Neighborhood Disadvantage is Associated with High Cytomegalovirus Seroprevalence in Pregnancy

Abstract

Background: Cytomegalovirus (CMV) is the most common infectious cause of fetal malformations and childhood hearing loss. CMV is more common among socially disadvantaged groups, and geographically clusters in poor communities. The Area Deprivation Index (ADI) is a neighborhood-level index derived from census data that reflects material disadvantage.

Methods: We performed a geospatial analysis to determine if ADI predicts the local odds of CMV seropositivity. We analyzed a dataset of 3527 women who had been tested for CMV antibodies during pregnancy. We used generalized additive models to analyze the spatial distribution of CMV seropositivity. Adjusted models included individual-level age and race and neighborhood-level ADI.

Results: Our dataset included 1955 CMV seropositive women, 1549 who were seronegative, and 23 with recent CMV infection based on low avidity CMV antibodies. High ADI percentiles, representing greater neighborhood poverty, were significantly associated with the nonwhite race (48 vs. 22, p < 0.001) and CMV seropositivity (39 vs. 28, p < 0.001). Our unadjusted spatial models identified clustering of high CMV odds in poor, urban neighborhoods and clustering of low CMV odds in more affluent suburbs (local odds ratio 0.41 to 1.90). Adjustment for both individual race and neighborhood ADI largely eliminated this spatial variability. ADI remained a significant predictor of local CMV seroprevalence even after adjusting for individual race.

Conclusions: Neighborhood-level poverty as measured by the ADI is a race-independent predictor of local CMV seroprevalence among pregnant women.

Keywords: Cytomegalovirus; Generalized additive model; Geographic information system; Health disparities; Poverty; Pregnancy; Spatial epidemiology.

Figure 1

Generalized additive models showing the geographic heterogeneity of maternal CMV seropositivity. In the unadjusted model maternal CMV is compared only to smoothed effects of longitude and latitude. The local odds ratio in the unadjusted model varied from 0.41 to 1.90 compared with the average odds. The odds of CMV seropositivity were significantly higher than average in the urban neighborhoods of Durham, while they were significantly low in the more affluent suburbs. The adjusted model included both neighborhood level ADI and an interaction term for individual age and race. This adjustment substantially blunted the odds ratio range (0.76 to 1.21) and effaced much of the geographic variability of CMV odds. Thus, the combination of neighborhood ADI and individual age and race statistically explains much of the distribution of CMV seropositivity.