A series of syphilis cases in Michigan reveal an unusual pattern of severe ocular and neurological symptoms in women, linked to a common intimate partner. This suggests the emergence of new, evolving strains of Treponema pallidum, the syphilis-causing bacteria, with potential implications for diagnosis, treatment, and public health.
Syphilis, a sexually transmitted infection caused by the bacterium Treponema pallidum, has been known to medicine since the late 1400s. Despite advances in diagnosis and treatment, recent cases in Michigan have highlighted an alarming evolution in the disease's presentation and severity, particularly among women experiencing rapid onset of ocular and neurological symptoms.
PC, a 43-year-old woman, presented to the emergency room with a headache, bilateral hearing loss, and diplopia (double vision). Her symptoms began two months prior with a unilateral headache on the left side, initially thought to be shingles, a reactivation of the varicella-zoster virus. She was treated with antiviral medication, which temporarily resolved the headache.
However, one month later, PC developed tinnitus (ringing in the ears), progressing to bilateral ear ringing and bloodshot eyes. Despite normal ear examinations and an MRI showing no abnormalities, her hearing loss worsened, and she experienced balance issues due to vestibular system involvement.
PC also suffered from polyarthralgia (joint pain in multiple joints), visual disturbances including seeing spots, and severe headaches. Blood tests indicated inflammation, and ocular examination confirmed eye inflammation. Given the combination of symptoms—headache, polyarthralgia, asymmetric sensorineural hearing loss with vestibular hypofunction, and ocular inflammation—doctors considered various diagnoses.
The rapid progression of symptoms over weeks suggested an inflammatory or infectious cause rather than vascular or cancerous origins. Autoimmune diseases such as lupus and ankylosing spondylitis were considered but ruled out due to lack of typical signs.
Lyme disease, caused by Borrelia burgdorferi from tick bites common in Michigan, was tested but not confirmed. Ultimately, testing revealed PC had syphilis with neurological involvement (neurosyphilis), confirmed by analysis of cerebrospinal fluid.
Following PC's diagnosis, the Michigan Department of Health and Human Services launched an investigation. They identified four additional women presenting with similar severe ocular and neurological symptoms, all linked to a single common intimate partner—a man who had multiple female partners and exhibited ulcerative lesions indicative of syphilis but was initially misdiagnosed and untreated.
These women experienced symptoms such as blurred vision, hearing loss, double vision, facial drooping, and rashes. The common link to one man and the severity of symptoms in women were unusual, as ocular syphilis typically occurs more frequently in men, especially those with HIV co-infection or men who have sex with men.
Syphilis cases in the United States have been rising since 2000. Ocular syphilis, inflammation of the eye caused by the infection, was underreported until the CDC issued a clinical advisory in 2016 to improve recognition and reporting.
Studies in Seattle and San Francisco in 2015 documented ocular syphilis cases primarily in men, often with HIV co-infection. These cases sometimes resulted in permanent vision loss.
Genomic sequencing of Treponema pallidum strains from patients in Seattle revealed multiple distinct strains, with some unusual variants associated with ocular symptoms. In 2023, a case of a 32-year-old man in Seattle showed infection with two distinct strains simultaneously, with genetic recombination creating a new strain. This man suffered severe symptoms including blindness and multiple ulcers.
This intrahost evolution and genetic recombination suggest that Treponema pallidum is changing in ways not previously observed, potentially leading to more severe disease presentations.
PC received intravenous penicillin for two weeks, the recommended treatment for neurosyphilis, which can penetrate the brain and nerves. Early syphilis without neurological involvement is typically treated with a single intramuscular dose.
The other women and the common partner also received treatment and presumably recovered to some extent.
Several important points arise from these cases:
This raises critical questions:
Historically, resistance to azithromycin, an alternative antibiotic, has been documented since the early 2000s, underscoring the need for vigilance.
The Michigan cluster of syphilis cases with severe ocular and neurological symptoms linked to a common partner highlights the evolving nature of Treponema pallidum. Continued surveillance, research, and public health efforts are essential to understand these changes, improve diagnosis, and ensure effective treatment.
If you suspect you may have syphilis or have been exposed, seek medical attention promptly to prevent complications and transmission.
Syphilis remains a significant public health challenge, but with awareness and appropriate care, outcomes can be improved.
Take care of your health and stay informed.
