Updates by Carol A. Kemper, FACP

Peroneal Anatomy and UTIs in Women

Source: Hooton TM, et al. Clin Infect Dis 1999;29:1600-1601.

In order to test the hypothesis that physiogomy and urine-voiding characteristics may affect the risk of urinary tract infection (UTI), Hooton and colleagues examined healthy nonpregnant women aged 18-30 years. Case subjects (n = 98) had a history of frequent UTI (> 3 in the past 12 months or > 2 in the past 6 months), while control subjects (n = 107) had no history of UTI during the previous year and no more than one UTI in any preceding year.

No difference in urinary flow characteristics (peak and average flow rate, volume, and voiding time) or post-void residuals were identified. Remarkably, however, the distance from the urethra to the anus as well as from the posterior fourchette to the anus in women with more frequent UTI was significantly shorter than that of control subjects (although the mean difference averaged only 0.2 cm). In women who did not use spermicides, a distance from the urethra to the anus of less than 4.5 cm was significantly more frequent in case subjects than controls (38% vs 10%, P = 0.0013), although this association was not observed in spermicide users. No difference in urethral length (average length ~3.5 cm) was detected.

In the absence of other risk factors, such as frequent sex or use of spermicides, Hooton et al argue that anatomic differences in peroneal anatomy may contribute to the frequency of UTI. While an interesting theory, I’m baffled as to how the seemingly minor differences detected in this study could be an important factor. Fecal pathogens can readily colonize Foley catheters in men within days of insertion, which entails migration from the perirectal area to the penile meatus (presumably a much longer distance). Furthermore, peroneal anatomy in this study was significantly associated with weight, height, and body mass index, but I know of no data suggesting that thin women are at greater risk for UTI than overweight ones. This seems like one of those statistical observations that deserves further exploration.

Which of the following is correct?

a. There remains no evidence that avian influenza virus (H5N1) can be transmitted from human to human.

b. The peroneal anatomy of young women (e.g., the distance from the urethra to the anus) is reported to be an important risk factor for the development of urinary tract infection in young women.

c. Granulocyte-macrophage colony-stimulating factor (GM-CSF) accelerates the intracellular replication and growth of Mycobacterium avium in macrophages.

d. Helicobacter pylori is absent from the vomitus of patients with gastric infection due to this organism.