In an alarming trend, doctors in Chicago have reported an increase in patients experiencing unusual symptoms caused by the sexually transmitted infection syphilis. Typically, syphilis is known to cause vision and hearing damage and psychiatric changes in cases that have gone undiagnosed and untreated for years. However, a new study presented at the 2024 Epidemic Intelligence Service Conference reveals that there were more than two dozen cases in Chicago last year where patients exhibited these symptoms, and surprisingly, nearly one-third of them were in the early stages of the infection.

The study, conducted by disease detective Dr. Amy Nham, found that over two-thirds of the patients (68%) did not exhibit the typical syphilis symptoms, such as a rash or chancre sore, which could have alerted doctors to the infection. These patients complained of various symptoms including vision and eye problems, headaches, hearing loss, and dizziness.

The rise in syphilis cases is a concerning nationwide trend, with over 207,000 cases reported in 2022, the highest number since the 1950s, according to the US Centers for Disease Control and Prevention (CDC). While men who have sex with men traditionally bear the highest burden of syphilis, infections have more than doubled in heterosexual men and women since 2019, indicating a shift in the demographics of the infection. Additionally, cases of congenital syphilis transmitted from pregnant women to their babies are also on the rise.

Dr. Nham's study focused specifically on cases with unusual symptoms, known as NOO syphilis (neurosyphilis, ocular syphilis, and otic syphilis), after reports from providers across the city suggested an increase in such cases. The study analyzed medical records from Chicago and identified 28 cases that met the criteria, with 75% of the patients being men and 71% being Black. Notably, half of the patients identified as heterosexual, challenging the traditional assumption that syphilis predominantly affects gay men. Surprisingly, only one in three patients was HIV positive, lower than expected considering the generally more severe symptoms of syphilis in people living with HIV.

The most common symptoms reported among the patients were headaches, personality changes or altered mental status, and eye problems such as vision loss, sensitivity to light, or eye swelling. Given the nonspecific nature of these symptoms, Dr. Nham emphasizes the importance of appropriate screening by healthcare providers, including thorough questioning about patients' sexual history and risk factors.

Syphilis, caused by the bacteria Treponema pallidum, progresses through stages and its symptoms can mimic those of other diseases, earning it the nickname "the great imitator." The initial stage includes the appearance of painless sores called chancres, followed by rashes or lesions in the mouth during the second stage. If left untreated, syphilis can progress to a potentially fatal third stage, and at any point, the infection can invade the nervous system, leading to brain, eye, and ear involvement.

While Dr. Nham's study focused on Chicago, she acknowledges similar reports from doctors in other parts of the country. The reasons behind the increase in cases with atypical symptoms are not entirely clear, but potential factors include inadequate or untreated patients, possibly due to a shortage of the preferred treatment, a long-acting form of penicillin, called Bicillin L-A. Men can opt for a different antibiotic, doxycycline, but it requires a longer course of treatment and can lead to non-compliance.

The study serves as a reminder to healthcare providers about the importance of screening and awareness of the changing landscape of syphilis infections. Early detection and treatment are crucial in preventing severe outcomes associated with syphilis.