Estimating the contribution of N. gonorrhoeae infection to pelvic inflammatory disease and tubal factor infertility in the United States and the Infertility Belt of Africa

Abstract

Gonorrhea is the second most common bacterial sexually transmitted infection (STI) globally. Persistent gonorrhea infection can cause pelvic inflammatory disease (PID), ectopic pregnancy (EP) and tubal factor infertility (TFI). Infertility disproportionately impacts women in high fertility countries, especially in the Infertility Belt of Africa from Gabon to Tanzania. To examine gonorrhea’s contribution to these reproductive tract outcomes, we 1) conducted a survey and medical record review at Dodoma Christian Medical Center (DCMC) in Dodoma, Tanzania, 2) analyzed U.S. administrative claims data, and 3) created a mathematical model of STI transmission and reproductive tract disease among U.S. women.First, we examined determinants of female infertility by interviewing and reviewing medical records of 168 women seeking infertility treatment at DCMC. Women with PID had 1.9 (95% CI: 1.3-2.9) times the prevalence of TFI compared to women with other infertility factors. Logistic barriers to treatment were most common, regardless of women’s geographic residence. Next, we analyzed the rates of PID, EP, and TFI after gonorrhea diagnosis using the IBM MarketScan national claims database from 2013-2018 and tested an interaction in rates over time. We found elevated rates of PID, EP and TFI among women with a prior gonorrhea diagnosis compared to women who had no prior gonorrhea diagnoses. These rate ratios were steady over time, indicating that higher reported STI rates reflect increased infection burden, not greater incidence resulting from increased testing. Finally, we created a mathematical model simulating the disease process to estimate the number of cases of PID and TFI due to gonorrhea or chlamydia. We estimated that 24% of PID episodes and 26% of undetected tubal damage occurred among women who were previously infected with gonorrhea. Findings from this dissertation are timely due to increasing rates of gonorrhea infection and may motivate and inform global STI prevention efforts.