Sequences derived from the endogenous plasmid of Chlamydia trachomatis and from the genes coding for ribosomal 16S RNA of Chlamydia psittaci were used as primers and oligonucleotide probes for detection of chlamydiae by the polymerase chain reaction. The endogenous plasmid primers generated specific amplified products of 517 bp with all known Chlamydia trachomatis serovars. No specific products of Chlamydia psittaci and Chlamydia pneumoniae could be detected using these primers. With the rRNA primers specific amplified products of 208 bp were generated with Chlamydia psittaci, Chlamydia trachomatis and Chlamydia pneumoniae. No specific amplified products were detected with DNA isolated from a variety of microorganisms from the urogenital and the respiratory tract. Of 156 clinical specimens used for evaluation of the polymerase chain reaction, 26 were found to be positive for Chlamydia trachomatis on culture. All 26 culture positive samples were also found to be positive for Chlamydia trachomatis DNA by the polymerase chain reaction with both primer sets. Two culture negative samples were also found to be positive by this technique. The polymerase chain reaction thus seems to be a sensitive and reliable method for detection of Chlamydia trachomatis.

The diagnostic value of the polymerase chain reaction (PCR) for detection of Chiamydia trachomatis in comparison with that of the culture technique was established in a follow-up study of 32 patients (81 samples) who were treated for a C. trachomatis infection. The PCR was performed with two different sets of primers, a genus-specific primer set directed against the rRNA genes and a C. trachomatis-specific set directed against the common endogenous plasmid. After treatment with doxycycline, all patients became culture negative after 1 week. Results for the detection of C. trachomatis by the PCR were in complete agreement with the results by the culture method of detection, except for one culture-negative sample, which was found to be positive by the P'CR. The results indicated that 1 week after treatment, no residual chlamydial DNA was found in the samples. Therefore, the PCR can be used for monitoring infections by chlamydiae.

Although it is now evident that human papillomaviruses (HPV) are strongly associated with cervical cancer, their etiological role in the oncogenesis of this disease is still unknown. However, HPV screening may identify women at risk of acquiring this disease. With the recent development of the polymerase chain reaction (PCR), it has become possible to detect small numbers of human papillomavirus genomes in clinical samples. The sensitivity and specificity of this technique, together with the possibility of performing the test on crude cervical scrapes, makes PCR the method of choice for screening. In this paper, data on the detection of human papillomavirus by PCR are presented and the applicability of this technique for the screening of human papillomavirus genotypes is evaluated. The question arises whether screening for diagnostic purposes must include all the human papillomavirus types associated with infections of the genital tract or only those which are strongly associated with cervical cancer (HPV 16 and HPV 18). It is proposed that an international council must be created that is responsible for standardised epidemiological screening strategies and follow-up programmes.