Causes of severe pneumonia requiring hospital admission in children without HIV infection from Africa and Asia: the PERCH multi-country case-control study

Haemophilus influenzae and pneumococci: Co-colonization, interactions, cooperation and competition

Nontypeable Haemophilus influenzae (NTHi) and Streptococcus pneumoniae (pneumococcus) are pathobionts that share common environmental niches within the upper respiratory tract. They can form part of the resident upper airway microbiota, but under certain environmental circumstances become pathogenic and induce disease. In children, both organisms have a considerable impact on the healthcare system, commonly causing acute otitis media and pneumonia. They are also associated with chronic biofilm-mediated respiratory infections, such as persistent middle ear effusions and chronic suppurative otitis media, and in the lower airways with protracted bacterial bronchitis and bronchiectasis. Consequently, both organisms are responsible for large numbers of antibiotic prescriptions and substantial healthcare costs. The complex relationship between NTHi and pneumococcal co-interaction during colonization, infection and biofilm formation is poorly understood and a greater understanding is needed to facilitate development of future therapies, and novel interventions and prevention strategies. Co-infections with both bacteria can result in more severe disease, with disease severity likely mediated by their ability to cooperate in some in vivo niches. However, this relationship is not always straightforward, as under certain conditions, these two bacteria compete rather than cooperate. Current opinion supports developing a vaccine targeting NTHi strains, as well as a combined vaccine targeting both NTHi and pneumococci to decrease the respiratory disease burden in young children. This review summarizes our current knowledge of the interactions between NTHi and pneumococci and speculates on the future directions of research to understand how these bacteria co-exist and how to better prevent and treat NTHi and pneumococcal infection.

Murine parainfluenza virus persists in lung innate immune cells sustaining chronic lung pathology

Common respiratory viruses, including the human parainfluenza viruses, threaten human health seasonally and associate with the development of chronic lung diseases. Evidence suggests that these viruses can persist, but the sources of viral products in vivo and their impact on chronic respiratory diseases remain unknown. Using the murine parainfluenza virus Sendai, we demonstrate that viral protein and RNA persist in lung macrophages, type 2 innate lymphoid cells (ILC2s) and dendritic cells long after the infectious virus is cleared. Cells containing persistent viral protein expressed Th2 inflammation-related transcriptomic signatures associated with the development of chronic lung diseases, including asthma. Lineage tracing demonstrated that distinct functional groups of cells contribute to the chronic pathology. Importantly, targeted ablation of infected cells significantly ameliorated chronic lung disease. Overall, we identified persistent infection of innate immune cells as a key factor in the progression from acute to chronic lung disease after infection with parainfluenza virus.

Respiratory syncytial virus infection among children younger than 2 years admitted to a paediatric intensive care unit with extended severe acute respiratory infection in ten Gavi-eligible countries: the RSV GOLD-ICU Network study

BACKGROUND

Patient-level data on life-threatening respiratory syncytial virus (RSV) infection in children in low-income and lower-middle-income countries (LMICs) are scarce, and this scarcity might limit demand for RSV interventions in LMICs who rely on support from Gavi, the Vaccine Alliance. We aimed to describe the characteristics of RSV-positive children younger than 2 years who were admitted to paediatric intensive care units (PICUs) with extended severe acute respiratory infection (eSARI) in Gavi-eligible countries.

METHODS

The RSV GOLD-ICU Network study is a 2-year prospective, multicountry, observational study of children younger than 2 years admitted to a PICU with eSARI. The study was conducted at 12 referral hospitals in Bolivia, Cameroon, The Gambia, Ghana, Haiti, Mozambique, Nepal, Nigeria, Sudan, and Tanzania. For comparison with a high-income country, patients were also included from two referral hospitals in the Netherlands. Children were eligible for inclusion if they were aged between 4 days and 2 years, admitted to a PICU, and met the WHO eSARI definition. RSV infection was confirmed within 72 h of PICU admission via a molecular point-of-care test at LMIC study sites and via a PCR test at the Dutch study sites. Clinical data were extracted from admission charts of patients; underlying conditions that were identified at admission were classified as comorbidities. Socioeconomic and demographic data were collected via a written, structured, parental questionnaire.

FINDINGS

Between April 28, 2021, and Sept 30, 2023, we included 2118 children who were admitted to a PICU with eSARI in the ten participating countries. 614 (29·0%; range 23·0-38·2) of 2118 children tested positive for RSV and 608 were included in descriptive analyses as six medical files were lost at one study site and data could not be retrieved. Among all 608 children infected with RSV, 379 (62%) were male and 229 (38%) were female. Median age at testing was 3·0 months (IQR 1·3-7·7). 30 (5%) of 608 children died from RSV infection. RSV fatality occurred at seven of ten participating LMIC study sites and was highest in Tanzania (seven [27%] of 26 children). Median age at testing of children who died with RSV infection was 1·8 months (IQR 1·1-4·2).

INTERPRETATION

To our knowledge, this is the first prospective, multicountry study reporting data from children admitted to a PICU with life-threatening RSV infection in Gavi-eligible countries. As there is no access to intensive care for most children in LMICs, RSV prevention is urgently needed.

FUNDING

Bill & Melinda Gates Foundation.

TRANSLATIONS

For the Arabic, Portuguese, Hausa and Nepali translations of the abstract see Supplementary Materials section.

Effect of Pneumococcal Conjugate Vaccines on Viral Respiratory Infections: A Systematic Literature Review

BACKGROUND

In addition to preventing pneumococcal disease, emerging evidence indicates that pneumococcal conjugate vaccines (PCVs) might indirectly reduce viral respiratory tract infections (RTIs) by affecting pneumococcal-viral interactions.

METHODS

We performed a systematic review of interventional and observational studies published during 2000-2022 on vaccine efficacy/adjusted effectiveness (VE) and overall effect of PCV7, PCV9, PCV10, or PCV13 against viral RTIs.

RESULTS

Sixteen of 1671 records identified were included. Thirteen publications described effects of PCVs against viral RTIs in children. VE against influenza ranged between 41% and 86% (n = 4), except for the 2010-2011 influenza season. In a randomized controlled trial, PCV9 displayed efficacy against any viral RTI, human seasonal coronavirus, parainfluenza, and human metapneumovirus. Data in adults were limited (n = 3). PCV13 VE was 4%-25% against viral lower RTI, 32%-35% against coronavirus disease 2019 outcomes, 24%-51% against human seasonal coronavirus, and 13%-36% against influenza A lower RTI, with some 95% confidence intervals spanning zero. No protection was found against adenovirus or rhinovirus in children or adults.

CONCLUSIONS

PCVs were associated with protection against some viral RTI, with the strongest evidence for influenza in children. Limited evidence for adults was generally consistent with pediatric data. Restricting public health evaluations to confirmed pneumococcal outcomes may underestimate the full impact of PCVs.

Severe respiratory syncytial virus infection in children: burden, management, and emerging therapies

The global burden of respiratory syncytial virus (RSV) lower respiratory tract infection (LRTI) in young children is high. The RSV prevention strategies approved in 2023 will be essential to lowering the global disease burden. In this Series paper, we describe clinical presentation, burden of disease, hospital management, emerging therapies, and targeted prevention focusing on developments and groundbreaking publications for RSV. We conducted a systematic search for literature published in the past 15 years and used a non-systematic approach to analyse the results, prioritising important papers and the most recent reviews per subtopic. Annually, 33 million episodes of RSV LRTI occur in children younger than 5 years, resulting in 3·6 million hospitalisations and 118 200 deaths. RSV LRTI is a clinical diagnosis but a clinical case definition and universal clinical tool to predict severe disease are non-existent. The advent of molecular point-of-care testing allows rapid and accurate confirmation of RSV infection and could reduce antibiotic use. There is no evidence-based treatment of RSV, only supportive care. Despite widespread use, evidence for high-flow nasal cannula (HFNC) therapy is insufficient and increased paediatric intensive care admissions and intubation indicate the need to remove HFNC therapy from standard care. RSV is now a vaccine-preventable disease in young children with a market-approved long-acting monoclonal antibody and a maternal vaccine targeting the RSV prefusion protein. To have a high impact on life-threatening RSV infection, infants at high risk, especially in low-income and middle-income countries, should be prioritised as an interim strategy towards universal immunisation. The implementation of RSV preventive strategies will clarify the full burden of RSV infection. Vaccine probe studies can address existing knowledge gaps including the effect of RSV prevention on transmission dynamics, antibiotic misuse, the respiratory microbiome composition, and long-term sequalae.

Comparison of characteristics of children hospitalized for respiratory syncytial virus infection during the pre- and post-COVID-19 eras: a multicenter retrospective study

BACKGROUND

Respiratory syncytial virus (RSV), a leading cause of lower respiratory tract infection (LRTI) among children, has resurged in the form of endemic or even pandemic in many countries and areas after the easing of COVID-19 containment measures. This study aimed to investigate the differences in epidemiological and clinical characteristics of children hospitalized for RSV infection during pre- and post-COVID-19 eras in Yunnan, China.

METHODS

A total of 2553 pediatric RSV inpatients from eight hospitals in Yunnan were retrospectively enrolled in this study, including 1451 patients admitted in 2018-2019 (pre-COVID-19 group) and 1102 patients admitted in 2023 (post-COVID-19 group). According to the presence or absence of severe LRTI (SLRTI), patients in the pre- and post-COVID-19 groups were further divided into the respective severe or non-severe subgroups, thus analyzing the risk factors for RSV-associated SLRTI in the two eras. Demographic, epidemiological, clinical, and laboratory data of the patients were collected for the final analysis.

RESULTS

A shift in the seasonal pattern of RSV activity was observed between the pre-and post-COVID-19 groups. The peak period of RSV hospitalizations in the pre-COVID-19 group was during January-April and October-December in both 2018 and 2019, whereas that in the post-COVID-19 group was from April to September in 2023. Older age, more frequent clinical manifestations (fever, acute otitis media, seizures), and elevated laboratory indicators [neutrophil-to-lymphocyte ratio (NLR), c-reactive protein (CRP), interleukin 6 (IL-6), co-infection rate] were identified in the post-COVID-19 group than those in the pre-COVID-19 group (all P < 0.05). Furthermore, compared to the pre-COVID-19 group, the post-COVID-19 group displayed higher rates of SLRTI and mechanical ventilation, with a longer length of hospital stay (all P < 0.05). Age, low birthweight, preterm birth, personal history of atopy, underlying condition, NLR, IL-6 were the shared independent risk factors for RSV-related SLRTI in both pre- and post-COVID-19 groups, whereas seizures and co-infection were independently associated with SLRTI only in the post-COVID-19 group.

