Respiratory syncytial and influenza viruses in children under 2 years old with severe acute respiratory infection (SARI) in Maputo, 2015

Risk factors and circulation pattern of respiratory syncytial virus in children under 2 years in Maputo, Mozambique

BACKGROUND

Evidence on risk factors for respiratory syncytial virus (RSV) in low-resource settings is limited. In Mozambican children <2 y of age with severe acute respiratory infection (SARI), we explored risk factors for RSV, described its seasonal variation and assessed associations between RSV and a life-threatening condition.

METHODS

We retrospectively included participants presenting in 2017-2018 in two hospitals in Maputo. RSV was detected and subtyped using real-time quantitative reverse transcription polymerase chain reaction on nasopharyngeal swabs. We used logistic regression and χ2 tests to assess associations and Spearman's correlation coefficient to assess the correlation between weather measurement and RSV positivity.

RESULTS

RSV was detected in 23.1% (n=109) of 472 included children and in 50.0% (20/40) of those <3 months old. Being <3 months (vs >1 y) was associated with RSV (adjusted odds ratio 4.3 [95% confidence interval 2.1-8.5]). RSV status was not associated with experiencing a life-threatening condition. RSV A and B co-circulated during the study period, but one type predominated in each year. In 2017, the RSV positivity rate was correlated with monthly average temperature (r=0.793, p=0.002) and precipitation (r=0.596, p=0.041).

CONCLUSIONS

In Mozambican children with SARI, RSV was prevalent, especially in neonates. However, RSV was not associated with a life-threatening condition.

Prevalence of Respiratory Syncytial Virus Among Children Under 5 Years of Age in Sub-Saharan Africa

Background. Pneumonia and bronchiolitis are common childhood illnesses caused by the respiratory syncytial virus. A systematic analysis of published epidemiological data in sub-Saharan African children under the age of 5 was conducted. Methods. To retrieve literature, electronic databases, indexing services, and directories such as PubMed/MEDLINE, Scopus, EMBASE (Elsevier), Google Scholar, and Worldcat were utilized. Data from the included studies were extracted after screening and eligibility evaluation. Results. The pooled prevalence rate of respiratory syncytial virus was 21% (95% CI: 17, 25). Subgroup analysis based on participants' ages showed that, prevalence was highest in children <6 months (32%). High prevalence was also found in children who were hospitalized (27%), children co-infected with HIV (28%), and children co-infected with bacteria respiratory pathogens (22%). Conclusion. The prevalence of respiratory syncytial virus infection was high in children in sub-Saharan African countries. Therefore, it should be prioritized as a major health problem.

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.

Acute lower respiratory infections among children under five in Sub-Saharan Africa: a scoping review of prevalence and risk factors

BACKGROUND

Acute lower respiratory tract infections (ALRTIs) among children under five are still the leading cause of mortality among this group of children in low and middle-income countries (LMICs), especially countries in sub-Saharan Africa (SSA). This scoping review aims to map evidence on prevalence and risk factors associated with ALRTIs among children under 5 years to inform interventions, policies and future studies.

METHODS

A thorough search was conducted via four main databases (PubMed, JSTOR, Web of Science and Central). In all, 3,329 records were identified, and 107 full-text studies were considered for evaluation after vigorous screening and removing duplicates, of which 43 were included in this scoping review.

FINDINGS

Findings indicate a high prevalence (between 1.9% to 60.2%) of ALRTIs among children under five in SSA. Poor education, poverty, malnutrition, exposure to second-hand smoke, poor ventilation, HIV, traditional cooking stoves, unclean fuel usage, poor sanitation facilities and unclean drinking water make children under five more vulnerable to ALRTIs in SSA. Also, health promotion strategies like health education have doubled the health-seeking behaviours of mothers of children under 5 years against ALRTIs.

CONCLUSION

ALRTIs among children under five still present a significant disease burden in SSA. Therefore, there is a need for intersectoral collaboration to reduce the burden of ALRTIs among children under five by strengthening poverty alleviation strategies, improving living conditions, optimising child nutrition, and ensuring that all children have access to clean water. There is also the need for high-quality studies where confounding variables in ALRTIs are controlled.

