Burden of pediatric influenza A virus infection post swine-flu H1N1 pandemic in Egypt

ObjectiveTo screen children with influenza like illness or with symptoms of acute respiratory tract infections for influenza A virus infection — post swine flu pandemic era — using rapid influenza diagnostic tests.MethodsDuring two years (2010 & 2011), 1 200 children with influenza like illness or acute respiratory tract infections (according to World Health Organization criteria) were recruited. Their ages ranged from 2-60 months. Nasopharyngeal aspirates specimens were collected from all children for rapid influenza A diagnostic test.ResultsInfluenza A virus rapid test was positive in 47.5% of the children; the majority (89.6%) were presented with lower respiratory tract infections. Respiratory rate and temperature were significantly higher among positive rapid influenza test patients.ConclusionsInfluenza A virus infection is still a major cause of respiratory tract infections in Egyptian children. It should be considered in all cases with cough and febrile episodes and influenza like symptoms even post swine flu pandemic.     

Burden of influenza in children in the community

BACKGROUND: Influenza vaccination of healthy children is encouraged because children are frequently hospitalized for influenza-attributable illnesses. However, most children with influenza are treated as outpatients, and scarce data are available on the burden of influenza in these children. METHODS: We performed a prospective study of respiratory infections in preenrolled cohorts of children < or = 13 years old during 2 consecutive respiratory seasons (2231 child-seasons of follow-up). At any sign of respiratory infection, we examined the children and obtained a nasal swab for the detection of influenza. The parents filled out daily symptom diaries. Of all the enrollees, 94% remained active participants in the study. RESULTS: The average annual rate of influenza was highest (179 cases/1000 children) among children < 3 years old. Acute otitis media developed as a complication of influenza in 39.7% of children < 3 years old. For every 100 influenza-infected children < 3 years old, there were 195 days of parental work loss (mean duration, 3.2 days). CONCLUSIONS: Influenza causes a substantial burden of illness on outpatient children and their families. Vaccination of children < 3 years old might be beneficial for reducing the direct and indirect costs of influenza in children.     

Association of nasopharyngeal bacterial colonization during upper respiratory tract infection and the development of acute otitis media.

Acute otitis media occurs mostly after upper respiratory tract infection; the causative bacteria are those colonized in the nasopharynx. We studied 709 episodes of upper respiratory tract infection and found that children with no bacteria in the nasopharynx were at low risk for acute otitis media, whereas children with 3 pathogenic bacteria were at the greatest risk.     

Burden of influenza during the first year of life

BackgroundEvery year, influenza viruses infect millions of children and cause an enormous burden of disease. Young children are at the highest risk for influenza‐attributable hospitalizations. Nevertheless, most young children are treated as outpatients, and limited data are available on the burden of influenza in these children.MethodsWe carried out a prospective cohort study and followed 431 infants born in June‐August 2017 for 10 months from September 1, 2017, to June 30, 2018. The parents filled out daily symptom diaries and were instructed to bring their child for clinical examination at our study clinic each time the child had fever or any signs or symptoms of respiratory tract infection. During each visit, we obtained nasopharyngeal swab specimens for determination of the viral etiology of the illness.ResultsA total of 55 episodes of laboratory‐confirmed influenza were diagnosed among the 408 actively participating children, which corresponds to an annual incidence rate of 135/1000 children (95% Cl, 102‐175). Excluding five children with double viral infection, acute otitis media developed as a complication of influenza in 23 (46%) children. One (2%) child with influenza was hospitalized because of febrile convulsion. The effectiveness of influenza vaccination was 48% (95% CI, −29%‐80%).ConclusionsThe burden of influenza during the first year of life is heavy in the outpatient setting where most infants with influenza are managed. Effective strategies for the prevention of influenza particularly in infants under 6 months of age are needed to diminish the burden of disease in this age group.     

Respiratory syncytial virus infections in previously healthy working adults.

