Litomosoides lemuris

Klein, Annette, Strube, Christina, Radespiel, Ute, Springer, Andrea & Zimmermann, Elke, 2019, Differences in infection patterns of vector-borne blood-stage parasites of sympatric Malagasy primate species (Microcebus murinus, M. ravelobensis), International Journal for Parasitology: Parasites and Wildlife 10, pp. 59-70 : 67

4.3. Considerations regarding potential vectors of Lemurfilaria lemuris

All filarial nematodes require a competent vector as intermediate host in which microfilariae can develop into mammalian-infective L 3 larvae to complete their life cycle. Known arthropod vectors are for example blood sucking flying insects of the order Diptera (e.g. Culicidae for Dirofilaria spp. , Wucheria spp. and Brugia spp. , or Simuliidae and Ceratopogonidae for Onchocerca spp. ), wingless insects (e.g. fleas and lice for for Acanthocheilonema spp. ) or Acari (e.g. mites for Litomosoides spp. ) ( Williams, 1948; Paily et al., 2009; Otranto et al., 2013). A previous investigation on ectoparasitic infestation of the mouse lemur populations sampled in this study revealed a significantly higher risk of infection with ticks for M. murinus compared to M. ravelobensis . The fact that M. murinus showed a higher prevalence for microfilaria in this study may therefore suggest that ticks could be potential vectors for L. lemuris . However, ticks are not common vectors for filarial nematodes and have so far only been identified as competent vectors for Acanthocheilonema ( Olmeda-García et al., 1993) and potential vectors for Cercopithifilaria spp. ( Otranto et al., 2012). Hokan et al., (2017) furthermore did not observe tick infestation in a sympatric larger lemur species, Avahi occidentalis , which showed a microfilaria prevalence of 66.7%. Comparing our results of the COI analyses to the comprehensive phylogenetic study of Lefoulon et al. (2015), L. lemuris would be affiliated with clade ONC5, a group of Onchocercidae comprised of several genera. While competent vectors for the human filariae included in this clade have been identified, the transmission routes for several animal associated species remain unknown. The current knowledge on vector range for different Onchocercidae genera would suggest a flying insect vector for the newly described L. lemuris , but empirical data will need to verify this hypothesis.