Congenital syphilis rising in US, tied to preterm birth, hospital stay, costs

Key takeaways:

• Rate of congenital syphilis rose with an annual percentage change of 24.6%.
• Congenital syphilis was tied to preterm birth, longer hospital stay and higher hospital costs.

U.S. congenital syphilis rates rose from 2016 to 2020 and were linked to preterm birth, longer hospital length of stay and higher costs with race/ethnicity, insurance, income, admission year and hospital characteristics tied to likelihood.

“It is critical to further understand the economic and public health effects of neonatal infection to inform public health efforts,” Han-Yang Chen, PhD, associate professor of epidemiology in the department of obstetrics, gynecology and reproductive sciences at McGovern Medical School at the University of Texas Health Science, and colleagues wrote in Obstetrics & Gynecology. “Despite the growing epidemic of congenital syphilis nationwide, contemporary data examining risk factors for congenital syphilis, associated with adverse outcomes and health care utilization and costs are lacking.”

Chen and colleagues conducted a retrospective, cross-sectional study using data from the National Inpatient Sample to identify 18,119,871 newborn hospitalizations in the U.S. from 2016 to 2020. Researchers identified newborns with congenital syphilis and examined adverse outcomes, hospital length of stay and hospital costs.

Rate of congenital syphilis rose from 2016 to 2020 from 27.5 to 60.5 per 100,000 newborn hospitalizations with an annual percentage change of 24.6%.

The following were associated with congenital syphilis:

• newborn of Black vs. Hispanic, white or other race and ethnicity (adjusted RR = 1.17; 95% CI, 0.94-1.45);
• Medicaid vs. private or self-pay insurance (aRR = 7.19; 95% CI, 5.07-10.2);
• household income in the 0 to 25^th vs. 26^th percentile or higher (aRR = 3.04; 95% CI, 2.33-3.96);
• hospital admission in 2019 (aRR = 1.79; 95% CI, 1.44-2.23) or 2020 (aRR = 2.24; 95% CI, 1.79-2.79) vs. earlier years;
• large vs. small or medium hospital bed size (aRR = 1.28; 95% CI, 1.06-1.56); and
• Southern (aRR = 2.26; 95% CI, 1.75-2.93) or Western (aRR = 4.2; 95% CI, 3.22-5.49) vs. Northeast or Midwest hospital location.

Congenital syphilis was associated with preterm birth before 37 (adjusted RR = 2.22; 95% CI, 2.02-2.44) and 34 weeks’ gestation (aRR = 2.39; 95% CI, 2.01-2.84). Researchers observed no association between low birth weight or neonatal in hospital death and congenital syphilis.

Hospital length of stay (adjusted mean ratio = 3.53; 95% CI, 3.38-3.68) and costs (adjusted mean ratio = 4.93; 95% CI, 4.57-5.32) were higher among newborns with vs. without congenital syphilis.

“Without support for targeted public health interventions addressing these challenges, the syphilis epidemic will likely persist within the minoritized and underserved populations,” the researchers wrote. “To catalyze change in national guidance and to mitigate preventable morbidity and mortality from congenial syphilis, future studies examining missed opportunities and sentinel events are essential."