Impact of breastfeeding on the incidence and severity of respiratory syncytial virus (RSV)-associated acute lower respiratory infections in infants: a systematic review highlighting the global relevance of primary prevention

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.

The Role of Breastfeeding in Acute Respiratory Infections in Infancy

BACKGROUND

Acute respiratory infections (ARIs) affect the respiratory tract, are often caused by viruses such as respiratory syncytial virus and rhinovirus, and present symptoms such as coughing, fever, respiratory distress and breathing difficulty. The global adherence to exclusive breastfeeding (BF) for the first 6 months of life has reached 44%, supported by World Health Organization and United Nations International Children's Emergency Fund efforts. BF provides vital nutrients and contributes to infant immune system development, protecting against infections. The role of BF in preventing and reducing complications of ARIs in infants is gaining attention, prompting a review of current data and future research needs. This review aims to summarize the evidence on the role of BF in reducing the risk and severity of ARIs in infants, elucidate the adaptations in breast milk composition during infections and identify relevant research needs.

METHODS AND RESULTS

Human milk (HM) is rich in immunoglobulins, antimicrobial peptides, and immunomodulatory factors that protect against various pathogens, including respiratory viruses. Several studies have demonstrated that BF is associated with a significant reduction in hospitalization, oxygen requirements, and mortality in infants with ARIs. The effectiveness of BF varies according to the specific respiratory virus, and a longer duration of exclusive BF appears to enhance its protective effect. It is documented that the composition of HM adjusts dynamically in response to infections, fortifying the infant's immune defenses. Specific immunological components of HM, including leukocytes and immunoglobulins, increase in response to infection in the infant, contributing to the enhancement of the immune defense in infants. Immune-boosting microRNAs enhance immune transfer to the infants and promote early gut maturation, and the HM microbiome along with other factors modifies the the infant's gut microbiome and immune system.

CONCLUSIONS

BF defends infants from respiratory infections, and the investigation of the microRNAs in HM offers new insights into its antiviral properties. The promotion of BF, especially in vulnerable communities, is of paramount importance in alleviating the global burden of ARIs in infancy.

The role of Nrf2 signaling in parasitic diseases and its therapeutic potential

In response to invading parasites, one of the principal arms of innate immunity is oxidative stress, caused by reactive oxygen species (ROS). However, oxidative stresses play dual functions in the disease, whereby free radicals promote pathogen removal, but they can also trigger inflammation, resulting in tissue injuries. A growing body of evidence has strongly supported the notion that nuclear factor erythroid 2-related factor 2 (NRF) signaling is one of the main antioxidant pathways to combat this oxidative burst against parasites. Given the important role of NRF2 in oxidative stress, in this review, we investigate the activation mechanism of the NRF2 antioxidant pathway in different parasitic diseases, such as malaria, leishmaniasis, trypanosomiasis, toxoplasmosis, schistosomiasis, entamoebiasis, and trichinosis.

Effectiveness of nirsevimab introduction against respiratory syncytial virus in the Valencian Community: A preliminary assessment

Respiratory syncytial virus (RSV) represents a high burden of disease in children and the primary cause of hospitalization, especially in children under 1 year old. In the Valencian Community (Spain), nirsevimab, a long-acting monoclonal antibody, was introduced for the RSV 2023-2024 season as a universal pre-exposure prophylaxis for high-risk children and those under 6 months old. This study examines its impact, coverage, and effectiveness. The campaign achieved 88.5 % coverage and 73.7 % of effectiveness. Analysis of over 27,000 susceptible children (over 24,000 immunized), showed that those immunized exhibited a threefold reduction in RSV incidence compared to non-immunized ones. To prevent one case, the number needed to immunize (NNI) was 63. Hospitalizations due to acute respiratory infections were almost two times lower in immunized children compared to non-immunized ones (0.9 % vs 1.6 %, respectively). These first results showcase the preliminary positive impact of this public health intervention.

Efficacy and safety of a synbiotic infant formula for the prevention of respiratory and gastrointestinal infections: a randomized controlled trial

BACKGROUND

Early life nutrition is crucial for the development of the gut microbiota that, in turn, plays an essential role in the maturation of the immune system and the prevention of infections.

