TY - JOUR
T1 - The natural history of bacterial vaginosis diagnosed by gram stain among women in Rakai, Uganda
AU - Thoma, Marie E.
AU - Gray, Ronald H.
AU - Kiwanuka, Noah
AU - Wang, Mei Cheng
AU - Sewankambo, Nelson
AU - Wawer, Maria J.
PY - 2011/11
Y1 - 2011/11
N2 - Background: Large datasets for investigating vaginal flora change at frequent, repeated intervals are limited and graphical methods for exploring such data are inadequate. We report 2-year weekly vaginal flora changes based on Gram stain using lasagna plots. Methods: Weekly vaginal flora patterns were evaluated among 211 sexually experienced women with 18 months of follow-up in Rakai, Uganda. Vaginal flora swabs were self-collected weekly and categorized by Nugent Gram stain criteria (0-3, normal; 4-6, intermediate; 7-10, bacterial vaginosis [BV]). Vaginal flora patterns were analyzed as the percentage of weekly observations with BV (longitudinal prevalence) and illustrated by lasagna plots. Characteristics of women were compared across tertiles of longitudinal prevalence of BV. Results: Ninety-five percent of women had at least 1 episode of BV over 2 years, with one-third of women spending more than half (52%-100%) of their time with BV. Vaginal pH >4.5 increased with increasing tertiles of longitudinal prevalence of BV (P < 0.001). Weekly fluctuation in vaginal flora states, as measured by a change in flora states from the before current visit, was highest in the middle (41.9%) compared with the lower (30.1%) and upper tertiles (27.8%, P < 0.001). HIV status and reported vaginal symptoms did not differ significantly across BV tertiles. Conclusions: Women exhibited different patterns of vaginal flora changes over time, which could not be described by baseline behaviors. Lasagna plots aided in describing the natural history of BV within and across women and may be applied to future BV natural history studies.
AB - Background: Large datasets for investigating vaginal flora change at frequent, repeated intervals are limited and graphical methods for exploring such data are inadequate. We report 2-year weekly vaginal flora changes based on Gram stain using lasagna plots. Methods: Weekly vaginal flora patterns were evaluated among 211 sexually experienced women with 18 months of follow-up in Rakai, Uganda. Vaginal flora swabs were self-collected weekly and categorized by Nugent Gram stain criteria (0-3, normal; 4-6, intermediate; 7-10, bacterial vaginosis [BV]). Vaginal flora patterns were analyzed as the percentage of weekly observations with BV (longitudinal prevalence) and illustrated by lasagna plots. Characteristics of women were compared across tertiles of longitudinal prevalence of BV. Results: Ninety-five percent of women had at least 1 episode of BV over 2 years, with one-third of women spending more than half (52%-100%) of their time with BV. Vaginal pH >4.5 increased with increasing tertiles of longitudinal prevalence of BV (P < 0.001). Weekly fluctuation in vaginal flora states, as measured by a change in flora states from the before current visit, was highest in the middle (41.9%) compared with the lower (30.1%) and upper tertiles (27.8%, P < 0.001). HIV status and reported vaginal symptoms did not differ significantly across BV tertiles. Conclusions: Women exhibited different patterns of vaginal flora changes over time, which could not be described by baseline behaviors. Lasagna plots aided in describing the natural history of BV within and across women and may be applied to future BV natural history studies.
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U2 - 10.1097/OLQ.0b013e3182275499
DO - 10.1097/OLQ.0b013e3182275499
M3 - Article
C2 - 21992981
AN - SCOPUS:80054119213
SN - 0148-5717
VL - 38
SP - 1040
EP - 1045
JO - Sexually transmitted diseases
JF - Sexually transmitted diseases
IS - 11
ER -