Respiratory syncytial virus, adenoviruses, and mixed acute lower respiratory infections in children in a developing country

Severe Pneumonia Caused by Respiratory Syncytial Virus and Adenovirus in Children from 2 to 24 Months at Children's Hospital 1 in Ho Chi Minh City, Vietnam

In Vietnam, due to the lack of facilities to detect respiratory viruses from patients' specimens, there are only a few studies on the detection of viral pathogens causing pneumonia in children, especially respiratory syncytial virus (RSV) and adenovirus (Adv). Here, we performed a cross-sectional descriptive prospective study on 138 children patients from 2 to 24 months old diagnosed with severe pneumonia hospitalized at the Respiratory Department of Children's Hospital 1 from November 2021 to August 2022. The number of patients selected in this study was based on the formula n = ([Z(1 - α/2)]2 × P [1 - P])/d2, with α = 0.05, p = 0.5, and d = 9%, and the sampling technique was convenient sampling until the sample size was met. A rapid test was used to detect RSV and Adv from the nasopharyngeal swabs and was conducted immediately after the patient's hospitalization. Laboratory tests were performed, medical history interviews were conducted, and nasotracheal aspirates were collected for multiplex real-time PCR (MPL-rPCR) to detect viral and bacterial pathogens. The results of the rapid test and the MPL-rPCR in the detection of both pathogens were the same at 31.9% (44/138) for RSV and 8.7% (7/138) for Adv, respectively. Using MPL-rPCR, the detection rate was 21% (29/138) for bacterial pathogens, 68.8% (95/138) for bacterial-viral co-infections, and 6.5% (9/138) for viral pathogens. The results showed few distinctive traits between RSV-associated and Adv-associated groups, and the Adv group children were more prone to bacterial infection than those in the RSV group. In addition, the Adv group experienced a longer duration of treatment and a higher frequency of re-hospitalizations compared to the RSV group. A total of 100% of Adv infections were co-infected with bacteria, while 81.82% of RSV co-infected with bacterial pathogens (p = 0.000009). This study might be one of the few conducted in Vietnam aimed at identifying viral pathogens causing severe pneumonia in children.

Disparities in prevalence and outcomes of respiratory disease in low- and middle-income countries

OBJECTIVES

To provide a comprehensive overview of disparities in prevalence and outcomes of respiratory diseases and notable challenges for providing optimal treatment to pediatric patients with respiratory diseases living in low- and middle-income countries (LMICs), as an input to help better understand the roots of respiratory health disparities.

METHODS

We conducted a narrative review of relevant literature published in electronic databases from inception to February 2023 that present data on disparities in prevalence and outcomes of respiratory disease in LMICs. Additionally, we included studies that describe and discuss challenges for providing optimal treatment to pediatric patients with respiratory diseases living in LMICs.

RESULTS

A number of early life exposures have been associated with adverse respiratory outcomes in later life. Several studies have shown marked geographical variations in the prevalence and burden of pediatric asthma, with consistently lower prevalence rates but significantly higher burdens and worse outcomes in LMICs. There is a wide range of challenges that adversely affect the efficient care of children with respiratory diseases that can be classified into three categories: patient-related factors, social/environmental factors, and factors related to healthcare providers or the healthcare system.

CONCLUSIONS

Respiratory health disparities in children living in LMICs represent a global public health issue mainly explained by an unequal distribution of preventable and modifiable risk factors for respiratory diseases across different demographic groups.

Human Adenovirus Associated Hepatic Injury

Human adenovirus (HAdV) is a common virus, but the infections it causes are relatively uncommon. At the same time, the methods for the detection of HAdV are varied, among which viral culture is still the gold standard. HAdV infection is usually self-limited but can also cause clinically symptomatic in lots of organs and tissues, of which human adenovirus pneumonia is the most common. In contrast, human adenovirus hepatitis is rarely reported. However, HAdV hepatitis has a high fatality rate once it occurs, especially in immunocompromised patients. Although human adenovirus hepatitis has some pathological and imaging features, its clinical symptoms are not typical. Therefore, HAdV hepatitis is not easy to be found in the clinic. There are kinds of treatments to treat this disease, but few are absolutely effective. In view of the above reasons, HAdV hepatitis is a disease that is difficult to be found in time. We reviewed and summarized the previously reported cases, hoping to bring some relatively common characteristics to clinicians, so as to facilitate early detection, early diagnosis, and early treatment of patients.

