Pediatric Acute Respiratory Infections Research Articles

Molecular evolution of respiratory syncytial virus subgroup A genotype NA1 and ON1 attachment glycoprotein (G) gene in central Vietnam

We performed molecular evolutionary analyses of the G gene C-terminal 3rd hypervariable region of RSV-A genotypes NA1 and ON1 strains from the paediatric acute respiratory infection patients in central Vietnam during the 2010–2012 study period. Time-scaled phylogenetic analyses were performed using Bayesian Markov Chain Monte Carlo (MCMC) method, and pairwise distances (p-distances) were calculated. Bayesian Skyline Plot (BSP) was constructed to analyze the time-trend relative genetic diversity of central Vietnam RSV-A strains. We also estimated the N-glycosylation sites within G gene hypervariable region. Amino acid substitutions under positive and negative selection pressure were examined using Conservative Single Likelihood Ancestor Counting (SLAC), Fixed Effects Likelihood (FEL), Internal Fixed Effects Likelihood (IFEL) and Mixed Effects Model for Episodic Diversifying Selection (MEME) models. The majority of central Vietnam ON1 strains detected in 2012 were classified into lineage 1 with few positively selected substitutions. As for the Vietnamese NA1 strains, four lineages were circulating during the study period with a few positive selection sites. Shifting patterns of the predominantly circulating NA1 lineage were observed in each year during the investigation period. Median p-distance of central Vietnam NA1 strains was wider (p-distance=0.028) than that of ON1 (p-distance=0.012). The molecular evolutionary rate of central Vietnam ON1 strains was estimated to be 2.55×10−2 (substitutions/site/year) and was faster than NA1 (7.12×10−3 (substitutions/site/year)). Interestingly, the evolutionary rates of both genotypes ON1 and NA1 strains from central Vietnam were faster than the global strains respectively. Furthermore, the shifts of N-glycosylation pattern within the G gene 3rd hypervariable region of Vietnamese NA1 strains were observed in each year. BSP analysis indicated the rapid growth of RSV-A effective population size in early 2012. These results suggested that the molecular evolution of RSV-A G gene detected in central Vietnam was fast with unique evolutionary dynamics.

Association of RSV-A ON1 genotype with Increased Pediatric Acute Lower Respiratory Tract Infection in Vietnam

Since the initial discovery of RSV-A ON1 in Canada in 2010, ON1 has been reported worldwide, yet information regarding its clinical impact and severity has been controversial. To investigate the clinical relevance of RSV-A ON1,acute respiratory infection (ARI) cases enrolled to our population-based prospective pediatric ARI surveillance at Khanh Hoa General Hospital, Central Vietnam from January 2010 through December 2012 were studied. Clinical-epidemiological information and nasopharyngeal samples were collected. Multiplex PCR assays were performed for screening 13 respiratory viruses. RSV-positive samples were further tested for subgroups (A/B) and genotypes information by sequencing the G-glycoprotein 2nd hypervariable region. Statistical analysis was performed to evaluate the clinical-epidemiological characteristics of RSV-A ON1. A total of 1854 ARI cases were enrolled and 426 (23.0%) of them were RSV-positive. During the study period, RSV-A and B had been co-circulating. NA1 was the predominant RSV-A genotype until the appearance of ON1 in 2012. RSV-related ARI hospitalization incidence significantly increased after the emergence of ON1. Moreover, multivariate analysis revealed that risk of lower respiratory tract infection was 2.26 (95% CI: 1.37–3.72) times, and radiologically-confirmed pneumonia was 1.98 (95% CI: 1.01–3.87) times greater in ON1 compared to NA1 cases. Our result suggested that ON1 ARI cases were clinically more severe than NA1.

Molecular Identification and Epidemiological Features of Human Adenoviruses Associated with Acute Respiratory Infections in Hospitalized Children in Southern China, 2012-2013.

