Molecular epidemiology of respiratory syncytial virus in children in sub-Saharan Africa

Molecular epidemiology of respiratory syncytial virus in children with acute respiratory illnesses in Africa: A systematic review and meta-analysis

Background

Globally, the respiratory syncytial virus (RSV) is the most common etiologic agent of acute respiratory illnesses in children. However, its burden has not been well addressed in developing countries. We aimed to estimate the molecular epidemiology of RSV in children less than 18 years of age with acute respiratory infections in Africa by conducting a systematic review and meta-analysis.

Methods

We systematically searched PubMed, Scopus, CINAHL, and Global Index Medicus databases to identify studies published from January 1, 2002, to April 27, 2022, following the PRISMA 2020 guideline. We assessed the study quality using the Joanna Brigg's Institute (JBI) critical appraisal checklists. We conducted a qualitative synthesis by describing the characteristics of included studies and performed the quantitative synthesis with random effects model using STATA-14. We checked for heterogeneity with Q statistics, quantified by I², and determined the prediction interval. We performed subgroup analyses to explain the sources of heterogeneity and assessed publication biases by funnel plots augmented with Egger's test.

Results

Eighty-eight studies with 105 139 participants were included in the review. The overall pooled prevalence of RSV in children <18 years of age was 23% (95% confidence interval (CI) = 20, 25%). Considerable heterogeneity was present across the included studies. The adjusted prediction interval was found to be 19%-27%. Heterogeneities were explained by subgroups analyses. The highest prevalence of RSV was found among inpatients, 28% (95% CI = 25, 31%) compared with inpatients/outpatients and outpatients, with statistically significant differences (P < 0.01). The RSV estimate was also highest among those with acute lower respiratory tract illnesses (ALRTIs), 28% (95% CI = 25, 31%) compared with acute upper respiratory tract illnesses (AURTIs) and both acute upper/lower respiratory manifestations, with statistically different prevalence (P < 0.01). RSV infection estimates in each sub-region of Africa were statistically different (P < 0.01). There were no statistically significant differences in RSV infections by designs, specimen types, and specimen conditions, despite them contributing to heterogeneity.

Conclusions

We found a high prevalence of RSV in pediatric populations with acute respiratory tract illnesses in Africa, highlighting that the prevention and control of RSV infections in children deserve more attention.

Registration

PROSPERO CRD42022327054.

Molecular epidemiology of respiratory syncytial virus in hospitalised children in Heidelberg, Southern Germany, 2014-2017

BACKGROUND

Respiratory syncytial virus (RSV) is the leading cause of hopitalisation in young children with respiratory tract infections (RTI). The aim of this research project was to analyse RSV genotypes and the diversification of RSV strains among hospitalised children in Heidelberg, Germany.

METHODS

We prospectively analysed nasopharyngeal swabs (NPS) from children who were hospitalised with acute RTI at the University Hospital Heidelberg, Germany, during winter seasons 2014 to 2017. RSV RT-PCR and RSV sequence analysis of the G gene coding for the attachment glycoprotein were performed. Clinical data was obtained using a standardised questionnaire.

RESULTS

RSV was detected in 405 out of 946 samples from hospitalised children. Most RSV positive children were below the age of two years (84.4%) and had a lower RTI (78.8%). The majority of RSV positive children was male, significantly younger than RSV negative children with a median age of 0.39 years and with more severe respiratory symptoms. Out of 405 positive samples, 317 RSV strains were successfully sub-grouped into RSV subtypes A (57.4%; 182/317) and B (42.6%; 135/317). Both RSV subtypes cocirculated in all analysed winter seasons. Phylogenetic analysis of 317 isolates revealed that the majority of RSV-A strains (180/182) belonged to the ON1 genotype, most RSV-B strains could be attributed to the BAIX genotype (132/135). ON1 and BAIX strains showed a sub-differentiation into different lineages and we were able to identify new (sub)genotypes.

CONCLUSION

Analysis of the molecular epidemiology of RSV from different seasons revealed the cocirculation and diversification of RSV genotypes ON1 and BAIX.

Determination of genetic characterization and circulation pattern of Respiratory Syncytial Virus (RSV) in children with a respiratory infection, Tehran, Iran, during 2018-2019

The RSV-associated disease accounts for a significant health burden particularly in infants and young children who need to be hospitalized. Since continuous surveillance of circulating RSV genotypes is crucial worldwide, this study aimed to investigate the genetic diversity of RSV circulating strains causing upper or lower acute respiratory infection. Our attention was geared towards studying the cases hospitalized or outpatient in children younger than 2 years of age in Iran during 2018/2019. In this study, nasopharyngeal swabs collected from 206 children who presented with respiratory infection symptoms, were admitted to the referral pediatric ward of Bahrami children's hospital in Tehran, Iran. RSV-positive samples were detected via Nested RT-PCR. The glycoprotein gene was sequenced, and virus genotypes were confirmed through phylogenetic analysis by the MEGA X program. A total of 74 (35.92%) samples tested positive for RSV. Among them, sequencing was done in 10 specimens from 2018 (RSV-A: RSV-B=4:6) and 19 specimens from 2019 (RSV-A: RSV-B=16:3). According to phylogenetic analysis, all RSV-A strains were assigned as ON1 genotype and RSV-B strains were assigned as BA9 genotype. A new N-glycosylation site in Iranian BA9 and positive selection in ON1 genotype was observed. Phylogenetic characterization of strains in the current study revealed co-circulation of ON1 and BA9 as the only prevalent genotypes of both RSV-A and -B groups.