Epidemiology and virology of acute respiratory infections during the first year of life: a birth cohort study in Vietnam

Burden of Respiratory Viruses in Children Less Than 2 Years Old in a Community-based Longitudinal US Birth Cohort

BACKGROUND

Respiratory viral infections are a major cause of morbidity and hospitalization in young children. Nevertheless, the population burden of respiratory viral infections, especially asymptomatic cases, is not known due to the lack of prospective community-based cohort studies with intensive monitoring.

METHODS

To address this gap, we enacted the PREVAIL cohort, a Centers for Disease Control and Prevention-sponsored birth cohort in Cincinnati, Ohio, where children were followed from 0 to 2 years of age. Weekly text surveys were administered to record acute respiratory illnesses (ARIs), which were defined as the presence of cough or fever (≥38°C). Weekly midturbinate nasal swabs were collected and tested using the Luminex Respiratory Pathogen Panel, which detected 16 viral pathogens. Viral infection was defined as ≥1 positive tests from the same virus or viral subtype ≤30 days of a previous positive test. Maternal report and medical chart abstractions identified healthcare utilization.

RESULTS

From 4/2017 to 7/2020, 245 mother-infant pairs were recruited and followed. From the 13 781 nasal swabs tested, a total of 2211 viral infections were detected, of which 821 (37%) were symptomatic. Children experienced 9.4 respiratory viral infections/child-year; half were rhinovirus/enterovirus. Viral ARI incidence was 3.3 episodes/child-year. Emergency department visits or hospitalization occurred with only 15% of respiratory syncytial virus infections, 10% of influenza infections, and only 4% of all viral infections. Regardless of pathogen, most infections were asymptomatic or mild.

CONCLUSIONS

Respiratory viral infections are common in children 0-2 years. Most viral infections are asymptomatic or non-medically attended, underscoring the importance of community-based cohort studies.

Comparing the Etiology of Viral Acute Respiratory Illnesses Between Children Who Do and Do Not Attend Childcare

BACKGROUND AND OBJECTIVE

Childcare attendance is a common risk factor for acute respiratory illness (ARI) in young children. Our goal was to better understand the specific respiratory viruses that predominate in childcare, which may support the development of tailored illness prevention and intervention strategies in childcare settings.

METHODS

Using data from a prospective household cohort of ARI surveillance, we assessed specimen from 1418 ARIs reported by 359 childcare-aged children over 6 study seasons (2012/2013 through 2017/2018). Respiratory swabs were tested by polymerase chain reaction for 9 respiratory viruses. A mixed-effect logistic regression model was used to compare odds of various viral detection outcomes. The Shannon's Diversity index was used to compare the richness (ie, number of species) and diversity (ie, relative species abundance) associated with respiratory viruses detected in both groups.

RESULTS

At least 1 virus was detected in 75.5% of childcare-associated ARIs and in 80.1% of homecare ARIs. Compared with illnesses among homecare children, childcare illnesses were associated with significantly higher odds of detected adenovirus (odds ratio = 1.86, 95% confidence interval = 1.05-3.28) and human metapneumovirus (odds ratio = 1.76, 95% confidence interval = 1.03-3.0). The pool of viruses associated with childcare ARI was found to be significantly richer and more diverse than that of viruses associated with homecare ARI (P < 0.0001).

CONCLUSIONS

Children attending childcare experience a higher risk of adenovirus and human metapneumovirus infection and are regularly exposed to a rich and diverse pool of respiratory viruses in childcare environments. Our results underscore the necessity of thorough and multifaceted viral prevention strategies in childcare settings.

Estimating the economic burden of respiratory syncytial virus infections in infants in Vietnam: a cohort study

BACKGROUND

Little information is available on the costs of respiratory syncytial virus (RSV) in Vietnam or other low- and middle-income countries. Our study estimated the costs of LRTIs associated with RSV infection among children in southern Vietnam.

METHODS

We conducted a prospective cohort study evaluating household and societal costs associated with LRTIs stratified by RSV status and severity among children under 2 years old who sought care at a major pediatric referral hospital in southern Vietnam. Enrollment periods were September 2019-December 2019, October 2020-June 2021 and October 2021-December 2021. RSV status was confirmed by a validated RT-PCR assay. RSV rapid detection antigen (RDA) test performance was also evaluated. Data on resource utilization, direct medical and non-medical costs, and indirect costs were collected from billing records and supplemented by patient-level questionnaires. All costs are reported in 2022 US dollars.

RESULTS

536 children were enrolled in the study, with a median age of 7 months (interquartile range [IQR] 3-12). This included 210 (39.2%) children from the outpatient department, 318 children (59.3%) from the inpatient respiratory department (RD), and 8 children (1.5%) from the intensive care unit (ICU). Nearly 20% (105/536) were RSV positive: 3.9 percent (21/536) from the outpatient department, 15.7% (84/536) from the RD, and none from the ICU. The median total cost associated with LRTI per patient was US$52 (IQR 32-86) for outpatients and US$184 (IQR 109-287) for RD inpatients. For RSV-associated LRTIs, the median total cost per infection episode per patient was US$52 (IQR 32-85) for outpatients and US$165 (IQR 95-249) for RD inpatients. Total out-of-pocket costs of one non-ICU admission of RSV-associated LRTI ranged from 32%-70% of the monthly minimum wage per person (US$160) in Ho Chi Minh City. The sensitivity and the specificity of RSV RDA test were 88.2% (95% CI 63.6-98.5%) and 100% (95% CI 93.3-100%), respectively.

CONCLUSION

These are the first data reporting the substantial economic burden of RSV-associated illness in young children in Vietnam. This study informs policymakers in planning health care resources and highlights the urgency of RSV disease prevention.

Metagenomic Analysis of Respiratory RNA Virome of Children with and without Severe Acute Respiratory Infection from the Free State, South Africa during COVID-19 Pandemic Reveals Higher Diversity and Abundance in Summer Compared with Winter Period

Viral respiratory infections contribute to significant morbidity and mortality in children. Currently, there are limited reports on the composition and abundance of the normal commensal respiratory virome in comparison to those in severe acute respiratory infections (SARIs) state. This study characterised the respiratory RNA virome in children ≤ 5 years with (n = 149) and without (n = 139) SARI during the summer and winter of 2020/2021 seasons in South Africa. Nasopharyngeal swabs were, collected, pooled, enriched for viral RNA detection, sequenced using Illumina MiSeq, and analysed using the Genome Detective bioinformatic tool. Overall, Picornaviridae, Paramoxyviridae, Pneumoviridae, Picobirnaviridae, Totiviridae, and Retroviridae families were the most abundant viral population in both groups across both seasons. Human rhinovirus and endogenous retrovirus K113 were detected in most pools, with exclusive detection of Pneumoviridae in SARI pools. Generally, higher viral diversity/abundance was seen in children with SARI and in the summer pools. Several plant/animal viruses, eukaryotic viruses with unclear pathogenicity including a distinct rhinovirus A type, were detected. This study provides remarkable data on the respiratory RNA virome in children with and without SARI with a degree of heterogeneity of known viruses colonizing their respiratory tract. The implication of the detected viruses in the dynamics/progression of SARI requires further investigations.

Prevalence of respiratory viruses among paediatric patients in acute respiratory illnesses in Malaysia

Objectives

Acute respiratory infections (ARIs) are one of the leading causes of childhood morbidity and mortality worldwide. However, there is limited surveillance data on the epidemiological burden of respiratory pathogens in tropical countries like Malaysia. This study aims to estimate the prevalence of respiratory pathogens causing ARIs among children aged <18 years old in Malaysia and their epidemiological characteristics.