Adenovirus: Epidemiology, Global Spread of Novel Types, and Approach to Treatment

Adenoviruses (AdVs) are DNA viruses that typically cause mild infections involving the upper or lower respiratory tract, gastrointestinal tract, or conjunctiva. Rare manifestations of AdV infections include hemorrhagic cystitis, hepatitis, hemorrhagic colitis, pancreatitis, nephritis, or meningoencephalitis. AdV infections are more common in young children, due to lack of humoral immunity. Epidemics of AdV infection may occur in healthy children or adults in closed or crowded settings (particularly military recruits). The vast majority of cases are self-limited. However, the clinical spectrum is broad and fatalities may occur. Dissemination is more likely in patients with impaired immunity (e.g., organ transplant recipients, human immunodeficiency virus infection). Fatality rates for untreated severe AdV pneumonia or disseminated disease may exceed 50%. More than 100 genotypes and 52 serotypes of AdV have been identified and classified into seven species designated HAdV-A through -G. Different types display different tissue tropisms that correlate with clinical manifestations of infection. The predominant types circulating at a given time differ among countries or regions, and change over time. Transmission of novel strains between countries or across continents and replacement of dominant viruses by new strains may occur. Treatment of AdV infections is controversial, as prospective, randomized therapeutic trials have not been done. Cidofovir has been the drug of choice for severe AdV infections, but not all patients require treatment. Live oral vaccines are highly efficacious in reducing the risk of respiratory AdV infection and are in routine use in the military in the United States but currently are not available to civilians.

Epidemiology and Seasonality of Childhood Respiratory Syncytial Virus Infections in the Tropics

Infections caused by respiratory syncytial virus (RSV) are a major cause of morbidity and mortality in young children worldwide. Understanding seasonal patterns of region-specific RSV activity is important to guide resource allocation for existing and future treatment and prevention strategies. The decades of excellent RSV surveillance data that are available from the developed countries of the world are incredibly instructive in advancing public health initiatives in those regions. With few exceptions, these developed nations are positioned geographically across temperate regions of the world. RSV surveillance across tropical regions of the world has improved in recent years, but remains spotty, and where available, still lacks the necessary longitudinal data to determine the amount of seasonal variation expected over time. However, existing and emerging data collected across tropical regions of the world do indicate that patterns of infection are often quite different from those so well described in temperate areas. Here, we provide a brief summary regarding what is known about general patterns of RSV disease activity across tropical Asia, Africa and South America, then offer additional country-specific details using examples where multiple reports and/or more robust surveillance data have become available.

Inhibition of Autophagy Does Not Affect Innate Cytokine Production in Human Lung Epithelial Cells During Respiratory Syncytial Virus Infection

Human respiratory syncytial virus (RSV) is one of the major causes of childhood acute lower respiratory tract infection worldwide. Autophagy is an intracellular pathway involved in nutrient recycling. Recently, autophagy has been reported to play a role in regulating host cytokine response to several viruses, including vesicular stomatitis virus and human immunodeficiency virus. Previous in vivo studies using mouse model has shown that inhibition of autophagy reduces RSV-induced cytokine production. However, the role of autophagy in modulating RSV-induced cytokine response in human cells has not been reported. We investigated the role of autophagy in regulating the production of the cytokines C-X-C motif ligand 8 (CXCL8) and C-C motif ligand 5 (CCL5), in RSV-infected human bronchial epithelium BEAS-2B cells. Fluorescent microscopic analysis showed that RSV infection induced autophagosome formation in BEAS-2B cells. This autophagy inducing ability of RSV was further confirmed by flow cytometry. The effects of pharmacological inhibition of autophagy by SAR405 or chloroquine on cell death and cytokine release were quantified using lactate dehydrogenase assay and enzyme-linked immunosorbent assay (ELISA), respectively. We found that SAR405 or chloroquine did not cause cell death. Importantly, ELISA analysis showed that pharmacological inhibition of autophagy by SAR405 or chloroquine did not affect the productions of both CXCL5 and CXCL8. In contrast to the previous studies using mouse model, our data suggest that pharmacological inhibition of autophagy may not be a suitable strategy in controlling RSV-induced airway inflammation.

