Global Seroprevalence of bluetongue virus in camels: a first systematic review and meta-analysis
摘要
Bluetongue (BT), caused by the bluetongue virus (BTV), is a non-contagious, vector-borne disease that primarily affects domestic and wild ruminants worldwide. Although recent evidence indicates BTV infection in camels, the epidemiological role of camels in the transmission and spread of the disease remains poorly understood. While some meta-analyses have evaluated the seroprevalence of BTV in traditional hosts, a comprehensive global meta-analysis specifically focusing on camels is lacking. This systematic review and meta-analysis aimed to estimate the global seroprevalence of BTV in camels and identify associated risk factors. Following a systematic approach, we reviewed 16 published articles (spanning 1979 to 2021) that reported BTV seroprevalence in camel populations worldwide. The overall pooled seroprevalence of BTV in camels was 37.2% (3,074/8,272, 95% CI: 36.13–38.19). The highest seroprevalence was observed in African regions (46.5%, 95% CI: 44.87–48.16), followed by Western and South Asia (39.4%, 95% CI: 37.72–41.21), with the lowest in Europe (14.3%, 95% CI: 12.73–16.02). Univariate meta-regression and chi-square tests indicated significant heterogeneity across studies (R² = 13.74%, I² = 99.75%, p < 0.0001). Temporal analysis showed a marked increase in seroprevalence over time: 14% (95% CI: 11.63–16.77) before 2005, 36.9% (95% CI: 35.74–38.07) during 2006–2015, and 55.2% (95% CI: 52.06–58.23) in or after 2016. These findings reveal substantial regional and temporal variations in BTV seroprevalence among camels, challenging traditional host paradigms. Our analysis underscores the importance of including camelid populations in national and international BTV surveillance and control strategies, particularly in endemic regions where camels co-exist with other susceptible livestock species.
Graphical Abstract