Cost-effectiveness of pharmaceutical strategies to prevent respiratory syncytial virus disease in young children: a decision-support model for use in low-income and middle-income countries

BACKGROUND

Respiratory syncytial virus (RSV) is a leading cause of respiratory disease in young children. A number of mathematical models have been used to assess the cost-effectiveness of RSV prevention strategies, but these have not been designed for ease of use by multidisciplinary teams working in low-income and middle-income countries (LMICs).

METHODS

We describe the UNIVAC decision-support model (a proportionate outcomes static cohort model) and its approach to exploring the potential cost-effectiveness of two RSV prevention strategies: a single-dose maternal vaccine and a single-dose long-lasting monoclonal antibody (mAb) for infants. We identified model input parameters for 133 LMICs using evidence from the literature and selected national datasets. We calculated the potential cost-effectiveness of each RSV prevention strategy (compared to nothing and to each other) over the lifetimes of all children born in the year 2025 and compared our results to a separate model published by PATH. We ran sensitivity and scenario analyses to identify the inputs with the largest influence on the cost-effectiveness results.

RESULTS

Our illustrative results assuming base case input assumptions for maternal vaccination ($3.50 per dose, 69% efficacy, 6 months protection) and infant mAb ($3.50 per dose, 77% efficacy, 5 months protection) showed that both interventions were cost-saving compared to status quo in around one-third of 133 LMICs, and had a cost per DALY averted below 0.5 times the national GDP per capita in the remaining LMICs. UNIVAC generated similar results to a separate model published by PATH. Cost-effectiveness results were most sensitive to changes in the price, efficacy and duration of protection of each strategy, and the rate (and cost) of RSV hospital admissions.

CONCLUSIONS

Forthcoming RSV interventions (maternal vaccines and infant mAbs) are worth serious consideration in LMICs, but there is a good deal of uncertainty around several influential inputs, including intervention price, efficacy, and duration of protection. The UNIVAC decision-support model provides a framework for country teams to build consensus on data inputs, explore scenarios, and strengthen the local ownership and policy-relevance of results.

What are the risk factors for death among children with pneumonia in low- and middle-income countries? A systematic review

Background

Knowledge of the risk factors for and causes of treatment failure and mortality in childhood pneumonia is important for prevention, diagnosis, and treatment at an individual and population level. This review aimed to identify the most important risk factors for mortality among children aged under ten years with pneumonia.

Methods

We systematically searched MEDLINE, EMBASE, and PubMed for observational and interventional studies reporting risk factors for mortality in children (aged two months to nine years) in low- and middle-income countries (LMICs). We screened articles according to specified inclusion and exclusion criteria, assessed risk of bias using the EPHPP framework, and extracted data on demographic, clinical, and laboratory risk factors for death. We synthesized data descriptively and using Forest plots and did not attempt meta-analysis due to the heterogeneity in study design, definitions, and populations.

Findings

We included 143 studies in this review. Hypoxaemia (low blood oxygen level), decreased conscious state, severe acute malnutrition, and the presence of an underlying chronic condition were the risk factors most strongly and consistently associated with increased mortality in children with pneumonia. Additional important clinical factors that were associated with mortality in the majority of studies included particular clinical signs (cyanosis, pallor, tachypnoea, chest indrawing, convulsions, diarrhoea), chronic comorbidities (anaemia, HIV infection, congenital heart disease, heart failure), as well as other non-severe forms of malnutrition. Important demographic factors associated with mortality in the majority of studies included age <12 months and inadequate immunisation. Important laboratory and investigation findings associated with mortality in the majority of studies included: confirmed Pneumocystis jirovecii pneumonia (PJP), consolidation on chest x-ray, pleural effusion on chest x-ray, and leukopenia. Several other demographic, clinical and laboratory findings were associated with mortality less consistently or in a small numbers of studies.

