Background: Vietnam and its region are regarded as an ixodid tick biodiversity hotspot for at least two genera: Haemaphysalis and Dermacentor. To contribute to our knowledge on the tick fauna of this country, ticks from these two genera as well as an Ixodes species were analyzed morphologically and their molecular-phylogenetic relationships were examined in taxonomic and geographical contexts. Methods: For this study, seven Haemaphysalis sp. ticks were removed from dogs and collected from the vegetation. These showed morphological differences from congeneric species known to occur in Vietnam. In addition, three Ixodes sp. ticks were collected from pygmy slow lorises (Xanthonycticebus pygmaeus), and a Dermacentor female had been previously collected from the vegetation. After DNA extraction, these were molecularly or phylogenetically analyzed based on the cytochrome c oxidase subunit I (cox1) and 16S rRNA genes. Results: The three species were morphologically identified as (i) Ixodes granulatus, which had nearly or exactly 100% sequence identities to conspecific ticks reported from large (approximately 2000 km) geographical distances but was more different (having lower, only 94.2% cox1 and 96.7% 16S rRNA sequence identity) from samples collected within 1000 km of Vietnam in Southern China and Malaysia, respectively; (ii) Haemaphysalis bispinosa, which showed 100% sequence identity to samples reported within both narrow and broad geographical ranges; and (iii) a new species, Dermacentor pseudotamokensis Hornok sp. nov., described here morphologically and shown to be phylogenetically a sister species to Dermacentor tamokensis. Conclusions: Haemaphysalis bispinosa shows genetic homogeneity in the whole of South and Southeast Asia, probably owing to its frequent association with domestic ruminants and dogs (i.e. frequently transported hosts). However, I. granulatus, the Asian rodent tick, has a mixed geographical pattern of haplotypes, probably because it may associate with either synanthropic or wild-living rodents as primary hosts. This tick species is recorded here, for the first time to our knowledge, as parasitizing lorises in Vietnam and its region. Based on phylogenetic analyses, D. pseudotamokensis Hornok sp. nov., recognized and described here for the first time, was almost certainly misidentified previously as Dermacentor steini, drawing attention to the need to barcode all Dermacentor spp. in Southern Asia.

Two species of Southeast Asian pangolins (the Chinese pangolin, Manis pentadactyla and the Malayan or Sunda pangolin, Manis javanica) are critically endangered species. Therefore, knowledge on their parasitic infections is very important, especially considering ticks that can transmit which pathogens. In this study, 32 pangolin ticks (Amblyomma javanense), that were collected in Vietnam and Laos, were analyzed with molecular methods for the presence of tick-borne pathogens. Two members of the family Anaplasmataceae were shown to be present in 14 pangolin ticks, i.e., Candidatus Anaplasma pangolinii and an Ehrlichia sp. In three ticks, a single Rickettsia genotype was also detected, and in seven ticks four 18S rRNA sequence variants of a Babesia sp. Most importantly, a novel protozoan agent, tentatively called here Trypanosoma sp. “PAT14” was detected in one A. javanense nymph. These results imply the first molecular finding of any species of Anaplasma, Ehrlichia and Babesia in pangolin ticks from Vietnam and Laos. On the other hand, detection of a new tick-associated Trypanosoma sp. in A. javanense from Southeast Asia is not only important from a taxonomic point of view, but it is also the first finding of any trypanosomes in the genus Amblyomma in Eurasia and adds pangolins to the potential placental mammalian hosts of any trypanosomes.

Background: Southeast Asia is regarded as a hotspot for the diversity of ixodid ticks. In this geographical region, Vietnam extends through both temperate and tropical climate zones and therefore has a broad range of tick habitats. However, molecular-phylogenetic studies on ixodid tick species have not been reported from this country. Methods: In this study, 1788 ixodid ticks were collected from cattle, buffalos and a dog at 10 locations in three provinces of northern Vietnam. Tick species were identified morphologically, and representative specimens were molecularly analyzed based on the cytochrome c oxidase subunit I (cox1) and 16S rRNA genes. Fifty-nine tick species that are indigenous in Vietnam were also reviewed in the context of their typical hosts in the region. Results: Most ticks removed from cattle and buffalos were identified as Rhipicephalus microplus, including all developmental stages. Larvae and nymphs were found between January and July but adults until December. Further species identified from cattle were Rhipicephalus linnaei, Rhipicephalus haemaphysaloides, Amblyomma integrum and Haemaphysalis cornigera. Interestingly, the latter three species were represented only by adults, collected in one province: Son La. The dog was infested with nymphs and adults of R. linnaei in July. Phylogenetically, R. microplus from Vietnam belonged to clade A of this species, and R. haemaphysaloides clustered separately from ticks identified under this name in China, Taiwan and Pakistan. Amblyomma integrum from Vietnam belonged to the phylogenetic group of haplotypes of an Amblyomma sp. reported from Myanmar. The separate clustering of H. cornigera from Haemaphysalis shimoga received moderate support. Conclusions: Three tick species (R. linnaei, A. integrum and H. cornigera) are reported here for the first time in Vietnam, thus increasing the number of indigenous tick species to 62. Clade A of R. microplus and at least R. linnaei from the group of Rhipicephalus sanguineus sensu lato occur in the country. There is multiple phylogenetic evidence that different species might exist among the ticks that are reported under the name R. haemaphysaloides in South and East Asia. This is the first report of A. integrum in Southeastern Asia. Graphical Abstract: (Figure presented.)