BackgroundAcute respiratory infections (ARI) are the major worldwide health problem associated with high morbidity and mortality rates. Human adenovirus (HAdV) is one of the most common pathogens associated with viral ARI, and thus calls for specific diagnosis and better understanding of the epidemiology and clinical characteristics.MethodsTotal 4,130 children with ARI requiring hospitalization from 2012 to 2013 were retrospectively studied. Throat swab specimens were collected from each patient. Fluorescence Quantitative PCR was performed to detect adenovirus as well as other common ARI-related pathogens. The seven HAdV hypervariable regions (HVRs) of the hexon gene from fifty-seven HAdVs-positive samples collected in the seasonal peaks were sequenced. Phylogenetic analysis of HVRs was also conducted to confirm the molecular types and genetic variation. In addition, epidemiological features and co-infection with other human respiratory pathogens were investigated and analyzed.ResultsOf 4,130 hospitalized pediatric patients tested, the positive rates of respiratory syncytial virus (RSV), Mycoplasma pneumoniae (MP), and HAdV were 13.7%, 13.2%, and 12.0%, respectively. The HAdV positive patients accounted for 7.9%, 17.2%, 17.5% and 10.7% in age groups <1, 1–3, 3–6 and 6–14 years, respectively. Eighty-four HAdV positive children were co-infected with other respiratory pathogens (84/495, 17.0%). The most common co-infection pathogens with HAdV were MP (57.1%) and Human Bocavirus (HBoV) (16.7%). The majority of HAdV infected patients were totally recovered (96.9%, 480/495); However, four (0.8%) patients, who were previously healthy and at the age of 2 years or younger died of pneumonia. Seasonal peaks of HAdV infection occurred in the summer season of 2012 and 2013; the predominant HAdV type was HAdV-3 (70%), followed by HAdV-7 (28%). These epidemiological features were different from those in Northern China. The HAdV-55 was identified and reported for the first time in Guangzhou metropolitan area. Phylogenetic analysis indicated that all the HVR sequences of the hexon gene of HAdV-3 and -7 strains have high similarity within their individual types, and these strains were also similar to those circulating in China currently, indicating the conservation of hexon genes of both HAdV-3 and HAdV-7.ConclusionsKnowledge of the epidemiological features and molecular types of HAdV, a major pathogen of pediatric ARI, as well as other co-infected respiratory pathogens circulating in Guangzhou, southern China, is vital to predict and prevent future disease outbreaks in children. This study will certainly facilitate HAdV vaccine development and treatment of HAdV infections in children.

Prevalence, codetection and seasonal distribution of upper airway viruses and bacteria in children with acute respiratory illnesses with cough as a symptom

Most studies exploring the role of upper airway viruses and bacteria in paediatric acute respiratory infections (ARI) focus on specific clinical diagnoses and/or do not account for virus–bacteria interactions. We aimed to describe the frequency and predictors of virus and bacteria codetection in children with ARI and cough, irrespective of clinical diagnosis. Bilateral nasal swabs, demographic, clinical and risk factor data were collected at enrollment in children aged <15 years presenting to an emergency department with an ARI and where cough was a symptom. Swabs were tested by polymerase chain reaction for 17 respiratory viruses and seven respiratory bacteria. Logistic regression was used to investigate associations between child characteristics and codetection of the organisms of interest. Between December 2011 and August 2014, swabs were collected from 817 (93.3%) of 876 enrolled children, median age 27.7 months (interquartile range 13.9–60.3 months). Overall, 740 (90.6%) of 817 specimens were positive for any organism. Both viruses and bacteria were detected in 423 specimens (51.8%). Factors associated with codetection were age (adjusted odds ratio (aOR) for age <12 months = 4.9, 95% confidence interval (CI) 3.0, 7.9; age 12 to <24 months = 6.0, 95% CI 3.7, 9.8; age 24 to <60 months = 2.4, 95% CI 1.5, 3.9), male gender (aOR 1.46; 95% CI 1.1, 2.0), child care attendance (aOR 2.0; 95% CI 1.4, 2.8) and winter enrollment (aOR 2.0; 95% CI 1.3, 3.0). Haemophilus influenzae dominated the virus–bacteria pairs. Virus–H. influenzae interactions in ARI should be investigated further, especially as the contribution of nontypeable H. influenzae to acute and chronic respiratory diseases is being increasingly recognized.

Knowledge gaps on paediatric respiratory infections in Morocco, Northern Africa.