Conclusions

Risk assessment for children with pneumonia should include routine evaluation for hypoxaemia (pulse oximetry), decreased conscious state (e.g. AVPU), malnutrition (severe, moderate, and stunting), and the presence of an underlying chronic condition as these are strongly and consistently associated with increased mortality. Other potentially useful risk factors include the presence of pallor or anaemia, chest indrawing, young age (<12 months), inadequate immunisation, and leukopenia.

Systematic literature review of the signs and symptoms of respiratory syncytial virus

Respiratory syncytial virus (RSV) is responsible for over 30 million lower respiratory tract infections (LRTIs) and 3 million hospitalizations worldwide each year. Despite the risk RSV poses to young children, older adults, and individuals with comorbidities or suppressed immunity, there is limited understanding of RSV symptom presentation across these at-risk groups, and there is no vaccine for RSV. We conducted two systematic literature reviews (SLRs) of studies that document signs and symptoms (S&S) of RSV in (1) children aged ≤5 years and (2) immunocompromised adolescents and adults, and adults at high risk for severe RSV due to age or comorbidities. Symptom duration and hospital length of stay (LOS) were explored. Electronic database searches were performed following PRISMA guidelines. Studies captured RSV S&S across community and hospital settings. Clinicians and caregivers reported (n = 25 studies) nasal discharge/congestion, cough, shortness of breath, feeding abnormalities, and fever in ≥40% of children across studies and settings. Median hospital stays for children ranged from 2 days in the United States to 7.5 days in China. High-risk adults with RSV (n = 6 studies) commonly (≥40% of adults) reported cough, sputum, dyspnea, and fever/feverishness. Median length of hospital stay in adults ranged from 6 to 15 days across studies. Caregivers and clinicians reported similar RSV S&S in young children, including upper and lower respiratory and systemic symptoms. In high-risk and immunocompromised adults, the most frequent (in multiple publications) and commonly reported RSV S&S were primarily LRTI symptoms. RSV symptoms could last for weeks and are variable based on geography.

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

Background

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

Methods

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

Results

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

Conclusions

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

Registration

PROSPERO CRD42022327054.

The Global Epidemiology of RSV in Community and Hospitalized Care: Findings From 15 Countries

BACKGROUND

Respiratory syncytial virus (RSV) is one of the leading causes of acute respiratory tract infections. To optimize control strategies, a better understanding of the global epidemiology of RSV is critical. To this end, we initiated the Global Epidemiology of RSV in Hospitalized and Community care study (GERi).

METHODS

Focal points from 44 countries were approached to join GERi and share detailed RSV surveillance data. Countries completed a questionnaire on the characteristics of their surveillance system.

RESULTS

Fifteen countries provided granular surveillance data and information on their surveillance system. A median (interquartile range) of 1641 (552-2415) RSV cases per season were reported from 2000 and 2020. The majority (55%) of RSV cases occurred in the <1-year-olds, with 8% of cases reported in those aged ≥65 years. Hospitalized cases were younger than those in community care. We found no age difference between RSV subtypes and no clear pattern of dominant subtypes.

CONCLUSIONS

The high number of cases in the <1-year-olds indicates a need to focus prevention efforts in this group. The minimal differences between RSV subtypes and their co-circulation implies that prevention needs to target both subtypes. Importantly, there appears to be a lack of RSV surveillance data in the elderly.

Respiratory syncytial virus in severe lower respiratory infections in previously healthy young Ethiopian infants

BACKGROUND

Respiratory Syncytial Virus (RSV) is the commonest cause of acute lower respiratory infections (ALRI) in infants. However, the burden of RSV is unknown in Ethiopia. We aimed to determine the prevalence, seasonality and predictors of RSV infection in young infants with ALRI for the first time in Ethiopia.

METHODS

We performed RSV immuno-chromatographic assay from nasopharyngeal swabs of infants, 29 days to 6 months of age. We included the first 10 eligible infants in each month from June 2018 to May 2019 admitted in a tertiary pediatric center. Clinical, laboratory and imaging data were also collected, and chi-square test and regression were used to assess associated factors with RSV infection.

