Co-Circulation of Tick-Borne Bandaviruses and Orthonairoviruses Across Humans, Livestock, and Rats in Pakistan: Serologic Evidence and Public Health Implications.

Tick-borne viruses (TBVs) pose significant public health and economic threats. Pakistan has endemic Crimean-Congo hemorrhagic fever virus (CCHFV), but evidence suggests broader TBV circulation. This study assessed the seroprevalence of thirteen TBVs (seven are members of the genus Orthonairovirus and six are members of the genus Bandavirus) in humans, livestock, and rats in Punjab, Pakistan. Serum samples (n = 794: 321 livestock, 253 human, and 220 rat) were collected from the Narowal, Lahore, and Faisalabad districts. Antibodies to viral NPs were detected using the luciferase immunoprecipitation system (LIPS). The overall seroprevalence was 19.14% (152/794); it was highest in livestock (27.10%), then humans (20.55%), and then rats (5.91%). The highest seroprevalence rates were 3.12% for CCHFV in livestock, 3.56% for Yezo virus (YEZV) in humans, and 0.91% for Tamdy virus (TAMV) and Tacheng tick virus 1 (TcTV-1) in rats. Neutralizing antibodies were detected against CCHFV (1 cattle, 4 humans), Bhanja virus (BHAV) (3 livestock, 1 rat), TAMV (1 cattle), Guertu virus (GTV) (1 cattle), and Dabie bandavirus (2 cattle). Sixteen samples showed antibodies to both orthonairoviruses and bandaviruses, indicating co-exposure. Further analysis showed that seropositivity was not randomly distributed. Livestock kept in commercial farming systems and people working mainly outdoors had distinctly higher exposure to TBVs than subsistence livestock and indoor workers. The results supported the circulation of TBVs among hosts within the close socio-economic/ecological integration area of Pakistan. These findings confirm the circulation of CCHFV, SFTSV, GTV, and TAMV; provide the first serologic evidence of BHAV in Pakistan; and underscore the need for further investigation into the potential circulation of additional TBVs. All results demonstrated that multiple TBVs have been circulating among humans, livestock, and rodents in Pakistan.