OBJECTIVES

The aim of this study was to investigate whether feeding synbiotic infants and follow-on formulas during the first year of life reduces the incidence rate (IR) of infectious diarrhea compared with standard formulas. Secondary endpoints included the IR of other infectious diseases as well as fecal milieu parameters.

METHODS

In this double-blind, controlled trial, 460 healthy, 1-mo-old infants were randomly assigned to receive a synbiotic [galacto-oligosaccharides (GOS)/Limosilactobacillus fermentum CECT 5716] (IF, n = 230) or a control formula (CF, n = 230) until 12 mo of age. A reference group of breastfed infants (HM, n = 80) was included. Data on infections were recorded throughout the study period and stool samples were collected at 4 and 12 mo of age.

RESULTS

IR of infectious diarrhea during the first year of life was 0.60 (CF), 0.56 (IF), and 0.29 (HM), with no statistically significant difference between groups. The IR of lower respiratory tract infections, 1 of the secondary endpoints, however, was lower in IF than in CF [0.79 compared with 1.01, IR ratio = 0.77 (0.60-1.00)]. Additionally, fecal pH was significantly lower at 4 mo (P < 0.0001), whereas secretory IgA was significantly higher at 12 mo of age (P = 0.015) in IF compared with CF.

CONCLUSIONS

Although no difference is observed in the incidence of diarrhea, consumption of a synbiotic formula containing L. fermentum CECT5716 and GOS in infancy may reduce the incidence of lower respiratory tract infections and affect the immune system and fecal milieu. Additional research is warranted to further investigate the potential interaction of the gut-lung axis. This trial was registered at clinicaltrials.gov as NCT02221687.

Maternal awareness, acceptability and willingness towards respiratory syncytial virus (RSV) vaccination during pregnancy in Ireland

BACKGROUND

Respiratory syncytial virus (RSV) is the world's leading cause of viral acute lower respiratory infections (ALRI) in infants. WHO has identified maternal RSV vaccination a priority and candidate vaccines are in development; however, vaccine hesitancy remains an impediment to successful implementation of maternal immunization. This study, the largest antenatal survey conducted to-date, aimed to examine maternal RSV awareness, likely acceptance of RSV vaccination in pregnancy, and attitudes to maternal vaccination.

METHODS

Pregnant women of all gestations attending antenatal clinic of a university maternity hospital in Ireland were invited to participate. An information leaflet provided, consent obtained, and survey administered examining RSV awareness, willingness to avail of antenatal RSV vaccination, factors influencing acceptability and preferred sources of assistance. Research Ethics Committee (REC) approval obtained, and general data protection regulation (GDPR) guidelines followed.

RESULTS

528 women completed the survey. A large proportion (75.6%) had never heard of RSV, yet 48.5% would still avail of a vaccine, 45.8% were undecided and only 5.3% would not. The main factor making vaccination acceptable to women (76.4%) was that it protects their infant from illness (p < .001, CV 0.336 for association with acceptance) and general practitioner (GP) was the preferred guidance source in decision-making (57.7%).

CONCLUSIONS

Despite low levels of maternal awareness of RSV, pregnant women in Ireland are open to availing of antenatal vaccination. Maternal immunization strategies need to focus on infant's protection from RSV-associated ALRI along with vaccine safety, and build on an interdisciplinary collaboration of maternal, neonatal, primary care and public health services.