During 1975-1995, a total of 2960 healthy adults, 18-60 years of age, were prospectively evaluated for respiratory virus infections. Of these subjects, 211 (7%) acquired respiratory syncytial virus (RSV) infection. The infections were symptomatic in 84% of subjects, involved only the upper respiratory tract in 74%, and included lower respiratory tract symptoms in 26%. Overall, 40% of the subjects were febrile. Lower respiratory tract signs developed in 26%. RSV illnesses were more prolonged than non-RSV respiratory illnesses. Compared with influenza, RSV infections were less frequently associated with fever and headache, but were associated significantly more often with nasal congestion, ear and sinus involvement, and productive cough. Absence from work during the acute phase of the illness resulted from 38% of RSV infections and 66% of influenza cases. The mean duration of RSV illness (9.5 days), however, was significantly longer than that of influenza (6.8 days). The occurrence of annual epidemics of RSV, the virus' potential to reinfect all age groups, and the morbidity associated with these reinfections suggest that RSV infections in working adults may result in appreciable costs for medical visits and absence from work.     

Respiratory syncytial virus infection and disease in infants and young children observed from birth in Kilifi District, Kenya.

BACKGROUND: In developing countries, there are few data that characterize the disease burden attributable to respiratory syncytial virus (RSV) and clearly define which age group to target for vaccine intervention. METHODS: Six hundred thirty-five children, recruited during the period 2002-2003, were intensively monitored until each experienced 3 epidemics of RSV infection. RSV infection was diagnosed using immunofluorescence of nasal washing specimens collected at each episode of acute respiratory infection. Incidence estimates were adjusted for seasonality of RSV exposure. RESULTS: For 1187 child-years of observation (CYO), a total of 409 (365 primary and 82 repeat) episodes of RSV infection were identified. Adjusted incidence estimates of lower respiratory tract infection (LRTI), severe LRTI, and hospital admission were 90 cases per 1000 CYO, 43 cases per 1000 CYO, and 10 cases per 1000 CYO, respectively, and corresponding estimates among infants were 104 cases per 1000 CYO, 66 cases per 1000 CYO, and 13 cases per 1000 CYO, respectively. The proportion of cases of all-cause LRTI, and severe LRTI and hospitalizations attributable to RSV in the cohort was 13%, 19%, and 5%, respectively. Fifty-five percent to 65% of RSV-associated LRTI and severe LRTI occurred in children aged >6 months. The risk of RSV disease following primary symptomatic infection remained significant beyond the first year of life, and one-quarter of all reinfections were associated with LRTI. CONCLUSIONS: RSV accounts for a substantial proportion of the total respiratory disease in this rural population; we estimate that 85,000 cases of severe LRTI per year occur in infants in Kenya. The majority of this morbidity occurs during late infancy and early childhood--ages at which the risk of disease following infection remains significant. Disease resulting from reinfection is common. Our results inform the debate on the target age group and effectiveness of a vaccine.     

Identification of respiratory virus antigens in middle ear fluids of children with acute otitis media

Antigens of respiratory viruses were tested by immunoassay of the middle ear fluids and nasopharyngeal secretions of 137 children with acute otitis media. The following were found: (1) an epidemic of infection with respiratory syncytial virus (RSV) caused a significant increase in the occurrence of acute otitis media. (2) Fifteen percent of the children had RSV antigens in middle ear fluid, and in 7% RSV was the sole pathogen found. Adenovirus antigens were found in the middle ear fluid of 3% of the children. (3) Bacteriologic findings in otitis media related and unrelated to viral (RSV) infection were similar. These findings indicate that some episodes of otitis media are associated with viral infection and that the disease may be solely due to viral infection. Thus, at least during an epidemic of respiratory virus infections, treatment failures--e.g., fever and earache unresponsive to antimicrobial therapy--may be due to a viral etiology of acute otitis media.     

Hospitalizations and deaths due to respiratory illnesses during influenza seasons: a comparison of community residents,senior housing residents,and nursing home residents

