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Epidemiology of penicillinase-producing Neisseria gonorrhoeae in Liverpool from 1977 to 1982
Abstract:
After the 1976 outbreak of penicillinase-producing Neisseria gonorrhoeae (PPNG) infections had been controlled, less than 1 per cent of cases of gonorrhoea in Liverpool in 1977 and 1978 were caused by PPNG. Thereafter the steady increase in PPNG infections to 5.6 per cent of all cases in 1982 was associated with marked changes in epidemiological pattern, plasmids and auxotypes. In 1976 nearly all PPNG infections were acquired by young black males living in the inner city from women frequenting clubs; the PPNG were all of the African 3.2 megadalton (MD) plasmid type and of arginine-requiring auxotype. Between 1977 and 1982 female patients were increasingly ship girl prostitutes associating with seamen who constituted more than 50 per cent of the male patients. These men and other travellers introduced PPNG into Liverpool from the Far East and West Africa. In 1978 PPNG of the Asian type with 4.4 MD plasmid with or without 24.5 MD transfer plasmids were isolated in Liverpool where in 1979 all PPNG carried 4.4 MD and 24.5 MD plasmids. In 1982 strains of the 'new' African type with 3.2 and 24.5 MD plasmids were isolated as were PPNG of the Asian type that had been acquired in West Africa. Auxotyping of the 1982 isolates showed that none were arginine-requiring but three other types were identified: proline-requiring: proline-arginine-requiring; non-requiring. For the control of PPNG, a strategy based on constant vigilance, appropriate diagnostic procedures, rapidly effective treatment and determined contact tracing is needed.
Insights
Penicillinase-producing Neisseria gonorrhoeae (PPNG) infections evolved in Liverpool, with changing epidemiology, plasmids, and auxotypes between 1977 and 1982. Control requires vigilance, diagnostics, treatment, and contact tracing.
Area of Science:
- Microbiology
- Epidemiology
- Public Health
Background:
- Penicillinase-producing Neisseria gonorrhoeae (PPNG) infections initially decreased after a 1976 outbreak but resurged in Liverpool.
- PPNG cases rose from less than 1% in 1977-78 to 5.6% by 1982, indicating a significant epidemiological shift.
Purpose of the Study:
- To analyze the changing patterns of PPNG infections in Liverpool.
- To investigate alterations in the epidemiological profile, plasmid types, and auxotypes of PPNG strains.
Main Methods:
- Retrospective analysis of PPNG cases in Liverpool from 1977 to 1982.
- Characterization of PPNG strains based on epidemiological data, plasmid content (e.g., 3.2 MD, 4.4 MD, 24.5 MD plasmids), and auxotyping (e.g., arginine-requiring, proline-requiring).
Main Results:
- Initial PPNG infections in 1976 were linked to young black males and African 3.2 MD plasmid type with arginine auxotype.
- Between 1977-1982, infections shifted, involving female prostitutes and seamen, with PPNG introduced from the Far East and West Africa.
- Plasmid types evolved to include Asian types (4.4 MD, with/without 24.5 MD) and later 'new' African types (3.2 and 24.5 MD).
- By 1982, auxotypes diversified, with proline-requiring, proline-arginine-requiring, and non-requiring strains identified, replacing the earlier arginine-requiring type.
Conclusions:
- The epidemiological patterns, plasmid profiles, and auxotypes of PPNG strains in Liverpool underwent significant changes between 1977 and 1982.
- The emergence of new strains and changing transmission routes highlight the need for ongoing surveillance.
- Effective control of PPNG necessitates a comprehensive strategy including constant vigilance, rapid diagnostics, effective treatment, and thorough contact tracing.