Methods

Nasopharyngeal swab specimens received at 12 laboratories located in different states of Malaysia from 2015–2019 were studied. Detection of 18 respiratory pathogens were performed using multiplex PCR.

Results

Data from a total of 23,306 paediatric patients who presented with ARI over a five-year period was studied. Of these, 18538 (79.5%) were tested positive. The most prevalent respiratory pathogens detected in this study were enterovirus/ rhinovirus (6837/ 23000; 29.7%), influenza virus (5176/ 23000; 22.5%) and respiratory syncytial virus (RSV) (3652/ 23000; 15.9%). Throughout the study period, RSV demonstrated the most pronounce seasonality; peak infection occurred during July to September. Whereas the influenza virus was detected year-round in Malaysia. No seasonal variation was noted in other respiratory pathogens. The risk of RSV hospitalisation was found to be significantly higher in children aged less than two years old, whereas hospitalisation rates for the influenza virus peaked at children aged between 3–6 years old.

Conclusion

This study provides insight into the epidemiology and the seasonality of the causative pathogens of ARI among the paediatric population in Malaysia. Knowledge of seasonal respiratory pathogens epidemiological dynamics will facilitate the identification of a target window for vaccination.

Maternal Antibodies Against Influenza in Cord Blood and Protection Against Laboratory-Confirmed Influenza in Infants

BACKGROUND

Studies that correlate maternal antibodies with protection from influenza A or B virus infection in young infants in areas with prolonged influenza circulation are lacking.

METHODS

We conducted a prospective, observational study to evaluate the effects of maternally transferred antibodies against influenza A and B viruses against laboratory-confirmed influenza in a cohort born over 24 months. Cord blood samples were retrieved at birth and infants were actively followed for the first 6 months of life. Nasal swabs were collected and tested for influenza A and B by reverse transcriptase-polymerase chain reaction whenever an illness episode was identified. Cord blood samples were tested by the hemagglutination inhibition (HAI) assay to viruses that circulated during the follow-up period.

RESULTS

1162 infants were born to 1140 recruited women: 1092 (94%) infants completed 6 months of follow-up. Proportions of cord blood with HAI antibody titers ≥40 against A(H1N1), A(H3N2), B/Victoria, and B/Yamagata were 31%, 24%, 31%, and 54%, respectively. Only 4% of women had maternal influenza vaccination. Cord blood antigen-specific HAI titers ≥40 were found to correlate with protection from infection only for influenza B/Yamagata. No influenza B virus infection occurred in infants ≤60 days old. Proportional hazards analysis showed that a cord blood HAI titer of 40 was associated with 83% (95% confidence interval, 44-95%) reduction in the risk of influenza B/Yamagata infections compared with a cord blood titer <10.

CONCLUSIONS

We documented that maternal immunity against influenza B/Yamagata was conferred to infants within the first 6 months of life.

Interactions of genetic variants and prenatal stress in relation to the risk for recurrent respiratory infections in children

Genetic variants may predispose children to recurrent respiratory infections (RRIs) but studies on genotype-environment interaction are rare. We hypothesized that the risk for RRIs is elevated in children with innate immune gene variants, and that prenatal exposure to maternal psychological distress further increases the risk. In a birth cohort, children with RRIs (n = 96) were identified by the age of 24 months and compared with the remaining cohort children (n = 894). The risk for RRIs in children with preselected genetic variants and the interaction between maternal distress during pregnancy and child genotype were assessed with logistic regression. The IL6 minor allele G was associated with elevated risk for RRIs (OR 1.55; 95% CI 1.14-2.12). Overall, there was no interaction between maternal psychological distress and child genotype. Exploratory analyses showed that, the association between the variant type of IL6 and the risk for RRIs was dependent on prenatal exposure to maternal psychological distress in males (OR 1.96; 95% CI 1.04-3.67). Our study didn't find genotype-environment interaction between prenatal maternal distress and child genotype. Exploratory analyses suggest sex differences in gene-environment interaction related to susceptibility to RRIs.

The incidence of acute respiratory infection in Indonesian infants and association with vitamin D deficiency

Background

Vitamin D deficiency has been associated with acute respiratory infection (ARI) in early life, but this has not been evaluated in Indonesia. We aimed to determine the incidence of ARI in Indonesian infants, and to evaluate the association with vitamin D deficiency.

Methods

From 23 December 2015 to 31 December 2017, we conducted a community-based prospective cohort study in Yogyakarta province. We enrolled 422 pregnant women and followed their infants from birth until 12 months of age for ARI episodes. Vitamin D status was measured at birth and at age six months. We performed Cox proportional hazard regression analysis to evaluate the association between vitamin D deficiency and pneumonia incidence.

Results

At study completion, 95% (400/422) of infants retained with a total of 412 child years of observation (CYO). The incidence of all ARI and of WHO-defined pneumonia was 3.89 (95% CI 3.70–4.08) and 0.25 (95% CI 0.21–0.30) episodes per CYO respectively. Vitamin D deficiency at birth was common (90%, 308/344) and associated with more frequent episodes of ARI non-pneumonia (adjusted odds ratio 4.48, 95% CI:1.04–19.34). Vitamin D status at birth or six months was not associated with subsequent pneumonia incidence, but greater maternal sun exposure during pregnancy was associated with a trend to less frequent ARI and pneumonia in infants.

Conclusion

ARI, pneumonia, and vitamin D deficiency at birth were common in Indonesian infants. Minimising vitamin D deficiency at birth such as by supplementation of mothers or safe sun exposure during pregnancy has the potential to reduce ARI incidence in infants in this setting.

Changing Epidemiology of Acute Respiratory Infections in Under-Two Children in Dhaka, Bangladesh

Objectives: Risk factors for acute respiratory infections (ARIs) in community settings are not fully understood, especially in low-income countries. We examined the incidence and risk factors associated with ARIs in under-two children from the Microbiota and Health study. Methods: Children from a peri-urban area of Dhaka (Bangladesh) were followed from birth to 2 years of age by both active surveillance of ARIs and regular scheduled visits. Nasopharyngeal samples were collected during scheduled visits for detection of bacterial facultative respiratory pathogens. Information on socioeconomic, environmental, and household conditions, and mother and child characteristics were collected. A hierarchical modeling approach was used to identify proximate determinants of ARIs. Results: Of 267 infants, 87.3% experienced at least one ARI episode during the first 2 years of life. The peak incidence of ARIs was 330 infections per 100 infant-years and occurred between 2 and 4 months of age. Season was the main risk factor (rainy monsoon season, incidence rate ratio [IRR] 2.43 [1.92-3.07]; cool dry winter, IRR 2.10 [1.65-2.67] compared with hot dry summer) in the first 2 years of life. In addition, during the first 6 months of life, young maternal age (<22 years; IRR 1.34 [1.01-1.77]) and low birth weight (<2,500 g; IRR 1.39 [1.03-1.89]) were associated with higher ARI incidence. Conclusions: Reminiscent of industrialized settings, cool rainy season rather than socioeconomic and hygiene conditions was a major risk factor for ARIs in peri-urban Bangladesh. Understanding the causal links between seasonally variable factors such as temperature, humidity, crowding, diet, and ARIs will inform prevention measures.

