Global Climate Change and Human Dirofilariasis in Russia

Human Dirofilariasis Infection in the Forehead: A Case Report

Human dirofilariasis is currently considered a zoonotic infection, a mosquito-borne disease caused by the filarial nematodes of dogs, mainly Dirofilaria repens and D. immitis. Human dirofilariasis has been reported from many parts of the world, including Africa, Australia, the Americas, Europe, and Asia. The climate of Bandar Abbas in Hormozgan province, Sothern of Iran, has favorable conditions for the growth and reproduction of different types of vector mosquitoes. A 20 yr old woman from Bandar Abbas, visited a surgeon where the presence of a nodule was diagnosed in the forehead. In histopathological examination, cross-sections of a worm surrounded by necrotic tissues were observed. By evaluating the sections, Dirofilaria sp. was the probable diagnosis. To our knowledge, in Iran, this is the first human dirofilariasis occurring in the forehead. Human cases of dirofilariasis need to be reported so that physicians could consider dirofilariasis in their differential diagnoses.

An updated list of mosquito species in Armenia and Transcaucasian region responsible for Dirofilaria transmission: A review

Canine dirofilariasis is a world-wide distributed mosquito-borne helminthiasis that has a potential zoonotic impact. This disease is a serious problem in Southern Caucasus region, including Armenia. Average extensity of Dirofilaria infection in canids in Armenia is 26.9%. At present, 77 mosquito species (Diptera: Culicidae) are presumed to have a role in the transmission of dirofilariasis. 80 species of Culicidae family mosquitoes are registered in Southern Caucasus Region, and 31 of them are described in Armenia. The following species of Culicidae can serve as vectors of Dirofilaria spp. in Armenia: Aedes vexans, Ae. caspius, Ae. albopictus, Ae. geniculatus, Culex pipiens, Cx. theileri, Cx. modestus, Anopheles maculipennis s.s., An. claviger, An. hyrcanus, An. superpictus, Coquillettidia richardi, Culiseta annulata and Uranotaenia unguiculta. We see a risk of transmission in active foci of dirofilariasis, as well as for human infection in Armenia. Comprehensive research should be conducted on detection of microfilariae in the target mosquito species and in target localities.

Diversity and geographic distribution of haplotypes of Dirofilaria immitis across European endemic countries

BACKGROUND

Dirofilaria immitis, also known as heartworm, is one of the most important parasitic nematodes of domestic dogs, causing a potentially serious disease, cardiopulmonary dirofilariosis, which can be lethal. This species seems to be less 'expansive' than its sister species Dirofilaria repens, and it is believed that climate change facilitates the spread of this parasite to new non-endemic regions.

METHODS

In total, 122 heartworm isolates were analysed from nine endemic countries in Europe (Portugal, Spain, Italy, Greece, Hungary, Romania, Slovakia, and Ukraine) and a single isolate from Bangladesh by amplification and sequencing of two mitochondrial (mt) DNA markers: cytochrome c oxidase subunit 1 (COI) and dehydrogenase subunit 1 (NADH). The main aim of the current study was to determine the genetic diversity of D. immitis and compare it with D. repens haplotype diversity and distribution. DNA was extracted from adult heartworms or microfilariae in blood. Most isolates originated from dogs (Canis lupus familiaris) while 10 isolates originated from wildlife species from Romania, including eight isolates from golden jackals (Canis aureus), one isolate from a Eurasian otter (Lutra lutra) and one isolate from a red fox (Vulpes vulpes).

RESULTS

Median spanning network analysis was based on the combined sequence (1721 bp) obtained from two mt markers and successfully delineated nine haplotypes (Di1-Di9). Haplotype Di1 was the dominant haplotype encompassing 91 out of the 122 sequences (75%) from all nine countries and four host species. Haplotype Di2 was the second most common haplotype, formed solely by 13 isolates from Italy. The remaining sequences were assigned to Di3-Di9 haplotypes, differing by 1-4 SNPs from the dominant Di1 haplotype. There was evidence for geographical segregation of haplotypes, with three unique haplotypes associated with Italy and four others associated with certain countries (Di4 and Di7 with Slovakia; Di8 with Greece; Di6 with Hungary).

CONCLUSION

Diversity in D. immitis mt haplotypes was lower by half than in D. repens (9 vs. 18 haplotypes in D. immitis and D. repens, respectively), which may be associated with the slower expansion of heartworm in Central and NE Europe. NADH gene appears to be conserved in Dirofilaria sp. by showing lower genetic diversity than the analysed COI gene.