Vaginal douching in Zambia: a risk or benefit to women in the fight against cervical cancer: a retrospective cohort study

Cancer is an emerging public health problem in Africa [1]. According to the GLOBOCAN 2018 estimates, the share of cancer deaths in Africa (7.3%) is higher than the share of incidence (5.8%) [2]. Cervical cancer ranks second in incidence and mortality behind breast cancer in lower human development index (HDI) settings, with Africa recording the highest regional incidence and mortality rates [2]. Zambia, Malawi, Mozambique, and Tanzania have among the highest cervical cancer rates (50 cases per 100,000) worldwide [3]. In Zambia, cervical cancer was the most commonly diagnosed cancer and the leading cause of cancer related deaths in 2013 among women [4]. The mortality rate from the disease could be attributed, in part, to the fact that most cases (about 80%) are advanced at presentation, when only palliative treatment can be given [5].

The cause of cervical cancer has been postulated to be multifactorial including behavioral factors such as vaginal douching. Vaginal douching is the process of intravaginal cleansing with a liquid solution [6]. It is used for personal hygiene or aesthetic reasons, for preventing or treating an infection [7], to cleanse after menstruation or sex, and to prevent pregnancy [8]. For example, alum, an astringent, was used for various purposes such as tightening of the vagina for enhancement of sexual pleasure, making the vagina ‘younger’, or to hide evidence of infidelity [9]. Another common practice is that associated with dry sex, where individuals prefer a dry, tight vagina during sexual intercourse [10]. Dry sex more often than not involves the use of plants to dry and contract the vagina, a popular practice in Africa that damages vaginal tissue and facilitates the spread of sexually transmitted diseases [11, 12].

Very few studies have examined the association between vaginal douching and abnormal cervical lesions. Studies that have examined the association have conflicting views on the benefits or harm associated with douching [6]. Nevertheless, most studies have hypothesized that frequent douching alters the vaginal chemical environment, making the cervix more susceptible to pathologic change, and serious gynecologic outcomes, including increased risk of cervical cancer, pelvic inflammatory disease, endometritis, and increased risk for sexually transmitted infections, including HIV [13‐16]. We determined factors associated with douching with any solution other than water. We also examined the association between abnormal cervical lesions and douching with such solutions among Zambian women.

The current study found that vaginal douching with any solution other than water increased the risk of abnormal cervical lesions, as women who used either vinegar/lemon/ginger/salt or sugar exhibited elevated risk. Our findings are consistent with those from similar studies, albeit the other studies looked at douching in general. In a survey conducted in the United States, authors posited that douching had the potential to increase the risk of cervical cancer as the former was high-risk for HPV infection. There was a 40% higher risk of a high-risk infection in women who douched [13]. In Taiwan, post-coital vaginal douching was a risk factor for the non-regression of low-grade squamous intraepithelial lesions (LSIL) (OR = 3.14; 95% CI: 1.04–9.49) [19]. In a review of evidence to discourage douching, Cottrell [14] cites increased risk of cervical cancer as one of the serious outcomes associated with douching. A study conducted among patients with cancer of the cervix in Buffalo and Kenmore, New York, revealed a direct association between the frequency of douching and the risk of both invasive cervical cancer and carcinoma in situ [20]. Peters et al. [21] found that the “frequency-years” of douching contributed independently and significantly to the risk of invasive cervical cancer among Latinas and non-Latinas in Los Angeles County. In a meta-analysis, Zhang et al. [15] found that douching was modestly associated with cervical cancer, when they aggregated studies that looked at both invasive cervical cancer and carcinoma in situ together or at invasive cervical cancer alone (RR = 1.25, 95% CI: 0.99, 1.59). However, other studies found inconsistent results with respect to vaginal douching and cervical cancer [22‐24].

An important finding of this study is that specific douches predispose women to the risk of abnormal cervical lesions. Our study found elevated risks of abnormal cervical lesions among women who used either vinegar, lemon, ginger, salt or sugar solutions for vaginal douching. Other douches had a protective effect albeit there was not enough statistical evidence to support the observed associations. Seay [25] also found an association between risk for HPV infection and specific douches. A similar observation was made by Martino et al. [6] who argued that whether or not douching had adverse effects was probably dependent on the type of solution used. Evidence showing that certain douches may interfere with the conditions suitable for the survival of lactobacilli strains and thereby compromising the epithelial cell integrity [26] could explain the increased risk for abnormal cervical lesions in our study.

The major limitation of our study is that the programmatic data that we used for investigating vaginal douching did not collect information on the frequency of douching per week or on the frequency years of engaging in the practice. As noted from some studies discussed in this paper, the risk of cervical lesions varied by the frequency and years of douching. However, we posit that the elevated risk among women who used vinegar/ginger, lemon/sugar or salt provides substantial evidence to discourage douching with these solutions among Zambian women.

We find elevated risk of abnormal cervical lesions among women who use certain douches. We argue, therefore, that certain douches could potentially put women at higher risk of abnormal cervical lesions relative to water. Health promotion messaging should therefore describe the possible health risks of vaginal douching with certain solutions such as vinegar, ginger, lemon, sugar and salt. These messages should be targeted, especially at younger women, house-wives, women with secondary education and women who use condoms sometimes, in whom the practice of vaginal douching with solutions other than water is higher. There is need for further research to examine the risk of abnormal cervical lesions among women who have ever vs never douched. Future research should also take into consideration the effect of frequency as well as years of douching on risk of abnormal cervical lesions.