Effectiveness of Palivizumab Against Respiratory Syncytial Virus Hospitalization Among Preterm Infants in a Setting With Year-Round Circulation

BACKGROUND

The year-round respiratory syncytial virus (RSV) circulation in tropical regions leads to different transmission patterns and burden of disease among infants born very preterm.

METHODS

We conducted a retrospective cohort study to estimate the effectiveness of palivizumab in preventing RSV hospitalization at 6 and 12 months after discharge, among infants born at <32 weeks' gestation in our tropical setting.

RESULTS

A total of 109 infants (26.3%) received palivizumab at discharge, of 415 who were eligible. All patients received ≥4 doses, with 105 infants (96.3%) completing 5 doses. Within 1 year after discharge, there were 35 RSV-associated admissions (3 [2.8%] in the palivizumab vs 32 [10.5%] in the nonpalivizumab group; P = .02). After adjustment for confounders, the effectiveness of palivizumab against RSV hospitalization was estimated to be 90% (95% confidence interval, 10%-99%) up to 6 months after discharge. The median time to RSV hospitalization was shorter in the nonpalivizumab than in the palivizumab group (median [range], 155 [15-358] vs 287 [145-359] days, respectively; P = .11). Five infants (14.3%), all from the nonpalivizumab group, required admission to the intensive care unit.

CONCLUSIONS

In our setting with year-round RSV circulation, palivizumab prophylaxis was effective in reducing RSV hospitalization among high-risk preterm infants of <32 weeks' gestation within the initial 6 months after discharge.

Endemic Non-SARS-CoV-2 Human Coronaviruses in a Community-Based Australian Birth Cohort

BACKGROUND AND OBJECTIVES

The coronavirus (CoV) disease 2019 pandemic has drawn attention to the CoV virus family. However, in community settings, there is limited information on these viruses in healthy children. We explored the epidemiology of the 4 endemic (non-severe acute respiratory syndrome CoV 2) human coronaviruses (HCoVs) by species, including acute illness episodes, risk factors, and health care burden in Australian children in the first 2 years of life.

METHODS

The Observational Research in Childhood Infectious Diseases community-based cohort was a prospective study of acute respiratory illnesses in children from birth until their second birthday. Parents recorded daily symptoms, maintained an illness-burden diary, and collected weekly nasal swabs, which were tested for 17 respiratory viruses, including HCoVs, by real-time polymerase chain reaction assays.

RESULTS

Overall, 158 children participating in Observational Research in Childhood Infectious Diseases provided 11 126 weekly swabs, of which 168 were HCoV-positive involving 130 incident episodes. HCoV-NL63 and HCoV-OC43 were most commonly detected, accounting for two-thirds of episodes. Whereas 30 children had different HCoVs detected on different occasions, 7 were reinfected with the same species. HCoV incidence in the first 2 years of life was 0.76 episodes per child-year (95% confidence interval [CI] 0.63 to 0.91), being greatest in the second year (1.06; 95% CI 0.84 to 1.33) and during winter (1.32; 95% CI 1.02 to 1.71). Fifty percent of HCoV episodes were symptomatic, and 24.2% led to health care contact.

CONCLUSIONS

In children, HCoV infections are common, recurrent, and frequently asymptomatic. In future studies, researchers should determine transmission pathways and immune mechanisms.

Circulation profile of respiratory viruses in symptomatic and asymptomatic children from Midwest Brazil

Acute respiratory infection (ARI) is a major cause of morbidity and mortality worldwide. Most of these infections are caused by viruses. Infections pose as important triggers of acute episodes of chronic respiratory diseases (CRD). This study sought to evaluate the frequency and circulation profile of respiratory viruses among ARI symptomatic patients and completely asymptomatic children in Midwest Brazil. The study enrolled symptomatic children with and without ARI symptoms. During 1 year, 225 nasal respiratory samples were obtained from patients aged 4–14 years old. The samples were screened by multiplex nested-PCR for 16 common respiratory viruses. From 225 samples, 42 had at least one virus detected. Samples from four different patients had multiple viruses detected. The viral detection rate in symptomatic (20.1%) and asymptomatic patients (14.8%) showed no significant difference. The most frequent viruses detected were rhinovirus (28.6%), FLUA (11.9%), adenovirus (11.9%), human bocavirus (HBoV) (11.9%), and respiratory syncytial virus (RSV) antigenic group A (9.5%). Monthly detection rate was higher during the rainy season. RSVs were detected during the months with higher rainfall indexes and higher air humidity, while FLU and HBoV were detected during the winter months. The obtained results reinforce the importance of viral pathogens in pediatric population, emphasizing similar viral occurrence in symptomatic and asymptomatic children.

Respiratory viruses in individuals with a high frequency of animal exposure in southern and highland Vietnam

Active surveillance for zoonotic respiratory viruses is essential to inform the development of appropriate interventions and outbreak responses. Here we target individuals with a high frequency of animal exposure in Vietnam. Three-year community-based surveillance was conducted in Vietnam during 2013-2016. We enrolled a total of 581 individuals (animal-raising farmers, slaughterers, animal-health workers, and rat traders), and utilized reverse transcription-polymerase chain reaction to detect 15 common respiratory viruses in pooled nasal-throat swabs collected at baseline or acute respiratory disease episodes. A respiratory virus was detected in 7.9% (58 of 732) of baseline samples, and 17.7% (136 of 770) of disease episode samples (P < .001), with enteroviruses (EVs), rhinoviruses and influenza A virus being the predominant viruses detected. There were temporal and spatial fluctuations in the frequencies of the detected viruses over the study period, for example, EVs and influenza A viruses were more often detected during rainy seasons. We reported the detection of common respiratory viruses in individuals with a high frequency of animal exposure in Vietnam, an emerging infectious disease hotspot. The results show the value of baseline/control sampling in delineating the causative relationships and have revealed important insights into the ecological aspects of EVs, rhinoviruses and influenza A and their contributions to the burden posed by respiratory infections in Vietnam.

Epidemiology and Phylogenetic Analysis of Viral Respiratory Infections in Vietnam

Acute respiratory infections (ARIs) impose a major public health burden on fragile healthcare systems of developing Southeast Asian countries such as Vietnam. The epidemiology, genetic diversity and transmission patterns of respiratory viral pathogens that circulate in this region are not well characterized. We used RT-PCR to screen for 14 common respiratory viruses in nasal/throat samples from 4326 ARI patients from 5 sites in Vietnam during 2012-2016. 64% of patients tested positive for viruses; 14% tested positive multiple co-infecting viruses. The most frequently detected viruses were Respiratory syncytial virus (RSV, 23%), Human Rhinovirus (HRV, 13%), Influenza A virus (IAV, 11%) and Human Bocavirus (HBoV, 7%). RSV infections peaked in July to October, were relatively more common in children <1 year and in the northernmost hospital. IAV infections peaked in December to February and were relatively more common in patients >5 years in the central region. Coinfection with IAV or RSV was associated with increased disease severity compared with patients only infected with HBoV or HRV. Over a hundred genomes belonging to 13 families and 24 genera were obtained via metagenomic sequencing, including novel viruses and viruses less commonly associated with ARIs. Phylogenetic and phylogeographic analyses further indicated that neighboring countries were the most likely source of many virus lineages causing ARIs in Vietnam and estimated the period that specific lineages have been circulating. Our study illustrates the value of applying the state-of-the-art virus diagnostic methods (multiplex RT-PCR and metagenomic sequencing) and phylodynamic analyses at a national level to generate an integrated picture of viral ARI epidemiology.

