Blood transcriptomes reveal novel parasitic zoonoses circulating in Madagascar's lemurs

Abstract

Zoonotic diseases are a looming threat to global populations, and nearly 75% of emerging infectious diseases can spread among wildlife, domestic animals and humans. A 'One World, One Health' perspective offers us an ideal framework for understanding and potentially mitigating the spread of zoonoses, and the island of Madagascar serves as a natural laboratory for conducting these studies. Rapid habitat degradation and climate change on the island are contributing to more frequent contact among humans, livestock and wildlife, increasing the potential for pathogen spillover events. Given Madagascar's long geographical isolation, coupled with recent and repeated introduction of agricultural and invasive species, it is likely that a number of circulating pathogens remain uncharacterized in lemur populations. Thus, it is imperative that new approaches be implemented for de novo pathogen discovery. To this end, we used nontargeted deep sequencing of blood transcriptomes from two species of critically endangered wild lemurs (Indri indri and Propithecus diadema) to characterize blood-borne pathogens. Our results show several undescribed vector-borne parasites circulating within lemurs, some of which may cause disease in wildlife, livestock and humans. We anticipate that advanced methods for de novo identification of unknown pathogens will have broad utility for characterizing other complex disease transmission systems.

Sleeping site ecology, but not sex, affect ecto- and hemoparasite risk, in sympatric, arboreal primates (Avahi occidentalis and Lepilemur edwardsi)

“…However, some individuals with a low body condition may have deceased quickly or fell victim to predators and may therefore not have been detected. Moreover, ectoparasites may also transmit vector-born diseases such as borreliosis [ 44 ] which may lead to rapid illness and mortality before being detected in differences in body weight. The absence of ectoparasites in the openly sleeping host A. occidentalis and their seasonal presence in the tree hole-sleeping L. edwardsi support the hypothesis that tree-holes may constitute a suitable habitat for ectoparasites.…”

Trypanosoma rangeli is phylogenetically closer to Old World trypanosomes than to Trypanosoma cruzi

“…Madagascar (Larsen et al, 2016) were included in the analysis; b) gGAPDH sequences of xxx new samples (from bats, rats, monkeys, and cimicid and triatomine bugs) aligned with xxx published T. cruzi clade sequences ( Supplementary Table S1); c) concatenated sequences of V7-V8 SSU rRNA and gGAPDH genes from trypanosomes of the T. cruzi clade, using T. lewisi and T. microti as outgroup taxa; d) HSP70 sequences from trypanosomes of the T. cruzi clade in isolation, or combined with V7-V8 SSU rRNA and gGAPDH sequences. All sequences determined in this study were submitted to GenBank (Accession numbers given in Supplementary Table 1).…”

“…trypanosomes from blood samples of lemurs from Madagascar (Larsen et al, 2016) were classified in the Australian clade, which is closely related to the Neobats clade formed by a diversity of trypanosomes so far exclusively from Neotropical bats (Cottontail et al, 2014;Pinto et al, 2015;Lima et al, 2015a) (Fig. 2).…”

“…This clade also comprises several species of trypanosomes of Neotropical bats (clade Neobats that includes Trypanosoma wauwau) that clustered with Trypanosoma noyesi from Australian marsupials, unnamed trypanosomes from Australian rodents (Cottontail et al, 2014;Lima et al, 2015a;Pinto et al, 2015;Botero et al, 2016;Barbosa et al, 2017), and with one trypanosome reported from lemurs in Madagascar (Larsen et al, 2016); all placed basal to the assemblage including T. rangeli and T. cruzi clades. T. livingstonei from African bats is currently positioned at the edge of the T. cruzi clade (Lima et al, 2013(Lima et al, , 2015aDario et al, 2017).…”

Intestinal parasite communities of six sympatric lemur species at Kirindy Forest, Madagascar

“…To our knowledge, this is the first systematic study comparing intestinal parasite communities of more than two sympatric lemur species. Although the number of studies investigating lemur parasitism has recently increased (e.g., Clough, 2010;Rasambainarivo et al, 2013;Larsen et al, 2016), knowledge on the parasitic fauna of these threatened primates still remains comparatively limited. The host species studied here share the same habitat and are thus theoretically exposed to the same set of parasites, but they differ in their degree of phylogenetic relatedness, body mass, Table 1.…”