The study describes an association between lead exposure and strep throat.
Children were included if they were 14 or younger, treated between 2010 and 2020, and had at least one blood lead test on file. A test counted only if it came before any strep or croup diagnosis, and children with multiple tests were counted by their highest reading.
Children were sorted into three groups by blood lead level, measured in micrograms per deciliter: under 1, 1 to 3.4, and 3.5 or higher. Roughly 28% of the children landed at or above it, according to the study.
Boys and girls were also analyzed separately, with similar results.
Children in the highest lead group had 2.74 times the odds compared with the lowest group. Odds weigh how many children in a group had strep against how many did not.
The rate ratios were 2.39 for the middle group and 2.65 for the top group, according to the paper.
The authors said a testing gap may explain the finding because children in the system were screened for lead at ages 1 and 2, and croup tends to strike very young children before testing. The lack of a link does not prove lead has no effect on croup, the researchers said.
Among Hispanic children, those in the m...