BACKGROUND: Although research indicates that influenza is a major cause of morbidity and mortality among older adults, few studies have tried to identify which seniors are particularly at risk of experiencing complications of influenza. The purpose of this study was to compare hospitalizations and deaths due to respiratory illnesses during influenza seasons among seniors (aged 65+) living in the community, senior residences (apartments reserved for seniors), and nursing homes. METHODS: Using administrative data, all hospital admissions and deaths due to respiratory illnesses (pneumonia and influenza, chronic lung disease, and acute respiratory diseases) were identified for all individuals aged 65 and older living in Winnipeg, Canada (approximately 88,000 individuals) during four influenza seasons (1995-1996 to 1998-1999). RESULTS: Hospitalization and death rates for respiratory illnesses increased significantly during influenza seasons, compared to fall periods (e.g., 42.7 vs 25.2 hospitalizations per 1000 population aged 80 and older). Moreover, hospitalization rates for pneumonia and influenza, chronic lung disease, and acute respiratory diseases were higher among individuals living in senior residences (42.5 per 1000 for all respiratory illnesses combined) than their counterparts living in the community (22.8 per 1000). Furthermore, deaths due to pneumonia and influenza and chronic lung disease were higher among senior housing residents (4.2 per 1000) than community residents (2.6 per 1000) and were particularly high among nursing home residents (52.1 per 1000). CONCLUSIONS: Individuals living in seniors residences are at increased risk of being hospitalized for and dying of respiratory illnesses during influenza seasons. Given that influenza vaccination is currently the best method to reduce influenza-associated illnesses among seniors, this suggests that influenza vaccination strategies should be targeted at this population.     

Otitis media among children in day care: epidemiology and pathogenesis

Acute and persistent middle-ear effusions are the most common complications of upper respiratory illness in young children. Knowledge of the impact of day care attendance on the incidence and prevalence of these conditions is not as complete as is desirable. Several studies suggest that the incidence of acute otitis media may be higher in children who attend group and home day care, but from these studies it is difficult to assess the magnitude of the risk of otitis media related to day care attendance. Research by Danish investigators indicates that the point prevalence of middle-ear effusion may be two to four times higher in children younger than four years old attending group day care centers than in children cared for at home or in smaller home day care settings. Recent epidemiologic and laboratory investigations have begun to elucidate the role of viral infections and of virus-bacteria interaction in the pathogenesis of acute middle-ear effusion. A thorough understanding of the relationship between day care attendance and the occurrence of otitis media with effusion would require studies that quantify the differential risk of disease in different care settings and that relate illness risk to the epidemiology of both viral and bacterial infections of the upper respiratory tract in the different environments. This type of research has not yet been conducted.     

Estimating influenza outpatients' and inpatients' incidences from 2009 to 2011 in a tropical urban setting in the Philippines

Objectives

Although the public health significance of influenza in regions with a temperate climate has been widely recognized, information on influenza burden in tropical countries, including the Philippines, remains limited. We aimed to estimate influenza incidence rates for both outpatients and inpatients then characterized their demographic features.

Design

An enhanced surveillance was performed from January 2009 to December 2011 in an urbanized highland city. The influenza-like illness (ILI) surveillance involved all city health centers and an outpatient department of a tertiary government hospital. The severe acute respiratory infection (sARI) surveillance was also conducted with one government and four private hospitals since April 2009. Nasal and/or oropharyngeal swabs were collected and tested for influenza A, influenza B, and respiratory syncytial virus.

Results and Conclusions

We obtained 5915 specimens from 13 002 ILI cases and 2656 specimens from 10 726 sARI cases throughout the study period. We observed year-round influenza activity with two possible peaks each year. The overall influenza detection rate was 23% in the ILI surveillance and 9% in the sARI surveillance. The mean annual outpatient incidence rate of influenza was 5·4 per 1000 individuals [95% confidence interval (CI), 1·83–12·7], and the mean annual incidence of influenza-associated sARI was 1·0 per 1000 individuals (95% CI, 0·03–5·57). The highest incidence rates were observed among children aged <5 years, particularly those aged 6–23 months. Influenza posed a certain disease burden among inpatients and outpatients, particularly children aged <5 years, in an urbanized tropical city of the Philippines.     

Comparison of severe acute respiratory illness (sari) and clinical pneumonia case definitions for the detection of influenza virus infections among hospitalized patients,western Kenya, 2009‐2013

Although the severe acute respiratory illness (SARI) case definition is increasingly used for inpatient influenza surveillance, pneumonia is a more familiar term to clinicians and policymakers. We evaluated WHO case definitions for severe acute respiratory illness (SARI) and pneumonia (Integrated Management of Childhood Illnesses (IMCI) for children aged <5 years and Integrated Management of Adolescent and Adult Illnesses (IMAI) for patients aged ≥13 years) for detecting laboratory‐confirmed influenza among hospitalized ARI patients. Sensitivities were 84% for SARI and 69% for IMCI pneumonia in children aged <5 years and 60% for SARI and 57% for IMAI pneumonia in patients aged ≥13 years. Clinical pneumonia case definitions may be a useful complement to SARI for inpatient influenza surveillance.     

