Failure to detect interfering agents in febrile respiratory illnesses

Patterns of infections with adenovirus types 4, 7 and 21 in military recruits during a 9-year survey

Investigations to define the epidemiological pattern of adenovirus infection in military recruits were carried out in a training centre at Ossendrecht, The Netherlands, during a 9-year period. Extensive outbreaks of adenovirus illness occurred in the winter and spring, and in some years in the late fall. The seasonal variation in total incidence of adenovirus infection as estimated by frequency of antibody rises in randomly selected recruits correlated well with that of adenovirus illness. In the cold season 20–60 of every 100 men were infected, whereas no or very little activity of adenovirus was found during the summer.

Type 7 was prevalent during the first 2 years of the study period, type 21 during the next 3 years and type 4 during the last 4 years. The proportion of adenovirus infection associated with clinical illness, the distribution of adenovirus illness by week of training and the immunity of incoming recruits against adenovirus infection as estimated by frequency of neutralizing antibody were compared for type 7, type 21 and type 4.

Adenovirus was responsible for about one third of all cases of acute respiratory illness. The next most common diagnostic category was influenza. Other respiratory agents (parainfluenza, RS and Coxsackie A-21 viruses, Mycoplasma pneumoniae and haemolytic streptococci) were of less importance.

This work was supported in part by the United States Department of the Army through its European Research Office.

We are indebted to the following persons who contributed to this study: C. P. A. van Boven, R. Brouwer, J. H. E. Custers, J. H. Dijkman, A. Prins and A. R. van der Werff, medical officers; Mr A. P. K. M. I. van Nieuwstadt, Miss M. C. J. van Nunen, Dr G. C. J. van der Ploeg and Dr H. J. A. Sonderkamp, members of the staff of our laboratory; and Misses C. H. Bronswijk, G. J. Hof, A. D. E. M. Leeuwenberg, W. T. C. J. Smulders and C. M. G. Stevens, and Mrs A. M. van Snik, technicians.

Major-General Dr H. J. van der Giessen and Brigadier General W. P. Blokpoel, former Directors-General of Medical Services of the Royal Netherlands Army, and Colonel Dr B. J. W. Beunders, former Head of the Division of Preventive Medicine, granted facilities for the conduct of this study.