[Respiratory viral infections in a cohort of children during the first year of life and their role in the development of wheezing]

Reduction of acute respiratory infections in day-care by non-pharmaceutical interventions: a narrative review

Objective

Children who start in day-care have 2-4 times as many respiratory infections compared to children who are cared for at home, and day-care staff are among the employees with the highest absenteeism. The extensive new knowledge that has been generated in the COVID-19 era should be used in the prevention measures we prioritize. The purpose of this narrative review is to answer the questions: Which respiratory viruses are the most significant in day-care centers and similar indoor environments? What do we know about the transmission route of these viruses? What evidence is there for the effectiveness of different non-pharmaceutical prevention measures?

Design

Literature searches with different terms related to respiratory infections in humans, mitigation strategies, viral transmission mechanisms, and with special focus on day-care, kindergarten or child nurseries, were conducted in PubMed database and Web of Science. Searches with each of the main viruses in combination with transmission, infectivity, and infectious spread were conducted separately supplemented through the references of articles that were retrieved.

Results

Five viruses were found to be responsible for ≈95% of respiratory infections: rhinovirus, (RV), influenza virus (IV), respiratory syncytial virus (RSV), coronavirus (CoV), and adenovirus (AdV). Novel research, emerged during the COVID-19 pandemic, suggests that most respiratory viruses are primarily transmitted in an airborne manner carried by aerosols (microdroplets).

Conclusion

Since airborne transmission is dominant for the most common respiratory viruses, the most important preventive measures consist of better indoor air quality that reduces viral concentrations and viability by appropriate ventilation strategies. Furthermore, control of the relative humidity and temperature, which ensures optimal respiratory functionality and, together with low resident density (or mask use) and increased time outdoors, can reduce the occurrence of respiratory infections.

Transmission route of rhinovirus - the causative agent for common cold. A systematic review

BACKGROUND

Human rhinoviruses (RVs) are the most common cause of acute respiratory tract illness and upper respiratory tract infections, traditionally defined as 'common colds'. Experimental transmission of RV has been studied for more than 50 years. However, there are divergent results as to whether hands and fomites or aerosols constitute the dominant route of transmission in natural settings.

METHODS

We have systematically reviewed the literature according to the PRISMA 2020 statement. Searches were run in PubMed and Web of Science until August 2022. Inclusion criteria were original studies of relevance for revealing the route of transmission of rhinovirus in humans.

RESULTS

The search yielded 663 results, and 25 studies met the inclusion criteria and were selected for this review. These articles addressing RV transmission routes were assigned to 1 of 3 groups: (1) indirect transmission by fomites and hands, (2) direct transmission via large aerosols (droplets) or small aerosols, or (3) transmission either direct via large aerosols (droplets) or small aerosols and fomite or hands.

CONCLUSIONS

We found low evidence, that transmission via hands and fomite followed by self-inoculation is the dominant transmission route in real-life indoor settings. We found moderate evidence, that airborne transmission either via large aerosols or small aerosols is the major transmission route of rhinovirus transmission in real-life indoor settings. This suggests that the major transmission route of RVs in many indoor settings is through the air (airborne transmission).

Understanding Rhinovirus Circulation and Impact on Illness

Rhinoviruses (RVs) have been reported as one of the main viral causes for severe respiratory illnesses that may require hospitalization, competing with the burden of other respiratory viruses such as influenza and RSV in terms of severity, economic cost, and resource utilization. With three species and 169 subtypes, RV presents the greatest diversity within the Enterovirus genus, and despite the efforts of the research community to identify clinically relevant subtypes to target therapeutic strategies, the role of species and subtype in the clinical outcomes of RV infection remains unclear. This review aims to collect and organize data relevant to RV illness in order to find patterns and links with species and/or subtype, with a specific focus on species and subtype diversity in clinical studies typing of respiratory samples.

