Co-infection of tick-borne bacterial pathogens in ticks in Inner Mongolia, China

Author summaryTicks carry and transmit a variety of pathogens, and their host animals are widely distributed in nature with diverse epidemic links, so that several tick-borne diseases can coexist in the same foci, and even one type of tick or one tick can carry a variety of pathogens at the same time, these factors pose a serious public health threat. In our study, we summarized the regional differences in tick infection and co-infection rates outcomes in all Inner Mongolia of China, and found that pathogen diversity varied with ecogeographic differences such as gobi desert, grassland and forest. A variety of tick-borne bacterial pathogens were identified, with an overall high prevalence rate (61.4% of ticks infected), among infected ticks, 24.3% were co-infected. An unexpected high infection and co-infection rates of ticks collected from the Forest region of eastern Inner Mongolia (sample area 1) was detected. Geographical differences affect tick species and tick-borne pathogens, so the potential threat to humans or animals is also different. In particular, that that knowledge of co-infections is important as they do not just present diagnostic challenges, but the pathogens might play different roles within their respective hosts, thus modulating disease severity. Tick-borne infectious diseases pose a serious health threat in certain regions of the world. Emerging infectious diseases caused by novel tick-borne pathogens have been reported that are causing particular concern. Several tick-borne diseases often coexist in the same foci, and a single vector tick can transmit two or more pathogens at the same time, which greatly increases the probability of co-infection in host animals and humans and can lead to an epidemic of tick-borne disease. The lack of epidemiological data and information on the specific clinical symptoms related to co-infection with tick-borne pathogens means that it is not currently possible to accurately and rapidly distinguish between a single pathogen infection and co-infection with multiple pathogens, which can have serious consequences. Inner Mongolia in the north of China is endemic for tick-borne infectious diseases, especially in the eastern forest region. Previous studies have found that more than 10% of co-infections were in host-seeking ticks. However, the lack of data on the specific types of co-infection with pathogens makes clinical treatment difficult. In our study, we present data on the co-infection types and the differences in co-infection among different ecological regions through genetic analysis of tick samples collected throughout Inner Mongolia. Our findings may aid clinicians in the diagnosis of concomitant tick-borne infectious diseases.