CONCLUSIONS

An off-season RSV endemic was observed in Yunnan during the post-COVID-19 era, with changed clinical features and increased severity. Age, low birthweight, preterm birth, personal history of atopy, underlying condition, NLR, IL-6, seizures, and co-infection were the risk factors for RSV-related SLRTI in the post-COVID-19 era.

Efficacy and safety of bivalent RSVpreF maternal vaccination to prevent RSV illness in Japanese infants: Subset analysis from the pivotal randomized phase 3 MATISSE trial

BACKGROUND

Maternal vaccination with respiratory syncytial virus prefusion F vaccine (RSVpreF) is effective at preventing RSV-associated lower respiratory tract illness (LRTI) in newborns/infants.

METHODS

This subgroup analysis from the global, phase 3, randomized, double-blind, placebo-controlled MATISSE (Maternal Immunization Study for Safety and Efficacy) trial evaluated participants enrolled in Japan. Pregnant women 24-36 weeks' gestation were randomized 1:1 to receive RSVpreF or placebo. Maternal safety endpoints included local reactions/systemic events within 7 days, adverse events (AEs) through 1 month, and serious AEs (SAEs) through 6 months after vaccination. In infants born to maternal participants, safety endpoints included specific birth outcomes, AEs through 1 month after birth, and SAEs and newly diagnosed chronic medical conditions through 12 or 24 months after birth. Vaccine efficacy in infants was assessed against RSV-positive, medically attended LRTI (RSV-MA-LRTI) and severe RSV-MA-LRTI through 180 days after birth.

RESULTS

In Japan, 230 maternal participants received RSVpreF and 232 received placebo; 218 and 216 infants born to these mothers, respectively, were analyzed. Observed vaccine efficacy (95 % CIs) against infant RSV-MA-LRTI within 90 and 180 days after birth was 100.0 % (30.9, 100.0; RSVpreF, 0 cases; placebo, 7 cases) and 87.6 % (7.2, 99.7; RSVpreF, 1 case; placebo, 8 cases), respectively. Vaccine efficacy (95 % CIs) against severe RSV-MA-LRTI within 90 and 180 days was 100.0 % (-140.9, 100.0; RSVpreF, 0 cases; placebo, 3 cases) and 75.1 % (-151.5, 99.5; RSVpreF, 1 case; placebo, 4 cases), respectively. No safety concerns were identified. AE rates ≤1 month after vaccination/birth were similar in the RSVpreF (maternal, 16.1 %; infant, 48.6 %) and placebo (19.8 %; 50.5 %) groups. Preterm birth rates were also similar (RSVpreF, 3.2 %; placebo, 6.0 %).

CONCLUSIONS

Safety and efficacy data in Japanese participants were consistent with overall MATISSE results, supporting the efficacy of maternal RSVpreF vaccination against severe MA-RSV-LRTI/MA-RSV-LRTI in infants, with no safety concerns. NCT04424316.

The severity of respiratory syncytial virus infection in children during the SARS-CoV-2/COVID-19 pandemic: A nationwide study of 11,915 cases in Germany

PURPOSE

Respiratory syncytial virus (RSV) infection is a major cause of childhood hospitalization. The COVID-19 pandemic has disrupted the usual seasonal pattern of RSV, resulting in high activity during the off-season. This study aims to evaluate the effects of the pandemic on the severity of RSV infections.

METHODS

Data from 11,915 children hospitalized due to RSV infection between 2016 and 2022 were analyzed. The hospitalized patients were categorized into two groups, from January 2016 to February 2020 (PreCoV19 group) and from March 2020 to December 2022 (CoV19 group). The hospitalization duration, intensive care unit (ICU) admissions, length of stay at ICU, mechanical ventilation requirement and duration, Elixhauser comorbidity index scores, and in-hospital mortality were analyzed.

RESULTS

Children in the PreCoV19 group had a mean age of 0.4 ± 0.7, whereas those in the CoV19 group had a mean age of 0.6 ± 1.0 years. Children during the pandemic had significantly shorter hospital stays (4.3 ± 2.6 days) compared to children of the pre-pandemic period (4.9 ± 3.3 days). Although ICU admission rates did not change, the duration of ICU stays decreased in the CoV19 group. Moreover, the in-hospital mortality did not differ between the groups. A multivariable analysis showed that younger age, regardless of the pandemic period, was associated with prolonged hospital stays, higher ICU admission rates, and an increased requirement for mechanical ventilation.

CONCLUSION

Our findings highlight significant changes of the clinical characteristics of RSV infections during the pandemic, with implications for clinical management and public health strategies.

The cost of care for children hospitalized with respiratory syncytial virus (RSV) associated lower respiratory infection in Kenya

BACKGROUND

Respiratory syncytial virus (RSV) is one of the main causes of hospitalization for lower respiratory tract infection in children under five years of age globally. Maternal vaccines and monoclonal antibodies for RSV prevention among infants are approved for use in high income countries. However, data are limited on the economic burden of RSV disease from low- and middle-income countries (LMIC) to inform decision making on prioritization and introduction of such interventions. This study aimed to estimate household and health system costs associated with childhood RSV in Kenya.

METHODS

A structured questionnaire was administered to caregivers of children aged < 5 years admitted to referral hospitals in Kilifi (coastal Kenya) and Siaya (western Kenya) with symptoms of acute lower respiratory tract infection (LRTI) during the 2019-2021 RSV seasons. These children had been enrolled in ongoing in-patient surveillance for respiratory viruses. Household expenditures on direct and indirect medical costs were collected 10 days prior to, during, and two weeks post hospitalization. Aggregated health system costs were acquired from the hospital administration and were included to calculate the cost per episode of hospitalized RSV illness.

RESULTS

We enrolled a total of 241 and 184 participants from Kilifi and Siaya hospitals, respectively. Out of these, 79 (32.9%) in Kilifi and 21(11.4%) in Siaya, tested positive for RSV infection. The total (health system and household) mean costs per episode of severe RSV illness was USD 329 (95% confidence interval (95% CI): 251-408 ) in Kilifi and USD 527 (95% CI: 405- 649) in Siaya. Household costs were USD 67 (95% CI: 54-80) and USD 172 (95% CI: 131- 214) in Kilifi and Siaya, respectively. Mean direct medical costs to the household during hospitalization were USD 11 (95% CI: 10-12) and USD 67 (95% CI: 51-83) among Kilifi and Siaya participants, respectively. Observed costs were lower in Kilifi due to differences in healthcare administration.

CONCLUSIONS

RSV-associated disease among young children leads to a substantial economic burden to both families and the health system in Kenya. This burden may differ between Counties in Kenya and similar multi-site studies are advised to support cost-effectiveness analyses.

Epidemiology and Diagnostic Accuracy of Respiratory Pathogens in Pediatric Populations: Insights From Global Studies

Lower respiratory tract infections (LRTIs) are the most common cause for going to the doctor's at pediatric age. Respiratory infections are still of interest because they are widespread, significantly impact public health by potentially leading to pandemics, drive antimicrobial resistance through antibiotic misuse, more often spread globally due to traveling, and benefit from ongoing advancements in diagnostics and research for better management. This paper's main aim was to offer a systematic review of the literature published over the last 10 years on the etiology of LRTIs. The search strategy was based on reviewing original articles, systematic reviews, position papers, and guidelines published in MEDLINE, EMBASE, Cochrane Library, and PubMed. The review was previously registered with PROSPERO. The final review included 27 articles that met the eligibility criteria (studies identifying the etiology of inferior respiratory infections in children, according to the WHO definition, published in the last 10 years). Statistical analysis was performed using Microsoft Excel Version 2406 (Microsoft Corporation, Redmond, Washington, USA) and SPSS Statistics V.23 (IBM Corp., Armonk, New York, USA). The total number of patients was 2,193,978. Eight articles focused on children younger than five years, and two included children under the age of two. The results revealed that Mycoplasma pneumoniae and respiratory syncytial virus (RSV) are significant respiratory pathogens with seasonal peaks and age-specific prevalence and that nasopharyngeal aspirates (NPAs) are more reliable than throat swabs for confirming infections due to their higher positive predictive value (PPV). The impact of COVID-19 interventions led to reduced infections from RSV, adenovirus, and influenza viruses, but an increase in rhinovirus post-reopening, with high co-infection rates. Co-infections are common, particularly with pathogens like human bocavirus (HBoV) and RSV, underscoring the need for comprehensive diagnostic approaches. The impact of non-pharmaceutical interventions during the COVID-19 pandemic significantly reduced the prevalence of many respiratory pathogens, except for rhinovirus, which increased post-reopening. Understanding these dynamics is crucial for managing respiratory infections, especially in pediatric populations.

Global, regional, and national incidence and mortality burden of non-COVID-19 lower respiratory infections and aetiologies, 1990-2021: a systematic analysis from the Global Burden of Disease Study 2021

BACKGROUND

Lower respiratory infections (LRIs) are a major global contributor to morbidity and mortality. In 2020-21, non-pharmaceutical interventions associated with the COVID-19 pandemic reduced not only the transmission of SARS-CoV-2, but also the transmission of other LRI pathogens. Tracking LRI incidence and mortality, as well as the pathogens responsible, can guide health-system responses and funding priorities to reduce future burden. We present estimates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 of the burden of non-COVID-19 LRIs and corresponding aetiologies from 1990 to 2021, inclusive of pandemic effects on the incidence and mortality of select respiratory viruses, globally, regionally, and for 204 countries and territories.

