Human and Animal Dirofilariasis: the Emergence of a Zoonotic Mosaic

Abstract

SUMMARY Dirofilariasis represents a zoonotic mosaic, which includes two main filarial species ( Dirofilaria immitis and D. repens ) that have adapted to canine, feline, and human hosts with distinct biological and clinical implications. At the same time, both D. immitis and D. repens are themselves hosts to symbiotic bacteria of the genus Wolbachia , the study of which has resulted in a profound shift in the understanding of filarial biology, the mechanisms of the pathologies that they produce in their hosts, and issues related to dirofilariasis treatment. Moreover, because dirofilariasis is a vector-borne transmitted disease, their distribution and infection rates have undergone significant modifications influenced by global climate change. Despite advances in our knowledge of D. immitis and D. repens and the pathologies that they inflict on different hosts, there are still many unknown aspects of dirofilariasis. This review is focused on human and animal dirofilariasis, including the basic morphology, biology, protein composition, and metabolism of Dirofilaria species; the climate and human behavioral factors that influence distribution dynamics; the disease pathology; the host-parasite relationship; the mechanisms involved in parasite survival; the immune response and pathogenesis; and the clinical management of human and animal infections.

Mosquito vector‐associated microbiota: Metabarcoding bacteria and eukaryotic symbionts across habitat types in Thailand endemic for dengue and other arthropod‐borne diseases

“…Dirofilaria are parasitic roundworms infecting certain mammals by way of mosquito vectors including Ae. aegypti (Simón et al., 2012). 18S rRNA sequences resembling Dirofilaria were also recovered from the same pool, although the sequence was not of sufficient quality to be represented in the final taxon list (data not shown, but Dirofilaria sp.…”

Evaluation of the Adulticidal Efficacy of Imidacloprid 10 %/Moxidectin 2.5 % (w/v) Spot-on (Advocate®, Advantage® Multi) against Dirofilaria repens in Experimentally Infected Dogs

“…The majority of human cases are attributed to Dirofilaria repens, a mosquito transmitted filarial nematode, which causes subcutaneous dirofilariosis in dogs, cats and wild canids (Simón et al 2012). It has been shown not only that infection rates are increasing in well-known endemic areas in southern Europe, but also that the disease is spreading towards northern and eastern areas formerly free of the infection (Genchi et al 2011, Tasić-Otašević et al 2015.…”

Culex pipiens as a potential vector for transmission of Dirofilaria immitis and other unclassified Filarioidea in Southwest Spain

“…pipiens, allowing it to use almost any kind of water collection as breeding site, and having a very broad period of seasonal activity. Changes in seasonal vector densities are likely to impact the rate of infection as previously described by Simón et al (2012) and several models for the transmission periods have been proposed based on DDU (Dirofilaria development units) . In fact, it has been shown that Spain is the European Union country with the longest transmission period for Dirofilaria .…”

“…Filarioid nematode parasites affect millions of people and animals worldwide, and represent a major health hazard with significant economic implications (Laaksonen et al, 2010). Canine dirofilariosis is a major veterinary health problem in tropical, subtropical and temperate regions of the world (Simón et al, 2012), with at least 70 species of mosquitoes being considered as potential vectors . Dirofilariosis is endemic in the Mediterranean region, affecting southern European countries including Portugal, Spain, France and Italy (Genchi et al, 2005 andMorchón et al, 2012).…”

“…transmission is undoubtedly relevant. Although Spain is an endemic country for canine heartworm disease ( Simón et al, 2012), the implementation of appropriate control measures call for a more profound understanding of the epidemiology of this disease, of which the identification of the vector species involved, is of paramount importance to understand the dynamics of filarioid transmission to both animals and humans. Despite the high level of risk for dirofilariosis in the Extremadura region of Spain , there is no information regarding the distribution and prevalence of filarioid nematodes in mosquito vectors.…”