BackgroundThe burden of acute respiratory infections (ARI) among Moroccan children remains significant. However, scarce information is available regarding trends in its epidemiology and etiology, or regarding its associated prognostic factors.The purpose of this work was to review available data on the burden of ARI among children under five years of age in Morocco.MethodsA systematic review was conducted for the period 1997–2014 using the PRISMA proposed methodology. Various online databases were screened, in addition to physical libraries of Moroccan medical schools, and official reports of the Moroccan Ministry of Health. Search queries in English and French languages included: Respiratory Tract Infections, pneumonia, epidemiology, etiology, microbiology, mortality and Morocco. The documents were included for analysis when they reported original data on the incidence, distribution, or a clinical description of the diseases or their etiology or described clinical management or national preventive strategies.ResultsThirty-two documents were included in the final analysis. 21 of which had been published. In 2012, ARI caused 13% of paediatric deaths, half of the consultations at health facilities and third of the paediatric admissions. The microorganisms more frequently identified among hospitalized children were Streptococcus pneumoniae (38%) and Haemophilus influenza type b (Hib) (15%). The MOH introduced Hib vaccines into the national immunization program (PNI) in 2007and the 13-valent vaccine against pneumococcus in 2010. The national first line antibiotics recommended for non-severe ambulatory treatment is Amoxicillin. Studies of antibiotic resistance showed from 1998 to 2008 a 22% increase in the rate of penicillin non-susceptibility among Streptococcus pneumoniae isolates. Viral respiratory infections and the role attributed to air pollution in the incidence of ARI have been poorly characterized.ConclusionsFurther efforts should be made towards the development of adequate surveillance programs to better clarify the epidemiology, etiology, antimicrobial susceptibility patterns and the effectiveness of the preventives and curatives strategies in place against paediatric ARIs in Morocco. Additionally, a holistical approach should be used to identify the heath determinants of ARIs among children.

Viral bacterial co-infection of the respiratory tract during early childhood.

Acute respiratory infection (ARI) is an important cause of morbidity in children. Mixed aetiology is frequent, with pathogenic viruses and bacteria co-detected in respiratory secretions. However, the clinical significance of these viral/bacterial co-infections has long been a controversial topic. While severe bacterial pneumonia following influenza infection has been well described, associations are less clear among infections caused by viruses that are more common in young children, such as respiratory syncytial virus. Although assessing the overall contribution of bacteria to disease severity is complicated by the presence of many confounding factors in clinical studies, understanding the role of viral/bacterial co-infections in defining the outcome of paediatric ARI will potentially reveal novel treatment and prevention strategies, improving patient outcomes. This review summarizes current evidence for the clinical significance of respiratory viral/bacterial co-infections in young children, discusses possible mechanisms of cooperative interaction between these pathogens and highlights areas that require further investigation.

Detection of viral and bacterial pathogens in hospitalized children with acute respiratory illnesses, Chongqing, 2009-2013.

Acute respiratory infections (ARIs) cause large disease burden each year. The codetection of viral and bacterial pathogens is quite common; however, the significance for clinical severity remains controversial. We aimed to identify viruses and bacteria in hospitalized children with ARI and the impact of mixed detections.Hospitalized children with ARI aged ≤16 were recruited from 2009 to 2013 at the Children's Hospital of Chongqing Medical University, Chongqing, China. Nasopharyngeal aspirates (NPAs) were collected for detection of common respiratory viruses by reverse transcription polymerase chain reaction (RT-PCR) or PCR. Bacteria were isolated from NPAs by routine culture methods. Detection and codetection frequencies and clinical features and severity were compared.Of the 3181 hospitalized children, 2375 (74.7%) were detected with ≥1 virus and 707 (22.2%) with ≥1 bacteria, 901 (28.3%) with ≥2 viruses, 57 (1.8%) with ≥2 bacteria, and 542 (17.0%) with both virus and bacteria. The most frequently detected were Streptococcus pneumoniae, respiratory syncytial virus, parainfluenza virus, and influenza virus. Clinical characteristics were similar among different pathogen infections for older group (≥6 years old), with some significant difference for the younger. Cases with any codetection were more likely to present with fever; those with ≥2 virus detections had higher prevalence of cough; cases with virus and bacteria codetection were more likely to have cough and sputum. No significant difference in the risk of pneumonia, severe pneumonia, and intensive care unit admission were found for any codetection than monodetection.There was a high codetection rate of common respiratory pathogens among hospitalized pediatric ARI cases, with fever as a significant predictor. Cases with codetection showed no significant difference in severity than those with single pathogens.

Viral aetiology of acute respiratory infections among children and associated meteorological factors in southern China.

