The Descriptive Epidemiology of Severe Lower Respiratory Tract Infections in Children in Kiel, Germany

Abstract

Background: Lower respiratory tract infections (LRI) inflict a high burden of disease in children worldwide. Longitudinal, descriptive epidemiological data on different forms of LRI are urgently needed to differentiate this burden, compare population-based incidence rates between countries and to recognize trends.
Patients and Methods: From July 1996 to June 2000, all children hospitalized with LRI, i. e. laryngo-tracheo-bronchitis (LTB), bronchitis, wheezing bronchitis-bronchiolitis (WBB), bronchopneumonia and pneumonia, in the municipal area of Kiel, Schleswig-Holstein, Germany, were analyzed by cross-sectional studies. Naso-pharyngeal aspirates (NPA) were analyzed by an in-house 9-valent multiplex-RT-PCR. Results: In the 4-year observational period, 1 072 children aged 0 to 16 years (median 23 months) were hospitalized with LRI: 12 % (median 28 months) with LTB, 11 % (median 17 months) with bronchitis, 28 % (median 13 months) with WBB, 26 % (median 26 months) with bronchopneumonia and 22 % (median 47 months) with pneumonia. The prevalence of chronic underlying conditions (20 %) and low gestational age (13 %) varied in the different forms of LRI. The cumulative incidence rate of LRI rose steadily over the 4 years. The highest fraction was contributed by WBB, while pneumonia declined. The highest incidence rate ratio was attributable to respiratory syncytial virus (RSV, 0.46) and to children under 2 years of age. Conclusions: LRI, especially obstructive forms of LRI, are increasing in Germany as described earlier for the USA, UK and Sweden. The major burden is carried by children under 2 years. RSV is the single pathogen with the highest impact.

Zusammenfassung

Hintergrund: Tiefe Atemwegsinfektionen (LRI) verursachen eine hohe Morbidität bei Kindern weltweit. Longitudinale, deskriptiv-epidemiologische Daten zu verschiedenen Formen von LRI werden dringend gebraucht, um diese Morbidität besser aufschlüsseln, die populationsbezogenen Inzidenzraten zwischen Ländern vergleichen und Trends erkennen zu können. Patienten und Methoden: Von Juli 1996 bis Juni 2000 wurden alle Kinder mit einer LRI, d. h. einer Laryngotracheobronchitis (LTB), Bronchitis, obstruktiven Bronchitis-Bronchiolitis (WBB), Bronchopneumonie und Pneumonie, im Raum Kiel, Schleswig-Holstein, mittels Querschnittsstudien erfasst. Nasopharyngeale Aspirate (NPA) wurden mittels einer eigenen 9-valenten multiplex-RT-PCR untersucht. Ergebnisse: In dem Beobachtungszeitraum von 4 Jahren wurden 1 072 Kinder im Alter von 0 bis 16 Jahre (Median 23 Monate) wegen LRI hospitalisiert: 12 % mit LTB (Median 28 Monate), 11 % mit Bronchitis (Median 17 Monate), 28 % mit WBB (Median 13 Monate), 26 % mit Bronchopneumonie (Median 26 Monate) und 22 % mit Pneumonie (47 Monate). Die Prävalenz von Patienten mit Grundkrankheiten (20 %) und Frühgeburtlichkeit (13 %) variierte zwischen den verschiedenen Formen der LRI. Die kumulative Inzidenz pro Jahr stieg in den vier Jahren kontinuierlich an. Den höchsten Anteil dabei hatten WBB während Pneumonien abnahmen. Die höchste Inzidenzratio mit 0,46 (46 %) konnte dem RS-Virus und Kindern unter zwei Jahren zugeordnet werden. Schlussfolgerungen: LRI, insbesondere LRI, die mit einer Obstruktion der Atemwege einhergehen, nehmen in Deutschland zu wie bereits schon früher in den USA, Großbritannien und Schweden beschrieben. Die Hauptlast tragen Kinder unter zwei Jahren. RS-Viren haben den höchsten Anteil.

Key words

Bronchiolitis - incidence - measles vaccine - respiratory syncytial virus - respiratory tract infection

Schlüsselwörter

Bronchiolitis - Inzidenz - Masern - Respiratory Syncytial Virus - Atemwegsinfektionen

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