SAN DIEGO – Cases of ocular syphilis are on the upswing in 2015, and many physicians are not up to speed regarding this serious complication, experts asserted at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
“I know that at my institution there’s been a lack of education about ocular syphilis. The housestaff are unaware that you can have ocular syphilis with a normal lumbar puncture,” said Dr. Kimberly A. Workowski, professor of medicine at Emory University in Atlanta and lead author of the Centers for Disease Control and Prevention 2015 STD guidelines (MMWR Recomm Rep. 2015;64[RR-03]:1-137).
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When she asked for a show of hands by physicians in the audience who had seen a case of ocular syphilis in the past 6 months, a lot of arms shot up.
“We’ve had a large increase in ocular syphilis at our institution, too,” Dr. Workowski noted.
Dr. Juliet Stoltey of the University of California, San Francisco, said that since the initial January 2015 report of an outbreak of ocular syphilis in the Seattle area, cases have been reported from around the country, prompting the CDC to issue a clinical advisory in April.
It remains unclear whether the increase in ocular syphilis cases is the result of a true outbreak of a more oculo/neurotrophic strain of Treponema pallidum or simply the result of greater awareness of the complication in the setting of a steep rise in syphilis overall, according to Dr. Stoltey.
Circulation of a more neurotrophic strain is biologically plausible based on animal studies. Data from the University of Washington, Seattle, point to strain type 14d/f as a potential culprit.
California surveillance data show a more than 140% increase in syphilis cases overall during 2006-2014. And while it appears that the proportion of cases with ocular or other forms of neurologic syphilis has increased to an even greater extent than the overall rise in syphilis, the significance of this observation is uncertain given that the surveillance system lacks a standard mechanism for reporting ocular syphilis.
Regardless, Dr. Stoltey continued, here’s what physicians really need to know about ocular syphilis: Syphilis can affect virtually all parts of the eye, neurosyphilis can occur at any stage of the infection, and delayed identification of ocular syphilis has been associated with visual loss.
A syphilis serology test should be ordered in patients who have visual complaints along with risk factors for syphilis, such as men who have sex with men, as well as in those who have ophthalmologic findings compatible with syphilis. Both a treponemal and nontreponemal test should be ordered since the false-negative prozone effect has been documented in patients with ocular syphilis.
Clinical characteristics of ocular syphilis include eye redness, eye pain, visual field deficits or a decline in visual acuity, and headache accompanying eye symptoms. Ophthalmologic findings can include uveitis, iritis, vitrial detachment, optic neuritis, and marked vision loss.
Any patient with visual complaints plus a positive syphilis serology should undergo ophthalmologic evaluation immediately, Dr. Stoltey emphasized. A lumbar puncture and CSF analysis is recommended for syphilis patients with eye or neurologic symptoms such as cranial nerve dysfunction, auditory disease, meningitis, loss of vibration sensation, stroke, or altered mental status.
“I see signs of potential neurosyphilis being missed all the time,” Dr. Workowski said. “And here is a really important point: Treat for neurosyphilis if a patient with syphilis has the signs or symptoms of neurologic, audiologic, or ophthalmologic involvement regardless of what the CSF shows.”
The guideline-recommended treatment for ocular or neurosyphilis is aqueous crystalline penicillin G, 18-24 million units daily, administered as 3-4 million units IV every 4 hours for 10-14 days.
Dr. Stoltey urged physicians to store frozen pre–antibiotic therapy clinical samples from their patients with ocular syphilis and to contact the CDC, which, together with investigators at the University of Washington, Seattle, is conducting a study aimed at determining whether an oculotrophic strain of T. pallidum is circulating.
Dr. Stoltey and Dr. Workowski reported having no financial conflicts of interest.