BackgroundAcute respiratory infections (ARIs) are common in children and mostly caused by viruses, but the significance of the detection of multiple viruses in ARIs is unclear. This study investigated 14 respiratory viruses in ARIs among children and associated meteorological factors in Shantou, southern China.MethodsPaired nasal/throat-flocked swabs collected from 1,074 children with ARIs, who visited outpatient walk-in clinics in a tertiary hospital between December 2010 and November 2011, were examined for fourteen respiratory viruses - influenza viruses (FluA, FluB), respiratory syncytial viruses (RSV A and B), human coronaviruses (hCoV: 229E, OC43, HKU1, NL63), human metapneumoviruses (hMPV A and B), parainfluenza viruses (PIV1-4), human rhinoviruses (HRV A, B, C), enteroviruses (EV), adenoviruses (ADV), human bocavirus (hBoV), and human parechoviruses (hPeV) - by multiplex real-time PCR.ResultsWe identified at least one virus in 82.3% (884/1,074) and multiple viruses in 38.6% (415/1,074) of patients. EV and HRV were the most frequently detected single viruses (42.3%, 374/884 and 39.9%, 353/884 respectively) and co-detected pair (23.1%, 96/415). Overlapping seasonal trends of viruses were recorded over the year, with dual peaks for EV and single peaks for the others. By logistic regression analysis, EV was positively associated with the average temperature and humidity, hCoV, and PIV4, but negatively with HRV, PIV3, and hBoV. HRV was inversely associated with EV and PIV3.ConclusionsThis study reports high viral detection and co-detection rates in pediatric ARI cases mainly due to EV and HRV. Many viruses circulated throughout the year with similar seasonal trends in association with temperature, humidity, and wind velocity. Statistically significant associations were present among the viruses. Understanding the polyviral etiology and viral interactions in the cases with multiple viruses warrants further studies.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-015-0863-6) contains supplementary material, which is available to authorized users.

Rapid viral diagnosis for acute febrile respiratory illness in children in the Emergency Department.

Pediatric acute respiratory infections (ARIs) represent a significant burden on pediatric Emergency Departments (EDs) and families. Most of these illnesses are due to viruses. However, investigations (radiography, blood, and urine testing) to rule out bacterial infections and antibiotics are often ordered because of diagnostic uncertainties. This results in prolonged ED visits and unnecessary antibiotic use. The risk of concurrent bacterial infection has been reported to be negligible in children over three months of age with a confirmed viral infection.Rapid viral testing in the ED may alleviate the need for precautionary testing and antibiotic use. To determine if the use of a rapid viral detection test for children with an acute respiratory infection (ARI) in Emergency Departments (EDs) changes patient management and resource use in the ED, compared to not using a rapid viral detection test. We hypothesized that rapid viral testing reduces antibiotic use in the ED as well as reduces the rate of ancillary testing and length of ED visits. We searched CENTRAL (2014, Issue 6), MEDLINE (1950 to July week 1, 2014), MEDLINE In-Process & Other Non-Indexed Citations (15 July 2014), EMBASE.com (1988 to July 2014), HealthStar (1966 to 2009), BIOSIS Previews (1969 to July 2014), CAB Abstracts (1973 to July 2014), CBCA Reference (1970 to 2007) and ProQuest Dissertations and Theses (1861 to 2009). Randomized controlled trials (RCTs) of rapid viral testing for children with ARIs in the ED. Two review authors used the inclusion criteria to select trials, evaluate their quality, and extract data. We obtained missing data from trial authors. We expressed differences in rate of investigations and antibiotic use as risk ratios (RRs), and expressed difference in ED length of visits as mean differences (MDs), with 95% confidence intervals (CIs). No new trials were identified in this 2014 update. We included four trials (three RCTs and one quazi-RCT), with 759 children in the rapid viral testing group and 829 in the control group. Three out of the four studies were comparable in terms of young age of participants, with one study increasing the age of inclusion up to five years of age. All studies included either fever or respiratory symptoms as inclusion criteria (two required both, one required fever or respiratory symptoms, and one required only fever). All studies were comparable in terms of exclusion criteria, intervention, and outcome data. In terms of risk of bias, one study failed to utilize a random sequence generator, one study did not comment on completeness of outcome data, and only one of four studies included allocation concealment as part of the study design. None of the studies definitively blinded participants.Rapid viral testing resulted in a trend toward decreased antibiotic use in the ED, but this was not statistically significant. We found lower rates of chest radiography (RR 0.77, 95% CI 0.65 to 0.91) in the rapid viral testing group, but no effect on length of ED visits, or blood or urine testing in the ED. No study made mention of any adverse effects related to viral testing. There is insufficient evidence to support routine rapid viral testing to reduce antibiotic use in pediatric EDs. Rapid viral testing may or may not reduce rates of antibiotic use, and other investigations (urine and blood testing); these studies do not provide enough power to resolve this question. However, rapid viral testing does reduce the rate of chest X-rays in the ED. An adequately powered trial with antibiotic use as an outcome is needed.

Immunogenicity of recombinant human bocavirus-1,2 VP2 gene virus-like particles in mice.

