THE INCIDENCE OF GONORRHEA AND THE ANTIBIOTIC-SENSITIVITY OF GONOCOCCI IN AUSTRALIA, 1981-1991

Objective-To review and analyse the changing incidence of gonorrhoea a nd the increasing antibiotic resistance in gonococci in Australia from 1981 to 1991. Design-Use of data from the sample of gonorrhoea in Aus tralia examined by the Australian Gonococcal Surveillance Programme (A GSP), a continuing long-term multi-centric study of gonococcal disease and gonococcal susceptibility to antibiotics, over the period 1 July, 1981 to 30 June, 1991. Results-Over 32,000 cases and strains from def ined sources were examined in the 10 year study period. The number of cases of gonorrhoea in the sample decline from a peak of 6599 in 1982- 1983 to 1121 in the final year under review, a reduction of 83%. Perio ds when greater than average reductions in incidence occurred in diffe rent groups were noted. Ano-rectal gonorrhoea in men decreased sharply in 1985 during an overall decline of 92.5% recorded between 1 july, 1 981 to 30 June, 1987. However, the incidence of ano-rectal cases in ma les rose in subsequent years while gonorrhoea, overall, continued to d ecrease and at a greater rate after 1985. Antibiotic resistance in gon ococci in Australia was manifested both as a progressive increase in t he levels of instrinsic resistance to the penicillins and through the appearance and spread of penicillinase-producing N gonorrhoeae (PPNG). At the end of the review period in June, 1991, 8.8% of gonococcal iso lates in Australia showed high levels of intrinsic resistance to the p enicillins and 13% of strains were PPNG. These separate mechanisms of resistance appeared at different times in different parts of Australia , and their importance also varied throughout the country. Most infect ions with PPNG were acquired by men overseas whereas most women with P PNG were infected locally. Endemic spread of PPNG was a significant pr oblem in Sydney and Melbourne, but decreased in importance in the late r years of the study. Conclusions-In the past decade a large reduction in the incidence of gonorrhoea and, by implication, other STDs has oc curred in the past decade in Australia. In some groups of patients the decline in incidence is continuing while in others a slight increase has been noted. Resistance to antibiotics of gonococci in Australia wa s mainly restricted to the penicillins, but through both chromosomal a nd plasmid-mediated mechanisms. This resistance was seen particularly in Sydney and Melbourne where endemic cycles of transmission of PPNG w ere established, and in infected travellers from S-E Asia in other cen tres. Valid and comparable, and regionally relevant data are a continu ing requirement for assessing and modifying antibiotic treatment regim ens for gonococcal disease.