Long-lasting effects of COVID-19 pandemic on hospitalizations and severity of bronchiolitis

Bronchiolitis is a common cause of hospitalization in infants. The long-lasting impact of hygiene and social behavior changes during the pandemic on this disease is debated. We investigated the prevalence of hospitalized cases, clinical severity, and underlying risk factors before and during pandemic. The study was conducted in 27 hospitals in Italy and included infants hospitalized for bronchiolitis during the following four periods: July 2018-March 2019, July 2020-March 2021, July 2021-March 2022, and July 2022-March 2023. Data on demographics, neonatal gestational age, breastfeeding history, underlying chronic diseases, presence of older siblings, etiologic agents, clinical course and outcome were collected. A total of 5330 patients were included in the study. Compared to 2018-19 (n = 1618), the number of hospitalizations decreased in 2020-21 (n = 121). A gradual increase was observed in 2021-22 (n = 1577) and 2022-23 (n = 2014). A higher disease severity (need and length of O2-supplementation, need for non-invasive ventilation, hospital stay) occurred in the 2021-22 and, especially, the 2022-23 periods compared to 2018-19. This tendency persisted after adjusting for risk factors associated with bronchiolitis severity.   Conclusions: Compared to adults, COVID-19 in infants is often asymptomatic or mildly symptomatic and rarely results in hospitalization. This study indicates that the pandemic has indirectly induced an increased burden of bronchiolitis among hospitalized infants. This shift, which is not explained by the recognized risk factors, suggests the existence of higher infant vulnerability during the last two seasons. What is known: • The pandemic led to a change in epidemiology of respiratory diseases • Large data on severity of bronchiolitis and underlying risk factors before and during COVID-19 pandemic are scarce What is new: • Compared to pre-pandemic period, hospitalizations for bronchiolitis decreased in 2020-21 and gradually increased in 2021-22 and 2022-23 • Compared to pre-pandemic period, higher disease burden occurred in 2021-22 and, especially, in 2022-23. This tendency persisted after adjusting for risk factors associated with bronchiolitis severity • The interplay among viruses, preventive measures, and the infant health deserves to be further investigated.

Association Between Exclusive Breastfeeding and Acute Respiratory Infections Among Infants Under the Age of 6 Months

Introduction: Acute respiratory infection (ARI) is the leading cause of childhood morbidity and mortality. Exclusive breastfeeding is considered the cornerstone of child health; however, the rate of exclusive breastfeeding is suboptimal in low- and middle-income countries (LMICs). This study aimed to assess the association between exclusive breastfeeding and ARI among infants under the age of 6 months in a LMIC. Methods: A secondary analysis of the 2014 Egypt Demographic Health Survey data was conducted. Mothers of infants under the age of 6 months (n = 1,340) were included. The outcome of interest was ARI symptoms among infants, defined by mother's report of a cough accompanied by fast or difficult breathing in the 2 weeks preceding the survey. The exposure variable was exclusive breastfeeding, defined by giving infants only breast milk during the first 6 months of life. Descriptive statistics and multivariate regression were performed. Results: Forty-one percent of the infants were exclusively breastfed and 9% had ARI symptoms. Exclusive breastfeeding reduced the odds of ARI symptoms (adjusted odds ratio [AOR] = 0.450, 95% confidence interval [CI]: 0.243-0.832). Infants of mothers 20-34 years of age (AOR = 0.421, 95% CI: 0.217-0.817) and ≥35 years (AOR = 0.308, 95% CI: 0.123-0.767) at childbirth were less likely to have symptoms of an ARI when compared with adolescent mothers. The likelihood of having ARI symptoms was higher among infants 2-3 months of age (AOR = 2.437, 95% CI: 1.093-5.435), and 4-5 months (AOR = 2.888, 95% CI: 1.193-6.992) compared with infants less than 2 months. Conclusion: Exclusive breastfeeding was protective against ARI symptoms among under-6-month infants, independent of potential confounders.

Impact of COVID-19 Pandemic on Breastfeeding by Family Vulnerability: An Observational Study Based on Record Linkage