Human bocavirus (HBoV), a recently identified pathogen with a worldwide distribution is closely related to paediatric acute respiratory infection and gastroenteritis. The present study was performed to evaluate the immunogenicity of HBoV1 and HBoV2 virus-like particles (VLPs) as vaccine candidates in mice. Both HBoV1 and HBoV2 VLPs were expressed in the bacmid virus–SF9 cell system. Mice were inoculated three times at 3-week intervals with HBoV VLPs at one dose intramuscular (i.m.) or intradermal (i.d.) with or without the addition of the alum adjuvant. ELISA was used to detected antibody, and ELISPOT was used to test cellular immune responses. HBoV-specific IgG antibodies were induced and alum adjuvant improved the antibody titres and avidity, while the inoculation pathway had no influence. T helper type 1/ type 2 immune responses were balanced induced by HBoV1 VLPs but not HBoV2 VLPs. Serum IgG antibody cross-reactivity rates of the two subtypes were similar, but cross-reactions of HBoV1 immunization groups were higher. The single i.m. group had more interferon-γ-secreting splenocytes. These data indicate that HBoV VP2 VLPs have good immunogenicity with induction of strong humoral and cellular immune responses, and they may be potential candidate vaccines for HBoV infection.

Impact of 2009 pandemic influenza among Vietnamese children based on a population‐based prospective surveillance from 2007 to 2011

BackgroundInfluenza virus is one of the major viral pathogens causing pediatric acute respiratory infection (ARI). The spread of pandemic influenza A (A(H1N1)pdm09) in 2009 around the globe had a huge impact on global health.ObjectiveTo investigate the impact of A(H1N1)pdm09 on pediatric ARI in Vietnam.Study designAn ongoing population-based prospective surveillance in central Vietnam was used. All children aged <15 years residing in Nha Trang city, enrolled to the ARI surveillance in Khanh Hoa General Hospital, from February 2007 through March 2011 were studied. Clinical data and nasopharyngeal swab samples were collected. Influenza A was detected and genotyped by multiplex polymerase chain reaction assays and sequencing.ResultsAmong enrolled 2736 hospitalized ARI cases, 354 (13%) were positive for influenza A. Genotyping results revealed that seasonal H3N2 and H1N1 (sea-H1N1) viruses were cocirculating before A(H1N1)pdm09 appeared in July 2009. The A(H1N1)pdm09 replaced the sea-H1N1 after the pandemic. The majority of influenza A cases (90%) were aged <5 years with incidence rate of 537 (387–775) per 100 000 population. Annual incidence rates of hospitalized influenza cases for pre-, initial and post-pandemic periods among children aged <5 year were 474, 452, and 387 per 100 000, respectively. Children with A(H1N1)pdm09 were elder, visited the hospital earlier, less frequently had severe signs, and were less frequently associated with viral coinfection compared with seasonal influenza cases.ConclusionsThe A(H1N1)pdm09 did not increase the influenza annual hospitalization incidence or disease severity compared with seasonal influenza among pediatric ARI cases in central Vietnam.

The Epidemiology and Aetiology of Infections in Children Admitted with Clinical Severe Pneumonia to a University Hospital in Rabat, Morocco

Scarce and limited epidemiological, clinical and microbiological data are available regarding paediatric respiratory tract infections in the Kingdom of Morocco, a middle-income country in northwestern Africa. The results of hospital-based surveillance aiming at describing the aetiology and epidemiology of respiratory distress among children <5 years of age are presented. Children admitted to the Hôpital d'Enfants de Rabat, Morocco, and meeting the World Health Organization clinical criteria for severe pneumonia were recruited over a period of 14 months and were thoroughly investigated to ascertain a definitive diagnosis. In total, 700 children were recruited for the study. Most frequent clinical diagnoses included wheezing-related conditions (bronchitis/asthma, 46%; bronchiolitis, 15%), while typical bacterial pneumonia was infrequent (only 19% of the cases). Invasive bacterial disease detected by classical microbiology or molecular methods was also uncommon, affecting only 3.5% of the patients, and with an overall low detection of pneumococcal or Haemophilus influenzae type b disease. Conversely, coverage of respiratory viral detection in the nasopharynx was almost universal among cases (92%), with the three most frequent viruses detected being rhinovirus (53%), respiratory syncytial virus (18%) and adenovirus (17%). The overall case fatality rate (CFR) among recruited patients with a known outcome was 4.1% (28/690). In Morocco, the epidemiological profile of paediatric acute respiratory infections is markedly shifted towards wheezing-related diseases and thus resembles that of high-income countries. However, the high associated CFRs found in this study call for an improvement in preventive and clinical management strategies.

Associations between co-detected respiratory viruses in children with acute respiratory infections.

