Prevalence and epidemiologic correlates of Mycoplasma genitalium and absence of macrolide resistance in M. genitalium among pregnant women attending antenatal care in Zambia

Daniel Schröder¹Sumire Sorano²Elena Shipitsyna¹Enesia Banda Chaponda³Daniel Golparian¹Ephraim Chikwanda⁴Vivian Mwewa⁵Joyce M Mulenga⁴Mike Chaponda⁴Chris Smith²Matsui Mitsuaki⁶Massimo Mirandola⁷Karel Blondeel⁸Igor Toskin⁸R Matthew Chico²Magnus Unemo^1*

• ¹WHO Collaborating Centre for Gonorrhoea and other STIs, Department of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
• ²Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
• ³Department of Biological Sciences, School of Natural Sciences, University of Zambia, Lusaka, Zambia
• ⁴Tropical Diseases Research Centre (TDRC), Ndola, Zambia
• ⁵St. Paul’s Mission Hospital, Nchelenge, Zambia
• ⁶School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Nagasaki, Japan
• ⁷Department of Diagnostics and Public Health, University of Verona, Verona, Veneto, Italy
• ⁸Department of Sexual and Reproductive Health and Research, World Health Organization, Geneva, Switzerland

Mycoplasma genitalium (MG) is a sexually transmitted bacterium of public health importance, associated with genitourinary disorders, and adverse reproductive and perinatal outcomes. Global data on MG prevalence and antimicrobial resistance (AMR) are primarily available from high-income countries, whereas there is a dearth of information from resource-constrained settings including sub-Saharan Africa. Furthermore, international data on MG rates and AMR in the antenatal population are scarce. This study investigated the prevalence and epidemiologic correlates of MG and the presence of macrolide resistance-associated mutations (MRAMs) among pregnant women attending antenatal care facilities in Zambia. A cross-sectional study was conducted at four antenatal care facilities in Nchelenge, Zambia, among 1021 pregnant women. Vaginal swabs were collected and tested using the Aptima Mycoplasma genitalium assay, Aptima Combo 2 assay and Aptima Trichomonas vaginalis assay on the Panther System (Hologic). MG-positive samples were further analyzed for MRAMs using the ResistancePlus™ MG assay (SpeeDx). The prevalence of MG was 12.6% (127 of 1005 valid samples) among the pregnant women. Only 12 MG-positive women (9.4%) had symptoms of a genitourinary infection, which was similar to the frequency of genitourinary symptoms among MG-negative women (6.1%). The rates of Chlamydia trachomatis, Neisseria gonorrhoeae, T. vaginalis, and HIV seropositivity were 7.4%, 8.3%, 23.0%, and 8.6%, respectively. The ResistancePlus™ MG assay detected MG in 66.1% (84/127) of samples positive by the Aptima M. genitalium assay, however, no MRAMs were detected in the 23S rRNA gene for any of these 84 samples. This study emphasizes the high prevalence of MG among pregnant women in Zambia, but also lack of MRAMs in MG. These findings suggest that azithromycin remains an efficacious treatment option for MG in this population. Nevertheless, continuous surveillance and judicious macrolide use to maintain treatment efficacy are imperative. Further research and sustained monitoring of MG are essential to inform public health strategies and clinical guidelines in Zambia and similar settings worldwide.