Respiratory morbidity associated with viral respiratory infections during neonatal stage in premature infants

BACKGROUND AND OBJECTIVE

Very low birth weight (VLBW) infants are highly susceptible to viral respiratory infections (VRIs), even during admission to the neonatal intensive care unit (NICU). Although the role of VRI in childhood in the development of recurrent wheezing and long-term asthma is well known, information on the impact in later morbidity of VRI in the neonatal period is lacking. We aimed to explore the occurrence of recurrent wheezing over the first 2 years of life according to VRI status during NICU admission.

METHODS

During April 2016 and December 2017, infants below 32 weeks of gestation were prospectively studied in VRI surveillance during NICU admission. Families were contacted between September 2018 and May 2019 by a telephone questionnaire.

RESULTS

A total of 99 patients were enrolled. The mean gestational age and birth weight were 28.8 (1.9) weeks and 1118 (329) g, respectively. During the first 2 years of life, neither episodes of wheezing nor the respiratory impairment-related hospital admissions differed between positive and negative VRI infants. Episodes of wheezing and respiratory impairment-related hospital admissions, as well as specific respiratory treatment prescription, were more frequent within the first 2 years in infants who had suffered symptomatic VRI during NICU admission.

CONCLUSION

Symptomatic VRI in VLBW infants is associated with long-term respiratory morbidity. The early surveillance of VRI in the preterm infant during NICU admission is justified for prognostic counseling and closely monitoring after discharge. Routine instruction on asthma-related risk factors and early prescription of antiasthmatic treatments, when indicated, should be established.

[Criteria heterogeneity in the diagnosis of acute bronchiolitis in Spain]

INTRODUCTION

Acute viral bronchiolitis (AB) is one of the most common respiratory diseases in infants. However, diagnostic criteria for AB are heterogeneous and not very well known.

OBJECTIVE

To identify the diagnostic criteria for AB used by experts and clinical paediatricians in Spain.

METHODS

Delphi study with Spanish AB experts, looking for the points of agreement about AB diagnosis. A subsequent cross-sectional study was conducted by means of an on-line questionnaire addressed to all Spanish paediatricians, reached through electronic mail messages sent by nine paediatric scientific societies. Descriptive and factorial analyses were carried out, looking for any association of diagnostic criteria with demographic or geographic variables, or with paediatric subspecialty.

RESULTS

Agreement was reached by 40 experts in many issues (first episode of respiratory distress and high respiratory frequency, diagnosis in any season of the year, and usefulness of virus identification in making diagnosis), but opposite views were maintained on key characteristics such as the maximum age for diagnosis. The on-line questionnaire was completed by 1297 paediatricians. Their diagnostic criteria were heterogeneous and strongly associated with their paediatric sub-specialty. Their agreement with the Spanish expert consensus and with international standards was very poor.

CONCLUSIONS

Diagnostic criteria for AB in Spain are heterogeneous. These differences could cause variability in clinical practice with AB patients.

Criteria heterogeneity in the diagnosis of acute bronchiolitis in Spain

INTRODUCTION

Acute viral bronchiolitis (AB) is one of the most common respiratory diseases in infants. However, diagnostic criteria for AB are heterogeneous and not very well known.

OBJECTIVE

To identify the diagnostic criteria for AB used by experts and clinical paediatricians in Spain.

METHODS

Delphi study with Spanish AB experts, looking for the points of agreement about AB diagnosis. A subsequent cross-sectional study was conducted by means of an online questionnaire addressed to all Spanish paediatricians, reached through electronic mail messages sent by nine paediatric scientific societies. Descriptive and factorial analyses were carried out, looking for any association of diagnostic criteria with demographic or geographic variables, or with paediatric subspecialty.

RESULTS

Agreement was reached by 40 experts in many issues (first episode of respiratory distress and high respiratory frequency, diagnosis in any season of the year, and usefulness of virus identification in making diagnosis), but opposite views were maintained on key characteristics such as the maximum age for diagnosis. The online questionnaire was completed by 1297 paediatricians. Their diagnostic criteria were heterogeneous and strongly associated with their paediatric sub-specialty. Their agreement with the Spanish expert consensus and with international standards was very poor.

CONCLUSIONS

Diagnostic criteria for AB in Spain are heterogeneous. These differences could cause variability in clinical practice with AB patients.