METHODS

We estimated mortality, incidence, and aetiology attribution for LRI, defined by the GBD as pneumonia or bronchiolitis, not inclusive of COVID-19. We analysed 26 259 site-years of mortality data using the Cause of Death Ensemble model to estimate LRI mortality rates. We analysed all available age-specific and sex-specific data sources, including published literature identified by a systematic review, as well as household surveys, hospital admissions, health insurance claims, and LRI mortality estimates, to generate internally consistent estimates of incidence and prevalence using DisMod-MR 2.1. For aetiology estimation, we analysed multiple causes of death, vital registration, hospital discharge, microbial laboratory, and literature data using a network analysis model to produce the proportion of LRI deaths and episodes attributable to the following pathogens: Acinetobacter baumannii, Chlamydia spp, Enterobacter spp, Escherichia coli, fungi, group B streptococcus, Haemophilus influenzae, influenza viruses, Klebsiella pneumoniae, Legionella spp, Mycoplasma spp, polymicrobial infections, Pseudomonas aeruginosa, respiratory syncytial virus (RSV), Staphylococcus aureus, Streptococcus pneumoniae, and other viruses (ie, the aggregate of all viruses studied except influenza and RSV), as well as a residual category of other bacterial pathogens.

FINDINGS

Globally, in 2021, we estimated 344 million (95% uncertainty interval [UI] 325-364) incident episodes of LRI, or 4350 episodes (4120-4610) per 100 000 population, and 2·18 million deaths (1·98-2·36), or 27·7 deaths (25·1-29·9) per 100 000. 502 000 deaths (406 000-611 000) were in children younger than 5 years, among which 254 000 deaths (197 000-320 000) occurred in countries with a low Socio-demographic Index. Of the 18 modelled pathogen categories in 2021, S pneumoniae was responsible for the highest proportions of LRI episodes and deaths, with an estimated 97·9 million (92·1-104·0) episodes and 505 000 deaths (454 000-555 000) globally. The pathogens responsible for the second and third highest episode counts globally were other viral aetiologies (46·4 million [43·6-49·3] episodes) and Mycoplasma spp (25·3 million [23·5-27·2]), while those responsible for the second and third highest death counts were S aureus (424 000 [380 000-459 000]) and K pneumoniae (176 000 [158 000-194 000]). From 1990 to 2019, the global all-age non-COVID-19 LRI mortality rate declined by 41·7% (35·9-46·9), from 56·5 deaths (51·3-61·9) to 32·9 deaths (29·9-35·4) per 100 000. From 2019 to 2021, during the COVID-19 pandemic and implementation of associated non-pharmaceutical interventions, we estimated a 16·0% (13·1-18·6) decline in the global all-age non-COVID-19 LRI mortality rate, largely accounted for by a 71·8% (63·8-78·9) decline in the number of influenza deaths and a 66·7% (56·6-75·3) decline in the number of RSV deaths.

INTERPRETATION

Substantial progress has been made in reducing LRI mortality, but the burden remains high, especially in low-income and middle-income countries. During the COVID-19 pandemic, with its associated non-pharmaceutical interventions, global incident LRI cases and mortality attributable to influenza and RSV declined substantially. Expanding access to health-care services and vaccines, including S pneumoniae, H influenzae type B, and novel RSV vaccines, along with new low-cost interventions against S aureus, could mitigate the LRI burden and prevent transmission of LRI-causing pathogens.

FUNDING

Bill & Melinda Gates Foundation, Wellcome Trust, and Department of Health and Social Care (UK).

Development of RPA-Cas12a assay for rapid and sensitive detection of Pneumocystis jirovecii

Pneumocystis jirovecii is a prevalent opportunistic fungal pathogen that can lead to life-threatening Pneumocystis pneumonia in immunocompromised individuals. Given that timely and accurate diagnosis is essential for initiating prompt treatment and enhancing patient outcomes, it is vital to develop a rapid, simple, and sensitive method for P. jirovecii detection. Herein, we exploited a novel detection method for P. jirovecii by combining recombinase polymerase amplification (RPA) of nucleic acids isothermal amplification and the trans cleavage activity of Cas12a. The factors influencing the efficiency of RPA and Cas12a-mediated trans cleavage reaction, such as RPA primer, crRNA, the ratio of crRNA to Cas12a and ssDNA reporter concentration, were optimized. Our RPA-Cas12a-based fluorescent assay can be completed within  30-40 min, comprising a 25-30 min RPA reaction and a 5-10 min trans cleavage reaction. It can achieve a lower detection threshold of 0.5 copies/µL of target DNA with high specificity. Moreover, our RPA-Cas12a-based fluorescent method was examined using 30 artificial samples and demonstrated high accuracy with a diagnostic accuracy of 93.33%. In conclusion, a novel, rapid, sensitive, and cost-effective RPA-Cas12a-based detection method was developed and demonstrates significant potential for on-site detection of P. jirovecii in resource-limited settings.

Identification of distinct genotypes in circulating RSV A strains based on variants in the virus replication-associated genes

Respiratory syncytial virus (RSV) is a common cause of respiratory infection that often leads to hospitalization of infected younger children and older adults. RSV is classified into two strains, A and B, each with several subgroups or genotypes. One issue with the definition of these subgroups is the lack of a unified method of identification or genotyping. We propose that genotyping strategies based on the genes coding for replication-associated proteins could provide critical information on the replication capacity of the distinct subgroups, while clearly distinguishing genotypes. Here, we analyzed the virus replication-associated genes N, P, M2, and L from de novo assembled RSV A sequences obtained from 31 newly sequenced samples from hospitalized patients in Philadelphia and 78 additional publicly available sequences from different geographic locations within the United States. In-depth analysis and annotation of variants in the replication-associated proteins identified the polymerase protein L as a robust target for genotyping RSV subgroups. Importantly, our analysis revealed non-synonymous variations in L that were consistently accompanied by conserved changes in its co-factor P or the M2-2 protein, suggesting associations and interactions between specific domains of these proteins. Similar associations were seen among sequences of the related human metapneumovirus. These results highlight L as an alternative to other RSV genotyping targets and demonstrate the value of in-depth analyses and annotations of RSV sequences as it can serve as a foundation for subsequent in vitro and clinical studies on the efficiency of the polymerase and fitness of different virus isolates.IMPORTANCEGiven the historical heterogeneity of respiratory syncytial virus (RSV) and the disease it causes, there is a need to understand the properties of the circulating RSV strains each season. This information would benefit from an informative and consensus method of genotyping the virus. Here, we carried out a variant analysis that shows a pattern of specific variations among the replication-associated genes of RSV A across different seasons. Interestingly, these variation patterns, which were also seen in human metapneumovirus sequences, point to previously defined interactions of domains within these genes, suggesting co-variation in the replication-associated genes. Our results also suggest a genotyping strategy that can prove to be particularly important in understanding the genotype-phenotype correlation in the era of RSV vaccination, where selective pressure on the virus to evolve is anticipated. More importantly, the categorization of pneumoviruses based on these patterns may be of prognostic value.

Multicentre case-control study of pneumococcal infections among children with pneumonia in Peninsular Malaysia (MY-Pneumo): a study protocol

BACKGROUND

S. pneumoniae (SPN) is the most common cause of pneumonia. The disease can be effectively prevented through immunisation. Since December 2020, the Malaysian Government has included the 10-valent pneumococcal conjugate vaccine (PCV10) for all infants born on or after 1 January 2020 as part of the National Immunisation Programme (NIP). However, the epidemiology of pneumonia remains poorly understood. To fill the knowledge gap, we established a multicentre surveillance study to understand the burden of pneumococcal pneumonia among young children in Peninsular Malaysia.

METHODS

MY-Pneumo is a multicentre prospective case-control study conducted in three sentinel sites located in three different states of Peninsular Malaysia - Kuala Lumpur, Pahang, and Kelantan. A cohort of at least 500 incident cases and 500 controls is enrolled beginning in October 2021 and matched for age. Cases are hospitalised children < 5 years with radiologically confirmed pneumonia, and the controls are children without any features suggestive of pneumonia. Clinical samples, including nasopharyngeal swabs (NPS) and urine, are collected according to the study protocol. Biological fluids such as blood, cerebrospinal fluid (CSF) and pleural fluid are obtained from invasive pneumonia disease (IPD) patients, if available. All children are tested for SPN using polymerase chain reaction (PCR) and pneumococcal urine antigen test (PUAT) using BinaxNow.

DISCUSSION

Surveillance data, including carriage rate, serotype variations and the phylogeny data structure of SPN among young children in Malaysia during PCV implementation, will be generated from this study. Trends and patterns of pneumococcal serotypes by different regions are important for targeted public health strategies. Our data will provide baseline information for estimating the impact of PCV10 implementation and will influence policymakers' decisions regarding the upgrade from PCV10 to a higher-valency conjugate vaccine in Malaysia.

TRIAL REGISTRATION

This project was registered at ClinicalTrials.gov (NCT04923035) on 2021, June 11. The study protocol was approved by the International Medical University Joint-Committee on Research & Ethics (4.15/JCM-216/2021) and the Institutional Review Board at sentinel sites (USM/JEPeM/21020190, IREC 2021-114, MREC ID No: 2021128-9769) and University of Southampton's Ethics and Research Governance (ERGo II 64844).

Nirsevimab: Alleviating the burden of RSV morbidity in young children

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infections (LRTIs) and hospital admissions in early childhood. Recent advancements in novel preventive therapies, including extended half-life monoclonal antibodies and antenatal vaccination, have afforded new opportunities to significantly reduce the burden of this infection. Nirsevimab is a novel monoclonal antibody that provides sustained protection against RSV for at least 5 months among newborns and young children. It has received regulatory approval in numerous countries and is being implemented across various settings. Two pivotal Phase 3 trials (MELODY, HARMONIE) demonstrated significant reductions in RSV-associated LRTI hospitalisations following nirsevimab administration, with treatment efficacy of 62.1% and 83.2%. Emerging real-world data from early adopters of nirsevimab corroborates these findings. Studies from Spain, Luxembourg, France and the USA report effectiveness rates between 82% and 90% in preventing RSV-associated hospitalisations among infants entering their first RSV season. Current implementation strategies for nirsevimab have primarily focused on seasonal administration for all infants, aligned to local RSV seasons, and often include catch-up doses for those born before the season begins. Available cost-effectiveness analyses indicate that while nirsevimab offers significant potential public health benefits, its adoption must carefully consider economic factors such as treatment costs, implementation strategies tailored to local viral epidemiology, and logistics for vaccine delivery. Overall, nirsevimab presents a promising opportunity to alleviate the burden of severe RSV infections in young children. However, ongoing surveillance and refinements in implementation strategies are crucial to optimise its impact and ensure sustainability across diverse health-care settings.

