Sexual partner networks in the transmission of sexually transmitted diseases. An analysis of gonorrhea cases in Sheffield, UK

Abstract

Background and objectives: Routine contact tracing data on patients with gonorrhea are used to identify sexual partner networks. These are combined with gonococcal typing data to study patterns of transmission. The role of persons in transmission is discussed.

Study design: Contact tracing data on patients with gonorrhea attending the Royal Hallamshire Hospital in Sheffield in 1988 and 1989 are analyzed. Gonococcal strains identified by auxotype/serovar (A/S) class are combined with these data to identify transmission paths.

Results: The network contained 1,272 persons, 724 (77%) of whom had gonorrhea during the study period. Four hundred two clusters of linked cases were identified. The largest cluster, containing 35 persons connected over 16 months, is discussed in greater detail to illustrate how these data may help identify patterns of transmission and the role of persons.

Conclusion: Contact tracing data can be used to identify sexual partner networks and to study transmission patterns. Microbiologic data can aid interpretation. An person's risk of acquiring infection depends on indirect links as well as direct links. To understand patterns of transmission it may be important to distinguish between those involved in transmission and those only acquiring infection. Networks established through gonococcal transmission are also relevant to the transmission of other sexually transmitted diseases.