Viruses are the major etiological agents of acute respiratory infections (ARIs) in young children. Although respiratory virus co-detections are common, analysis of combinations of co-detected viruses has never been conducted in Japan. Nineteen respiratory viruses or subtypes were surveyed using multiplex real-time PCR on 1,044 pediatric (patient age < 6 years) ARI specimens collected in Osaka City, Japan between January 2010 and December 2011. In total, 891 specimens (85.3%) were virus positive (1,414 viruses were detected), and 388 of the virus-positive specimens (43.5%, 388/891) were positive for multiple viruses. The ratio of multiple/total respiratory virus-positive specimens was high in children aged 0-35 months. Statistical analyses revealed that human bocavirus 1 and human adenovirus were synchronously co-detected. On the other hand, co-detections of human parainfluenza virus type 1 (HPIV-1) with HPIV-3, HPIV-3 with human metapneumovirus (hMPV), hMPV with respiratory syncytial virus A (RSV A), hMPV with influenza virus A (H1N1) 2009 (FLUA (H1N1) 2009), RSV A with RSV B, and human rhinovirus and FLUA (H1N1) 2009 were exclusive. These results suggest that young children (<3 years) are highly susceptible to respiratory viruses, and some combinations of viruses are synchronously or exclusively co-detected.

Population based cohort study for pediatric infectious diseases research in Vietnam.

A population-based cohort study on pediatric infectious diseases was established at Khanh Hoa Province, central Vietnam in 2006, to determine the etiology and risk factors for severe pediatric infectious diseases (SPID) such as acute respiratory infection (ARI), diarrhea and dengue which are the major causes of under 5 mortality. A population census survey was conducted in Nha-Trang and Ninh-Hoa to collect demographic, social-behavioral data and disease burden on SPID. The study site covered a population of 353,525 residing in 75,826 households with 24,781 children less than 5 years. Hospital databases from two hospitals covering the region were obtained. Linking the census and hospital databases, we were able to investigate on a variety of SPID such as environmental tobacco smoking exposure and increased risked of pediatric pneumonia hospitalization, population density, water supply and risk of dengue fever and animal livestock and risk of hospitalized diarrhea. To determine incidence, viral etiology and risk factors for pediatric ARI/pneumonia, we setup a population based prospective hospitalized Pediatric ARI surveillance at Khanh Hoa General Hospital, Nha-Trang in February 2007. The study has revealed RSV, rhinovirus and influenza A as major viral pathogens, role of multiple viral infection and its interaction with bacteria in the development of pneumonia. In addition, we are also conducting a birth cohort study to investigate the incidence of congenital infection and its impact on physical-neurological development, and role of host genetic polymorphism on SPID hospitalization in Vietnam. Population mobility, high cost of regular census update and low mortality are the challenges.

Serum zinc levels as a predictor of clinical features and outcome of paediatric acute lower respiratory infections in Nigeria

Background: Malnutrition, especially macronutrient deficiency, has been shown to be interrelated with ALRI-related morbidity and mortality. However the import of zinc deficiency has only recently become the focus of research attention.Objective: The current study was carried out in Ilorin, Kwara State, Nigeria to determine the relationship between serum zinc levels, clinical features and outcome in hospitalized children with acute lower respiratory infections(ALRI).Method: A descriptive crosssectional hospital-based study involving 120 children aged two months to five years with ALRI. Socio-demographic, clinical and laboratory data were obtained. The serum zinc was analyzed with a Jenway™ spectrophotometer after initial preparation with theQuantiChrom™ zinc assay kit.Results: Children with tachypnoea and crepitations had significantly lower mean serum zinc levels compared to the corresponding values in those without these features (each p&lt;0.05). Significantly higher mean serum zinc level was recorded in children with grunting respiration compared with thosewithout grunting (p=0.028). Agerelated tachypnoea, grunting, and crepitations remained significant (each p&lt;0.05) following a linear regression analysis. The mean serum zinc level in children with multiple complications was significantly lower than the corresponding level recorded in children who had one complication, p=0.020. No significant differencewas found between the mean serum zinc level of the children who were discharged compared with the corresponding level recorded in those that died, p=0.589.Conclusion: The presence of crepitations had the strongest clinical association with a low serum zinc level. Children managed for ALRI would benefit from post-treatment zinc supplements and appropriate zinc-rich sources of food at discharge.Keywords: Children zinc respiratory infections

Molecular Characterization of Circulating Respiratory Syncytial Virus (RSV) Genotypes in Gilgit Baltistan Province of Pakistan during 2011-2012 Winter Season