RESULTS

Among a total of 117 study children, 65% were male and mean age was 3 months. Bronchiolitis was the commonest diagnosis (49%). RSV was isolated from 26 subjects (22.2%) of all ALRI, 37% of bronchiolitis and 11% of pneumonia patients. Although RSV infection occurred year round, highest rate extended from June to November. No clinical or laboratory parameter predicted RSV infection and only rainy season (Adjusted Odds Ratio (AOR) 10.46 [95%. C.I. 1.95, 56.18]) was independent predictor of RSV infection.

CONCLUSIONS

RSV was isolated in a fifth of young infants with severe ALRI, mostly in the rainy season. Diagnosis of RSV infection in our setting require specific tests as no clinical parameter predicted RSV infection. Since RSV caused less than a quarter of ALRI in our setting, the other causes should be looked for in future studies.

The epidemiology of seasonal influenza after the 2009 influenza pandemic in Africa: a systematic review

Background

Influenza infection is a serious public health problem that causes an estimated 3 to 5 million cases and 250,000 deaths worldwide every year. The epidemiology of influenza is well-documented in high- and middle-income countries, however minimal effort had been made to understand the epidemiology, burden and seasonality of influenza in Africa. This study aims to assess the state of knowledge of seasonal influenza epidemiology in Africa and identify potential data gaps for policy formulation following the 2009 pandemic.

Method

We reviewed articles from Africa published into four databases namely: MEDLINE (PubMed), Google Scholar, Cochrane Library and Scientific Research Publishing from 2010 to 2019.

Results

We screened titles and abstracts of 2070 studies of which 311 were selected for full content evaluation and 199 studies were considered. Selected articles varied substantially on the basis of the topics they addressed covering the field of influenza surveillance (n=80); influenza risk factors and co-morbidities (n=15); influenza burden (n=37); influenza vaccination (n=40); influenza and other respiratory pathogens (n=22) and influenza diagnosis (n=5).

Conclusion

Significant progress has been made since the last pandemic in understanding the influenza epidemiology in Africa. However, efforts still remain for most countries to have sufficient data to allow countries to prioritize strategies for influenza prevention and control.

Comparison of viral and epidemiological profiles of hospitalized children with severe acute respiratory infection in Beijing and Shanghai, China

Background

No comparison data have been reported on viral and epidemiological profiles of hospitalized children with severe acute respiratory infection (SARI) in Beijing or Shanghai, China.

Methods

We collected 700 nasopharyngeal aspirates (NPA) from hospitalized children with SARI in Beijing (northern China) and Shanghai (southern China). Multiple respiratory viruses (including 15 common viruses) were screened by validated polymerase chain reaction (PCR) or real-time reverse transcription-PCR assays and confirmed by sequencing. Demographic data and the distribution of viral infections were also examined.

Results

Of 700 samples, 547 (78.1%) tested positive for viral infections. The picornaviruses (PIC), which included rhinovirus (RV) and enterovirus (EV), were the most common (34.0%), followed by respiratory syncytial virus (RSV) (28.3%), human bocavirus (HBoV) (19.1%), adenovirus (ADV) (13.7%), human coronaviruses (HCoV) (10.7%), influenza A and B (8.9%), parainfluenza virus (PIV 1–3) (7.9%), and human metapneumovirus (HMPV) (5.0%). PIC (RV/EV) and RSV were the most prevalent etiological agents of SARI in both cities. The total and age-matched prevalence of RSV, HCoV, and hMPV among SARI children under 5 years old were significantly higher in Beijing than in Shanghai. Different age and seasonal distribution patterns of the viral infections were found between Beijing and Shanghai.

Conclusions

Viral infection was tested and shown to be the most prevalent etiological agent among children with SARI in either the Beijing or the Shanghai area, while showing different patterns of viral and epidemiological profiles. Our findings provide a better understanding of the roles of geographic location and climate in respiratory viral infections in hospitalized children with SARI.