Prevalence and associated risk factors of Mycoplasma genitalium infection in women in Western Cameroon: A cross sectional study

Introduction

Mycoplasma genitalium has garnered attention as a cause for sexually transmitted infection (STI) in women genitourinary disorders. This STI could present with diverse symptoms, although the majority of M. genitalium infections remain asymptomatic. The burden of M. genitalium can be significant, particularly in terms of its impact on sexual and reproductive health. In low-risk women population in the United Kingdom and United States, the prevalence of M. genitalium infection ranges from 1% to 2%, with the highest frequency observed among women aged 16–19 years.^1,2 However, in women attending STI clinics, the prevalence significantly escalates, ranging from 7.0% to 19.2%.^3,4 Despite these global insights, there is a dearth of research on M. genitalium infections within the Cameroonian population, with a recent study from the southwestern region reporting a 7% prevalence among infertile women.⁵ Consequently, a more comprehensive understanding of the spectrum of M. genitalium infections within the population is imperative for effective prevention and treatment strategies. We carried out this study in Western Cameroon to investigate the prevalence of M. genitalium and identify various correlates and factors associated with M. genitalium infection in women attending the clinic.

Material and Methods

A cross-sectional study was conducted in hospitals of five districts of Western Cameroon (Dschang, Bafang, Mbouda, Bafoussam and Bangangte) including women attending for antenatal, prenuptial and contraception consultations between January 2020 and July 2020. Participants who provided consent were administered a questionnaire to collect sociodemographic information and assess potential risk factors. This study was approved by the Institutional Review Board (IRB), and written informed consent was obtained from all subjects. Participants included in the study were more than 18 years old, had no sexual contact in the last 48 hours, and had not received antibiotic treatment in the last 30 days. Individuals not meeting these criteria were excluded from the study. A total of 680 endocervical swabs (ECS) were obtained from women using a sterile speculum and a nonabrasive Bactopick Swab. Collected samples were stored in tubes containing 1 mL of sterile saline (0.9% NaCl) and preserved at –20°C until further processing.⁶ The DNA from the ECS was extracted using the QIAamp DNA mini kit (Qiagen, CA, USA) as per manufacturer’s instructions including 200 μL of nuclease free water as DNA extraction control. DNA thus extracted was stored at –20°C till further use. The M. genitalium was detected by real-time PCR for the MgPa and pdhD genes of M. genitalium using the primers mentioned in Supplementary Table 1. The qPCR amplification was performed in a 20 µL reaction volume containing 10 µL of SYBR green Master Mix (Invitrogen), 0.5 µM of each primer and 5 µL of DNA in C1000 Thermal cycler (Bio-Rad Laboratories, USA). The PCR conditions for performing amplification were as per the previous study by Jensen et al^.7,8 Data analysis was performed using Statistical Package for the Social Sciences (SPSS) 25.0 for Mac OS (SPSS, Inc., Chicago, IL, USA). Categorical variables were assessed by χ2 test, and continuous variables by the Wilcoxon–Mann–Whitney test. p < 0.05 was considered statistically significant.

Results

The study was conducted in five district hospitals in the West region of Cameroon.. These hospitals include Dschang (235 women), Bafang (110 women), Mbouda (123 women), Bafoussam (109 women) and Bangangté (103 women). A total of 680 women ECS samples, with a mean age of 27.4 ± 7.5 years (range: 18–49 years), were included in the study. The population comprised 50.7% (n = 347) in the age group of less than 25 years and 49.3% (n = 333) in the age group of more than 25 years. Predominantly, the population belonged to the Semi Bantu race/ethnicity (93.3%, n = 638), followed by Bantu (4.4%, n = 30) and Soudano sao (1.8%, n = 12). A significant proportion of the population (85.2%, n = 583) demonstrated knowledge of STI transmission. Regarding relationship status, 61.7% (n = 422) were in monogamous relationships, while 25.7% (n = 176) were in polygamous relationships. The age of first sexual intercourse varied, with 50% (n = 347) reporting initiation between 15 and 17 years, 44.7% (n = 306) after 18 years, and 3.9% (n = 27) before 15 years [Table 1]. The overall prevalence of M. genitalium infection was 5.2% being highest among women aged less than 25 years (n = 22, 62.9%) comprising the majority. The overall prevalence of M. genitalium infection was 5.2% and <25 years accounts for 62.9% of the total prevalence. Furthermore, lack of prior education and knowledge of STI-related infections and higher age at first intercourse (>18 years) were not statistically significant, but the 1.5 times higher odds suggest a risk of M. genitalium infection. We observed, having more than one sexual partner was significantly associated with three times higher prevalence of M. genitalium infection (p value: 0.043, OR: 2.9; CI 1.1–8.5) [Table 2].

