Table 2.

The key functions of viral infections and their relationship to thyroid diseases.

Virus infection	Direct cell entry	Cytokine modulation	Thyroid autoantibody	Thyroid dysfunction	AITD	TC	References
Epstein–Barr virus (EBV)	√	×	√	√	√	√	Nagata et al. (2015), Mertowska et al. (2024), Almeida et al. (2020), Karaarslan et al. (2024), Lu et al. (2024)
α-human herpesvirus (αHHV)	√	√	√	√	√	×	Smith et al. (2000), Sanfilippo et al. (2004), Thomas et al. (2008), Jensen et al. (2010)
HHV-6A	√	√	×	√	√	√	Caselli et al. (2012), Jasirwan et al. (2014), Eliassen et al. (2018), Mardente et al. (2023)
Human papillomavirus (HPV)	√	×	×	√	√	×	Archin Dialameh et al. (2021), Stamatiou et al. (2015), Hviid et al. (2018)
Hepatitis C virus (HCV)	×	√	√	√	√	×	Antonelli et al. (2004), Antonelli et al. (2007), Jadali (2013), Ferrari et al. (2019)
Human immunodeficiency virus (HIV)	×	×	×	√	×	×	Gangannavar et al. (2020), Dutta and Kalita (2023), Mohamed et al. (2025)
Human parvovirus B19 (B19V)	√	√	√	√	√	×	Wang et al. (2010), Weider et al. (2022), Chandramoorthy et al. (2024), Tzang et al. (2025)
SARS-CoV-2	√	√	×	√	√	×	Brancatella et al. (2020, 2023), Soldevila et al. (2022), Clarke et al. (2022), Lui et al. (2024)