The clinical presentation and outcomes of children infected with newly identified respiratory tract viruses

Numerous emerging respiratory tract viruses have been identified as significant causes of acute upper and lower respiratory tract illness in children. Human metapneumovirus is a paramyxovirus discovered in 2001 in the Netherlands, with a seasonal occurrence and spectrum of clinical illness most similar to the closely related respiratory syncytial virus. Several new members of the corona-virus family have been identified, including the truly novel agent of severe acute respiratory syndrome and others that probably have been circulating undetected. Avian influenza strains have caused numerous outbreaks with high mortality, including children, and are potential causes of pandemic influenza. Several zoonotic paramyxoviruses, including Nipah and Hendra viruses, have emerged as occasional causes of sever outbreaks of respiratory tract illness in children and adults.     

A prospective observational cohort study to assess the incidence of acute otitis media among children 0–5 years of age in Southern Brazil

Objectives

To estimate acute otitis media incidence among young children and impact on quality of life of parents/caregivers in a southern Brazilian city.

Vaccine prevention of acute otitis media

The incidence of acute otitis media (AOM) in infants and young children has increased dramatically in recent years in the United States. AOM often follows upper respiratory tract infections due to pathogens such as respiratory syncytial virus (RSV), influenza virus, and parainfluenza virus (PIV). These viruses cause eustachian tube dysfunction that is critical to the pathogenesis of AOM. Vaccines against these viruses would likely reduce the incidence of AOM. In three previous studies, influenza virus vaccines reduced the incidence of AOM by 30% to 36%. Vaccines to prevent infections with RSV and PIV type 3 are undergoing clinical testing at this time. Streptococcus pneumoniae, nontypeable Haemophilus influenzae (NTHi), and Moraxella catarrhalis are the three most common AOM pathogens. Heptavalent pneumococcal conjugate vaccine is effective in preventing invasive disease and AOM caused by serotypes contained in the vaccine. Vaccine candidates for NTHi and M. catarrhalis are under development.     

Gender differences in hospitalization rates for respiratory tract infections in Danish youth

Overall morbidity and mortality rates in childhood are reported to be higher in males than females. As respiratory tract infections constitute the leading cause of childhood hospitalization, we examined the gender difference in rates of hospitalization due to respiratory tract infections in Danish youth (under age 25). We studied a total of 64,049 hospitalizations for otitis media, pneumonia, influenza, and other acute respiratory tract infections from 1995 to 1999, with calculation of hospitalization rates by age and gender. The male-female hospitalization rate ratio (HRR) for admission due to a respiratory tract infection decreased from 1.45 (95% confidence interval (CI) 1.42-1.48) in the age group 0 - < 5 y, to 1.62 (95% CI 1.55-1.70) in the age group 5 - < 10 y, 1.13 (95% CI 1.04-1.22) in the age group 10 - < 15 y, 0.83 (95% CI 0.76-0.90) in the age group 15 - < 20 y, and 0.87 (95% CI 0.80-0.95) in the age group 20 - < 25 y. In young children, boys were hospitalized more often than girls, but the reverse applied in children and adolescents 15-25 y of age. The study generates the hypothesis that gender plays a role in the susceptibility for respiratory infections in early childhood.     

Acute respiratory viral infections in ambulatory children of urban northeast Brazil.

The morbidity of acute respiratory infections in young children and the role of respiratory viruses were evaluated in a 29-month household-based study in an impoverished urban population in Fortaleza, Brazil; subjects were 175 children less than 5 years of age in 63 families. Home visits were conducted three times weekly during which staff recorded the presence of respiratory and systemic symptoms and collected upper respiratory tract samples for viral isolation. A large and sustained burden of respiratory illness was observed, and respiratory viruses were isolated in 35% of the samples collected. Of the isolates, 45.6% were rhinoviruses, 16% parainfluenza viruses, 15.8% enteroviruses, 9.9% adenoviruses, 7.0% herpes simplex viruses, and 5.7% influenza viruses. The results indicate that poor children in northeast Brazil have a high prevalence of respiratory illness and that rhinovirus is the most frequent respiratory virus.