Incidence of influenza in Finnish children.

BACKGROUND: Influenza is an important cause of respiratory illness in children, but data on virologically confirmed influenza infections in children treated as outpatients are limited. METHODS: We carried out a prospective cohort study of normal children younger than 13 years (n = 1338) in the winter of 2000 to 2001. During the study period of 32 weeks, the children were examined at the study clinic whenever they had fever or signs of respiratory infection. Nasal swabs were obtained during each episode of infection for determination of the viral etiology of the illness. RESULTS: The overall attack rate of influenza in the cohort was 18.8%. Influenza viruses were isolated from the children from the beginning of November 2000 through May 2001. Virtually in each week between mid-November and the end of April (a period of 24 weeks), influenza viruses accounted for at least 5% of all respiratory infections in the children. During the peak of the epidemic, the percentage of influenza-positive children exceeded 20%. CONCLUSIONS: This study confirms the important role of influenza as a cause of acute respiratory infections in children, even in winters of mild or moderate influenza activity. The study also shows that influenza viruses may circulate in the community at substantial levels much longer than previously thought.

Symptoms and signs of community-acquired pneumonia in children.

OBJECTIVE: The aim of this investigation was to identify the clinical symptoms and signs of pneumonia in hospitalised patients with confirmed aetiologic diagnosis and to study whether it is possible to differentiate viral from bacterial pneumonia by these means. DESIGN: A 3-year prospective study. SETTING: Turku University Hospital, Turku, Finland. PATIENTS: 254 children with radiologically confirmed community-acquired pneumonia. MAIN OUTCOME MEASURES: Data on symptoms and signs were collected from the hospital records of patient files. A standardised case record form was used. RESULTS: Eleven percent of the patients presented the illness without any respiratory symptoms. Patients with viral pneumonia versus those with bacterial pneumonia were younger (means 2.8 vs 4.1 years) and more often had acute otitis media (41% vs 18%), dyspnea (48% vs 25%) and rhonchi on auscultation (47% vs 26%). Thoracic pain, headache and decreased breathing sounds were more common in patients with bacterial pneumonia. CONCLUSIONS: Although the clinical findings in viral pneumonia showed some differences from those in bacterial pneumonia, they were largely overlapping. This similarity and the frequent occurrence of mixed infections make it impossible to differentiate between viral and bacterial pneumonia simply by clinical symptoms and signs.

Clinical response to antibiotic therapy for community-acquired pneumonia.

UNLABELLED: Childhood community-acquired pneumonia is a common and potentially serious problem worldwide. Unless the patient has bacteraemia or pleural empyema, aetiological diagnostics are limited and antibiotic treatment is empirical. Published data on expected response to therapy are scarce. To determine the clinical response to antibiotic treatment in a developed country in otherwise healthy children with community-acquired pneumonia, we conducted a prospective study of 153 hospitalised children with pneumonia. The role of 17 microbes as potential causative agents was evaluated. The duration of fever (>37.5 degrees C) and hospitalisation were studied as objective measures of recovery. A potential aetiology was found in 83% of 153 patients: 29% of the patients had sole viral and 26% sole bacterial and 29% mixed viral-bacterial infections. The median duration of fever after the onset of antibiotic treatment (mainly penicillin G) was 14 h and the median duration of hospitalisation was 48 h. Patients with mixed viral-bacterial infection became afebrile more slowly than those with either sole viral or sole bacterial infections. CONCLUSION: the findings indicate that in a developed country, children with pneumonia make a rapid, uneventful recovery needing only a short hospital stay. Expensive and time-consuming microbiological investigations are not required once bacterial sepsis has been excluded.

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.