A quality assessment of reporting sources for microcephaly in Utah, 2003 to 2013

Abstract

Background Obtaining accurate microcephaly prevalence is important given the recent association between microcephaly and Zika virus. Assessing the quality of data sources can guide surveillance programs as they focus their data collection efforts. The Utah Birth Defect Network (UBDN) has monitored microcephaly by data sources since 2003. The objective of this study was to examine the impact of reporting sources for microcephaly surveillance. Methods All reported cases of microcephaly among Utah mothers from 2003 to 2013 were clinically reviewed and confirmed. The UBDN database was linked to state vital records and hospital discharge data for analysis. Reporting sources were analyzed for positive predictive value and sensitivity. Results Of the 477 reported cases of microcephaly, 251 (52.6%) were confirmed as true cases. The UBDN identified 94 additional cases that were reported to the surveillance system as another birth defect, but were ultimately determined to be true microcephaly cases. The prevalence for microcephaly based on the UBDN medical record abstraction and clinical review was 8.2 per 10,000 live births. Data sources varied in the number and accuracy of reporting, but a case was more likely to be a true case if identified from multiple sources than from a single source. Conclusion While some reporting sources are more likely to identify possible and true microcephaly cases, maintaining a multiple source methodology allows for more complete case ascertainment. Surveillance programs should conduct periodic assessments of data sources to ensure their systems are capturing all possible birth defects cases.

Population‐based microcephaly surveillance in the United States, 2009 to 2013: An analysis of potential sources of variation

“…In this issue of the journal, investigators with the Utah Birth Defect Network (UBDN) evaluated their ascertainment of microcephaly (Steele et al, ). Their results demonstrated the variability of ascertainment depending on the source and method of case finding.…”

Congenital microcephaly hospitalizations in California infants: 1999–2013

“…Overall, 37% of microcephaly cases in this registry had a genetic anomaly and 31% were in premature infants (Graham, ). Steele et al (), reviewing data from the Utah Birth Defect Network between 2003 and 2013, reported a microcephaly prevalence rate of 8.2/10,000 live births. The case definition for microcephaly in this cohort was a head circumference < 10th percentile at birth, ≤5th percentile at 1 year of age or ≤2nd percentile at 18 months of age, or a microcephaly diagnostic code of 742.1 (Steele et al, ).…”

“…Steele et al (), reviewing data from the Utah Birth Defect Network between 2003 and 2013, reported a microcephaly prevalence rate of 8.2/10,000 live births. The case definition for microcephaly in this cohort was a head circumference < 10th percentile at birth, ≤5th percentile at 1 year of age or ≤2nd percentile at 18 months of age, or a microcephaly diagnostic code of 742.1 (Steele et al, ). Overall, the reported rates of microcephaly in the above US birth defect registries and population‐based surveillance programs varied significantly.…”

Zika Virus-Induced Microcephaly and Its Possible Molecular Mechanism

“…This is significantly smaller than normal for the person's age and sex [43,44]. In humans, microcephaly represents a severe congenital defect [45]. Two types of microcephaly are recognized.…”

“…The other relates to a normal brain size at birth but failure to grow subsequently due to the loss of dendritic connections [46]. Some authors have classified 3 types of microcephaly on the basis of Giacomino's classification: (i) microcephalia vera, where the size of the brain remains small without any sign of injury or deformation, (ii) microcephalia spuria, which shows some pathological changes and injury to the brain, and (iii) microcephalia combinata, which reflects a small brain size with a trace of injury [45]. The etiology of microcephaly can be both genetic and non-genetic.…”