Respiratory syncytial virus (RSV) is the major cause of acute lower respiratory tract infections in young children, but very little is known about its epidemiology and circulating genotypes in Pakistan. This study analyzed the epidemiological and molecular characteristics of RSV genotypes detected in Pakistani children less than 2 years of age with acute respiratory tract infections (ARIs) in a tertiary care hospital in Gilgit Baltistan (GB) province during 2011-12 winter season. RSV was detected in 75 out of 105 children presenting with acute respiratory infection. Male infants between 2-6 months age made up the highest percentage of RSV positive cases. Epidemiological factors such as pre-maturity, mean weight, clinical features and diagnosis when compared between RSV positive and negative groups were found to be statistically insignificant. Phylogenetic analysis classified all 75 of the RSV strains into 71 strains of subgroups A and 4 strains of subgroup B, respectively. Strains belonging to subgroups A and B were further subdivided into NA1/GA2 and BA, respectively. The nucleotide and deduced amino acid sequence identities were relatively high among these strains (>90%). Both RSV-A and RSV-B isolates had two potential N-glycosylation sites in HVR2 of G protein and with heavy O-glycosylation of serine and threonine residues (G scores of 0.5-0.7). This report highlights the significance of RSV as a dominant viral etiologic agent of pediatric ARIs, and need for continued molecular epidemiological surveys for early detection of prevalent strains and newly emerging genotypes to understand epidemiology of RSV infections in various regions of Pakistan.

Common WU polyomavirus infection in a Beijing population indicated by surveillance for serum IgG antibody against capsid protein VP2

BackgroundWU polyomavirus (WU virus) was identified as a novel polyomavirus in 2007 from specimens of pediatric patients with acute respiratory infection (ARI). A lack of permissive cell lines has limited investigations into WU virus pathogenesis and prevalence.MethodsThe encoding region of the capsid protein VP2 gene was amplified from a WU virus DNA-positive clinical specimen and expressed as a recombinant Histagged protein in Escherichia coli BL21 (DE3). The expressed VP2 was identified by expected molecular weight and immunoreactivity with anti-His monoclonal antibody in Western blotting assay. Serum samples collected from 455 individuals of all ages in Beijing without symptoms of ARI were tested for IgG antibodies against the affinity-purified recombinant VP2 protein by Western blotting to investigate the prevalence of natural WU virus infection. In addition, serum samples from four ARI pediatric patients, whose nasopharyngeal aspirates were positive for WU virus DNA and negative for all other respiratory-related viruses, were tested for IgM antibody against the recombinant VP2.ResultsOf the 455 serum samples, 238 reacted with the recombinant VP2, yielding an overall positive rate of 52.3% for IgG against VP2 of WU virus. The positive rate was the highest in serum samples from infants and children between 1 to 4 years of age. One of four ARI pediatric patients was positive for IgM against WU virus VP2, implicating WU virus as the causative disease agent.ConclusionsThe high prevalence of IgG against WU polyomavirus in Beijing-based study population indicates that WU virus infection is common in Beijing. WU virus may be responsible for some pediatric ARI cases, and primary infection of this virus may occur mostly in childhood.

Frequency of Pediatric Acute Respiratory Tract Infections in Iran; A Systematic Review

Introduction: Acute respiratory infections (ARIs) continue as the leading cause of mortality in under 5-year-old children worldwide. We decided to review available data about the incidence and prevalence of all diseases included in this category in Iran. Methods: A systematic review was designed to obtain related data from English and Farsi sources, published or unpublished. An internet search of known data sources and websites of Iranian medical universities was conducted. In addition, we reviewed abstract books of related Persian seminars and prevalence reports of ARI in children from different departments in the Ministry of Health and Medical Education of Iran. After deleting duplicates obtained material was evaluated by two epidemiologists and selected documents underwent quality assessment through data extraction checklists. We have included the most valid studies in this review. Results: Only 19 out of 98 documents reported frequency of a disease in a defined population, a group of outpatients, or hospitalized patients. Almost all of the studies had some limitations. In addition, there were no similarities in methods or place/time to make a summary on any ARIs frequency. So, we discussed each study, separately. Conclusion: Available data about frequency of ARIs in Iran were not beneficial enough to calculate burden of related diseases and make decision analysis for suggested interventions. Valid and large longitudinal population-based studies should be designed in different regions of the country supported by the Ministry and research centers.

