To prevent such incidents in the future, the paper has implemented additional procedures to screen all strips before publication.

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The larger question is whether women who are told they have dense breasts should get additional imaging to screen for cancer.

WSJ: Dense Breasts Pose a Dilemma in the Search for Breast Cancer

U.S. officials also are asking scientists whether additional measures to screen for flu symptoms were needed at U.S. ports of entry, she said.

CNN: WHO raises pandemic alert to second-highest level