Identification of Amblyomma Javanense and Detection of Tick-Borne Ehrlichia Spp. In Confiscated Malayan Pangolins
Abstract BackgroundDue to habitat destruction and illegal hunting and trade, the number of pangolins has been sharply reduced. To prevent their extinction, relevant departments are combined and active action have been taken. A total of 21 confiscated Malayan pangolins were rescued in 2019, but died continuously for unknown reasons. This study aimed to investigate the reasons for the death of these pangolin and rescue them.MethodsRecused Malayan pangolins were checked for clinical symptoms. Ticks on the surface of pangolins were collected and identified using morphological and molecular biological methods. Dead pangolins were autopsied for the gross lesion and tissues were collected for microscopic lesion using HE staining. Viral and protozoa pathogens’ detection were carried on ticks firstly and further confirmed in dead pangolin pathological tissues using PCR.ResultsWhen rescued, pangolins were in bad situation. More than 90% (19/21) of the rescued pangolins had ticks on their body surfaces. A total of 303 ticks were removed and identified as Amblyomma javanense (A. javanense) according to their morphology and the sequences of PCR product of 16S rRNA and internal transcribed spacer 2 (ITS2). Autopsy of the dead pangolins showed multiorgan damage, especially congestion and hemorrhage in lung, heart and kidney. Histopathological analysis revealed marked presence of inflammation in tissues. Pathogens’ nucleic acid detection showed ticks were only positive for Ehrlichia spp, with 56.7% positive rate of collected ticks (127/224), which was further confirmed in tissues from dead pangolins. Sick pangolins reduced clinical symptoms after medical treatment of intramuscular injection with doxycycline and kept alive before transfer.ConclusionsOur findings confirm that ehrlichiosis caused by Ehrlichia spp. from A. javanense might be one of the reasons for the confiscated pangolins’ death. More attention should be payed to tick-elimination work and the diagnoses and treatment of tick-borne diseases in the follow-up rescue operation.