Evaluation of the detection of diarrhoea-associated RNA viruses in immunocompromised children in Iran

Background

Gastroenteritis accounts for about 10% of the deaths among children, especially in immunocompromised children. Few studies on the prevalence of gastrointestinal infections caused by RNA viruses have been done in Iran. The aim of the study was to evaluate the detection of RNA viruses causing diarrhoea using a multiplex PCR.

Methods

Stool samples were collected from 130 paediatric patients with diarrhoea who had acute lymphocytic leukaemia, non-Hodgkin lymphoma, and retinoblastoma. After RNA extraction and synthesis of cDNA, multiplex PCR was done to evaluate the presence of rotavirus, norovirus, astrovirus, and enterovirus.

Results

There were 9 (6.9%), 7 (5.4%), 3 (2.3%), and 6 (4.6%) cases of rotavirus, norovirus, astrovirus, and enterovirus detected, respectively. One case of co-infection with astrovirus and norovirus was observed.

Conclusions

This is the first report from Iran which identified the presence of common RNA viruses causing diarrhoea in immunocompromised children. Increased awareness of these viruses will enable healthcare professionals to improve strategies and policies to control spread and infection caused by these viruses.

Circulating rotavirus strains in children with acute gastroenteritis in Iran, 1986 to 2023 and their genetic/antigenic divergence compared to approved vaccines strains (Rotarix, RotaTeq, ROTAVAC, ROTASIIL) before mass vaccination: Clues for vaccination policy makers

In the present study, first, rotaviruses that caused acute gastroenteritis in children under five years of age during the time before the vaccine was introduced in Iran (1986 to 2023) are reviewed. Subsequently, the antigenic epitopes of the VP7 and VP4/VP8 proteins in circulating rotavirus strains in Iran and that of the vaccine strains were compared and their genetic differences in histo-blood group antigens (HBGAs) and the potential impact on rotavirus infection susceptibility and vaccine efficacy were discussed. Overall data indicate that rotavirus was estimated in about 38.1 % of samples tested. The most common genotypes or combinations were G1 and P[8], or G1P[8]. From 2015 to 2023, there was a decline in the prevalence of G1P[8], with intermittent peaks of genotypes G3P[8] and G9P[8]. The analyses suggested that the monovalent Rotarix vaccine or monovalent vaccines containing the G1P[8] component might be proper in areas with a similar rotavirus genotype pattern and genetic background as the Iranian population where the G1P[8] strain is the most predominant and has the ability to bind to HBGA secretors. While the same concept can be applied to RotaTeq and RotasIIL vaccines, their complex vaccine technology, which involves reassortment, makes them less of a priority. The ROTASIIL vaccine, despite not having the VP4 arm (P[5]) as a suitable protection option, has previously shown the ability to neutralize not only G9-lineage I strains but also other G9-lineages at high titers. Thus, vaccination with the ROTASIIL vaccine may be more effective in Iran compared to RotaTeq. However, considering the rotavirus genotypic pattern, ROTAVAC might not be a good choice for Iran. Overall, the findings of this study provide valuable insights into the prevalence of rotavirus strains and the potential effectiveness of different vaccines in the Iranian and similar populations.

Prevalence and genotypes of group A rotavirus among outpatient children under five years old with diarrhea in Beijing, China, 2011-2016

BACKGROUND

Rotavirus is a leading cause of severe diarrheal disease, and one of the common causes of death in children aged under five years old. The dominant epidemic strains may change in different years in the same area. In order to provide evidence for rotavirus epidemic control and inform vaccine development, we analyzed epidemiological patterns and genetic characteristics of rotavirus in Beijing during 2011-2016.

METHODS

Stool specimens of outpatient children under five years old were collected from three children's hospitals on a weekly basis. Group A rotavirus antigens were detected using enzyme-linked immunosorbent assay (ELISA) kit. The partial VP4 genes and VP7 genes of rotavirus were both amplified and sequenced. Genotyping and phylogenetic analyses were performed. Logistic regression and Chi-square tests were performed to determine differences across age groups, districts and years in rotavirus prevalence and genotype distribution.

RESULTS

A total of 3668 stool specimens from children with acute diarrhea identified through hospital-based surveillance were collected from 2011 to 2016 in Beijing. A total of 762 (20.8%) specimens tested positive for rotavirus. The rotavirus-positive rate was highest among the 1-2 years old age group (29.0%, 310/1070). November, December and January were the highest rotavirus-positive rate months each year. G9 was the most common G genotype (64.4%, 461/716), and P [8] was the most common P genotype (87.0%, 623/716) among the 716 rotavirus-positive specimens. G9P [8], G3P [8] and G2P [4] were the most common strains. The rotavirus-positive rates of samples in 2012 and 2013 were higher than that in 2011, and the dominant genotype changed from G3P [8] to G9P [8] in 2012 and 2013. VP7 gene sequences of G9 strains in this study clustered into two main lineages. Most of the G9 strains exhibited the highest nucleotide similarity (99.1%~ 100.0%) to the strain found in Japan (MI1128). VP4 gene sequences of P [8] strains were almost P[8]b.

CONCLUSIONS

Rotavirus accounted for more than one fifth of childhood diarrhea in Beijing during the study period. Targeted measures such as immunization with effective rotavirus vaccines should be carried out to reduce the morbidity and mortality due to rotavirus.