Clinical Signs, Prevention and Treatment of Viral Infections in Infants

Certain infectious diseases are common in infants than any other age groups and are associated with morbidities in childhood and adulthood, and even mortality in severe cases. Environment, epidemic and maternal immunity are the main causes of these infections. Early diagnosis using molecular methods and treatment is therefore important to prevent future complications. Vaccines are recommended during infancy and childhood to prevent these infections. This review highlights some of the most commonly reported viral infections in children, their clinical signs, prevention and treatment.

Use of the ReSVinet Scale for parents and healthcare workers in a paediatric emergency service: a prospective study

INTRODUCTION

Most scales for acute respiratory infection (ARI) are limited to healthcare worker (HCW) use for clinical decision-making. The Respiratory Syncytial Virus network (ReSVinet) Scale offers a version for parents that could potentially help as an early warning system.

OBJECTIVE

To determine whether or not the ReSVinet Scale for ARI in infants can be reliably used by HCWs and parents in an emergency service.

METHODS

A prospective study was done of infants with ARI who were admitted to a paediatric emergency room to assess the ReSVinet Scale when used by faculty (paediatric doctor-professors), residents (doctors doing their first specialty in paediatrics) and parents. Spearman's correlation and a weighted kappa coefficient were used to measure interobserver agreement. Internal consistency was also tested by Cronbach's alpha test.

RESULTS

Overall, 188 patients, 58% male, were enrolled. A Spearman's correlation of 0.92 for faculty and resident scoring and 0.64 for faculty or resident and parent scoring was found. The weighted kappa coefficients were 0.78 for faculty versus residents, 0.41 for faculty versus parents, and 0.41 for residents versus parents. Cronbach's alpha test was 0.67 for faculty, 0.62 for residents and 0.69 for parents.

CONCLUSION

There was good correlation in the ReSVinet scores between health professionals when used in the paediatric emergency area. Agreement between parents and health professionals was found to be more variable. Future studies should focus on finding ways to improve its reliability when used by parents before the scale is used in the emergency room.

Challenges in the prevention or treatment of RSV with emerging new agents in children from low- and middle-income countries

INTRODUCTION

Respiratory syncytial virus (RSV) causes approximately 120,000 deaths annually in children <5 years, with 99% of fatalities occurring in low- and middle-income countries (LMICs).

AREAS COVERED

There are numerous RSV interventions in development, including long-acting monoclonal antibodies, vaccines (maternal and child) and treatments which are expected to become available soon. We reviewed the key challenges and issues that need to be addressed to maximize the impact of these interventions in LMICs. The epidemiology of RSV in LMICs was reviewed (PubMed search to 30 June 2020 inclusive) and the need for more and better-quality data, encompassing hospital admissions, community contacts, and longer-term respiratory morbidity, emphasized. The requirement for an agreed clinical definition of RSV lower respiratory tract infection was proposed. The pros and cons of the new RSV interventions are reviewed from the perspective of LMICs.

EXPERT OPINION

We believe that a vaccine (or combination of vaccines, if practicable) is the only viable solution to the burden of RSV in LMICs. A coordinated program, analogous to that with polio, involving governments, non-governmental organizations, the World Health Organization, the manufacturers and the healthcare community is required to realize the full potential of vaccine(s) and end the devastation of RSV in LMICs.

Human adenoviruses associated with respiratory illness in neonates, infants, and children in the Sousse area of Tunisia

Background

The human Adenovirus (HAdV) is a common agent of acute respiratory infections (ARIs). Its clinical impact in immunocompetent children and in the context of coinfections remains unclear in Tunisia.

Material and methods

HAdV‐ARIs were studied in hospitalized patients from birth to the age of 5 years from 2013 to 2014. Clinical and demographic characteristics, coinfections, and molecular characterization of HAdV were established.

Results

HAdV‐positivity was detected in 114/583 specimens (19.6%) including 6.1% single infections and 93.9% coinfections. Adenoviral coinfections mostly comprised human Rhinovirus (50.9%), Streptococcus pneumoniae (34.2%), human Respiratory Syncytial virus A/B (29.8%), and human Coronaviruses (21.9%). HAdV infection was predominant in the pediatric population (25.0% vs 10.0% in neonates, P < .001) and peaked in February 2014 (21.1%). HAdV severity of pediatric cases is characterized by low saturation of oxygen (<94%, 33.8%, P = .05) and long duration of oxygen support (≥5 days, 32.7%, P = .02). Severe HAdV infections were described with S. pneumoniae coinfection, which seemed to increase the risk of death. HAdV genotyping identified HAdV‐C as the most common species. Severe ARIs were observed in all HAdV‐identified types. Phylogenetic analysis revealed that sequences were variable suggesting the circulation of different HAdV strains sharing more similarities to strains circulating in Europe or Asia than those from Africa.

