STORCH Infections Among Very Low Birth Weight and Preterm Infants: 2018-2020.

Abstract

Syphilis, toxoplasmosis, other infections (varicella zoster virus, parvovirus B19), rubella, cytomegalovirus, and herpes simplex virus (STORCH) infections may result in neonatal disease and neurologic sequalae.1 Population-based prevalence rates of STORCH infections among very low birth weight (VLBW) and/or preterm infants in the United States are lacking.Vermont Oxford Network (VON) is a voluntary worldwide community of practice. VON members submitted standardized data on live-born infants 401 to 1500 g or 22 to 29 completed weeks’ gestational age who were inborn or transferred to the reporting hospital within 28 days of birth from January 1, 2018, to December 31, 2020.2 Infant data were collected during the initial birth hospitalization. Transferred infants were tracked to determine their ultimate disposition and length of stay. The Institutional Review Board at The University of Vermont determined that use of the VON database for this study was not human subjects research.A STORCH infection was defined as acquired in utero or during birth from a list that included toxoplasmosis, rubella, syphilis, cytomegalovirus (CMV), herpes simplex, parvovirus B19, Zika, and varicella zoster. Maternal race and ethnicity were determined by personal interview with the mother or review of the birth certificate or medical record, in that order of preference.2 Congenital anomalies included an anomaly on a specific list or, if not on the list, an anomaly that was the primary cause of death or required surgical or medical therapy before discharge.2 Small for gestational age (SGA) was defined as birth weight <10th percentile, and microcephaly was defined as a head circumference less than the third percentile for gestational age and sex.3 Isolated microcephaly was defined as microcephaly without SGA. Statistical analyses were performed by using SAS 9.4 (SAS Institute, Inc, Cary, NC).Data were reported by 777 hospitals in the United States. Overall, 944 of 128 141, or 7.37 per 1000 VLBW and/or preterm infants were diagnosed with STORCH infections. CMV (3.37 per 1000), syphilis (2.01 per 1000), and herpes simplex (1.82 per 1000) were the infections reported most frequently (Table 1). Eleven infants had >1 infection.Infants with CMV had the lowest birth weights and were nearly twice as likely to be SGA or microcephalic as infants without infections, although infants with CMV were least likely to have isolated microcephaly (Table 2). Survivors with CMV also had the longest lengths of stay. Only 70.5% of mothers of infants diagnosed with syphilis received any prenatal care, compared with 96.1% of mothers of infants without infections.Infants with STORCH infections had similar rates of survival (86.3%) as infants without STORCH infections (87.4%).Prevalence of STORCH infections was 7.37 per 1000 among VLBW and/or preterm infants. In a population of VLBW and/or preterm infants in California from 2005 to 2016, prevalence of CMV infection was 2.7 per 1000,4 lower than that in the current study.In this cohort, a large proportion of infants with CMV were SGA or microcephalic. In a study using health care data from 2000 to 2015 in the United States, congenital CMV diagnosis was associated with a sevenfold increased birth prevalence of microcephaly.5 A report from a single center found the yield of routinely testing infants who were SGA for STORCH infections was extremely low.6 A survey of neonatologists found that the most frequent reasons for pursuing STORCH testing were pathologic findings of physical and ophthalmologic examinations, such as microcephaly.7In 2019, the VON VLBW database included >90% of US live births, making this study nearly population-based and the largest report of STORCH infections among VLBW and/or preterm infants. VON does not have population-based data on moderate preterm, late preterm, or term populations. We do not know whether NICUs performed universal screening for STORCH infections or routine testing based on clinical criteria, such as SGA or microcephaly, so we have underestimated the true prevalence. We do not know what tests were used to diagnose STORCH infections. Understanding testing practices may be important to assess differences in ascertainment and to develop strategies to increase identification of STORCH infections. STORCH infection tests may not be covered by health insurance; therefore, identifying high-risk populations in which testing is cost-effective is an important public health issue. These data may be useful to monitor trends and identify health disparities in STORCH infections among infants in the United States.We thank our colleagues who submit data to VON on behalf of infants and their families. The centers contributing data to this study are listed in Supplemental Table 3.