Update on the epidemiology of rotavirus in the Middle East and North Africa

Rotavirus (RV) is the leading cause of severe acute gastroenteritis (AGE) worldwide. Consequently, we conducted a systematic literature review on articles studying RV in the 25 countries of the MENA region during the past 15years (2000-2015). The methods and reporting were set according to the 2015 preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) and based on the elements from the international prospective register of systematic reviews (PROSPERO). Our literature search identified 169 studies meeting our predefined inclusion criteria. Studies reporting on RV were conducted in 19 out of the 24 countries of the MENA region. The largest number of studies was reported in Turkey (n=32), Iran (n=31), Saudi Arabia (n=19) and Egypt (n=17). The majority of studies reporting on RV gastroenteritis rates were clinical observational studies. In 115 studies out of 169, RV was reported among in-patients whereas 35 studies reported RV among outpatients. The predominantly reported RV genotype in the region was G1[P8] followed by G2[P4] and G9[P8]. The majority of studies (n=108) were conducted among children less than 5years of age whereas the remaining studies reported on AGE among other age groups and rarely adults. In MENA countries, RV infection was reported all year round with peaks described in cold as well as hot months. This systematic review provides a current update on the epidemiology of RV-associated gastroenteritis in countries of the MENA region and draws attention to the major gaps existing in the continuous monitoring of RV.

Cost-effectiveness analysis of the introduction of rotavirus vaccine in Iran

BACKGROUND

Although the mortality from diarrheal diseases has been decreasing dramatically in Iran, it still represents an important proportion of disease burden in children <5 years old. Rotavirus vaccines are among the most effective strategies against diarrheal diseases in specific epidemiological conditions. This study aimed to evaluate the cost-effectiveness of the introduction of rotavirus vaccine (3 doses of pentavalent RotaTeq (RV5)) in Iran, from the viewpoints of Iran's health system and society.

METHODS

The TRIVAC decision support model was used to calculate total incremental costs, life years (LYs) gained, and disability-adjusted life years (DALYs) averted due to the vaccination program. Necessary input data were collected from the most valid accessible sources as well as a systematic review and meta-analysis on epidemiological studies. We used WHO guidelines to estimate vaccination cost. An annual discount rate of 3% was considered for both health gain and costs. A deterministic sensitivity analysis was performed for testing the robustness of the models results.

RESULTS

Our results indicated that total DALYs potentially lost due to rotavirus diarrhea within 10 years would be 138,161, of which 76,591 could be prevented by rotavirus vaccine. The total vaccination cost for 10 cohorts was estimated to be US$ 499.91 million. Also, US$ 470.61 million would be saved because of preventing outpatient visits and inpatient admissions (cost-saving from the society perspective). We estimated a cost per DALY averted of US$ 2868 for RV5 vaccination, which corresponds to a highly cost-effective strategy from the government perspective. In the sensitivity analysis, all scenarios tested were still cost-saving or highly cost-effective from the society perspective, except in the least favorable scenario and low vaccine efficacy and disease incidence scenario.

CONCLUSION

Based on the findings, introduction of rotavirus vaccine is a highly cost-effective strategy from the government perspective. Introducing the vaccine to the national immunization program is an efficient use of available funds to reduce child mortality and morbidity in Iran.

Prevalence and correlates for diarrhoea in the mountainous informal settlements of Huye town, Rwanda

Dwellers of urban informal settlements in developing countries are consistently reported to be victims of high diarrhoea prevalence. Studies have frequently reported the association between high diarrhoea prevalence and other factors, such as poor living conditions, inadequate hygiene, and sanitation in these settings. However, little is known about the dynamics of diarrhoea prevalence in mountainous urban informal settlements similar to the Rwandan context. This study was conducted in the Matyazo cell of Huye town to review the prevalence and correlates of diarrhoea. A survey of 214 households and transect walks in the neighbourhoods were conducted during the rainy and dry seasons. Logistic regression was used to analyse the survey data while the thematic analysis technique was used to analyse qualitative data. Results indicated a substantial reduction of diarrhoea prevalence from the rainy to the dry season. It was also found that the prevalence was unequally distributed in the neighbourhoods according to household location. After controlling for other household characteristics and sanitation conditions of around homes, the study indicated that households established at 1800 metres or more above sea level were protected against diarrhoea during both rainy seasons (Adjusted Odds Ratio_ AOR: .42, 95% Confidence Interval_ CI: .13-.81) and dry seasons (AOR: .58, CI: .12-.90) while households found further from the road were likely to suffer from diarrhoea during rainy seasons (AOR: 3.32, CI: 1.47-7.48) as well as in dry seasons (AOR: 1.60, CI: 1.26-4.10). Poor sanitation within and around homes was also found to be associated with the increase of diarrhoea in either season. However, the evidence was not sufficient enough to confirm a significant association between diarrhoea prevalence and other household characteristics. We believe this is due to the strength of environmental factors in mountainous settings.

Epidemiology of viral gastroenteritis in Iran

Viruses are prominent causative agents of acute gastroenteritis in children <5 years of age per year. In the present review, all viral gastroenteritis studies in Iran were assessed, and the mean prevalences of rotaviruses, noroviruses, enteric adenoviruses, sapoviruses and astroviruses associated with acute gastroenteritis were 39.9%, 6%, 5.7%, 4.2% and 2.7%, respectively. In 2 studies, human bocavirus and human parechovirus were detected in 21.8% and 23.7% of children with acute gastroenteritis, respectively.