Background: Congenital syphilis is a serious infection transmitted from an infected mother to the fetus during pregnancy, potentially leading to adverse outcomes such as miscarriage, stillbirth, preterm birth, or neonatal death. The global COVID-19 pandemic and associated lockdown measures have posed significant challenges not only to individuals but also to national socio-economic systems, adversely affecting the quality and accessibility of healthcare services. Aim: This study aimed to compare the incidence of congenital syphilis in Mongolia during the pre-COVID-19 period (2016–2020) and the post-COVID-19 period (2021–2025). Materials and Methods: A cross-sectional study design was employed. Data from all 361 registered cases of congenital syphilis between 2016 and 2025 were included in the analysis. Results: The incidence of congenital syphilis per 100,000 live births decreased from 65.8 in 2016–2020 to 34.5 in 2021–2025, representing a 47.6% reduction (RR=0.52, 95% CI: 0.42–0.66, p<0.001). Overall, 67% of cases were concentrated in Ulaanbaatar. The proportion of cases among mothers aged 15–19 years increased from 11.5% to 21.3%, and the majority of mothers had completed secondary education. Conclusion Although the incidence of congenital syphilis declined significantly following the COVID-19 pandemic, 13.0% of pregnant women receiving antenatal care did not undergo serological testing. This underscores the need to strengthen surveillance and reporting systems and to implement continuous education and awareness programs, particularly targeting young women and mothers.

Background: Mycoplasma and Ureaplasma species are considered part of the normal genitourinary microbiota; however, when present in excessive amounts, they may become pathogenic and cause symptoms such as dysuria, vaginal discharge, and lower abdominal pain. Due to the lack of specific clinical manifestations, these infections may remain undiagnosed or be misidentified as other inflammatory conditions. Disseminated infection caused by Mycoplasma and Ureaplasma is rare. Case Presentation: A 27-year-old female presented with progressive pelvic pain and was initially discharged without a definitive diagnosis. The disease subsequently worsened, and laboratory as well as imaging studies revealed a complicated pelvic infection with concurrent pregnancy. Despite surgical intervention and intensive treatment, the patient died due to severe pelvic purulent inflammation, sepsis, septic shock, and multiple organ failure. Multiplex PCR testing was positive for Mycoplasma genitalium (+), Mycoplasma hominis (+), Ureaplasma parvum (+), and Ureaplasma urealyticum (+). The final clinical diagnosis was consistent with the pathological findings. Conclusion Pelvic disease caused by Mycoplasma and Ureaplasma often presents with nonspecific symptoms, making differential diagnosis challenging. In this case, concurrent pregnancy and the use of analgesic medication may have obscured the disease progression. Comprehensive clinical assessment, close observation, appropriate diagnostic testing, and contact tracing with epidemiological investigation are essential in suspected sexually transmitted infections.