Sampling individuals with large sexual networks: an evaluation of four approaches.

BACKGROUND

Methods for accessing large sexual networks are essential for investigating the mechanisms for the spread of sexually transmitted infections.

GOAL: Four samples of cases were compared with the total population to determine which identified the largest networks.

STUDY

DESIGN

Individuals with positive test results for chlamydia during a 6-month period were selected from a laboratory database and linked with sex partner information from a notifiable disease registry. Sexual networks were constructed for a random sample, people with positive results from two or more tests for chlamydia, people with positive tests results for both gonorrhea and chlamydia, and the preceding two groups combined.

RESULTS

The coinfected people combined with the repeaters yielded the highest proportion (47.8%) of large networks (>10 people), followed by the coinfected people, the repeaters, and finally the random sample.

CONCLUSIONS

People coinfected with chlamydia and gonorrhea and those with repeated chlamydial infection present ideal opportunities for both research and prevention.