Discussion

STIs pose a significant burden on individuals, communities and healthcare systems. This study holds potential as we tested a significant number of women in Western Cameroon, where M. genitalium testing is not performed routinely to provide data on the epidemiology of M. genitalium relative to other STIs. In our study, the prevalence of M. genitalium was 5.2%, aligning with rates reported in various regions. For instance, Andersen et al. reported a prevalence of 2.3% among Danish women, while a study from South Africa found a higher prevalence of 9.6% among asymptomatic adolescents and young women.^9,10 A meta-analysis demonstrated even lower prevalence estimates in asymptomatic patients (0.8%), indicating variability across populations^.11 The differences in prevalence across countries underscore the impact of factors such as sampling methods, target demographics, specimen collection and detection techniques. Previous studies from Western Cameroon region have primarily focused on other genital mycoplasmas (Ureaplasma urealiticum and Mycoplasma hominis) infection, neglecting M. genitalium.^12,13 Our study addresses this gap by providing data on M. genitalium prevalence and associated risk factors in the region. On comparing findings of our study with previous studies from the same region, we noted variations in prevalence rates. Pepin et al. observed a prevalence of 26.3% among West African female-sex workers, which is very high in comparison to the current study, as this study included women participants who are primarily at high risk of acquiring STI.¹⁴ Morency et al. observed 20% patients harbouring M. genitalium as an aetiological agent in the urethral discharge in Bangui, Central African Republic.¹⁵ Our study was conducted among women participants attending hospital for the routine consultations. Thus, the prevalence was low in our study in comparison to other studies reported from the same region. This data offers valuable insights into M. genitalium epidemiology in Western Cameroon.

Additionally, we explored associated risk factors by identifying factors contributing to M. genitalium infection. In this study, we explore the association of various sexual behavioural risk factors, for their association with M. genitalium infection. Although not significant, the majority of women in the M. genitalium positive group (62.9%) were <25 years. The link between young age and STI may be attributed to inconsistent condom use in younger women and/or a higher prevalence of STIs in adolescent males. While a few studies have found no evidence of a link between high-risk sexual behaviour and M. genitalium,^15,16 findings in studies involving women attending STI clinics highlight the influence of study populations.^17,18

In the current study, the mean age of the first sexual intercourse was between 15 and 17 years in 50% of the women. This finding was consistent with other studies, where the mean age for first sexual contact was less than 20 years.^19,20 In the current study, odds of prevalent infection in the group less than 25 years age group was 1.7 times higher than that in the more than 25 years age group. Similar observations were made by Hancock et al., where women less than 20 years were nearly twice as likely to have M. genitalium infection compared to older women.²¹ The younger age group may be more likely to have sexual partners who have STIs, which increases their risk of infection.^22,23

Bivariate analysis revealed that having more than one sexual partner was independently associated with three times higher odds of prevalent M. genitalium infection. Andersen et al. observed a similar trend, where women with more than 3 partners in the previous 6 months had significantly higher odds of infection.⁹ However, Sena et al. reported no association between M. genitalium infection and high-risk activity, suggesting potential confounding factors such as age, race and socioeconomic status.²⁴

In our study, non-usage or occasional use of condoms was not associated with prevalent M. genitalium infection respectively. However, Zhang et al, observed that use of a condom during all sexual encounters decreased chances of infection with M. genitalium.²⁵ On the contrary, a few studies reported that the regular condom use was not significantly protective against M. genitalium infection.^9,19 This indicates potential limitations in the efficacy of condoms against M. genitalium compared to other STIs. It is important to note that condom use may not provide complete protection against M. genitalium infection, as the bacteria can be transmitted through non-penetrative sexual contact routes.

Limitations

The present study is subject to several limitations. First, the cross-sectional approach prevents the investigation of temporal relationships between risk behaviours, HIV/STI and M. genitalium. Second, the freezing of M. genitalium specimens for approximately one year until PCR testing, may have reduced the detection rate.

Conclusion

This study holds significance as it was conducted on a large number of women in Western Cameroon, where routine M. genitalium testing is not a standard practice, thereby offering valuable epidemiological data concerning M. genitalium. Consequently, our findings contribute to the limited body of knowledge on M. genitalium epidemiology and may play a role in formulating national clinical standards for testing and screening strategies.

Ethical approval

The research/study was approved by the Institutional Review Board at Institutional Ethics Committees, PGIMER, Chandigarh (Ethics approval no IEC-05/2020-1670) and Institutional Ethics Committees, University of Dschang, Dschang, Cameroon (Ethics approval no. N02018/05/1022/CE/ CNERSH/SP), dated 2020.