Vaginal self-swab specimen collection in a home-based survey of older women: methods and applications

Abstract

Objectives: To describe the methods used for, cooperation with, assays conducted on, and applications of vaginal specimens collected by older women in their homes.

Methods: Community-residing women (N = 1,550), ages 57-85 years, participated in a nationally representative probability survey. Vaginal self-swab specimen collection and in-home interviews were conducted between 2005 and 2006. Specimens were analyzed for bacterial vaginosis (BV), vaginal candidiasis (VC), high-risk human papillomavirus (HR-HPV), and cytological characteristics. Field methods, consent procedures, the swab protocol, laboratory procedures, and results reporting are described.

Results: One thousand twenty-eight respondents (67.5% weighted) agreed to provide a vaginal specimen; 99.1% were successful. The specimen adequacy rates were BV and VC, 94.1%; HR-HPV, 99.7%; and cytology, 85.5%. The most common recorded reason for nonparticipation was a physical or health problem (38% of nonresponders). Responders were significantly more likely than nonresponders to be younger and more educated, and were more likely to report a recent pelvic examination, menopausal hormone use, and recent sexual activity.

Discussion: Collection of vaginal self-swab specimens from older women in a population-based study is feasible and provides novel data on microenvironmental characteristics of the female genital tract relevant to analyses of gynecologic health, sexual activity and problems, and immune and inflammatory function.

Figure 1.

Illustrated instructions for self-collected vaginal swab by older women. Illustration by Rachel Seelen (Chicago, IL) in collaboration with Stacy Tessler Lindau.

Figure 2.

Normal vaginal flora, bacterial vaginosis (BV), and vaginal candidiasis (VC). Normal vaginal flora: A gram-stained vaginal swab–based sample that was given a score of 1, which is indicative of normal flora. The field contains epithelial cells with significant numbers of Lactobacillus spp. (arrow) but lacked small gram-negative rods (×1,000 magnification). BV: A gram-stained vaginal swab–based sample that was given a score of 10, which is indicative of BV. The field contains a single epithelial cell with significant numbers of small gram-negative rods and lacked any Lactobacillus spp. (×1,000 magnification). VC: A gram-stained vaginal swab–based sample. The field contains several gram-positive yeast cells, including one that is budding (arrow) (×1,000 magnification). microscope: Nikon Eclipse E600; Code No. 2CE-MVZH-9; Nikon Corporation (Tokyo, Japan).

Figure 3.

Vaginal self-swab cooperation and specimen disposition^b. Vaginal swab not offered. These were also used for cytological analysis. +Both the BV/yeast swab and HPV swab from one subject were lost. ^bMWRI, Magee-Women's Research Institute; BV= bacterial vaginosis; vc= vaginal candidiasis; hpv= human papillomavirus; HPV hc2= Hybrid Capture 2® High-Risk HPV DNA Test™.

Figure 4.

Variations of the vaginal maturation index (MI) from NSHAP self-swab specimens. (A) An estrogenized sample of superficial cells and intermediate cells; MI = 0:60:40, Pap stain, ×100, arrow designates a superficial cell. (B) A moderately estrogenized sample of intermediate cells; MI = 0:100:0, Pap stain, ×100, arrow designates an intermediate cell. (C) An atrophic sample of parabasal, intermediate, and superficial cells; MI = 70:30:0, Pap stain, ×100, upper arrow designates a parabasal cell (lower arrow designates a basal cell). All images were captured with Carl Zeiss Axioskop microscope and Carl Zeiss Axiocam Color camera. Image acquired using Improvision Openlab Imaging Software.

Figure 5.

Vaginal epithelial samples from NSHAP self-swab specimens categorized as excellent, (A) adequate, and inadequate based on the cell number criterion. (B) Adequate sample, 50–99 cells visible, Pap stain, ×100. (C) Inadequate sample, fewer than 50 cells visible, Pap stain, ×100. All images were captured with Carl Zeiss Axioskop microscope and Carl Zeiss Axiocam Color camera. Images acquired using Improvision Openlab Imaging Software.