Conclusion

This first molecular study of HAdV in Tunisia demonstrated that it has an important role in severe ARIs with HAdV‐C being the most common species. S. pneumoniae codetection seems to increase the severity of HAdV‐ARIs.

Disability-adjusted life years for respiratory syncytial virus in children under 2 years

BACKGROUND

Respiratory syncytial virus infection is the leading cause of bronchiolitis in Colombia. There is growing evidence about the impact of Respiratory syncytial virus on society in terms of years of life lost due to this condition. The objective of the present study is to determine the Disability-Adjusted Life Years for respiratory syncytial virus in children under 2 years in Colombia.

METHODS

Data from the national epidemiological surveillance system were used to estimate DALYs, calculated from the sum of years of life lost and years lived with disability due to RSV infection in Colombia. A bootstrapped method with 10,000 iterations was used to estimate each statistical parameter using the package DALY calculator in R.

RESULTS

In 2019, 260,873 years of life (CI95% 208,180-347,023) were lost due to RSV bronchiolitis in Colombian children under 2 years. The estimated rate was 20 DALYs / 1000 person-year (95% CI 16-27).

CONCLUSION

This is the first report estimating the impact of RSV bronchiolitis morbidity and mortality in Colombia. The findings of the present study suggest that the actual burden and cost of bronchiolitis due to RSV is high. Prevention strategies, such as RSV vaccination, to reduce morbidity associated with RSV infection should be encouraged in our country.

Systematic review on respiratory syncytial virus epidemiology in adults and the elderly in Latin America

OBJECTIVES

The present study provides a comprehensive review of the recently published data on RSV epidemiology in adults and the elderly in Latin America.

METHODS

A systematic literature search was carried out in Medline, Scielo, Lilacs, and Cochrane Library. The search strategy aimed at retrieving studies focusing on RSV prevalence, burden, risk factors, and the routine clinical practice in the prevention and management of RSV infections in Latin American countries. Only articles published between January 2011 and December 2017 were considered.

RESULTS

Eighteen studies were included. Percentages of RSV detection varied highly across included studies for adult subjects with respiratory infections (0% to 77.9%), influenza-like illness (1.0% to 16.4%) and community-acquired pneumonia (1.3% to 13.5%). Considerable percentages of hospitalization were reported for RSV-infected adults with influenza-like illness (40.9% and 69.9%) and community-acquired pneumonia (91.7%).

CONCLUSIONS

Recent RSV data regarding adult populations in Latin America are scarce. RSV was documented as a cause of illness in adults and the elderly, being identified in patients with acute respiratory infections, influenza-like illness and community-acquired pneumonia. The studies suggest that RSV infections may be a significant cause of hospitalization in adult populations in Latin America, including younger adults.

Prevalence, risk factors and clinical characteristics of respiratory syncytial virus-associated lower respiratory tract infections in Kelantan, Malaysia

Respiratory syncytial virus (RSV) is a common pathogen affecting the respiratory tract in infants. To date, there is limited data on RSV occurrence in Malaysia especially in the northeast of Peninsular Malaysia which is significantly affected by the rainy (monsoon) season. This study aimed to determine the prevalence, risk factors (the presence of a male sibling and older school-age siblings, parental education level, monthly income, chronic lung disease, immunocompromised, being a passive smoker, multipara, breastfeeding, prematurity, congenital heart disease, nursery attendance, and rainy season) as well as clinical manifestations of RSV in hospitalized infants and children with lower respiratory tract infection (LRTI). Patients' nasopharyngeal aspirates were tested for RSV antigen, questionnaires, and seasonal variations were used to assess RSV infection. Approximately 22.6% of children were infected with RSV; mean age 7.68 ± 5.45 months. The peak incidence of RSV as a causative agent for LRTI in infants was less than or equal to 1-year old (83%) with approximately 50.5% of the affected children in the younger age group (6 months amd below). RSV infection was significantly but independently associated with the rainy season (odds ratio, 3.307; 95% confidence interval, 1.443-3.688; P < 0.001). The infection was also associated ( P < 0.05) with a higher number of severe clinical courses, poor feeding, vomiting, increased need for medical care and a shorter mean duration of symptoms before hospital admission. Our study suggested administration of the passive prophylaxis for RSV to high-risk infants during the rainy season in the months of October to January.