Respiratory syncytial virus in the Western Pacific Region: a systematic review and meta-analysis

Background

Respiratory syncytial virus (RSV) is the leading cause of viral pneumonia and bronchiolitis, especially in younger children. The burden of RSV infection in adults, particularly in the older age group, is increasingly recognised. However, RSV disease burden and molecular epidemiology in the World Health Organization (WHO) Western Pacific Region (WPR) has not been reviewed systematically. The aim of this systematic review is to investigate the epidemiological aspects of RSV (incidence, prevalence, seasonality and hospitalisation status) and the associated molecular data in the WPRO countries.

Methods

A systematic search was conducted in international literature databases (MEDLINE, EMBASE, Scopus and Web of Science) to identify RSV-related publications from January 2000 to October 2017 in the WPR countries.

Results

A total of 196 studies from 15 WPR countries were included. The positivity rate for RSV among respiratory tract infection patients was 16.73% (95% confidence interval (CI) = 15.12%-18.4%). The RSV-positive cases were mostly found in hospitalised compared with outpatients (18.28% vs 11.54%, P < 0.001), and children compared with adults (20.72% vs 1.87%, P < 0.001). The seasonality of RSV in the WPR countries follows the latitude, with the peak of RSV season occurring in the winter in temperate countries, and during the rainy season in tropical countries. The molecular epidemiology pattern of RSV in WPR countries was similar to the global pattern, with NA1 (RSV A) and BA (RSV B) being the predominant genotypes.

Conclusions

The available data on RSV are limited in several countries within the WPR, with most data focusing on children and hospitalised patients. Further studies and surveillance, incorporating laboratory testing, are needed to determine the burden of RSV infection in the WPR countries.

Human coronavirus OC43 and other respiratory viruses from acute respiratory infections of Egyptian children

Respiratory infections have a significant impact on health worldwide. Viruses are major causes of acute respiratory infections among children. Limited information regarding its prevalence in Egypt is available. This study investigated prevalence of 10 respiratory viruses; Adenovirus, influenza A, B, respiratory syncytial virus (RSV), Parainfluenza virus (PIV)type 1-4, enterovirus, and human coronavirus OC43 (HCoV-OC43) among children in Alexandria, Egypt presenting with acute lower respiratory tract infections.The study was conducted on children <14 years of age selected from ElShatby Pediatric Hospital, Alexandria University, Egypt. One hundred children presenting during winter season with influenza-like illness were eligible for the study. Oropharyngeal swabs were collected and subjected to viral RNA and DNA extraction followed by polymerase chain reaction.Viral infections were detected in 44% of cases. Adenovirus was the most common, it was found in 19% of the patients. Prevalence of PIV (3 and 4) and enterovirus was 7% each. Prevalence of RSV and HCoV-OC43 was 5% and 3% respectively. Two percentage were Influenza A positive and 1% positive for influenza B. Mixed viral infection was observed in 7%.To the best of our knowledge, this is the first report of the isolation of HCoV-OC43 from respiratory infections in Alexandria, Egypt.

Age-specific incidence rates and risk factors for respiratory syncytial virus-associated lower respiratory tract illness in cohort children under 5 years old in the Philippines

Background

Respiratory syncytial virus (RSV) is one of the main viral causes of lower respiratory tract illness (LRTI), especially in young children. RSV vaccines, including maternal and infant vaccines, are under development; however, more epidemiological studies are needed to develop effective vaccination strategies.

Objectives

To estimate detailed age‐specific incidence rates and severity of RSV‐associated LRTI (RSV‐LRTI) using data from a community‐based prospective cohort study in the Philippines.

Patients/Methods

Cohort children who visited health facilities due to acute respiratory symptoms were identified, and nasopharyngeal swabs were collected to detect RSV. The severity of RSV‐LRTI was assessed using the severity definition proposed by the World Health Organization. Risk factors for developing RSV‐LRTI and contribution of SpO₂ measurement were also evaluated.

Results

A total of 395 RSV episodes which occurred in children aged 2‐59 months were categorised as 183 RSV‐LRTI, 72 as severe RSV‐LRTI and 29 as very severe RSV‐LRTI. Children aged 3‐5 months had the highest incidence rate of RSV‐LRTI, at 207.4 per 1000 child‐years (95% CI: 149.0‐279.5). Younger age group, place of living and low educational level of caregivers were associated with developing RSV‐LRTI. Clinical manifestations had low levels of agreement with hypoxaemia as measured by pulse oximeter.

Conclusion

The highest burden of RSV was observed in young infants aged 3‐5 months, whereas the burden was also high in those aged 12‐20 months. Future vaccination strategies should consider the protection of older children, especially those aged one year, as well as young infants.

Recurrent respiratory tract infections or acute otitis media were not a risk factor for vocabulary development in children at 13 and 24 months of age

AIM

This study examined associations between recurrent respiratory tract infections (RTI) and acute otitis media (AOM) during the first one and two years of life and vocabulary size at 13 and 24 months of age.

METHODS

We studied 646 children born between January 2008 and April 2010 and followed up from birth to two years of age with daily diary and study clinic visits during RTIs and AOM. The families were recruited from maternity health care clinics or delivery wards in south-west Finland. Parents completed the MacArthur Communicative Development Inventory at 13 and 24 months, and the vocabularies of children with high rates of RTIs or AOM were compared to children without recurrent issues.

RESULTS

Of the 646 children, 9.6% had recurrent RTIs and 9.9% had recurrent AOM from 0 to 24 months. Children with high rates of RTIs or AOM did not have smaller vocabularies than children without recurrent RTIs or AOM. Girls had larger vocabularies and higher parental socioeconomic status was associated with a larger expressive vocabulary at 24 months.

CONCLUSION

The child's gender and parental socioeconomic status played a more critical role in vocabulary development in the first two years than a high burden of RTIs or AOM.

Inequalities on mortality due to acute respiratory infection in children: A Colombian analysis

INTRODUCTION

Acute respiratory infections (ARI) are a leading public health issue worldwide.

OBJECTIVE

To explore the inequalities in ARI mortality rates in under-5, according to socioeconomic characteristics.

MATERIALS AND METHODS

We conducted an ecological analysis to study inequalities at municipal level due to ARI mortality in children under 5 years. The data were obtained from official death records of the Departamento Administrativo Nacional de Estadística. The analysis of inequalities in the under-5 mortality rate (U5MR) included: 1) Classification of the population in different socio-economic strata, and 2) measurement of the degree of inequality. We used the ARI-U5MR as an outcome measurement.The mortality rates were estimated at national and municipal levels for the years 2000, 2005, 2010, and 2013. Rate ratios, rates differences, and concentration curves were calculated to observe the inequalities.

RESULTS

A total of 18,012 children under 5 years died by ARI in Colombia from 2000 to 2013. ARIU5MR was greater in boys than in girls. During this period, an increase in the infant mortality relative gap in both boys and girls was observed. In 2013, the U5MR evidenced that for boys from municipalities with the highest poverty had a 1.6-fold risk to die than those in municipalities with the lowest poverty (low tercile). In girls, the ARI-U5MR for 2005 and 2013 in the poorest tercile was 1.5 and 2 times greater than in the first tercile, respectively.

CONCLUSION

Colombian inequalities in the ARI mortality rate among the poorest municipalities compared to the richest ones continue to be a major challenge in public health.