Phylogeography and reassortment patterns of human influenza A viruses in sub-Saharan Africa

The role of sub-Saharan Africa in the global spread of influenza viruses remains unclear due to insufficient spatiotemporal sequence data. Here, we analyzed 222 codon-complete sequences of influenza A viruses (IAVs) sampled between 2011 and 2013 from five countries across sub-Saharan Africa (Kenya, Zambia, Mali, Gambia, and South Africa); these genomes were compared with 1209 contemporaneous global genomes using phylogeographical approaches. The spread of influenza in sub-Saharan Africa was characterized by (i) multiple introductions of IAVs into the region over consecutive influenza seasons, with viral importations originating from multiple global geographical regions, some of which persisted in circulation as intra-subtype reassortants for multiple seasons, (ii) virus transfer between sub-Saharan African countries, and (iii) virus export from sub-Saharan Africa to other geographical regions. Despite sparse data from influenza surveillance in sub-Saharan Africa, our findings support the notion that influenza viruses persist as temporally structured migrating metapopulations in which new virus strains can emerge in any geographical region, including in sub-Saharan Africa; these lineages may have been capable of dissemination to other continents through a globally migrating virus population. Further knowledge of the viral lineages that circulate within understudied sub-Saharan Africa regions is required to inform vaccination strategies in those regions.

Efficacy of Antibiotic Regimens for Pneumonia in Young Infants Aged 0-59 Days: A Systematic Review

CONTEXT

Pneumonia is a leading cause of death in young infants.

OBJECTIVES

To evaluate the efficacy of different antibiotic regimens to treat young infant pneumonia on critical clinical outcomes.

DATA SOURCES

MEDLINE, Embase, CINAHL, World Health Organization (WHO) Global Index Medicus, Cochrane Central Registry of Trials.

STUDY SELECTION

We included randomized controlled trials of young infants aged 0 to 59 days with pneumonia (population) comparing the efficacy of antibiotic regimens (intervention) with alternate regimens or management (control) on clinical outcomes.

DATA EXTRACTION

We extracted data and assessed risk of bias in duplicate. We used Grading of Recommendations, Assessment, Development, and Evaluation to assess certainty of evidence.

LIMITATIONS

Trials were heterogeneous, which precluded data pooling.

RESULTS

Of 2601 publications screened, 10 randomized controlled trials were included. Seven trials were hospital-based (n = 869) and 3 were nonhospital-based (n = 4329). No hospital-based trials evaluated WHO-recommended first-choice regimens. One trial found the WHO-recommended second-choice antibiotic, cefotaxime, to have similar rates of treatment success as non-WHO-recommended regimens of either amoxicillin-clavulanate (RR 0.99, 95% confidence interval 0.82-1.10) or amoxicillin-clavulanate/cefotaxime (RR 1.02, 95% confidence interval 0.86-1.12). Among 3 nonhospital-based trials comparing oral amoxicillin to alternate regimens to treat isolated tachypnea among infants aged 7-59 days, there were no differences in treatment failure between amoxicillin and alternate regimens. Certainty of evidence was low or very low for all primary outcomes.

CONCLUSIONS

We found limited evidence to support the superiority of any single antibiotic regimen over alternate regimens to treat young infant pneumonia.

Epidemiological study of post-pandemic pediatric common respiratory pathogens using multiplex detection

BACKGROUND

The burden and characteristics of respiratory viral infections in children hospitalized for acute respiratory tract infections (ARTIs) during the post-COVID-19 pandemic era are unclear. We analyzed the epidemiological and clinical characteristics of pediatric patients hospitalized with common respiratory virus infections before and after relaxation of non-pharmaceutical interventions in Hangzhou, China and evaluated the diagnostic value of the six-panel respiratory pathogen detection system.

METHODS

Six types of respiratory viruses were detected in respiratory samples from children with suspected ARTIs by multiplex real-time quantitative polymerase chain reaction (RT-qPCR). Changes in virus detection rates and epidemiological and clinical characteristics, obtained from electronic health records, were analyzed. Binary logistic regression was used to identify respiratory tract infections risk factors. Multiplex RT-qPCR and targeted next-generation sequencing results were compared in random samples.

RESULTS

Among the 11,056 pediatric samples, 3228 tested positive for one or more of six common respiratory pathogens. RSV and PIV-3 detection rates differed significantly across age groups (both P < 0.001), and were more common in younger children. PIV-1 was more common in infants, toddlers, and preschoolers than in school-age children (P < 0.001). FluB was predominantly detected in school-age children (P < 0.001). RSV-, ADV-, and PIV-1-positivity rates were higher in 2022 than in 2023. Seasonal viral patterns differed across years. RSV (OR 9.156. 95% CI 5.905-14.195) and PIV-3 (OR 1.683, 95% CI 1.133-2.501) were risk factors for lower respiratory tract infections. RSV-positivity was associated with severe pneumonia (P = 0.044). PIV-3 (OR 0.391, 95% CI 0.170-0.899), summer season (OR 1.982, 95% CI 1.117-3.519), and younger age (OR 0.938, 95% CI 0.893-0.986) influenced pneumonia severity. Multiplex RT-qPCR showed good diagnostic performance.

CONCLUSION

After changes in COVID-19 prevention and control strategies, six common respiratory viruses in children were prevalent in 2022-2023, with different seasonal epidemic characteristics and age proclivities. RSV and PIV-3 cause lower, and FluA, FluB, and ADV more typically cause upper respiratory tract infections. Infancy and summer season influence severe pneumonia risk. Multiplex RT-qPCR is valuable for accurate and timely detection of respiratory viruses in children, which facilitates management, treatment, and prevention of ARTIs.

Clinical Impact of Serious Respiratory Disease in Children Under the Age of 2 Years During the 2021-2022 Bronchiolitis Season in England, Scotland, and Ireland

BACKGROUND

Interventions introduced to reduce the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to a widespread reduction in childhood infections. However, from spring 2021 onwards the United Kingdom and Ireland experienced an unusual out-of-season epidemic of respiratory disease.

METHODS

We conducted a prospective observational study (BronchStart), enrolling children 0-23 months of age presenting with bronchiolitis, lower respiratory tract infection, or first episode of wheeze to 59 emergency departments across England, Scotland, and Ireland from May 2021 to April 2022. We combined testing data with national admissions datasets to infer the impact of respiratory syncytial virus (RSV) disease.

RESULTS

The BronchStart study collected data on 17 899 presentations for 17 164 children. Risk factors for admission and escalation of care included prematurity and congenital heart disease, but most admissions were for previously healthy term-born children. Of those aged 0-11 months who were admitted and tested for RSV, 1907 of 3912 (48.7%) tested positive. We estimate that every year in England and Scotland 28 561 (95% confidence interval, 27 637-29 486) infants are admitted with RSV infection.

CONCLUSIONS

RSV infection was the main cause of hospitalizations in this cohort, but 51.3% of admissions in infants were not associated with the virus. The majority of admissions were in previously healthy term-born infants.

A novel combined nomogram for predicting severe acute lower respiratory tract infection in children hospitalized for RSV infection during the post-COVID-19 period

Introduction

Off-season upsurge of respiratory syncytial virus (RSV) infection with changed characteristics and heightened clinical severity during the post-COVID-19 era are raising serious concerns. This study aimed to develop and validate a nomogram for predicting the risk of severe acute lower respiratory tract infection (SALRTI) in children hospitalized for RSV infection during the post-COVID-19 era using machine learning techniques.

Methods

A multicenter retrospective study was performed in nine tertiary hospitals in Yunnan, China, enrolling children hospitalized for RSV infection at seven of the nine participating hospitals during January-December 2023 into the development dataset. Thirty-nine variables covering demographic, clinical, and laboratory characteristics were collected. Primary screening and dimension reduction of data were performed using Least Absolute Shrinkage and Selection Operator (LASSO) regression, followed by identification of independent risk factors for RSV-associated SALRTI using Logistic regression, thus finally establishing a predictive nomogram model. Performance of the nomogram was internally evaluated by receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) based on the development dataset. External validation of our model was conducted using same methods based on two independent RSV cohorts comprising pediatric RSV inpatients from another two participating hospitals between January-March 2024.

Results

The development dataset included 1102 patients, 239 (21.7%) of whom developed SALRTI; while the external validation dataset included 249 patients (142 in Lincang subset and 107 in Dali subset), 58 (23.3%) of whom were diagnosed as SALRTI. Nine variables, including age, preterm birth, underlying condition, seizures, neutrophil-lymphocyte ratio (NLR), interleukin-6 (IL-6), lactate dehydrogenase (LDH), D-dimer, and co-infection, were eventually confirmed as the independent risk factors of RSV-associated SALRTI. A predictive nomogram was established via integrating these nine predictors. In both internal and external validations, ROC curves indicated that the nomogram had satisfactory discrimination ability, calibration curves demonstrated good agreement between the nomogram-predicted and observed probabilities of outcome, and DCA showed that the nomogram possessed favorable clinical application potential.

Conclusion

A novel nomogram combining several common clinical and inflammatory indicators was successfully developed to predict RSV-associated SALRTI. Good performance and clinical effectiveness of this model were confirmed by internal and external validations.

The nasopharyngeal microbiome in South African children with lower respiratory tract infection: a nested case-control study of the Drakenstein Child Health Study

Background

Lower respiratory tract infection (LRTI) is a leading cause of infant morbidity and mortality globally. LRTI may be caused by viral or bacterial infections, individually or in combination. We investigated associations between LRTI and infant nasopharyngeal (NP) viruses and bacteria in a South African birth cohort.

Methods

In a case-control study of infants enrolled in the Drakenstein Child Health Study (DCHS), LRTI cases were identified prospectively and age-matched with controls from the cohort. NP swabs were tested using quantitative real-time polymerase chain reaction (qPCR) and 16S rRNA gene amplicon sequencing. We calculated adjusted Conditional Odds Ratios (aORs) for qPCR targets and used mixed effects models to identify differentially abundant taxa between LRTI cases and controls and explore viral-bacterial interactions.