Simulation of four respiratory viruses and inference of epidemiological parameters

While influenza has been simulated extensively to better understand its behavior and predict future outbreaks, most other respiratory viruses have seldom been simulated. In this study, we provide an overview of four common respiratory viral infections: respiratory syncytial virus (RSV), respiratory adenovirus, rhinovirus and parainfluenza, present specimen data collected 2004–2014, and simulate outbreaks in 19 overlapping regions in the United States. Pairing a compartmental model and data assimilation methods, we infer key epidemiological parameters governing transmission: the basic reproductive number R₀ and length of infection D. RSV had been previously simulated, and our mean estimate of D and R₀ of 5.2 days and 2.8, respectively, are within published clinical and modeling estimates. Among the four virus groupings, mean estimates of R₀ range from 2.3 to 3.0, with a lower and upper quartile range of 2.0–2.8 and 2.6–3.2, respectively. As rapid PCR testing becomes more common, estimates of the observed virulence and duration of infection for these viruses could inform decision making by clinicians and officials for managing patient treatment and response.

Low birth weight contributed to increased serum IL-6 levels in infantile respiratory syncytial virus infection

Background

To evaluate the role of serum cytokines in the pathogenesis of respiratory syncytial virus (RSV) infection in infants with low birth weight (LBW).

Methods

A prospective observational study was performed, and hospitalized children with lower respiratory tract infection (LRTI) were recruited. Three hundred fifty-eight patients < 1 year met the inclusion criteria: 116 patients had only RSV infection (RSV group); 242 patients had no RSV or other specific pathogen (non-RSV group). Serum interleukin-2 (IL-2), IL-4, IL-6, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were detected through flow cytometry.

Results

No significant differences in serum IL-2, 4, 6, 10, and IFN-γ levels were observed between the RSV and non-RSV groups. For RSV infected infants with or without wheezing, delivery mode had no obvious effect on the changes of serum cytokine levels. However, the level of IL-6 in the RSV-infected infants with LBW was significantly higher than that in infants with normal birth weight.

Conclusions

Serum IL-6 level was significantly increased in RSV infected infants with LBW. It is likely that the specific serum cytokine pattern will contribute to our understanding of the pathogenesis of RSV infections, especially in RSV-infected infants with LBW.

Child undernutrition in one of the cities with greater nutritional risk in Brazil: population-based study in the Western Brazilian Amazon

Objective:

To estimate the prevalence of child undernutrition and associated factors in a municipality with high nutritional risk in Brazil.

Methods:

This cross-sectional, population-based study was conducted with a sample of 478 children aged under 5 years in the city of Jordão, Acre, Brazil. The following indicators were calculated: weight for age (W/A), height for age (H/A), and weight for height (W/H), using the growth curves of the WHO as reference, which adopts a cutoff of -2 z scores for identification of malnourished children. Adjusted prevalence ratios (PRs) were obtained using multiple Poisson regression models with robust error estimate (p < 0.05).

Results:

A high prevalence of stunting (35.8%) was observed. Children with indigenous ancestry living in rural areas showed the highest prevalence of malnutrition (59.4%). After controlling for age, gender, and indigenous ancestry, the factors associated with stunting risk were: living in rural area (PR = 1.6; 95%CI 1.2 - 2.1); lower tertile of household wealth index (PR = 1.6; 95%CI 1.1 - 2.3); living in houses made of walking palm (PR = 1.6; 95%CI 1.1 - 2.4); maternal height less than or equal to 146.4 cm (PR = 3.1; 95%CI 1.9 - 5.0); and history of introduction of cow's milk before 30 days of age (PR = 1.4; 95%CI 1.0 - 1.8). Children with updated vaccination cards were inversely associated with stunting risk (PR = 0.7; 95%CI 0.5 - 0.9).

Conclusion:

Child undernutrition remains a serious public health problem in the Amazon, indicating additional difficulties in facing the problem in this region of the country.