Burden, Etiology, and Risk Factors of Respiratory Virus Infections Among Symptomatic Preterm Infants in the Tropics: A Retrospective Single-Center Cohort Study

Background

The burden of respiratory viral infections (RVIs) among preterm infants in the first few years of life, especially those living in the tropics with year-long transmissions of respiratory viruses, remains unknown. We aimed to describe the clinical epidemiology and associated risk factors for RVIs among symptomatic preterm infants ≤32 weeks up to 2 years of life.

Methods

We performed a data linkage analysis of clinical and hospital laboratory databases for preterm infants born at KK Women's and Children's Hospital, Singapore, from 2005 to 2015. RVI episodes during initial admission and subsequent hospital readmissions were included.

Results

Of 1854 infants in the study, 270 (14.5%) infants were diagnosed with at least 1 RVI. A total of 285 (85.3%) episodes were diagnosed postdischarge, with the highest risk for RVIs being from 3 to 5 months of age. The incidence of RVI in this population was 116 per 1000 infant-years and respiratory syncytial virus was the main overall causative pathogen. Infants with RVIs were more likely to be born at ≤27 weeks' gestational age (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.2-2.3), to have received postnatal steroids (OR, 1.5; 95% CI, 1.0-2.1), and to be diagnosed with bronchopulmonary dysplasia (OR, 1.7; 95% CI, 1.2-2.4).

Conclusions

The burden of RVIs is high in preterm infants in the tropics, affecting >1 of 10 infants born at ≤32 weeks' gestation before 2 years of age. Respiratory syncytial virus was the main causative pathogen identified. Risk factors for RVI included extremely low gestational age, receipt of postnatal steroids, and bronchopulmonary dysplasia.

Parents' depression and loneliness during pregnancy and respiratory infections in the offspring: A prospective birth cohort study

Background

An association between maternal prenatal stress and increased rates of respiratory tract infections in the offspring has been described earlier. Data regarding the father’s role is lacking. In this study our aim was to evaluate, whether mothers’ and fathers’ depressive symptoms and loneliness during pregnancy predict higher rates of respiratory tract infections in the offspring.

Methods

In this longitudinal cohort study we gathered information on parental psychological risk during gestational week 20 using the BDI-II and UCLA loneliness scale questionnaires for the parents of 929 children. Loneliness was divided into social and emotional components, the former describing patterns of social isolation and the latter a perceived lack of intimate attachments. Episodes of acute otitis media, physician visits due to respiratory tract infections, and antibiotic consumption relating to respiratory tract infections were documented in the infants, excluding twins, from birth until 10 months of age using study diaries. Analyses were carried out by structural equation modeling, which provides dynamic estimates of covariances.

Results

Maternal depressive symptoms during pregnancy predicted higher rates of acute otitis media in the infant and maternal emotional loneliness predicted higher rates of physician visits. Acute otitis media, physician visits and antibiotic consumption in the infant were slightly less frequent for families who reported social loneliness in the father or mother. Associations remained when taking into account confounders.

Conclusions

Maternal prenatal depression and emotional loneliness predicted a higher burden of respiratory tract infections in the offspring. The protective influence of parental social loneliness on the burden of respiratory tract infections in infants was not in line with our study hypothesis, but could be explained by reduced use of healthcare services in these socially isolated families.

Primary care influenza-like illness surveillance in Ho Chi Minh City, Vietnam 2013-2015

Background

Year‐round transmission of influenza has been detected in Vietnam through both national surveillance and other epidemiological studies. Understanding the demographic and clinical features of influenza‐like illness (ILI) presenting to primary care in urban Vietnam is vital to understand these transmission dynamics.

Methods

An observational study of patients with ILI in Ho Chi Minh City, Vietnam, was conducted between August 2013 and November 2015 in a mix of public and private primary care settings. Molecular testing for influenza A and influenza B and 12 other respiratory viruses was performed.

Results

A total of 1152 ILI patients were recruited. 322 and 136 subjects tested positive for influenza A and influenza B, respectively. 193 subjects tested positive for another respiratory virus; most commonly rhinovirus and parainfluenza virus 3. Influenza was detected in 81% of the 116 study weeks. Three peaks of influenza activity were detected; an H3N2 peak April‐June 2014, an influenza B peak July‐December 2014, and a mixed H3N2 and H1N1 peak March‐September 2015. Subjects recruited from private clinics were more likely to have higher income and to have reported previous influenza vaccination. Antibiotic use was common (50.3%) despite limited evidence of bacterial infection.

Conclusion

Influenza in southern Vietnam has complex transmission dynamics including periods of intense influenza activity of alternating types and subtypes. Broadening surveillance from hospital to the community in tropical settings is feasible and a valuable for improving our understanding of the global spread and evolution of the virus.

Age-related prevalence of common upper respiratory pathogens, based on the application of the FilmArray Respiratory panel in a tertiary hospital in Greece

The FilmArray Respiratory Panel (FA-RP) is an FDA certified multiplex PCR that can detect 17 viruses and 3 bacteria responsible for upper respiratory tract infections, thus it is potentially useful to the assessment of the age-related prevalence of these pathogens.In this observational study, we retrospectively analyzed the results of all the respiratory samples, which had been processed during 1 year-period (November 2015 to November 2016) with the FA-RP, in the Central Laboratories of Hygeia & Mitera General Hospitals of Athens, Greece. In order to have an age-related distribution, the following age groups were implemented: (<2), (≥2, <5), (≥5, <10), (≥10, <18), (≥18, <45), (≥45, <65), and (≥65) years old.Among 656 respiratory samples tested, 362 (55%) were from male and 294 (45%) from female patients, while 356 (54.3%) were positive and 300 (45.7%) negative. In the first age-group (<2), 41/121 samples (33.9%) revealed human rhinovirus/enterovirus (HRV) and 16 (13.2%) adenovirus (Adv), followed by respiratory syncytial virus (RSV), coronavirus, human metapneumovirus (Hmpv), and parainfluenza viruses (PIV). In the age-group (≥2, <5), Adv predominated with 37/147 samples (25.2%), followed by HRV, RSV, coronavirus (all types), and influenza, Hmpv and PIV. In the age-group (≥5, <10), HRV was identified in 25/80 samples (31.3%), Adv in 18 (22.5%), influenza in 11 (13.8%), and Hmpv in 6 (7.5%). Influenza predominated in the age-group (≥10, <18), with 4/22 samples (18.2%), while in the remaining age-groups (≥18), HRV was the commonest isolated pathogen, 33/286 (11.5%), followed by influenza with 20 (7%) (influenza A H1-2009, 11/20).In our patient series, HRV seemed to prevail in most age-groups, followed by Adv, although Influenza was the second most frequent pathogen isolated in the age-groups (≥18). Moreover, increasing age corresponded to increasing possibility of having a negative sample, indicating that FilmArray may be more useful before adolescence.

Population-Based Pediatric Hospitalization Burden of Lineage-Specific Influenza B in Hong Kong, 2004-2014

Background

Influenza B virus has been perceived to cause less disease burden and milder disease compared with influenza A, but recent studies suggest that influenza B does have a significant impact. We aimed to estimate the burden of influenza B virus infections on hospitalizations in Hong Kong, in the context of virus lineage changes over time.