Results

Respiratory Syncytial Virus (RSV) [aOR: 5.69, 95% CI: 3.03-10.69], human rhinovirus (HRV) [1.47, 1.03-2.09], parainfluenza virus [3.46, 1.64-7.26], adenovirus [1.99, 1.08-3.68], enterovirus [2.32, 1.20-4.46], Haemophilus influenzae [1.72, 1.25-2.37], Klebsiella pneumoniae [2.66, 1.59-4.46], or high-density (> 6.9 log10 copies/mL) Streptococcus pneumoniae [1.53, 1.01-2.32] were associated with LRTI. Using 16S sequencing, LRTI was associated with increased relative abundance of Haemophilus (q = 0.0003) and decreased relative abundance of Dolosigranulum (q = 0.001), Corynebacterium (q = 0.091) and Neisseria (q = 0.004). In samples positive for RSV, Staphylococcus and Alloprevotella were present at lower relative abundance in cases than controls. In samples positive for parainfluenza virus or HRV, Haemophilus was present at higher relative abundance in cases.

Conclusions

The associations between bacterial taxa and LRTI are strikingly similar to those identified in high-income countries, suggesting a conserved phenotype. RSV was the major virus associated with LRTI. H. influenzae appears to be the major bacterial driver of LRTI, acting synergistically with viruses. The Gram-positive bacteria Dolosigranulum and Corynebacteria may protect against LRTI, while Staphylococcus was associated with reduced risk of RSV-related LRTI.

Funding

National Institutes of Health of the USA, Bill and Melinda Gates Foundation, National Research Foundation South Africa, South African Medical Research Council, L'Oréal-UNESCO For Women in Science South Africa, Australian National Health and Medical Research Council.

Respiratory syncytial virus-associated pneumonia in primary care in Malawi

OBJECTIVE

To identify the prevalence of respiratory syncytial virus (RSV) in a cohort of children under 5 years of age with World Health Organization (WHO)-defined pneumonia and the factors associated with developing severe RSV-associated community-acquired pneumonia (CAP) in primary care in a single centre in Northern Malawi.

METHODS

The BIOmarkers TO diagnose PnEumonia (BIOTOPE) study was a prospective cohort study conducted from March to June 2016 that took place in a primary care centre in Northern Malawi. Data from this study was used to identify the characteristics of children under 5 years of age who presented with RSV and WHO-defined CAP. Means, standard deviations, medians and ranges were calculated for continuous variables. A univariate logistic regression was performed to examine the potential predictor variables.

RESULTS

Four hundred and ninety-four infants presented with CAP and were eligible for inclusion in the study; RSV infection was detected in 205 (41.6%) of the infants. Eight factors were associated with increased risk for RSV CAP in the univariate model: age, born at term, presenting for care in June, crowded living environment, not being exclusively breastfed, not having received zinc or vitamin A supplementation in the last six months. Infants with RSV were more likely to have an oxygen saturation ≤92% compared to infants with other causes of pneumonia and more likely to have severe pneumonia as defined by the WHO.

CONCLUSION

This study supports that RSV-associated CAP is linked to modifiable and non-modifiable risk factors; further research is indicated to determine which interventions would be most impactful. Developing and implementing an infant or maternal vaccine could be a cost-effective way to prevent RSV-associated CAP and mortality in developing nations. More research is needed to understand seasonal patterns of CAP and research over extended periods can offer valuable insights on host, environmental and pathogen-specific factors that contribute to RSV-associated CAP.

RSV Prevention Within Reach for Older Infants and Toddlers: The Role of Active Immunization

This review article will summarize the vaccines and monoclonal antibodies currently under evaluation for the prevention of RSV disease in older infants, toddlers and young children. We will review the rationale for passive protection during the first months of life, and the role of active immunization afterwards, either with live attenuated, protein-based or mRNA vaccines.

Determining the aetiology of lower respiratory tract illness in children

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Variability in the Timing of Respiratory Syncytial Virus Epidemics in Guatemala, 2008-2018

BACKGROUND

The description of local seasonality patterns in respiratory syncytial virus (RSV) incidence is important to guide the timing of administration of RSV immunization products.

METHODS

We characterized RSV seasonality in Guatemala using the moving epidemic method (MEM) with absolute counts of RSV-associated acute respiratory infections (ARI) from hospital surveillance in Santa Rosa and Quetzaltenango departments of Guatemala.

RESULTS

From Week 17 of 2008 through Week 16 of 2018, 8487 ARI cases tested positive for RSV by rRT-PCR. Season onsets varied up to 5 months; early seasons starting in late May to early August and finishing in September to November were most common, but late seasons starting in October to November and finishing in March to April were also observed. Both epidemic patterns had similar durations ranging from 4 to 6 months. Epidemic thresholds (the levels of virus activity that signal the onset and end of a seasonal epidemic) calculated prospectively using previous seasons' data captured between 70% and 99% of annual RSV detections. Onset weeks differed by 2-10 weeks, and offset weeks differed by 2-16 weeks between the two surveillance sites.

CONCLUSIONS

Variability in the timing of seasonal RSV epidemics in Guatemala demonstrates the difficulty in precisely predicting the timing of seasonal RSV epidemics based on onset weeks from past seasons and suggests that maximal reduction in RSV disease burden would be achieved through year-round vaccination and immunoprophylaxis administration to at-risk infants.

Widespread human exposure to ledanteviruses in Uganda: A population study

Le Dantec virus (LDV), assigned to the species Ledantevirus ledantec, genus Ledantevirus, family Rhabdoviridae has been associated with human disease but has gone undetected since the 1970s. We describe the detection of LDV in a human case of undifferentiated fever in Uganda by metagenomic sequencing and demonstrate a serological response using ELISA and pseudotype neutralisation. By screening 997 individuals sampled in 2016, we show frequent exposure to ledanteviruses with 76% of individuals seropositive in Western Uganda, but lower seroprevalence in other areas. Serological cross-reactivity as measured by pseudotype-based neutralisation was confined to ledanteviruses, indicating population seropositivity may represent either exposure to LDV or related ledanteviruses. We also describe the discovery of a closely related ledantevirus in blood from the synanthropic rodent Mastomys erythroleucus. Ledantevirus infection is common in Uganda but is geographically heterogenous. Further surveys of patients presenting with acute fever are required to determine the contribution of these emerging viruses to febrile illness in Uganda.

Features and global impact of invasive fungal infections caused by Pneumocystis jirovecii: A systematic review to inform the World Health Organization fungal priority pathogens list

This systematic review evaluates the current global impact of invasive infections caused by Pneumocystis jirovecii (principally pneumonia: PJP), and was carried out to inform the World Health Organization Fungal Priority Pathogens List. PubMed and Web of Science were used to find studies reporting mortality, inpatient care, complications/sequelae, antifungal susceptibility/resistance, preventability, annual incidence, global distribution, and emergence in the past 10 years, published from January 2011 to February 2021. Reported mortality is highly variable, depending on the patient population: In studies of persons with HIV, mortality was reported at 5%-30%, while in studies of persons without HIV, mortality ranged from 4% to 76%. Risk factors for disease principally include immunosuppression from HIV, but other types of immunosuppression are increasingly recognised, including solid organ and haematopoietic stem cell transplantation, autoimmune and inflammatory disease, and chemotherapy for cancer. Although prophylaxis is available and generally effective, burdensome side effects may lead to discontinuation. After a period of decline associated with improvement in access to HIV treatment, new risk groups of immunosuppressed patients with PJP are increasingly identified, including solid organ transplant patients.

Characterization of bacterial and viral pathogens in the respiratory tract of children with HIV-associated chronic lung disease: a case-control study

INTRODUCTION

Chronic lung disease is a major cause of morbidity in African children with HIV infection; however, the microbial determinants of HIV-associated chronic lung disease (HCLD) remain poorly understood. We conducted a case-control study to investigate the prevalence and densities of respiratory microbes among pneumococcal conjugate vaccine (PCV)-naive children with (HCLD +) and without HCLD (HCLD-) established on antiretroviral treatment (ART).

METHODS

Nasopharyngeal swabs collected from HCLD + (defined as forced-expiratory-volume/second < -1.0 without reversibility postbronchodilation) and age-, site-, and duration-of-ART-matched HCLD- participants aged between 6-19 years enrolled in Zimbabwe and Malawi (BREATHE trial-NCT02426112) were tested for 94 pneumococcal serotypes together with twelve bacteria, including Streptococcus pneumoniae (SP), Staphylococcus aureus (SA), Haemophilus influenzae (HI), Moraxella catarrhalis (MC), and eight viruses, including human rhinovirus (HRV), respiratory syncytial virus A or B, and human metapneumovirus, using nanofluidic qPCR (Standard BioTools formerly known as Fluidigm). Fisher's exact test and logistic regression analysis were used for between-group comparisons and risk factors associated with common respiratory microbes, respectively.

RESULTS

A total of 345 participants (287 HCLD + , 58 HCLD-; median age, 15.5 years [IQR = 12.8-18], females, 52%) were included in the final analysis. The prevalence of SP (40%[116/287] vs. 21%[12/58], p = 0.005) and HRV (7%[21/287] vs. 0%[0/58], p = 0.032) were higher in HCLD + participants compared to HCLD- participants. Of the participants positive for SP (116 HCLD + & 12 HCLD-), 66% [85/128] had non-PCV-13 serotypes detected. Overall, PCV-13 serotypes (4, 19A, 19F: 16% [7/43] each) and NVT 13 and 21 (9% [8/85] each) predominated. The densities of HI (2 × 104 genomic equivalents [GE/ml] vs. 3 × 102 GE/ml, p = 0.006) and MC (1 × 104 GE/ml vs. 1 × 103 GE/ml, p = 0.031) were higher in HCLD + compared to HCLD-. Bacterial codetection (≥ any 2 bacteria) was higher in the HCLD + group (36% [114/287] vs. (19% [11/58]), (p = 0.014), with SP and HI codetection (HCLD + : 30% [86/287] vs. HCLD-: 12% [7/58], p = 0.005) predominating. Viruses (predominantly HRV) were detected only in HCLD + participants. Lastly, participants with a history of previous tuberculosis treatment were more likely to carry SP (adjusted odds ratio (aOR): 1.9 [1.1 -3.2], p = 0.021) or HI (aOR: 2.0 [1.2 - 3.3], p = 0.011), while those who used ART for ≥ 2 years were less likely to carry HI (aOR: 0.3 [0.1 - 0.8], p = 0.005) and MC (aOR: 0.4 [0.1 - 0.9], p = 0.039).

