a potential extra N-linked glycosylation site. The Tunisian G4 RVA were closely related to the G4 vaccine strain in RotaTeq, belonging to the same lineage, but the alignment of their VP7 amino acids revealed an insertion of an asparagine residue at position 76 which is close to a glycosylation site (aa 69-71). Despite several differences detected between Tunisian and vaccine strains, which may affect binding of neutralizing antibodies, both vaccines are known to protect against the vast majority of the circulating genotypes, providing an indication of the high vaccine efficiency that can be expected in a future rotavirus immunization program.