Age at menarche in relation to prenatal rainy season exposure and altitude of residence: results from a nationally representative survey in a tropical country

Intrauterine exposure to the rainy season in the tropics may be accompanied by high rates of infection and nutritional deficiencies. It is unknown whether this exposure is related to the extrauterine timing of development. Our aim was to evaluate the relations of prenatal exposure to the rainy season and altitude of residence with age at menarche. The study included 15,370 girls 10 to <18 years old who participated in Colombia's 2010 National Nutrition Survey. Primary exposures included the number of days exposed to the rainy season during the 40 weeks preceding birth, and altitude of residence at the time of the survey. We estimated median menarcheal ages and hazard ratios with 95% confidence interval (CI) according to exposure categories using Kaplan-Meier cumulative probabilities and Cox proportional hazards models, respectively. All tests incorporated the complex survey design. Girls in the highest quintile of gestation days exposed to the rainy season had an earlier age at menarche compared with those in the lowest (adjusted hazard ratios (HR)=1.08; 95% CI 1.00-1.18, P-trend=0.03). Girls living at altitudes ⩾2000 m had a later age at menarche compared with those living <1000 m (adjusted HR=0.88; 95% CI 0.82-0.94, P-trend <0.001). The inverse association between gestation days during the rainy season and menarche was most apparent among girls living at altitudes ⩾2000 m (P, interaction=0.04). Gestation days exposed to the rainy season and altitude of residence were associated with the timing of sexual maturation among Colombian girls independent of socioeconomic status and ethnicity.

Clinical Impact of Mixed Respiratory Viral Infection in Children with Adenoviral Infection

Background

Although adenovirus (ADV) infection occurs steadily all year round in Korea and the identification of respiratory viral coinfections has been increasing following the introduction of multiplex real-time polymerase chain reaction tests, the clinical impact of viral coinfection in children with ADV infection has rarely been reported.

Materials and Methods

Medical records of children diagnosed with ADV infection were retrospectively reviewed. The enrolled children were divided into two groups based on the identified respiratory viruses: ADV group and coinfection group. Clinical and laboratory parameters were compared between the two groups.

Results

In total, 105 children (60 males and 45 females) with a median age of 29 months (range: 0-131 months) diagnosed with an ADV infection were enrolled. Fever (99.0%) was by far the most frequent symptom, followed by respiratory (82.9%), and gastrointestinal (22.9%) symptoms. Upper and lower respiratory tract infections were diagnosed in 56 (53.3%), and 32 (30.5%) children, respectively. Five (4.8%) children received oxygen therapy, and no child died due to ADV infection. Coinfection was diagnosed in 32 (30.5%) children, with rhinovirus (46.9%), and respiratory syncytial virus (21.9%) being the most frequent. The proportions of children younger than 24 months (P <0.001), with underlying medical conditions (P = 0.020), and diagnosed with lower respiratory tract infection (P = 0.011) were significantly higher in the coinfection group than in the ADV group. In a multivariate analysis, only the younger age was significantly associated with coinfection (P <0.001). Although more children in the coinfection group received oxygen therapy (P = 0.029), the duration of fever and hospitalization was not significantly different between the two groups.

Conclusion

Respiratory viral coinfection with ADV occurred more frequently in children younger than 24 months of age compared with children aged 24 months or older. Respiratory viral coinfection may increase the severity of ADV infection, however, appropriate therapy prevented prolonged hospitalization and poor prognosis due to coinfection.

Haze is a risk factor contributing to the rapid spread of respiratory syncytial virus in children

This study investigated whether respiratory syncytial virus (RSV) infection in children was associated with ambient temperature and air pollutants in Hangzhou, China. A distributed lag non-linear model (DLNM) was used to estimate the effects of daily meteorological data and air pollutants on the incidence of RSV infection among children. A total of 3650 childhood RSV infection cases were included in the study. The highest air pollutant concentrations were in January to May and October to December during the year. The yearly RSV-positive rate was 10.0 % among children with an average age of 4.3 months. The highest RSV-positive rate occurred among patients 0 to 3 months old. Children under 6.5 months old accounted for 80 % of the total patients infected by RSV. A negative correlation was found between ambient temperature and RSV infection, and it was strongest with minimum ambient temperature (r = -0.804, P < 0.001). There was a positive correlation between the infection rate and the particulate matter (PM) 2.5 (r = 0.446, P < 0.001), PM10 (r = 0.397, P < 0.001), SO₂ (r = 0.389, P < 0.001), NO₂ (r = 0.365, P < 0.001) and CO (r = 0.532, P < 0.001). The current study suggested that temperature was an important factor associated with RSV infection among children in Hangzhou. Air pollutants significantly increased the risk of RSV infection with dosage, lag and cumulative effects.