CONCLUSION

Children with HCLD + were more likely to be colonized by SP and HRV and had higher HI and MC bacterial loads in their nasopharynx. The role of SP, HI, and HRV in the pathogenesis of CLD, including how they influence the risk of acute exacerbations, should be studied further.

TRIAL REGISTRATION

The BREATHE trial (ClinicalTrials.gov Identifier: NCT02426112 , registered date: 24 April 2015).

Penicillin V versus amoxicillin for pneumonia in children-a Swedish nationwide emulated target trial

OBJECTIVES

Although most countries recommend amoxicillin for paediatric pneumonia, there is a long tradition of treatment with penicillin V (PcV) in Sweden, thus not empirically covering Haemophilus influenzae. There are, however, large regional differences in treatment practice. The aim was to compare clinical outcomes (treatment failure and severe complications), in children aged 1-59 months treated with PcV vs. amoxicillin for pneumonia.

METHODS

This population-based emulated target trial included all children born in Sweden between 2001 and 2021, using national health, sociodemographic, and population registers. All pneumonia cases from hospitals and paediatric outpatient clinics in children aged 1-59 months treated as outpatients with PcV or amoxicillin between July 2005 and December 2021, were identified. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for treatment failure (newly dispensed antibiotic prescription or pneumonia-associated hospitalization day 1-14) and severe complications (lung complications, an invasive bacterial disease, admission to intensive care unit or death day 1-28) were calculated with logistic regression analysis.

RESULTS

PcV was prescribed in 14 766 cases and amoxicillin in 10 566. Treatment failure occurred in 7.7% with PcV vs. 4.7% with amoxicillin, aOR 1.76 (95% CI: 1.54-2.00). Severe complications were rare, with no significant difference between PcV and amoxicillin (0.3% vs. 0.2%, aOR 0.96, 95% CI: 0.53-1.73). Sensitivity and interaction analyses showed consistent results.

DISCUSSION

PcV treatment compared with amoxicillin, was associated with an increased risk for treatment failure but not for severe complications. The absolute risks for adverse outcomes were low in both groups suggesting a minor role of H. influenzae in paediatric pneumonia.

Multiplexed bacterial pathogen detection and clinical characteristics of orthopedic infection in hospitalized patients

Introduction

Accurate identification of the etiology of orthopedic infection is very important for correct and timely clinical management, but it has been poorly studied. In the current study we explored the association of multiple bacterial pathogens with orthopedic infection.

Methods

Hospitalized orthopedic patients were enrolled in a rural hospital in Qingdao, China. Wound or exudate swab samples were collected and tested for twelve bacterial pathogens with both culture and multiplex real time PCR.

Results and discussion

A total of 349 hospitalized orthopedic patients were enrolled including 193 cases presenting infection manifestations upon admission and 156 with no sign of infection. Orthopedic infection patients were mainly male (72.5%) with more lengthy hospital stay (median 15 days). At least one pathogen was detected in 42.5% (82/193) of patients with infection while 7.1% (11/156) in the patients without infection (P < 0.001). S. aureus was the most prevalent causative pathogen (15.5%). Quantity dependent pathogen association with infection was observed, particularly for P. aeruginosa and K. pneumoniae, possibly indicating subclinical infection. Most of the patients with detected pathogens had a previous history of orthopedic surgery (odds ratio 2.8, P = 0.038). Pathogen specific clinical manifestations were characterized. Multiplex qPCR, because of its high sensitivity, superior specificity, and powerful quantification could be utilized in combination with culture to guide antimicrobial therapy and track the progression of orthopedic infection during treatment.

Exploring the Relationship between Wind Patterns and Hospital Admissions Due to Respiratory Symptoms in Children

Respiratory disorders significantly impact adolescents' health, often resulting in hospital admissions. Meteorological elements such as wind patterns have emerged as potential contributors to respiratory symptoms. However, it remains uncertain whether fluctuations in wind characteristics over extended periods have a tangible impact on respiratory health, particularly in regions characterized by distinct annual wind patterns. Crete is situated in the central-eastern Mediterranean Sea and frequently faces southerly winds carrying Sahara Desert sand from Africa and northerly winds from the Aegean Sea. This retrospective study analyzes long-term wind direction data and their relationship to respiratory symptoms observed in children up to 14 years old admitted at the University Hospital of Heraklion between 2002 and 2010. Symptoms such as headache, dyspnea, dry cough, dizziness, tachypnea, throat ache, and earache were predominantly reported during the presence of southern winds. Fever, productive cough, and chest pain were more frequently reported during northern winds. Cough was the most common symptom regardless of the wind pattern. Southern winds were significantly associated with higher probabilities of productive or non-productive cough, headache, dyspnea, tachypnea, dizziness, earache, and throat ache. Northern winds were related to a higher incidence of productive cough. Rhinitis, asthma, allergies, pharyngitis, and sinusitis were related to southern winds, while bronchiolitis and pneumonia were associated with northern winds. These findings underscore the critical role of local climatic factors, emphasizing their potential impact on exacerbating respiratory conditions in children. Moreover, they point out the need for further research to elucidate the underlying mechanisms and develop targeted interventions for at-risk populations.

Prevalence and predictors of antibiotic prescription among patients hospitalized with viral lower respiratory tract infections in Southern Province, Sri Lanka

BACKGROUND

Antimicrobial overprescription is common for lower respiratory tract infections (LRTI), as viral and bacterial infections generally present with similar clinical features. Overprescription is associated with downstream antimicrobial resistance. This study aims to identify the prevalence and predictors of antibiotic prescription among patients hospitalized with viral LRTI.

METHODS

A prospective cohort study was conducted among patients aged ≥1 year hospitalized with viral LRTI in a tertiary care hospital in Southern Province, Sri Lanka from 2018-2021. Demographic, clinical, and laboratory data were recorded. Nasopharyngeal and blood samples were collected for multiplex polymerase chain reaction testing for 21 respiratory pathogens and procalcitonin (PCT) detection, respectively. Demographic and clinical features associated with antibiotic prescription were identified using Chi Square and t-tests; significant variables (p<0.05) were further included in multivariable logistic regression models. The potential impact of biomarker testing on antibiotic prescription was simulated using standard c-reactive protein (CRP) and PCT cut-offs.

RESULTS

Of 1217 patients enrolled, 438 (36.0%) had ≥1 respiratory virus detected, with 48.4% of these patients being male and 30.8% children. Influenza A (39.3%) and human rhinovirus/ enterovirus (28.3%) were most commonly detected. A total of 114 (84.4%) children and 266 (87.8%) adults with respiratory viruses were treated with antibiotics. Among children, neutrophil percentage (median 63.6% vs 47.6%, p = 0.04) was positively associated with antibiotic prescription. Among adults, headache (60.6% vs 35.1%, p = 0.003), crepitations/crackles (55.3% vs 21.6%, p<0.001), rhonchi/wheezing (42.9% vs 18.9%, p = 0.005), and chest x-ray opacities (27.4% vs 8.1%, p = 0.01) were associated with antibiotic prescription. Access to CRP and procalcitonin test results could have potentially decreased inappropriate antibiotic prescription in this study by 89.5% and 83.3%, respectively.

CONCLUSIONS

High proportions of viral detection and antibiotic prescription were observed among a large inpatient cohort with LRTI. Increased access to point-of-care biomarker testing may improve antimicrobial prescription.

Ensuring progress on sustainable access to effective antibiotics at the 2024 UN General Assembly: a target-based approach

Rising antimicrobial resistance (AMR) is a global health crisis for countries of all economic levels, alongside the broader challenge of access to antibiotics. As a result, development goals for child survival, healthy ageing, poverty reduction, and food security are at risk. Preserving antimicrobial effectiveness, a global public good, requires political will, targets, accountability frameworks, and funding. The upcoming second high-level meeting on AMR at the UN General Assembly (UNGA) in September, 2024, is evidence of political interest in addressing the problem of AMR, but action on targets, accountability, and funding, absent from the 2016 UNGA resolution, is needed. We propose ambitious yet achievable global targets for 2030 (relative to a prepandemic 2019 baseline): a 10% reduction in mortality from AMR; a 20% reduction in inappropriate human antibiotic use; and a 30% reduction in inappropriate animal antibiotic use. Given national variation in current levels of antibiotic use, these goals (termed the 10-20-30 by 2030) should be met within a framework of universal access to effective antibiotics. The WHO Access, Watch, Reserve (AWARE) system can be used to define, monitor, and evaluate appropriate levels of antibiotic use and access. Some countries should increase access to narrow-spectrum, safe, and affordable (Access) antibiotics, whereas others should discourage the inappropriate use of broader-spectrum (Watch) and last-resort (Reserve) antibiotics; AWARE targets should use a risk-based, burden-adjusted approach. Improved infection prevention and control, access to clean water and sanitation, and vaccination coverage can offset the selection effects of increased antibiotic use in low-income settings. To ensure accountability and global scientific guidance and consensus, we call for the establishment of the Independent Panel on Antimicrobial Access and Resistance and the support of leaders from low-income and middle-income countries.

Nutritional supplementation in children with severe pneumonia in Uganda and Kenya (COAST-Nutrition): a phase 2 randomised controlled trial

Background

Severe pneumonia in African children results in poor long-term outcomes (deaths/readmissions) with undernutrition as a key risk factor. We hypothesised additional energy/protein-rich Ready-to-Use Therapeutic Foods (RUTF) would meet additional nutritional requirements and improve outcomes.

Methods

COAST-Nutrition was an open-label Phase 2 randomised controlled trial in children (aged 6 months-12 years) hospitalised with severe pneumonia (and hypoxaemia, SpO2 <92%) in Mbale, Soroti, Jinja, Masaka Regional Referral Hospitals, Uganda and Kilifi County Hospital, Kenya (ISRCTN10829073 (registered 6th June 2018) PACTR202106635355751 (registered 2nd June 2021)). Children were randomised (ratio 1:1) to enhanced nutritional supplementation with RUTF (plus usual diet) for 56 days vs usual diet (control). The primary outcome was change in mid-upper arm circumference (MUAC) at 90 days as a composite with mortality. Secondary outcomes include anthropometric status, mortality, and readmissions at Days 28, 90 and 180.

