Crimean-Congo Hemorrhagic Fever Virus in Humans and Livestock, Pakistan, 2015–2017

C rimean-Congo hemorrhagic fever (CCHF) is caused by CCHF virus (CCHFV), an emerging zoonotic virus belonging to the order Bunyavirales within the family Nairoviridae.The virus is maintained through a tick-vertebrate transmission cycle (1); the primary vectors are ticks from the genus Hyalomma (2,3).Wild and domestic mammals, including livestock species such as sheep, goats, and cattle, are amplifying hosts (2).CCHFV is listed as a high-priority zoonotic pathogen of humans in the World Health Organization Research and Development Blueprint (https://www.who.int/blueprint/priority-diseases) because of its potential to cause a public health emergency and the absence of specific treatment and vaccines.Most human infections occur through the bite of infected ticks.Blood and other bodily fluids of infected animals represent an additional source for human infections.In humans, CCHF is manifested by fever, headache, vomiting, diarrhea, and muscular pain; bleeding diathesis with multiorgan dysfunction is seen in severe cases (4-6).CCHFV is endemic over a wide geographic area, spanning from western Asia to southern Europe and over most of Africa (2).Since the earliest identified CCHF case in 1976 (7), several outbreaks of CCHFV infection have been reported from Pakistan.Although Pakistan has the fourth highest number of human cases in Asia (2), no comprehensive surveillance study has been conducted to determine the disease prevalence in human and animal populations of Pakistan.Therefore, we determined the countrywide risk for CCHFV infection by detecting the virus and antibodies in livestock, ticks, and humans. The StudyDuring 2017-2018, we tested 3,710 serum samples from 1,872 humans and 1,838 domestic animals (311 buffaloes, 480 camels, 183 cattle, 440 goats, and 424 sheep) for antibodies against CCHFV (Appendix, https://wwwnc.cdc.gov/EID/article/26/4/19-1154-App1.pdf).We also screened 98 blood plasma samples (24 from goats, 28 from buffalo, and 46 from cows) and 774 ticks (509 Hyalomma spp., 134 Rhipicephalus spp., 77 Haemaphysalis spp., and 54 Rhipicephalus [Boophilus] spp.), sampled from livestock in Punjab Province, for CCHFV antigen by commercial ELISA (VectoCrimea-CHF-antigen ELISA; Vector-Best, https://vector-best.ru).