Congenital syphilis in Russia: the value of counting epidemiologic cases and clinical cases

BACKGROUND: Congenital syphilis (CS) reports in Russia increased 26-fold from 1991 to 1999. Case reports included only infants who were clinical cases, had persistent serologic changes, or confirmed syphilitic stillbirth. Although not reported, policies stipulate that infants of inadequately treated or untreated mothers receive preventive penicillin treatment. GOAL: We examined whether risk factors and consequences for epidemiologic cases of CS (infants of inadequately treated mothers) resembled those of clinical cases and differed from those of noncases (infants of adequately treated mothers). STUDY DESIGN: A retrospective record review from Maternity Houses in 5 sites identified 715 syphilis-infected women who gave birth. RESULTS: Among women with maternal syphilis, 11% (n = 81) of infants were clinical cases, 56% (n = 402) were epidemiologic cases, and 33% (n = 232) were noncases of CS. Compared with noncases, maternal risk factors for epidemiologic cases included nonresidence (P <0.01), late syphilis (P <0.01), unemployment (P <0.01), no prenatal care (P <0.01), and syphilis testing at >/=28 weeks (P <0.01). Each of these was also significant for being a clinical case. Associated consequences of CS for the epidemiologic cases included increases in stillbirth (P <0.01), preterm birth (P <0.01), low birth weight (P <0.01), transfer to a pediatric hospital (P <0.01), and abandonment (P <0.05). Each of these except stillbirth was significantly elevated among clinical cases. Nearly half of the epidemiologic cases had no record of any penicillin treatment for the infant. Epidemiologic cases were significantly more likely than noncases to have no clinical or laboratory follow up. CONCLUSION: In Russia, maternal risk factors and perinatal consequences for epidemiologic cases of CS resembled those of clinical cases. Expanding national reporting to include epidemiologic cases would strengthen CS prevention and monitoring.