Methods

The pediatric age-specific rates of influenza B hospitalization in Hong Kong for 2004-2014 were estimated based on admissions to 2 hospitals that together catered for 72.5% of all pediatric admissions on Hong Kong Island. Influenza B virus was detected by immunofluorescence and culture on nasopharyngeal aspirates. Lineage typing was performed by real-time reverse-transcription polymerase chain reaction.

Results

A total of 5085 children were recruited on 1 designated day each week, year-round during the 11 years, and 221 (4.3%) tested positive for influenza B. Hospitalization rates were highest in children aged 2 to <5 years with year-to-year variation. Victoria-lineage viruses appeared to be associated with a greater fraction of influenza B hospitalizations in children than of influenza B infections in the general community. Influenza B did not cause significant hospitalization in infants <1 year of age.

Conclusions

We report one of the first population-based, age- and lineage-specific studies of pediatric hospitalization for influenza B. We found that changes in lineage were associated with higher hospitalization rates and documented that Victoria lineage viruses were associated with greater pediatric hospitalization burden compared with Yamagata lineage viruses.

Retrospective analysis assessing the spatial and temporal distribution of paediatric acute respiratory tract infections in Ho Chi Minh City, Vietnam

BACKGROUND

Acute respiratory tract infections (ARIs) are the leading cause of morbidity and mortality in young children in low/middle-income countries. Using routine hospital data, we aimed to examine the spatial distribution, temporal trends and climatic risk factors of paediatric ARIs in Vietnam.

METHODS

Data from hospitalised paediatric (<16 years) patients with ARIs residing in Ho Chi Minh City (HCMC) between 2005 and 2010 were retrieved from the two main Children's Hospitals and the Hospital for Tropical Diseases in HCMC. Spatial mapping and time series analysis were performed after disaggregating data into upper respiratory tract infections (URIs) and lower respiratory tract infections (LRIs).

RESULTS

Over the study period, there were 155 999 paediatric patients admitted with ARIs (33% of all hospital admissions). There were 68 120 URIs (14%) and 87 879 LRIs (19%). The most common diagnoses were acute pharyngitis (28% of all ARI), pneumonia (21%), bronchitis (18%) and bronchiolitis (16%). A significant increasing trend over time was found for both URIs (mean weekly incidence per 1000 population, I=3.12), incidence rate ratio for 1-week increase in time (RR 1.0, 95% CI 1.02 to 1.17) for URI and (I=4.02, RR 1.08 (95% CI 1.006 to 1.16)) for LRI. The weekly URI incidence peaked in May-June and was significantly associated with lags in weekly URI incidence and the average humidity, rainfall and water level. The weekly LRI incidence exhibited significant seasonality (P<0.0001), with an annual peak in September-October and was significantly associated with lags in weekly LRI incidence and lags in weekly average temperature, rainfall and water level.

CONCLUSIONS

ARIs are a leading cause of childhood hospitalisation in HCMC, Vietnam. The incidence of ARIs was higher in the wet season and in specific HCMC districts. These results may guide health authorities in where and when to effectively allocate resources for the prevention and control of ARIs.

Acute effects of ambient air pollution on lower respiratory infections in Hanoi children: An eight-year time series study

BACKGROUND

Lower respiratory diseases are the most frequent causes of hospital admission in children worldwide, particularly in developing countries. Daily levels of air pollution are associated with lower respiratory diseases, as documented in many time-series studies. However, investigations in low-and-middle-income countries, such as Vietnam, remain sparse.

OBJECTIVE

This study investigated the short-term association of ambient air pollution with daily counts of hospital admissions due to pneumonia, bronchitis and asthma among children aged 0-17 in Hanoi, Vietnam. We explored the impact of age, gender and season on these associations.

METHODS

Daily ambient air pollution concentrations and hospital admission counts were extracted from electronic databases received from authorities in Hanoi for the years 2007-2014. The associations between outdoor air pollution levels and hospital admissions were estimated for time lags of zero up to seven days using Quasi-Poisson regression models, adjusted for seasonal variations, meteorological variables, holidays, influenza epidemics and day of week.

RESULTS

All ambient air pollutants were positively associated with pneumonia hospitalizations. Significant associations were found for most pollutants except for ozone and sulfur dioxide in children aged 0-17. Increments of an interquartile range (21.9μg/m³) in the 7-day-average level of NO₂ were associated with a 6.1% (95%CI 2.5% to 9.8%) increase in pneumonia hospitalizations. These associations remained stable in two-pollutant models. All pollutants other than CO were positively associated with hospitalizations for bronchitis and asthma. Associations were weaker in infants than in children aged 1-5.

CONCLUSION

Strong associations between hospital admissions for lower respiratory infections and daily levels of air pollution confirm the need to adopt sustainable clean air policies in Vietnam to protect children's health.

Evaluation of the Luminex xTAG Respiratory Viral Panel FAST v2 assay for detection of multiple respiratory viral pathogens in nasal and throat swabs in Vietnam

Background: Acute respiratory infections (ARI) are among the leading causes of hospitalization in children ≤5 years old. Rapid diagnostics of viral pathogens is essential to avoid unnecessary antibiotic treatment, thereby slowing down antibiotic-resistance. We evaluated the diagnostic performance of the Luminex xTAG Respiratory Viral Panel FAST v2 against viral specific PCR as reference assays for ARI in Vietnam.Methods: Four hundred and forty two nose and throat swabs were collected in viral transport medium, and were tested with Luminex xTAG Respiratory Viral Panel FAST v2. Multiplex RT-PCR and single RT-PCR were used as references.   Results: Overall, viral pathogens were detected in a total count of 270/294 (91.8%, 95% CI 88.1-94.7) by the Luminex among reference assays, whilst 112/6336 (1.8%, 95% CI, 1.4-2.1) of pathogens were detected by the Luminex, but not by reference assays. Frequency of pathogens detected by Luminex and reference assays was 379 and 292, respectively. The diagnostic yield was 66.7% (295/442, 95%CI 62.1-71.1%) for the Luminex assay and 54.1% (239/442, 95% CI, 49.3-58.8%) for reference assays. The Luminex kit had higher yields for all viruses except influenza B virus, respiratory syncytial virus, and human bocavirus. High agreements between both methods [mean (range): 0.91 (0.83-1.00)] were found for 10/15 viral agents.Conclusions: The Luminex assay is a high throughput multiplex platform for rapid detection of common viral pathogens causing ARI. Although the current high cost may prevent Luminex assays from being widely used, especially in limited resource settings where ARI are felt most, its introduction in clinical diagnostics may help reduce unnecessary use of antibiotic prescription.

Evaluation of the Luminex xTAG Respiratory Viral Panel FAST v2 assay for detection of multiple respiratory viral pathogens in nasal and throat swabs in Vietnam

BACKGROUND

Acute respiratory infections (ARI) are among the leading causes of hospitalization in children ≤5 years old. Rapid diagnostics of viral pathogens is essential to avoid unnecessary antibiotic treatment, thereby slowing down antibiotic-resistance. We evaluated the diagnostic performance of the Luminex xTAG Respiratory Viral Panel FAST v2 against viral specific PCR as reference assays for ARI in Vietnam.

