Patients infected with avian influenza A H7N9 virus have abnormally low thyroid hormone levels.

Abstract

In March 2013, the novel avian influenza A H7N9 virus spread throughout China. This study evaluated whether thyroid function was altered in patients infected with H7N9 virus. We analyzed thyroid-stimulating hormone (TSH), total triiodothyronine (TT3), total tetraiodothyronine (TT4), free triiodothyronine (FT3), and free tetraiodothyronine (FT4) levels in 17 patients infected with H7N9 on admission to our hospital and compared the values to the reference ranges for these thyroid hormones. Of the 17 patients, 12 (70.6%) patients had abnormally low TT3 levels, 10 (58.8%) patients had abnormally low FT3 and TSH levels, and 5 (29.4%) patients had abnormally low TT4 and FT4 levels (below the lower limit of the reference ranges for each hormone). Abnormally low thyroid hormone levels was common in patients infected with H7N9.