Discussion Questions

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  What was the aim of this study?

  
  
  
  

  
  

  See related article, page 476

  
  
  
  

  
  

  For a summary and analysis of this discussion, see page 532

  
  
  
  
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  What was the study design?

  
  
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  What were the results?

  
  
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  What is the difference between incidence and prevalence?

  
  
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  What direction might future research take?

Introduction

Mycoplasma genitalium ( M genitalium ) is a fairly unfamiliar entry in the catalog of sexually transmitted microorganisms. In fact, information on its role in urethritis and cervicitis is new to the Center for Disease Control and Prevention’s most recent Sexually Transmitted Diseases (STDs) Treatment Guidelines. Yet, this parasitic bacterium is now linked to 15-25% of the nongonoccocal urethritis cases that occur in the United States. Limited data also indicate that like Chlamydia trachomatis ( C trachomatis ) and Neisseria Gonorrhoeae , M genitalium can be a culprit in cervicitis and pelvic inflammatory disease (PID). In a new study, Bjartling and colleagues determined the prevalence of M genitalium in a gynecologic emergency clinic and then assessed all associated outcomes.

George A. Macones, MD, MSCE, Associate Editor

Introduction

Mycoplasma genitalium ( M genitalium ) is a fairly unfamiliar entry in the catalog of sexually transmitted microorganisms. In fact, information on its role in urethritis and cervicitis is new to the Center for Disease Control and Prevention’s most recent Sexually Transmitted Diseases (STDs) Treatment Guidelines. Yet, this parasitic bacterium is now linked to 15-25% of the nongonoccocal urethritis cases that occur in the United States. Limited data also indicate that like Chlamydia trachomatis ( C trachomatis ) and Neisseria Gonorrhoeae , M genitalium can be a culprit in cervicitis and pelvic inflammatory disease (PID). In a new study, Bjartling and colleagues determined the prevalence of M genitalium in a gynecologic emergency clinic and then assessed all associated outcomes.

George A. Macones, MD, MSCE, Associate Editor

Study Design

Macones: Thank you for discussing this interesting article on M genitalium. What was the aim of this study?

Cahill: The study focused on M genitalium and its potential connection to cervicitis and PID. Prior work on this had been conflicting, and importantly, had been conducted among high-risk women; ie, women who presented to an STD clinic. This study aimed to improve on prior data by examining the infection’s prevalence in a heterogeneous population, including women who were in the early months of pregnancy.

Macones: Do you think this is an important question?

Cahill: Absolutely. I think understanding potential etiologic factors for both cervicitis and PID is quite important. These health outcomes can be associated with long-term sequelae, such as infertility. Thus, I do think that careful study in this area is important.

Macones: What was the study design?

Odibo: The authors describe this as a cross-sectional case-control study. They assessed factors associated with the presence or absence of M genitalium and also looked at outcomes associated with M genitalium infection. The assessment of PID and cervicitis in those with M genitalium resembled a cohort study, but I do believe it was more cross-sectional in nature.

Macones: Who was included in this study?

Odibo: The authors recruited women from an emergency gynecologic clinic at University Hospital of Skane in Malmo, Sweden. A high proportion of women who were approached agreed to enroll in the study (89.6%), which I think is a major strength. The methods of collection and testing for chlamydia and M genitalium were described in great detail, and I have great confidence that this was done well. Importantly, the results from M genitalium testing were not disclosed until the study was over, so essentially, providers and women were blinded to infection status. Subjects with chlamydia and M genitalium were compared to women who had neither of these infections.

Macones: What types of data were collected?

Odibo: There seemed to be very robust data collection on the infected women, as well as the uninfected. This included information on demographics, clinical diagnosis, and clinical signs and symptoms—the primary outcomes of interest.

Macones: How were the data analyzed?

Cahill: The analysis was very straightforward. It included bivariate analysis and appropriate multivariable models that controlled for confounding factors.