Sexually transmitted diseases reported by STD services in The Netherlands, 1984-1990

To present general trends in sexually transmitted disease (STD) in the Netherlands during the period 1984-1990 and to describe characteristics of the patients in order to get insight into possible factors underlying these trends.

Since 1984 patients diagnosed with STD visiting STD clinics and local public health services in the Netherlands are reported by the nursing staffs. In addition to diagnosis and gender of the patient epidemiological background information is registered. The reported annual cases of gonorrhoea, syphilis and Chlamydia trachomatis infections are presented. Further, the epidemiological features of over 25,000 patients with infections due to Chlamydia trachomatis, gonorrhoea or syphilis infections were compared.

During the period 1984-1990 an overall decrease in the total number of gonorrhoea infections was reported; among homosexual males; however, an increase in gonorrhoea rates and an increasing number of sexual partners after 1989 was reported. Furthermore, the percentage of gonorrhoea infections caused by penicillinase-producing Neisseria gonorrhoeae was found to be on the increase in various subgroups but not in homosexual males. Syphilis rates among females declined from 1984 to 1987 after which an increase was reported reaching a peak in 1989; syphilis rates among males peaked during 1989. After 1988 Chlamydia trachomatis infections increased which, however, is largely due to the introduction of screening among all visitors of the Amsterdam STD service resulting in improved case-detection. Finally, it appeared that STDs are not randomly distributed over the population but are associated with certain patient characteristics.

The data provided by STD services reveal an epidemiological pattern for STDs in the Netherlands. The increase in the reported number of gonorrhoea infections among homosexuals together with the increasing number of sexual partners among homosexual males suggest that a group of highly sexually active individuals switch or return to higher risk behaviours. Further research is needed to determine the causes of the described trends and behavioural changes in order to undertake preventive activities.