Adenovirus: Epidemiology, Global Spread of Novel Serotypes, and Advances in Treatment and Prevention

Adenoviruses (AdVs) are DNA viruses that typically cause mild infections involving the upper or lower respiratory tract, gastrointestinal tract, or conjunctiva. Rare manifestations of AdV infections include hemorrhagic cystitis, hepatitis, hemorrhagic colitis, pancreatitis, nephritis, or meningoencephalitis. AdV infections are more common in young children, due to lack of humoral immunity. Epidemics of AdV infection may occur in healthy children or adults in closed or crowded settings (particularly military recruits). The disease is more severe and dissemination is more likely in patients with impaired immunity (e.g., organ transplant recipients, human immunodeficiency virus infection). Fatality rates for untreated severe AdV pneumonia or disseminated disease may exceed 50%. More than 50 serotypes of AdV have been identified. Different serotypes display different tissue tropisms that correlate with clinical manifestations of infection. The predominant serotypes circulating at a given time differ among countries or regions, and change over time. Transmission of novel strains between countries or across continents and replacement of dominant viruses by new strains may occur. Treatment of AdV infections is controversial, as prospective, randomized therapeutic trials have not been conducted. Cidofovir is the drug of choice for severe AdV infections, but not all patients require treatment. Live oral vaccines are highly efficacious in reducing the risk of respiratory AdV infection and are in routine use in the military in the United States, but currently are not available to civilians.

Alternate circulation and genetic variation of human respiratory syncytial virus genotypes in Chengdu, West China, 2009-2014

Human respiratory syncytial virus (HRSV) is a major pathogen that causes worldwide seasonal epidemic disease in infants due to its genetic variations. However, published information on the molecular epidemiology of HRSV was never reported particularly in Chengdu of West China. During five consecutive seasons (from 2009 to 2014), 433 (23.7%) of 1827 samples from hospitalized patients were identified as HRSV positive. Epidemiological characteristics of HRSV revealed that subtype A viruses (62.7%) prevailed in the first three epidemic seasons and faded in the next two seasons, while subtype B viruses (37.3%) kept circulating in five epidemic periods. According to the phylogenetic analysis of glycoprotein (G) gene, five HRSV genotypes NA1, ON1, BA9, BA-C, and CB1 were found in Chengdu. The predominant circulating genotype changed from NA1 in the period of 2010-2012 to BA9 of 2013-2014. The newly emerging ON1 was first reported in West China in October 2013. The early genotypes BA-C and CB1 were replaced by the prevailing BA9 after the third epidemic peak. Genetic mutations in glycosylation sites of G protein were found in HRSV variants, suggesting the virus is able to escape the immune recognition and attack. This study elucidated the local HRSV epidemic was associated with the alternate circulation of multiple genotypes and with the change of glycosylation sites of G protein. J. Med. Virol. 89:32-40, 2017. © 2016 Wiley Periodicals, Inc.

Predictors of severe disease in a hospitalized population of children with acute viral lower respiratory tract infections

Although predictors of severe viral acute lower respiratory infections (ALRIs) in children have been reported, there have been few research studies performed in low- and middle-income countries (LMIC). The aim of the present study was to determine predictors of disease severity in a population of Colombian children <5 years of age with ALRI. In a prospective cohort study, we determined independent predictors of severe ALRI in a hospitalized population of children under 5 years old with ALRI during a 1-year period. We included both underlying disease conditions and the infecting respiratory viruses as predictor variables of severe disease. We defined severe disease as the necessity of pediatric intensive care unit admission. Of a total of 1,180 patients admitted with a diagnosis of ALRI, 416 (35.3%) were included because they were positive for any kind of respiratory virus. After controlling for potential confounders, it was found that a history of pulmonary hypertension (RR 3.62; CI 95% 2.38-5.52; P < 0.001) and a history of recurrent wheezing (RR 1.77; CI 95% 1.12-2.79; P = 0.015) were independent predictors of severe disease. The present study shows that respiratory viruses are significant causes of ALRI in infants and young children in Colombia, a typical tropical LMIC, especially during the rainy season. Additionally, the results of the present study show that clinical variables such as a history of pulmonary hypertension and a history of recurrent wheezing are more relevant for predicting ALRI severity than the infecting respiratory viruses.