METHODS

Four hundred and forty two nose and throat swabs were collected in viral transport medium, and were tested with Luminex xTAG Respiratory Viral Panel FAST v2. Multiplex RT-PCR and single RT-PCR were used as references.    Results: Overall, viral pathogens were detected in a total count of 270/294 (91.8%, 95% CI 88.1-94.7) by the Luminex among reference assays, whilst 112/6336 (1.8%, 95% CI, 1.4-2.1) of pathogens were detected by the Luminex, but not by reference assays. Frequency of pathogens detected by Luminex and reference assays was 379 and 292, respectively. The diagnostic yield was 66.7% (295/442, 95%CI 62.1-71.1%) for the Luminex assay and 54.1% (239/442, 95% CI, 49.3-58.8%) for reference assays. The Luminex kit had higher yields for all viruses except influenza B virus, respiratory syncytial virus, and human bocavirus. High agreements between both methods [mean (range): 0.91 (0.83-1.00)] were found for 10/15 viral agents.

CONCLUSIONS

The Luminex assay is a high throughput multiplex platform for rapid detection of common viral pathogens causing ARI. Although the current high cost may prevent Luminex assays from being widely used, especially in limited resource settings where ARI are felt most, its introduction in clinical diagnostics may help reduce unnecessary use of antibiotic prescription.

Disease spectrum and management of children admitted with acute respiratory infection in Viet Nam

OBJECTIVE

To assess the acute respiratory infection (ARI) disease spectrum, duration of hospitalisation and outcome in children hospitalised with an ARI in Viet Nam.

METHODS

We conducted a retrospective descriptive study of ARI admissions to primary (Hoa Vang District Hospital), secondary (Da Nang Hospital for Women and Children) and tertiary (National Hospital of Paediatrics in Ha Noi) level hospitals in Viet Nam over 12 months (01/09/2015 to 31/08/2016).

RESULTS

Acute respiratory infections accounted for 27.9% (37 436/134 061) of all paediatric admissions; nearly half (47.6%) of all children admitted to Hoa Vang District Hospital. Most (64.6%) of children hospitalised with an ARI were <2 years of age. Influenza/pneumonia accounted for 69.4% of admissions; tuberculosis for only 0.3%. Overall 284 (0.8%) children died; most deaths (269/284; 94.7%) occurred at the tertiary referral hospital. The average duration of hospitalisation was 7.6 days (median 7 days). The average direct hospitalisation cost per ARI admission was 157.5 USD in Da Nang Provincial Hospital. In total, 62.6% of admissions were covered by health insurance.

CONCLUSION

Acute respiratory infection is a major cause of paediatric hospitalisation in Viet Nam, characterised by prolonged hospitalisation for relatively mild disease. There is huge potential to reduce unnecessary hospital admission and cost.

Polymorphisms of Mannose-binding Lectin and Toll-like Receptors 2, 3, 4, 7 and 8 and the Risk of Respiratory Infections and Acute Otitis Media in Children

BACKGROUND

Mannose-binding lectin (MBL) and toll-like receptors (TLRs) are important components of the innate immune system. We assessed the susceptibility of children with genetic variants in these factors to respiratory infections, rhinovirus infections and acute otitis media.

METHODS

In a prospective cohort study, blood samples from 381 Finnish children were analyzed for polymorphisms in MBL2 at codons 52, 54 and 57, TLR2 Arg753Gln, TLR3 Leu412Phe, TLR4 Asp299Gly, TLR7 Gln11Leu and TLR8 Leu651Leu. Children were followed up for respiratory infections until 24 months of age with daily diaries. Polymerase chain reaction and antigen tests were used for detection of respiratory viruses from nasal swabs.

RESULTS

Children with MBL variant genotype had a mean of 59 days with symptoms of respiratory infection per year, compared with 49 days in those with wild-type (P = 0.01). TLR8 polymorphisms were associated with an increased risk and TLR7 polymorphisms with a decreased risk of recurrent rhinovirus infections (P = 0.02 for both). TLR2 polymorphisms were associated with recurrent acute otitis media (P = 0.02). MBL polymorphisms were associated with an increased and TLR7 polymorphisms with a decreased risk of rhinovirus-associated acute otitis media (P = 0.03 and P = 0.006, respectively).

CONCLUSIONS

Genetic polymorphisms in MBL and TLRs promote susceptibility to or protection against respiratory infections. In addition to environmental factors, genetic variations may explain why some children are more prone to respiratory infections.

Exposure to paternal tobacco smoking increased child hospitalization for lower respiratory infections but not for other diseases in Vietnam

Exposure to environmental tobacco smoke (ETS) is an important modifiable risk factor for child hospitalization, although its contribution is not well documented in countries where ETS due to maternal tobacco smoking is negligible. We conducted a birth cohort study of 1999 neonates between May 2009 and May 2010 in Nha Trang, Vietnam, to evaluate paternal tobacco smoking as a risk factor for infectious and non-infectious diseases. Hospitalizations during a 24-month observation period were identified using hospital records. The effect of paternal exposure during pregnancy and infancy on infectious disease incidence was evaluated using Poisson regression models. In total, 35.6% of 1624 children who attended follow-up visits required at least one hospitalization by 2 years of age, and the most common reason for hospitalization was lower respiratory tract infection (LRTI). Paternal tobacco smoking independently increased the risk of LRTI 1.76-fold (95% CI: 1.24-2.51) after adjusting for possible confounders but was not associated with any other cause of hospitalization. The population attributable fraction indicated that effective interventions to prevent paternal smoking in the presence of children would reduce LRTI-related hospitalizations by 14.8% in this epidemiological setting.

Assessment of the Usefulness of Multiplex Real-Time PCR Tests in the Diagnostic and Therapeutic Process of Pneumonia in Hospitalized Children: A Single-Center Experience

The aim of the study was assessment of the usefulness of multiplex real-time PCR tests in the diagnostic and therapeutic process in children hospitalized due to pneumonia and burdened with comorbidities. Methods. The study group included 97 children hospitalized due to pneumonia at the Karol Jonscher Teaching Hospital in Poznań, in whom multiplex real-time PCR tests (FTD respiratory pathogens 33; fast-track diagnostics) were used. Results. Positive test results of the test were achieved in 74 patients (76.3%). The average age in the group was 56 months. Viruses were detected in 61 samples (82% of all positive results); bacterial factors were found in 29 samples (39% of all positive results). The presence of comorbidities was established in 90 children (92.78%). On the basis of the obtained results, 5 groups of patients were established: viral etiology of infection, 34 patients; bacterial etiology, 7 patients; mixed etiology, 23 patients; pneumocystis, 9 patients; and no etiology diagnosed, 24 patients. Conclusions. Our analysis demonstrated that the participation of viruses in causing severe lung infections is significant in children with comorbidities. Multiplex real-time PCR tests proved to be more useful in establishing the etiology of pneumonia in hospitalized children than the traditional microbiological examinations.

Burden of Recurrent Respiratory Tract Infections in Children: A Prospective Cohort Study

BACKGROUND

The burden of recurrent respiratory infections is unclear. We identified young children with recurrent respiratory infections in order to characterize the clinical manifestations, risk factors and short-term consequences.

METHODS

In this prospective cohort study, 1089 children were followed from birth to 2 years of age for respiratory infections by a daily symptom diary. Nasal swabs taken during respiratory infections were analyzed for viruses from 714 children. Nasopharyngeal swabs collected at 2 months of age were cultured for bacteria. The 10% of children with the highest number of annual respiratory illness days were defined to have recurrent respiratory tract infections.

