Human Ocular Dirofilariasis in Hong Kong

Kwok, R. W. M.; Chow, Prudence Po Chee; Lam, Jasmine Kee Ming; Fok, Andrew Chung-tin; Jhanji, Vishal; Wong, Vivian K.; Young, Alvin L.

doi:10.1097/opx.0000000000000770

Cited by 12 publications

(8 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…repens is limited to the old world with endemic areas in Southern and Eastern Europe, many parts of Asia and presumably Africa, although there is only sparse information for the latter continent [ 4 ]. A new Dirofilaria species, Candidatus Dirofilaria hongkongensis has been proposed as a causative agent of subcutaneous or subconjunctival dirofilariosis in humans in Hong Kong and was also detected in dogs [ 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

The Mitochondrial Genomes of the Zoonotic Canine Filarial Parasites Dirofilaria (Nochtiella) repens and Candidatus Dirofilaria (Nochtiella) Honkongensis Provide Evidence for Presence of Cryptic Species

et al. 2016

View full text Add to dashboard Cite

BackgroundCutaneous dirofilariosis is a canine mosquito-borne zoonosis that can cause larva migrans disease in humans. Dirofilaria repens is considered an emerging pathogen occurring with high prevalence in Mediterranean areas and many parts of tropical Asia. In Hong Kong, a second species, Candidatus Dirofilaria hongkongensis, has been reported. The present study aimed to compare mitochondrial genomes from these parasites and to obtain population genetic information.Methods and FindingsComplete mitochondrial genomes were obtained by PCR and Sanger sequencing or ILLUMINA sequencing for four worms. Cytochrome oxidase subunit 1 sequences identified three as D. repens (all from Europe) and one as C. D. hongkongensis (from India). Mitochondrial genomes have the same organization as in other spirurid nematodes but a higher preference for thymine in the coding strand. Phylogenetic analysis was in contradiction to current taxonomy of the Onchocercidae but in agreement with a recent multi-locus phylogenetic analysis using both mitochondrial and nuclear markers. D. repens and C. D. hongkongensis sequences clustered together and were the common sister group to Dirofilaria immitis. Analysis of a 2.5 kb mitochondrial genome fragment from macrofilaria or canine blood samples from Europe (42), Thailand (2), India (1) and Vietnam (1) revealed only small genetic differences in the D. repens samples including all European and the Vietnam sample. The Indian C. D. hongkongensis and the two Thai samples formed separate clusters and differences were comparatively large.ConclusionGenetic differences between Dirofilaria spp. causing cutaneous disease can be considerable whereas D. repens itself was genetically quite homogenous. C. D. hongkongensis was identified for the first time from the Indian subcontinent. The full mitochondrial genome sequence strengthens the hypothesis that it represents an independent species and the Thai samples might represent another cryptic species, Candidatus Dirofilaria sp. ‘Thailand II’, or a quite divergent population of C. D. hongkongensis.

show abstract

Section: Introductionmentioning

confidence: 99%

The Mitochondrial Genomes of the Zoonotic Canine Filarial Parasites Dirofilaria (Nochtiella) repens and Candidatus Dirofilaria (Nochtiella) Honkongensis Provide Evidence for Presence of Cryptic Species

et al. 2016

View full text Add to dashboard Cite

show abstract

“…A new species of Dirofilaria infecting dogs and humans has been first described from Hong Kong and designated as Dirofilaria sp. “hongkongensis” [262, 265]. This new species was proposed on the basis of relative short DNA sequences from the mitochondrial cytochrome c oxidase 1 and the nuclear ITS1 locus.…”

