A Cluster of Ocular Syphilis Cases with a Common Sex Partner — Southwest Michigan, 2022

Investigation and Results

In Michigan, all reactive syphilis laboratory test results are routinely reported to the Michigan Disease Surveillance System (MDSS). Syphilis case investigation and contact tracing are centralized to the Michigan Department of Health & Human Services (MDHHS), whereas treatment and care are coordinated by local public health departments and health care facilities. On April 21, 2022, a local public health physician at Kalamazoo County Health and Community Services Department (KCHCSD) alerted MDHHS that two cases of ocular syphilis had been identified during the previous 5 weeks in two hospitalized women (patient A and patient B) who were from the same geographic area (Figure). An epidemiologic link was established between patients A and B when a common male sex partner was identified. MDHHS and KCHCSD, which includes a sexual health clinic with comprehensive testing, treatment, and counseling services, coordinated response and investigation of the patients in the cluster. Molecular typing to investigate the genetic strain of syphilis was not possible because of a lack of genetic material in the limited available specimens. This activity was reviewed by CDC, deemed not research, and was conducted consistent with applicable federal law and CDC policy.*

Clinical and Epidemiologic Characteristics of Cluster Patients

Among all five women eventually identified in the cluster, prophylactic treatment was offered to every sex partner for whom contact information was available. Each of the five women in the cluster lived in a different southwest Michigan county and were aged 40–60 years (mean = 49.0 years) and identified as White race. All were hospitalized and received intravenous penicillin treatment (Table 1). All were HIV-negative, and none reported drug use or transactional sex. Reported routes of sexual exposure among the five women included anal (40%), oral (40%), and vaginal (100%).

Patient A was referred to KCHCSD in March 2022 by an ophthalmologist for a reactive treponemal antibody test result. Patient A noted blurred vision, fear of blindness, and no improvement in genital lesions with valacylocvir, which the patient had been taking for presumed recurrent herpes simplex virus infection. She received a diagnosis of primary and ocular syphilis, and care was coordinated with hospital A for treatment. An interview identified a recent male sex partner whom patient A had met online. Patient A stated she had no other sex partners during the previous 12 months.

Patient B was identified by KCHCSD’s communicable disease surveillance team in April 2022, having been admitted to hospital A for neurosyphilis. Before admission, she reported headache, mild hearing loss, and worsening blurry vision and double vision for 4 weeks; she had been treated in ambulatory care settings with amoxicillin, oral and intranasal steroids, and antiinflammatory medications, and was referred to an emergency department by an ophthalmologist who noted cranial nerve abnormalities. Patient B named the same recent sex partner named by patient A; patient B also met this partner online. A second named partner of patient B was contacted and received a negative syphilis test result.

Patient C received a reactive syphilis test result and was reported by a clinician to a local health department in southwest Michigan in May 2022. Patient C had a full body rash and peeling skin on the palms of her hands; she reported spots drifting through her field of vision (floaters) and photophobia. The patient was prescribed oral steroids, evaluated by an ophthalmologist, underwent a magnetic resonance imaging study of the brain, and was treated with 1 dose of intramuscular penicillin. MDHHS disease intervention specialists^† and a local public health physician coordinated inpatient evaluation at hospital A, where the patient was found to have cranial nerve abnormalities. Patient C named the same male sex partner named by patients A and B; patient C also met this partner online. After follow-up by disease intervention specialists, patient C named three additional sex partners, and reported that each of these partners told her that they had received a negative syphilis test result.

Patient D received a diagnosis of ocular syphilis from an ophthalmologist in June 2022, after referral to hospital B for worsening vision. During the preceding months, patient D had experienced genital sores and a rash on her hands and abdomen, for which steroids were prescribed. Patient D named the same male sex partner named by patients A, B, and C as a sexual contact during January 2022. Two other sex partners of patient D received negative syphilis test results.

Patient E sought evaluation at hospital B’s ophthalmology clinic in May 2022 for visual floaters, seeing flashing lights, and worsening vision after cataract surgery 3 months earlier. She received a reactive treponemal test result, but a nontreponemal test was not performed. Since only a fraction of reactive treponemal test results identify active infections that can be transmitted to others, MDHHS protocols defer certain investigations until additional results are reported. In July, patient E was admitted to hospital B with neurosyphilis and ocular syphilis. A reactive cerebrospinal fluid venereal disease research laboratory result triggered an MDHHS investigation. During February–April 2022, patient E had sexual contact with the same male partner reported by patients A, B, C, and D. Two other partners of patient E were unnamed; therefore, they could not be contacted.

Common Male Sex Partner

The common male sex partner of patients A–E was contacted by telephone and text message on multiple occasions by MDHHS disease intervention specialists during March–May 2022. He provided limited information, stated that he had traveled out of Michigan, and did not attend a scheduled appointment for evaluation in April. In May 2022, after patient C named the same male partner as patients A and B, a local public health physician reviewed the common partner’s electronic medical records and discovered that he had sought care at hospital A’s emergency department in January 2022 with ulcerative penile and anal lesions. At that time, he was treated with acyclovir for presumed herpes simplex virus infection, a nucleic acid amplification test for herpes simplex virus was negative, and no syphilis serology tests were ordered. After a MDHHS disease intervention specialist renewed contact with him, the common partner scheduled and kept an appointment at KCHCSD in May 2022. Upon evaluation, no signs or symptoms of syphilis were found, and he reported no visual or hearing impairment. On sexual history, he reported having multiple female sex partners during the previous 12 months, but he declined to disclose their identities; he reported no male or transgender sexual contact. He received a diagnosis of laboratory-confirmed early latent syphilis and was treated with 1 dose of intramuscular penicillin. In follow-up interviews, both patient A and patient B stated that the male sex partner had a sore on his penis in January 2022.

Additional Ocular Syphilis Patients

Public health officials used MDSS to compare patients in this ocular syphilis cluster to other patients with ocular syphilis occurring during a similar time frame (Table 2). Among 43 ocular syphilis patients who were not part of the cluster, 19% were HIV-positive, 2% reported injection drug use, and 7% reported transactional sex.

A sixth patient, identified in April 2022, was determined to be unrelated to the cluster because no sexual link to the five other ocular syphilis cases or the common sex partner was found. This male patient sought treatment at KCHCSD, and received a diagnosis of secondary syphilis with ocular and otic manifestations, and was admitted to hospital A. A cerebrospinal fluid nontrepenomal antibody test was reactive, and the patient was treated with 14 days of intravenous penicillin. He named two male sex partners, which did not include the same common male sex partner reported by the five female patients.

Public Health Response

In late April 2022, MDHHS and KCHCSD distributed an infographic to Michigan health care providers via local and state public health sexually transmitted infection email distribution lists regarding signs and symptoms of ocular syphilis, otosyphilis, and neurosyphilis. The MDHHS infographic prompted one physician to notify the sixth patient that his symptoms might indicate ocular syphilis; this resulted in the patient’s seeking medical evaluation. In early May 2022, KCHCSD issued a health advisory to area clinicians and to surrounding counties via the Michigan Health Alert Network describing 1) the ocular syphilis cases to date; 2) signs and symptoms of ocular syphilis, otosyphilis, and neurosyphilis; 3) recommendations for obtaining thorough sexual histories, conducting medical evaluations, reporting cases to public health, and consulting with specialists; and 4) recommended treatment options. In early June 2022, KCHCSD, MDHHS, and the New York City STD/HIV Training and Prevention Center presented a training webinar on syphilis diagnosis and treatment, highlighting the southwest Michigan ocular syphilis cluster to county health department nurses, physicians, and sexually transmitted infection staff members from across Michigan.