Objective: The aim of this study was to assess the impact of the coronavirus disease 2019 (COVID-19) pandemic on breastfeeding, overall and across degrees of family vulnerability. Study Design: A repeated cross-sectional study was conducted based on record linkage analysis of regional administrative databases providing data on breastfeeding prevalence in children, collected at the time of months of age. Breastfeeding data were linked to maternal characteristics to calculate a breastfeeding vulnerability score. Data over a 3-year period were considered as follows: 2019 (prepandemic), 2020 (lockdown and strict COVID-19 control measures), and 2021 (milder COVID-19 control measures). Results: During the study period, 110,925 immunization records were registered; data on breastfeeding were available for 107,138 records. The prevalence of full breastfeeding at 3 months of age decreased from 57.1% in 2019 to 56.1% in 2021 (p-value = 0.003), whereas prevalence of full breastfeeding at 5 months of age increased (from 44.1% in 2019 to 47.6% in 2021; p-value <0.001). The vulnerability score was calculated for the 70,253 records (63.3% of the initial sample) for which data were accessible: 5% of the sample was in the lowest vulnerability class and 15% in the highest one. As the vulnerability score increased, the prevalence of full breastfeeding at 3 and 5 months of age decreased in each of the three study years. Breastfeeding prevalence within each vulnerability class was not affected by the pandemic. On the other hand, the percentage of children in the high vulnerability class (score ≥3) increased by 3.6% in 2021 compared with 2019. Conclusions: The pandemic has not significantly impacted the prevalence of breastfeeding (-1% at 3 months and +3.5% at 5 months), but the proportion of children in the most vulnerable class increased significantly: action should be taken to ensure that during crises or emergencies the most vulnerable groups receive increased breastfeeding protection, promotion, and support.

Association of the presence of a COVID-19 infection at the time of birth and the rates of exclusive breastfeeding upon discharge in BFHI hospitals: a multicenter, prospective cohort study

BACKGROUND

Very few studies have assessed the association between COVID-19 infection and the rates of exclusive breastfeeding (EBF) upon discharge following the first waves of the pandemic and after initiation of vaccination. The primary objective of this study is to compare the rates of EBF since birth upon discharge in mothers diagnosed with COVID-19 infection at the time of the delivery versus a group of non-infected mothers in maternity hospitals with Baby Friendly Hospital Initiative (BFHI) accreditation. The secondary objectives include determining the rates of any breastfeeding at three and six months of life in both groups, as well as determining the possible factors associated with EBF rates observed upon discharge.

METHODS

An observational, Spanish multi-center hospital, prospective cohort study conducted from 1 to 2021 to 31 March 2022 and with follow-up during the first six months of life. Follow-up was performed via telephone contact with calls performed at three and six months. A multivariate logistic regression analysis model was used to identify the factors related to a lower probability of EBF upon discharge.

RESULTS

308 mother-infant pairs participated in the study, 111 in the cohort of women with COVID infection and 197 in the comparison group. EBF upon discharge was 62.7% in the COVID group vs. 81.2% in the comparison group (p = 0.002); at three months; 52.4% vs. 57.0% (p = 0.33) were performing EBF, with the rates of EBF at six months being 43.0% vs. 39.3% (p = 0.45), respectively. Exposure to COVID-19 at delivery (AOR 5.28; 95% CI 2.01, 13.86), not practicing BF previously (AOR 36.3; 95% CI 7.02, 187.74), birth via Cesarean section (AOR 5.06; 95% CI 1.62, 15.79) and low birth weight of the newborn (AOR 1.01; 95% CI 1.01, 1.01) were associated with a greater risk of not performing EBF upon discharge.

CONCLUSIONS

Mothers with a mild or asymptomatic COVID-19 infection at the time of the delivery were less likely to have exclusively breastfed during their hospital stay than other mothers in these BFHI-accredited hospitals. However, there were no differences in breastfeeding rates between the groups at three and six months postpartum.

Risk Factors for Severe Respiratory Syncytial Virus Infection in Hospitalized Children

BACKGROUND

RSV often leads to hospitalization, and accurate knowledge of risk factors is crucial.

METHODS

We retrospectively analyzed laboratory-confirmed RSV hospitalizations regarding pregnancy factors, birth status, cigarette smoke exposure, nutrition, social conditions, clinical presentation, and severe disease defined as a need for passive oxygen therapy (pO2Tx), the presence of pneumonia, respiratory failure, intensive care unit (ICU) transfer, and prolonged hospitalization.

