3.1 Significance of the previous research by Traavik and colleagues
The previous prospective research by Traavik and colleagues has made innovative contributions in several areas, especially in Acarology, Ecology and Virology. The knowledge about the coronavirus circulating among the I. uriae and its seabird hosts provide a hint about the possibilities of ticks to harbour and transmit coronavirus. Although, their results cannot be claimed to universally be the case for all different kinds of tick species and coronavirus. It is hard to comprehend why this knowledge should be excluded from the raised questions about the possibilities of any tick species be able to harbour and circulate coronavirus like SARC-CoV-2. Thus, the information is vital since there is ample of evidence about the different kinds of tick species that share ecological niches with potential vertebrate reservoir, such as bats, seabirds and pangolins (Olival et al., 2017; Fagre & Kading, 2019; Málková et al., 1985; Dietrich, Go´mez-Dı´az, & McCoy, 2010; Ramos et al., 2001; Gao et al., 2020; Khatri-Chhetri et al., 2016; Mohapatra, Panda, Nair, & Acharjyo, 2016; Robinson, 1983).
Classification of ticks is well done in pangolins consisting of eight genera and twenty species of ticks described from six species of pangolins namely, Manis pentadactyla, M. javanica, M.crassicaudataM. gigantea, M. tricuspis and M. temminckii . The most intriguing finding is that unassigned ticks that were described from M. tetradactyla by Robinson (1983).Amblyomma , Rhipicephalus and Aponomma genera of ticks have been described from the above mentioned Asian and African pangolin species. Asian pangolins namely, M. pentadactyla, M. javanica and M. crassicaudata have been associated withAmblyomma javanense . While, African pangolins namely, M. temminckii, M. tricuspis and M. gigantean have been associated with Amblyomma  compressum  (Sanyal, De, Rao, & Acharjyo, 1987; Parola et al., 2003; Mohapatra, Panda, Nair, & Acharjyo, 2016). Possible geographic distribution of hard ticks linked with pangolins is provided in figure 2. The geographic distribution was developed from different research work of Hassan, Sulaiman and Lian (2013), Kollars and Sithiprasasna (2000), Parola et al. (2003), Li, Lin, Lan, Pei and Su (2011), Mediannikov et al. (2012) and Njiokou et al. (2006).
Different reviews of the literature undertaken by Nuttall (1984) and Chastel (1980), reported that seabird ticks harbour approximately 60 viruses or variants. Evidence about viraemic transmission to seabirds has been provided by Nunn et al. (2006). Moreover, Dietrich et al. (2010), reported that hard ticks prefer to infest seabird colonies in higher latitudes. The main example is I. uriae , which is the most significant species when focusing on its host species assortment and geographical distribution (Pettersson et al., 2020). Possible geographic distribution of hard ticks linked with seabirds is provided in figure 3. The geographic distribution was developed from the research work of Dietrich et al. (2010).
Several landmark studies observed associate phylogenetically viruses in bats with various arboviruses which can be transmitted by ticks (Fagre & Kading, 2019). Isolation results are providing evidence of bats being responsible for viruses isolated from either soft ticks or hard ticks. For instance, a study of Málková et al. (1985), provides evidence, whereOrnithodoros tadaridae ticks obtained from a palm tree colonized by Cuban bats were found to be infected with Estero real virus. Recently, different kinds of Ixodes species (i.e. Ixodes ariadnae , I. simplex and I. vespertilionis ) andDermacentor reticulatus have been associated with bats (Sándor et al., 2019). Possible geographic distribution of hard ticks linked with bats is provided in figure 4. The geographic distribution was developed from different research work of Zahn and Rupp (2004), Hornok et al. (2014) and Hornok et al. (2016).