Section: Mitochondrial Genotypes and Potential Cryptic Speciesmentioning

confidence: 99%

Recent advances on Dirofilaria repens in dogs and humans in Europe

et al. 2018

View full text Add to dashboard Cite

Dirofilaria repens is a nematode affecting domestic and wild canids, transmitted by several species of mosquitoes. It usually causes a non-pathogenic subcutaneous infection in dogs and is the principal agent of human dirofilariosis in the Old World. In the last decades, D. repens has increased in prevalence in areas where it has already been reported and its distribution range has expanded into new areas of Europe, representing a paradigmatic example of an emergent pathogen. Despite its emergence and zoonotic impact, D. repens has received less attention by scientists compared to Dirofilaria immitis. In this review we report the recent advances of D. repens infection in dogs and humans, and transmission by vectors, and discuss possible factors that influence the spread and increase of this zoonotic parasite in Europe. There is evidence that D. repens has spread faster than D. immitis from the endemic areas of southern Europe to northern Europe. Climate change affecting mosquito vectors and the facilitation of pet travel seem to have contributed to this expansion; however, in the authors’ opinion, the major factor is likely the rate of undiagnosed dogs continuing to perpetuate the life-cycle of D. repens. Many infected dogs remain undetected due to the subclinical nature of the disease, the lack of rapid and reliable diagnostic tools and the poor knowledge and still low awareness of D. repens in non-endemic areas. Improved diagnostic tools are warranted to bring D. repens diagnosis to the state of D. immitis diagnosis, as well as improved screening of imported dogs and promotion of preventative measures among veterinarians and dog owners. For vector-borne diseases involving pets, veterinarians play a significant role in prevention and should be more aware of their responsibility in reducing the impact of the zoonotic agents. In addition, they should enhance multisectorial collaboration with medical entomologists and the public health experts, under the concept and the actions of One Health-One Medicine.Electronic supplementary materialThe online version of this article (10.1186/s13071-018-3205-x) contains supplementary material, which is available to authorized users.

show abstract

“…In Asia (Figure 3(b)), Sri Lanka, with 135 cases [78, 79], and India, with at least 100 subcutaneous/ocular cases and 3 pulmonary cases [80], are the countries with the highest level of incidence for human subcutaneous/ocular dirofilariasis. In other countries very few cases have been reported [43, 81–83]. Pulmonary dirofilariasis caused by D. immitis predominates in Japan, with 280 registered cases [5, 84–86] by only 3 subcutaneous cases [87].…”

Section: Epidemiologymentioning

confidence: 99%

The Complexity of Zoonotic Filariasis Episystem and Its Consequences: A Multidisciplinary View

Simón

González‐Miguel

Diosdado

et al. 2017

BioMed Research International

View full text Add to dashboard Cite

Vector-borne transmitted helminthic zoonosis affects the health and economy of both developing and developed countries. The concept of episystem includes the set of biological, environmental, and epidemiological elements of these diseases in defined geographic and temporal scales. Dirofilariasis caused by different species of the genus Dirofilaria is a disease affecting domestic and wild canines and felines and man, transmitted by different species of culicid mosquitoes. This complexity is increased because Dirofilaria species harbor intracellular symbiont Wolbachia bacteriae, which play a key role in the embryogenesis and development of dirofilariae and in the inflammatory pathology of the disease. In addition, the vector transmission makes the dirofilariasis susceptible to the influence of the climate and its variations. The present review addresses the analysis of dirofilariasis from the point of view of the episystem, analyzing the complex network of interactions established between biological components, climate, and factors related to human activity, as well as the different problems they pose. The progress of knowledge on human and animal dirofilariasis is largely due to the multidisciplinary approach. Nevertheless, different aspects of the disease need to continue being investigated and cooperation between countries and specialists involved should be intensified.

show abstract

Human Ocular Dirofilariasis in Hong Kong

Abstract: Ophthalmic dirofilariasis is a rare condition. Clinicians should be aware of this disease entity so that prompt diagnosis and treatment could be offered to the patients.

Cited by 12 publications

References 11 publications

The Mitochondrial Genomes of the Zoonotic Canine Filarial Parasites Dirofilaria (Nochtiella) repens and Candidatus Dirofilaria (Nochtiella) Honkongensis Provide Evidence for Presence of Cryptic Species

The Mitochondrial Genomes of the Zoonotic Canine Filarial Parasites Dirofilaria (Nochtiella) repens and Candidatus Dirofilaria (Nochtiella) Honkongensis Provide Evidence for Presence of Cryptic Species

Recent advances on Dirofilaria repens in dogs and humans in Europe

The Complexity of Zoonotic Filariasis Episystem and Its Consequences: A Multidisciplinary View

Contact Info

Product

Resources

About