Findings

Between 12 August 2018 and 22 April 2022, 846 eligible children were randomised, 424 to RUTF and 422 to usual diet, and followed for 180-days [12 (1%) lost-to-follow-up]. RUTF supplement was initiated in 417/419 (>99%). By Day 90, there was no significant difference in the composite endpoint (probabilistic index 0.49, 95% CI 0.45-0.53, p = 0.74). Respective 90-day mortality (13/420 3.1% vs 14/421 3.3%) and MUAC increment (0.54 (SD 0.85) vs 0.55 (SD 0.81)) were similar between arms. There was no difference in any anthropometric secondary endpoints to Day 28, 90 or 180 except skinfold thickness at Day 28 and Day 90 was greater in the RUTF arm. Serious adverse events were higher in the RUTF arm (n = 164 vs 108), mainly due to hospital readmission for acute illness (54/387 (14%) vs 37/375 (10%).

Interpretation

Our study suggested that nutritional supplementation with RUTF did not improve outcomes to 180 days in children with severe pneumonia.

Funding

This trial is part of the EDCTP2 programme (grant number RIA-2016S-1636-COAST-Nutrition) supported by the European Union, and UK Joint Global Health Trials scheme: Medical Research Council, Department for International Development, Wellcome Trust (grant number MR/L004364/1, UK).

Safety and Immunogenicity of an mRNA-Based hMPV/PIV3 Combination Vaccine in Seropositive Children

OBJECTIVES

Human metapneumovirus (hMPV) and parainfluenza virus type 3 (PIV3) are common respiratory illnesses in children. The safety and immunogenicity of an investigational mRNA-based vaccine, mRNA-1653, encoding membrane-anchored fusion proteins of hMPV and PIV3, was evaluated in hMPV/PIV3-seropositive children.

METHODS

In this phase 1b randomized, observer-blind, placebo-controlled, dose-ranging study, hMPV/PIV3-seropositive children were enrolled sequentially into 2 dose levels of mRNA-1653 administered 2 months apart; children aged 12 to 36 months were randomized (1:1) to receive 10-μg of mRNA-1653 or placebo and children aged 12 to 59 months were randomized (3:1) to receive 30-μg of mRNA-1653 or placebo.

RESULTS

Overall, 27 participants aged 18 to 55 months were randomized; 15 participants received 10-μg of mRNA-1653 (n = 8) or placebo (n = 7), whereas 12 participants received 30-μg of mRNA-1653 (n = 9) or placebo (n = 3). mRNA-1653 was well-tolerated at both dose levels. The only reported solicited local adverse reaction was tenderness at injection site; solicited systemic adverse reactions included grade 1 or 2 chills, irritability, loss of appetite, and sleepiness. A single 10-μg or 30-μg mRNA-1653 injection increased hMPV and PIV3 neutralizing antibody titers (geometric mean fold-rise ratio over baseline: hMPV-A = 2.9-6.1; hMPV-B = 6.2-13.2; PIV3 = 2.8-3.0) and preF and postF binding antibody concentrations (geometric mean fold-rise ratio: hMPV preF = 5.3-6.1; postF = 4.6-6.5 and PIV3 preF = 13.9-14.2; postF = 11.0-12.1); a second injection did not further increase antibody levels in these seropositive children. Binding antibody responses were generally preF biased.

CONCLUSIONS

mRNA-1653 was well-tolerated and boosted hMPV and PIV3 antibody levels in seropositive children aged 12 to 59 months, supporting the continued development of mRNA-1653 or its components for the prevention of hMPV and PIV3.

Impact of respiratory viral infections on nasopharyngeal pneumococcal colonization dynamics in children

PURPOSE OF REVIEW

Prevention of acute respiratory illnesses (ARI) in children is a global health priority, as these remain a leading cause of pediatric morbidity and mortality throughout the world. As new products and strategies to prevent respiratory infections caused by important pathogens such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza, respiratory syncytial virus and pneumococcus are advancing, increasing evidence suggests that these and other respiratory viruses and pneumococci may exhibit interactions that are associated with altered colonization and disease dynamics. We aim to review recent data evaluating interactions between respiratory viruses and pneumococci in the upper respiratory tract and their potential impact on pneumococcal colonization patterns and disease outcomes.

RECENT FINDINGS

While interactions between influenza infection and subsequent increased susceptibility and transmissibility of colonizing pneumococci have been widely reported in the literature, emerging evidence suggests that human rhinovirus, SARS-CoV-2, and other viruses may also exhibit interactions with pneumococci and alter pneumococcal colonization patterns. Additionally, colonizing pneumococci may play a role in modifying outcomes associated with respiratory viral infections. Recent evidence suggests that vaccination with pneumococcal conjugate vaccines, and prevention of colonization with pneumococcal serotypes included in these vaccines, may be associated with reducing the risk of subsequent viral infection and the severity of the associated illnesses.

SUMMARY

Understanding the direction and dynamics of viral-pneumococcal interactions may elucidate the potential effects of existing and emerging viral and bacterial vaccines and other preventive strategies on the health impact of these important respiratory pathogens.

Burden of bacterial antimicrobial resistance in low-income and middle-income countries avertible by existing interventions: an evidence review and modelling analysis

National action plans enumerate many interventions as potential strategies to reduce the burden of bacterial antimicrobial resistance (AMR). However, knowledge of the benefits achievable by specific approaches is needed to inform policy making, especially in low-income and middle-income countries (LMICs) with substantial AMR burden and low health-care system capacity. In a modelling analysis, we estimated that improving infection prevention and control programmes in LMIC health-care settings could prevent at least 337 000 (95% CI 250 200-465 200) AMR-associated deaths annually. Ensuring universal access to high-quality water, sanitation, and hygiene services would prevent 247 800 (160 000-337 800) AMR-associated deaths and paediatric vaccines 181 500 (153 400-206 800) AMR-associated deaths, from both direct prevention of resistant infections and reductions in antibiotic consumption. These estimates translate to prevention of 7·8% (5·6-11·0) of all AMR-associated mortality in LMICs by infection prevention and control, 5·7% (3·7-8·0) by water, sanitation, and hygiene, and 4·2% (3·4-5·1) by vaccination interventions. Despite the continuing need for research and innovation to overcome limitations of existing approaches, our findings indicate that reducing global AMR burden by 10% by the year 2030 is achievable with existing interventions. Our results should guide investments in public health interventions with the greatest potential to reduce AMR burden.

Sufficient and Necessary Conditions for the Identifiability of DINA Models with Polytomous Responses

Cognitive diagnosis models (CDMs) provide a powerful statistical and psychometric tool for researchers and practitioners to learn fine-grained diagnostic information about respondents' latent attributes. There has been a growing interest in the use of CDMs for polytomous response data, as more and more items with multiple response options become widely used. Similar to many latent variable models, the identifiability of CDMs is critical for accurate parameter estimation and valid statistical inference. However, the existing identifiability results are primarily focused on binary response models and have not adequately addressed the identifiability of CDMs with polytomous responses. This paper addresses this gap by presenting sufficient and necessary conditions for the identifiability of the widely used DINA model with polytomous responses, with the aim to provide a comprehensive understanding of the identifiability of CDMs with polytomous responses and to inform future research in this field.

Effect of maternal vaccination on infant morbidity in Bangladesh

BACKGROUND

Risk factors of infant mortality in Africa and south Asian countries have been broadly discussed. However, infant morbidity is largely underestimated. We analyzed the data from a randomized vaccine trial in Bangladesh to identify and assess the effect of risk factors on infant morbidity.

METHODS

Pregnant women were randomly assigned to receive either inactivated influenza vaccine or pneumococcal polysaccharide vaccine and the infants were randomly assigned to receive 7-valent pneumococcal conjugate vaccine or Hib conjugate vaccine at week 6, 10 and 14. The data were collected from August 2004 through December 2005. Each pair of infant and mother were followed for 24 weeks after birth with weekly visits. Generalized estimating equations (GEE) for repeated measurements and Poisson regression models were used to identify the risk factors and evaluate their effect on the longitudinal incidence and total number of episodes of respiratory illness with fever (RIF), diarrhea disease, ear problem and pneumonia.

RESULTS

A total of 340 pregnant women were randomized with mean age of 25 years. The baseline mother and infant characteristics were similar between two treatment groups. Exclusive breastfeeding and higher paternal education level were common factors associated with lower infant morbidity of RIF (adjusted OR = 0.40 and 0.94 with p < 0.01 and p = 0.02, respectively), diarrhea disease (adjusted OR = 0.39 and 0.95 with p < 0.01 and p = 0.04, respectively), and ear problem (adjusted OR = 0.20 and 0.76 with p < 0.01 and p < 0.01, respectively). Maternal influenza vaccine significantly reduced the incidence of RIF (adjusted OR = 0.54; p < 0.01) but not diarrhea disease or ear problem (p > 0.05). Female infants had lower incidence of diarrhea disease (adjusted OR = 0.67; p = 0.01) and ear problem (adjusted OR = 0.12; p = 0.01).

CONCLUSIONS

Maternal influenza vaccination, exclusive breastfeeding, female children, and higher paternal education level significantly reduced the infant morbidity within the 24 weeks after birth in Bangladesh.

The full value of immunisation against respiratory syncytial virus for infants younger than 1 year: effects beyond prevention of acute respiratory illness

Respiratory syncytial virus (RSV) is a leading cause of severe respiratory illness and death among children worldwide, particularly in children younger than 6 months and in low-income and middle-income countries. Feasible and cost-effective interventions to prevent RSV disease are not yet widely available, although two new products aimed at preventing RSV disease-long-acting monoclonal antibodies and maternal vaccines-have been licensed within the past 2 years. The primary target of these products is reduction of the substantial burden of RSV-associated acute lower respiratory tract infections (LRTI) in infants younger than 1 year. However, other important public health benefits might also accrue with the prevention of RSV-associated LRTI during the first year of life. Mounting evidence shows that preventing RSV-associated LRTI in infants younger than 1 year could prevent secondary pneumonia caused by other pathogens, reduce recurrent hospitalisations due to other respiratory diseases in later childhood, decrease all-cause infant mortality, ameliorate the burden of respiratory diseases on health-care systems, reduce inappropriate antibiotic use, and possibly improve lung health beyond infancy. We herein review current evidence and suggest approaches to better assess the magnitude of these potential secondary effects of RSV prevention, which, if proven substantial, are likely to be relevant to policy makers in many countries as they consider the use of these new products.

