Re-Evaluation of Gonorrhea Risk Factors: Assessing a Need for Primary Chlamydial Contact Investigation

BACKGROUND: Lane County Oregon has experienced an increase in STDs in the recent years, and a major focus has been on the reduction of N. gonorrheae infections across the county. A three year strategic plan was developed to reduce STDs in the county with an objective being to identify high risk groups and behaviors. Current STD contact investigation in Lane County is limited to syphilis, gonorrhea, HIV, and chlamydia diagnosed during pregnancy.

METHODS: Retrospective cohort of 588 reported N. gonorrheae infections in Lane County, Oregon between January 1^st 2012 and September 30^th, 2014. Using the state reportable disease tool, Oregon Public Health Epi User System (ORPHEUS), Lane County Public Health investigated high risk groups (gender, age, race) as well as behaviors (sexual orientation, orifices involved, and number of partners) associated with risk of N. gonorrheae infection. During this analysis co-infections were also investigated, as were any incidence of pre-gonorrheal STDs. Case line listings were reviewed for co-infections (STDs reported at the same time as gonorrhea) or history of previous STDs (past occurrence of any STD including pre-2012 gonorrhea).

RESULTS: 259 of 588 (44%) individuals with reported gonorrhea between January 1^st 2012 and September 30^th 2014 had a history of co-infection or previous STD infection. Of the 259 individuals 120 (46%) had a pre-gonorrhea chlamydial infection which accounted for 20% of total gonorrheal infections. Within the 120 individuals with a history of chlamydial infection 62% were female and 32% had a history of multiple chlamydial infections. The review also found that 106 (18%) of the 588 gonorrhea cases were concurrently diagnosed with chlamydia. Of those with concurrent infections, only 40% were female.

CONCLUSIONS: A previously overlooked risk factor for Lane County cases of gonorrhea was previous history of chlamydial infection. Little in the way of education and follow-up has been directed at chlamydia cases due to the large number of cases per year in the county. Investigation of first chlamydial infection may play a role in the reduction of not only multiple chlamydial infections via contact investigation and treatment of partners identified, but may also have a role in reducing gonorrhea cases in the county. The three year STD strategic plan recommends the addition of a pilot study aimed at contact investigation of first reported chlamydial infections in individuals to protectively intervene on sexual behaviors that may lead to gonorrhea infections later in life.