Clinical Impact of RT-PCR for Pediatric Acute Respiratory Infections: A Controlled Clinical Trial

Real-time polymerase chain reaction (RT-PCR) testing is a quick sensitive method for detecting respiratory pathogens. We evaluated the diagnostic yield of RT-PCR assays and measured the effect of rapid reporting on patient care. In a controlled clinical trial, nasal wash specimens were obtained from patients <12 years of age with suspected acute respiratory infections. In addition to the standard hospital protocol, RT-PCR assays for 17 pathogens were performed. The RT-PCR results were communicated to the clinicians within 12 to 36 hours in the intervention group and after 4 weeks in the control group. A total of 583 patients were included (mean age: 8.1 months [range: 0-107.5 months]): 298 in the intervention group and 285 in the control group. Eighty-two percent of nasal wash specimens tested positive for ≥1 pathogen. Respiratory syncytial virus was the most frequently encountered (55%) pathogen. There were no significant differences between the groups with respect to hospital admissions (intervention group: 223 admissions; control group: 211 admissions; P = .825), length of hospital stay (mean ± SD: 3.68 ± 2.68 days [intervention group] and 3.96 ± 2.67 days [control group]; P = .178), or duration of antibiotic use (mean ± SD: 6.52 ± 2.15 days [intervention group] and 6.97 ± 2.86 days [control group]; P = .490), when antibiotic treatment had been initiated. RT-PCR testing has a high yield of viral diagnoses, but rapid communication does not lead to decreases in hospital admissions, shorter hospital stays, or less antibiotic use for children with acute respiratory infections.

Cochrane Review: Rapid viral diagnosis for acute febrile respiratory illness in children in the Emergency Department.

BackgroundPediatric acute respiratory infections (ARIs) represent a significant burden on pediatric emergency departments (ED) and families. Most of these illnesses are due to viruses. However, investigations (radiography, blood and urine testing) to rule out bacterial infections and antibiotics are often ordered because of diagnostic uncertainties. This results in prolonged ED visits and unnecessary antibiotic use. The risk of concurrent bacterial infection has been reported to be negligible in children over three months of age with a confirmed viral infection. Rapid viral testing in the ED may alleviate the need for precautionary testing and antibiotic use.ObjectivesTo determine the effect of rapid viral testing in the ED on the rate of precautionary testing, antibiotic use and ED length of visit.Search strategyWe searched the Cochrane Central register of Controlled Trials (CENTRAL) (The Cochrane Library, 2009, issue 1) which contains the ARI Group's Specialized Register, MEDLINE (1950 to April Week 3 2009), EMBASE (1988 to Week 16, 2009), MEDLINE In‐Process & Other Non‐Indexed Citations (April 27, 2009), HealthStar (1966 to 2009), BIOSIS Previews (1969 to 2009), CAB s (1973 to 2007), CBCA Reference (1970 to 2007), and Proquest Dissertations and Theses (1861 to 2009).Selection criteriaRandomized controlled trials (RCTs) of rapid viral testing for children with ARIs in the ED.Data collection and analysisTwo review authors used the inclusion criteria to select trials, evaluate their quality and extract data. Missing data were obtained from trial authors. Differences in rate of investigations and antibiotics use were expressed as risk ratios (RR) and difference in ED length of visits was expressed as mean difference, with 95% confidence interval (CI).Main resultsFour trials were included, three RCTs and one quazi‐RCT, with 759 children in the rapid viral testing and 829 in the control group. Rapid viral testing did not reduce antibiotic use in the ED significantly, neither clinically nor statistically. We found lower rates of chest radiography (RR 0.77, 95% CI 0.65 to 0.91) in the rapid viral testing group but no effect on length of ED visits, blood or urine testing in the ED.Authors' conclusionsCurrent evidence is insufficient, although promising, to support routine rapid viral testing as a means to reduce antibiotic use in pediatric EDs. Results suggest that rapid viral testing may be beneficial but are not statistically significant due to lack of power. A large trial addressing these outcome measures is needed.Plain Language Summary Does rapid viral testing in the Emergency Department affect the treatment of children with fever and respiratory problems? Children admitted to Emergency Departments (ED) with fever and respiratory symptoms represent a major burden to the health care system, as well as significant anxiety and expense to parents and caregivers. Physicians often order diagnostic tests and may prescribe antibiotics when they are unsure of the cause of the illness and are concerned about the possibility of serious bacterial infection. However, in most cases, fever and respiratory symptoms are caused by viruses. In addition, in children in whom a virus is found to be the cause of their illness, the risk of serious bacterial infection is very low. This review was conducted to assess whether a rapid viral test done in the ED changes what physicians do when treating these children. We found that in previously healthy children coming to the ED with fever and respiratory symptoms, a rapid viral test reduces the use of chest X‐rays and that there is a trend toward less antibiotic usage, and blood and urine investigations. The true impact of this intervention on the latter three outcomes requires trials with larger enrollment numbers.