Risk Factors for Poor Outcomes in Children Hospitalized With Virus-associated Acute Lower Respiratory Infections: A Systematic Review and Meta-analysis

BACKGROUND

Acute lower respiratory infection (ALRI) caused by respiratory viruses is among the most common causes of hospitalization and mortality in children. We aimed to identify risk factors for poor outcomes in children <5 years old hospitalized with ALRI caused by respiratory syncytial virus (RSV), influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

METHODS

We searched Embase, Medline and Global Health databases and included observational studies reporting risk factors for poor outcomes (defined as use of supplemental oxygen, mechanical ventilation, intensive care unit admission, prolonged hospital stay and mortality) published between January 2011 and January 2023. Two authors independently extracted data on study characteristics, outcomes and risk factors. Due to limited data, meta-analyses were only conducted for RSV-ALRI poor outcome risk factors using random effects model when there were at least 3 studies.

RESULTS

We included 30 studies. For RSV-related ALRI, significant risk factors based on meta-analysis were: neurological disease [odds ratio (OR): 6.14; 95% confidence intervals (CIs): 2.39-15.77], Down's syndrome (5.43; 3.02-9.76), chronic lung disease (3.64; 1.31-10.09), immunocompromised status (3.41; 1.85-6.29), prematurity (2.98; 1.93-4.59), congenital heart disease (2.80; 1.84-4.24), underlying disease (2.45; 1.94-3.09), age <2 months (2.29; 1.78-2.94), age <6 months (2.08; 1.81-2.39), viral coinfection (2.01; 1.27-3.19), low birth weight (1.88; 1.19-2.95) and being underweight (1.80; 1.38-2.35). For influenza-related ALRI, chronic conditions and age 6-24 months were identified as risk factors for poor outcomes. Cardiovascular disease, immunosuppression, chronic kidney disease, diabetes and high blood pressure were reported as risk factors for mortality due to SARS-CoV-2 associated ALRI.

CONCLUSIONS

These findings might contribute to the development of guidelines for prophylaxis and management of ALRI caused by RSV, influenza and SARS-CoV-2.

Identification of distinct genotypes in circulating RSV A strains based on variants on the virus replication-associated genes

Respiratory syncytial virus is a common cause of respiratory infection that often leads to hospitalization of infected younger children and older adults. RSV is classified into two strains, A and B, each with several subgroups or genotypes. One issue with the definition of these subgroups is the lack of a unified method of identification or genotyping. We propose that genotyping strategies based on the genes coding for replication-associated proteins could provide critical information on the replication capacity of the distinct subgroup, while clearly distinguishing genotypes. Here, we analyzed the virus replication-associated genes N, P, M2, and L from de novo assembled RSV A sequences obtained from 31 newly sequenced samples from hospitalized patients in Philadelphia and 78 additional publicly available sequences from different geographic locations within the US. In-depth analysis and annotation of the protein variants in L and the other replication-associated proteins N, P, M2-1, and M2-2 identified the polymerase protein L as a robust target for genotyping RSV subgroups. Importantly, our analysis revealed non-synonymous variations in L that were consistently accompanied by conserved changes in its co-factor P or the M2-2 protein, suggesting associations and interactions between specific domains of these proteins. These results highlight L as an alternative to other RSV genotyping targets and demonstrate the value of in-depth analyses and annotations of RSV sequences as it can serve as a foundation for subsequent in vitro and clinical studies on the efficiency of the polymerase and fitness of different virus isolates.

Observations of Respiratory Syncytial Virus (RSV) Nucleic Acids in Wastewater Solids Across the United States in the 2022-2023 Season: Relationships with RSV Infection Positivity and Hospitalization Rates

Respiratory syncytial virus (RSV) is a leading cause of respiratory illness and hospitalization, but clinical surveillance detects only a minority of cases. Wastewater surveillance could determine the onset and extent of RSV circulation in the absence of sensitive case detection, but to date, studies of RSV in wastewater are few. We measured RSV RNA concentrations in wastewater solids from 176 sites during the 2022-2023 RSV season and compared those to publicly available RSV infection positivity and hospitalization rates. Concentrations ranged from undetectable to 107 copies per gram. RSV RNA concentration aggregated at state and national levels correlated with infection positivity and hospitalization rates. RSV season onset was determined using both wastewater and clinical positivity rates using independent algorithms for 14 states where both data were available at the start of the RSV season. In 4 of 14 states, wastewater and clinical surveillance identified RSV season onset during the same week; in 3 states, wastewater onset preceded clinical onset, and in 7 states, wastewater onset occurred after clinical onset. Wastewater concentrations generally peaked in the same week as hospitalization rates but after case positivity rates peaked. Differences in onset and peaks in wastewater versus clinical data may reflect inherent differences in the surveillance approaches.

Parental awareness and attitudes towards prevention of respiratory syncytial virus in infants and young children in Australia

AIM

To assess parental awareness of respiratory syncytial virus (RSV) and the level of acceptance of future RSV prevention strategies.

METHODS

A cross-sectional online survey was implemented targeting "future" and "current" parents of children aged ≤5 years in Australia.

RESULTS

From 1992 eligible participants, two non-mutually exclusive subgroups were formed: "current" parents (N = 1931) and "pregnant/planning" parents (N = 464: 403 also "current" parents and 61 "future" parents). Participants were predominantly (86.6%) aged 25-39 years and 68.5% with university education. The majority (89.6% current; 78.7% future) had heard of RSV. Of those, 64.2% (current) and 50.0% (future) were aware that pneumonia is associated with RSV; 71.8% (current) and 52.1% (future) were aware that bronchiolitis is associated with RSV. In multivariable logistic regression analyses, Australian-born parents (aOR = 2.47 [95% CI: 1.48-4.12]), living in the eastern states (e.g., New South Wales: aOR = 6.15 [95% CI:2.10-18.04]), with a university-level education (aOR = 2.61 [95% CI:1.38-4.94]) and being a current parent (aOR = 12.26 [95% CI:2.82-53.28]) were associated with higher RSV awareness. There was a high level of acceptance for maternal vaccines (future: 79.3%) and infant immunisation (all: 81.7%).

CONCLUSION

While RSV awareness and immunisation acceptance were high, there was limited knowledge of severity of RSV, especially in future parents. Education campaigns need to be developed to increase RSV knowledge.

Global disease burden of and risk factors for acute lower respiratory infections caused by respiratory syncytial virus in preterm infants and young children in 2019: a systematic review and meta-analysis of aggregated and individual participant data

BACKGROUND

Infants and young children born prematurely are at high risk of severe acute lower respiratory infection (ALRI) caused by respiratory syncytial virus (RSV). In this study, we aimed to assess the global disease burden of and risk factors for RSV-associated ALRI in infants and young children born before 37 weeks of gestation.

METHODS

We conducted a systematic review and meta-analysis of aggregated data from studies published between Jan 1, 1995, and Dec 31, 2021, identified from MEDLINE, Embase, and Global Health, and individual participant data shared by the Respiratory Virus Global Epidemiology Network on respiratory infectious diseases. We estimated RSV-associated ALRI incidence in community, hospital admission, in-hospital mortality, and overall mortality among children younger than 2 years born prematurely. We conducted two-stage random-effects meta-regression analyses accounting for chronological age groups, gestational age bands (early preterm, <32 weeks gestational age [wGA], and late preterm, 32 to <37 wGA), and changes over 5-year intervals from 2000 to 2019. Using individual participant data, we assessed perinatal, sociodemographic, and household factors, and underlying medical conditions for RSV-associated ALRI incidence, hospital admission, and three severity outcome groups (longer hospital stay [>4 days], use of supplemental oxygen and mechanical ventilation, or intensive care unit admission) by estimating pooled odds ratios (ORs) through a two-stage meta-analysis (multivariate logistic regression and random-effects meta-analysis). This study is registered with PROSPERO, CRD42021269742.

FINDINGS

We included 47 studies from the literature and 17 studies with individual participant-level data contributed by the participating investigators. We estimated that, in 2019, 1 650 000 (95% uncertainty range [UR] 1 350 000-1 990 000) RSV-associated ALRI episodes, 533 000 (385 000-730 000) RSV-associated hospital admissions, 3050 (1080-8620) RSV-associated in-hospital deaths, and 26 760 (11 190-46 240) RSV-attributable deaths occurred in preterm infants worldwide. Among early preterm infants, the RSV-associated ALRI incidence rate and hospitalisation rate were significantly higher (rate ratio [RR] ranging from 1·69 to 3·87 across different age groups and outcomes) than for all infants born at any gestational age. In the second year of life, early preterm infants and young children had a similar incidence rate but still a significantly higher hospitalisation rate (RR 2·26 [95% UR 1·27-3·98]) compared with all infants and young children. Although late preterm infants had RSV-associated ALRI incidence rates similar to that of all infants younger than 1 year, they had higher RSV-associated ALRI hospitalisation rate in the first 6 months (RR 1·93 [1·11-3·26]). Overall, preterm infants accounted for 25% (95% UR 16-37) of RSV-associated ALRI hospitalisations in all infants of any gestational age. RSV-associated ALRI in-hospital case fatality ratio in preterm infants was similar to all infants. The factors identified to be associated with RSV-associated ALRI incidence were mainly perinatal and sociodemographic characteristics, and factors associated with severe outcomes from infection were mainly underlying medical conditions including congenital heart disease, tracheostomy, bronchopulmonary dysplasia, chronic lung disease, or Down syndrome (with ORs ranging from 1·40 to 4·23).

INTERPRETATION

Preterm infants face a disproportionately high burden of RSV-associated disease, accounting for 25% of RSV hospitalisation burden. Early preterm infants have a substantial RSV hospitalisation burden persisting into the second year of life. Preventive products for RSV can have a substantial public health impact by preventing RSV-associated ALRI and severe outcomes from infection in preterm infants.

FUNDING

EU Innovative Medicines Initiative Respiratory Syncytial Virus Consortium in Europe.