Incidence of Syphilis 3-Fold Greater in Patients with ESRD

Amidst the general rise in sexually transmitted infections (STIs) in the United States, clinicians treating seemingly unrelated conditions may need to turn their attention to possible coinfections. A new study suggests screening for syphilis in certain high-risk patients with end-stage renal disease (ESRD) after discovering the incidence of syphilis is >3-fold higher in this population when compared with the general population.

In what appears to be the first study of its kind comparing the 2 variables, syphilis infection rates for patients with ESRD have been found to exceed those of the general population. The article in Clinical Kidney Journal identified neurosyphilis as the second most common diagnosis, prompting investigators to recommend particular attention to syphilis screening for patients on dialysis who develop confusion.

Investigators from Augusta University used the United States Renal Data System to identify 383 diagnoses of syphilis after screening 759,066 patients with ESRD, with the greatest incidence observed among those on the East and West Coasts. Those diagnosed were also more likely to be young and black with non-Hispanic ethnicity, pointing to regional and demographic areas of concern which might help guide the decision to screen.

Generalized linear modeling was used to examine the relative risk for the disease among patients with ESRD, with controls for demographics and other risk factors. Incidence of syphilis per 100,000 patients with ESRD in 2011 was 53.84 compared with 14.9 for the general population. The common occurrence of neurosyphilis was also unusual relative to the general population.

Study authors noted that it is “important to appreciate the prevalence of syphilis in this group, because if detected, the disease is easily treatable.” Although neurosyphilis is treatable, when left untreated it can cause lasting damage to the central nervous system. Identification of neurosyphilis in this population is complicated by the fact that confusion is sometimes a side effect of the dialysis treatments that patients with ESRD undergo, as dialysis can lead to electrolyte imbalances and is simply not as effective as healthy kidneys at processing toxins.

It is also noteworthy that patients with ESRD have a higher incidence of associated factors for syphilis, given HIV, herpes, and hepatitis can cause kidney damage. Study investigators pointed out that their results demonstrate that patients with ESRD who are coinfected with sexually transmitted viruses may be at high risk for contracting syphilis. The relative risk for syphilis was significantly higher in patients who had viral infections that are often sexually transmitted such as HIV, herpes, and hepatitis C and B.

STIs are not just on the rise among patients with risk factors. In 2018, the number of STIs in the United States rose for the fifth consecutive year. Syphilis cases, in particular, increased 13.3%.

Although the exact frequency of screening will have to be worked out in future research, the Clinical Kidney Journal study results indicate a definite need to pay close attention to syphilis risk in patients with ESRD.