RESULTS

The 90th percentile in the number of annual respiratory illness days was 98. Children above this limit (n = 109) had a median of 9.6 acute respiratory infections per year. Rhinovirus was detected in 58% of their infections. Of the children with recurrent infections, 60% were diagnosed with at least 3 episodes of acute otitis media, 73% received at least 3 antibiotic treatments and 21% were hospitalized for an acute respiratory infection. Tympanostomy was performed for 35% and adenoidectomy for 13% of the children. Asthma was diagnosed in 12% by 24 months of age. Older siblings increased the risk of recurrent respiratory infections. Early nasopharyngeal colonization with Streptococcus pneumoniae was common in children who later developed recurrent infections.

CONCLUSIONS

Children with recurrent respiratory infections frequently use health care services and antibiotics, undergo surgical procedures and are at risk for asthma in early life. Having older siblings increases the risk of recurrent infections.

A review on antiviral activity of the Himalayan medicinal plants traditionally used to treat bronchitis and related symptoms

Objectives

Bronchitis is a common respiratory tract infection of humans mainly caused by influenza virus, rhinovirus, adenovirus, coronavirus and respiratory syncytial virus. The aim of this review was to gather fragmented literature on ethnomedicinal plants used against bronchitis in the Himalayan region and their in-vitro validation against bronchitis causing viral pathogens.

Key findings

Present review contains ethnomedicines of total 55 plants from different countries of the Himalayas. Most of the literature reported was from India followed by Pakistan, China and Nepal. Familiarly used plant families for bronchitis treatment in the Himalayan region were Leguminosae (six plants) and Lamiaceae (five plants). Leaves and roots were the most common parts used in ethnomedicines against bronchitis. Of these 55 plants, only six plants have been studied in vitro against viral pathogens causing bronchitis. Different compounds like monoterpenoids, flavonoids, triterpenoids, iridoid glycosides, sesquiterpenes, benzoic and phenolic compounds were reportedly isolated from these plant extracts having strong antiviral potential.

Summary

The Himalayan regions possess variety of ethnomedicinal plants used against respiratory diseases, but still there are only few studies related with their in-vitro validation. We invite the attention of researchers for detailed ethnopharmacological and phytochemical studies on unexplored plants used to treat bronchitis for the development of novel antiviral drugs.

Rhinovirus Infections in the First 2 Years of Life

BACKGROUND AND OBJECTIVES

Rhinoviruses frequently cause respiratory infections in young children. We aimed to establish the burden of acute respiratory infections caused by rhinovirus during the first 2 years of life.

METHODS

In this prospective birth cohort study, we followed 923 children for acute respiratory infections from birth to 2 years of age. Data on respiratory infections were collected by daily symptom diaries, study clinic visits, and from electronic registries. Respiratory viruses were detected by reverse transcription-polymerase chain reaction and antigen assays during respiratory infections and at the age of 2, 13, and 24 months. The rates of rhinovirus infections and associated morbidities were determined.

RESULTS

We documented 8847 episodes of acute respiratory infections, with an annual rate of 5.9 per child (95% confidence interval [CI], 5.7-6.1). Rhinovirus was detected in 59% of acute respiratory infections analyzed for viruses. Rhinovirus was associated with 50% of acute otitis media episodes, 41% of wheezing illnesses, 49% of antibiotic treatments, and 48% of outpatient office visits for acute respiratory infections. The estimated mean annual rate of rhinovirus infections was 3.5 per child (95% CI, 3.3-3.6), 47 per 100 children (95% CI, 42-52) for rhinovirus-associated acute otitis media, and 61 per 100 children (95% CI, 55-68) for rhinovirus-associated antibiotic treatment. The prevalence of rhinovirus at 2, 13, or 24 months of age was 14 to 24%, and 9% of asymptomatic children were positive for rhinovirus.

CONCLUSIONS

Rhinovirus infections impose a major burden of acute respiratory illness and antibiotic use on young children.

Maternal vaccination for the prevention of influenza: current status and hopes for the future

Influenza is an important cause of morbidity and mortality among pregnant women and young infants, and influenza infection during pregnancy has also been associated with adverse obstetric and birth outcomes. There is substantial evidence - from randomized trials and observational studies - that maternal influenza immunization can protect pregnant women and their infants from influenza disease. In addition, there is compelling observational evidence that prevention of influenza in pregnant women can also protect against certain adverse pregnancy outcomes, including stillbirth and preterm birth. In this article we will review and evaluate the literature on both the burden of influenza disease in pregnant women and infants, as well as the multiple potential benefits of maternal influenza immunization for mother, fetus, and infant. We will also review key clinical aspects of maternal influenza immunization, as well as identify remaining knowledge gaps, and discuss avenues for future investigation.

Human bocaviruses: Possible etiologic role in respiratory infection

Four species of human bocaviruses (HBoV) are currently included in the Bocavirus genus. There is satisfactory evidence demonstrating an association between HBoV1 and respiratory disease in children, and there is evidence that HBoV2 (and possibly the HBoV3 and HBoV4 species) are associated with gastroenteritis. In particular, HBoV1 has been associated with a prolonged period of persistence in the mucosa of the respiratory tract. Virus persistence does play a role in the high frequency of co-infections with proper pathogens of the upper and lower respiratory tracts. The high detection rate of multiple respiratory viruses in up to 83% of respiratory specimens and the presence of asymptomatic HBoV1 infections complicate the elucidation of the pathogenic role of the agent. Overall, a large amount of data are available concerning HBoV1, whereas little information is available about other bocavirus species. High viral loads are often associated with symptoms, and viremia may be associated with systemic manifestations such as encephalopathy. The effects and mechanisms of latency, persistence, reactivation, and reinfection are poorly understood. Thus, particularly in co-infections, the pathogenic contribution of the detected bocavirus species cannot be accurately stated. This review summarizes the current knowledge of HBoV species and provides perspectives for future clinical studies.

The epidemiology and aetiology of diarrhoeal disease in infancy in southern Vietnam: a birth cohort study

•

The diarrhoeal disease burden in a large, prospective infant cohort in Vietnam is defined.

•

Minimum incidence of clinic-based diarrhoea in infants: 271/1000 infant-years.

•

Rotavirus was most commonly identified, followed by norovirus and bacterial pathogens.

•

Frequent repeat infections with the same pathogen within 1 year.

•

Inclusion of rotavirus in the immunization schedule for Vietnam is warranted.

Objectives

Previous studies indicate a high burden of diarrhoeal disease in Vietnamese children, however longitudinal community-based data on burden and aetiology are limited. The findings from a large, prospective cohort study of diarrhoeal disease in infants in southern Vietnam are presented herein.

Methods

Infants were enrolled at birth in urban Ho Chi Minh City and a semi-rural district in southern Vietnam, and followed for 12 months (n = 6706). Diarrhoeal illness episodes were identified through clinic-based passive surveillance, hospital admissions, and self-reports.

Results

The minimum incidence of diarrhoeal illness in the first year of life was 271/1000 infant-years of observation for the whole cohort. Rotavirus was the most commonly detected pathogen (50% of positive samples), followed by norovirus (24%), Campylobacter (20%), Salmonella (18%), and Shigella (16%). Repeat infections were identified in 9% of infants infected with rotavirus, norovirus, Shigella, or Campylobacter, and 13% of those with Salmonella infections.

Conclusions

The minimum incidence of diarrhoeal disease in infants in both urban and semi-rural settings in southern Vietnam was quantified prospectively. A large proportion of laboratory-diagnosed disease was caused by rotavirus and norovirus. These data highlight the unmet need for a rotavirus vaccine in Vietnam and provide evidence of the previously unrecognized burden of norovirus in infants.