RESULTS

A univariate analysis included 594 children (median age 4 months) and revealed a pO2Tx relationship with age ≤ 3 months (OR = 1.56), prematurity (OR = 1.71), being born during RSV season (OR = 1.72), smoke exposure during pregnancy (both parents (OR = 2.41, father (OR = 1.8)), dyspnea (OR = 5.09), and presence of apnea (OR = 5.81). Pneumonia was associated with maternal smoke exposure (OR = 5.01), fever (OR = 3.92), dyspnea (OR = 1.62), history of aspiration (OR = 4.63), and inversely with age ≤ 3 months (OR = 0.45). Respiratory failure was associated with prematurity (OR = 3.13) and apnea (OR = 18.78), while the lower odds were associated with older age (OR = 0.57 per month) and presence of fever (OR = 0.11). ICU transfer was associated with apnea (OR = 17.18), but an inverse association was observed with age (OR = 0.54) and fever (OR = 0.11). A prolonged hospital stay was associated with prematurity (OR = 1.76), low birth weight (OR = 2.89), aspiration (OR = 4.93), and presence of fever (OR = 1.51).

CONCLUSIONS

Age (up to 3 months), prematurity, and presence of apnea are risk factors for a severe RSV course.

P-Wave Axis of Schoolchildren Who Were Once Breastfed

BACKGROUND

It has been known for decades that breastfeeding leads to a lower risk of asthma, respiratory infections, or metabolic syndrome at school age. In addition, evidence is now accumulating on the influence of breast milk on the shape, volume, or function of the heart and lungs. Within this field of research into the effects of breast milk on the structure of the heart and lungs, we have set out to analyze the differential electrocardiographic characteristics of schoolchildren who were once breastfed.

METHOD

This was an observational cross-sectional study, including 138 children aged 6 or 12 consecutively presenting to a well-child clinic between May and December 2022.

INCLUSION CRITERIA

The ability to perform reproducible ECG records, the feasibility of weighing and measuring patient, and breastfeeding data collected from birth were used as the inclusion criteria.

RESULTS

Using the 40° cut-off value for the mean P-wave axis among schoolchildren, 76% of never-breastfed children in our sample have a P-wave axis in a more vertical position than the mean as compared to 58% of ever-breastfed children (OR: 2.25; 95% CI: 3.13-1.36); there was no other significant difference between infant feeding groups in somatometric characteristics or ECG parameters.

CONCLUSION

We found a significant difference of the mean values of the P-wave axis between never- and ever-breastfed children. Although this report should be approached cautiously, these findings add to the renewed interest in discerning developmental interventions to improve cardiovascular health.

Breast Milk Conferred Immunity to Infants Against COVID-19

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has notably impacted healthcare systems and everyday life worldwide. Regulatory authorities have approved the emergency use of SARS-CoV-2 vaccines due to the rapid spread of the virus. However, during vaccination testing, pregnant and breastfeeding women were initially excluded, leading to a lack of evidence-based recommendations. When taking the COVID-19 pandemic into account, breastfeeding has emerged as a potential defense mechanism against this infection due to its numerous benefits for newborns. Human breast milk contains immunoglobulins (IgA, IgG, and IgM), lactoferrin, and various cells that play an inevitable role in the newborn's protection against respiratory infections and immune system development. Various studies have highlighted that the onset and severity of respiratory infections in infants can be reduced through breastfeeding, and the effects are noticeable during the first six months of life and that breast milk also has the potential to enhance mucosal immunity and promote a diverse microbiome, reducing the risk of asthma, allergies, and enteric diseases through the provision of specific antibodies and immunological factors. Researchers have indicated that breastfeeding mothers who contracted and recovered from COVID-19 or received vaccination passed protective antibodies to their infants through breast milk. Although rare cases of detection of SARS-CoV-2 RNA in breast milk have been reported, the virus has not been cultured from these samples, suggesting a low risk of transmission to the breastfed baby. However, further research is essential to understand the extent of protection provided by breast milk against COVID-19 and the potential effect of distinct phases of lactation. Nonetheless, the current evidence supports the benefits and safety of breastfeeding during the pandemic. With appropriate safety measures, promoting breastfeeding can contribute to the overall health and well-being of infants during the phase of COVID-19.