The descriptive epidemiology of severe lower respiratory tract infections in children in Kiel, Germany.

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.