Circulation of Dirofilaria repens and Dirofilaria immitis in Moldova. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Șuleșco, Tatiana; von Thien, Heidrun; Toderaș, Lidia; Toderaș, Ion; Lühken, Renke; Tannich, Egbert
• Is Part Of: Parasites & vectors. Volume 9:Issue 1(2016)
• Page Start: 1
• Page End: 10
• Publication Date: 2016-12
• Subjects: Dirofilaria repens -- Dirofilaria immitis -- Vectors -- Dirofilaria development units; Parasitism -- Periodicals; Parasites -- Periodicals; Vector-pathogen relationships -- Periodicals; Animals as carriers of disease -- Periodicals; Insects as carriers of disease -- Periodicals; 616.96
• DOI: 10.1186/s13071-016-1916-4
• Languages: English
• ISSNs: 1756-3305

Abstract

Abstract Background Over the last two decades, a significant spread of dirofilariasis has been observed in eastern and central Europe. However, data on the circulation ofDirofilaria spp. in Moldova were absent although direct neighbor states reported high incidence rates of human dirofilariasis. Methods Daily mean temperature data were used to calculateDirofilaria spp. development units, which were used to estimate the potential for complete extrinsic development in the mosquitoes (= sum of potentialDirofilaria spp. transmission days). In addition, 4, 481 adult female mosquitoes were collected from 25 trapping sites. From 2010 to 2015, sampling was conducted with Centers for Disease Control miniature light traps, indoor resting mosquito collections as well as human landing catches in urban, rural and natural areas. Mosquitoes were analyzed for the presence ofD. repens andD. immitis DNA using a duplex real-time PCR assay targeting nucleotide differences within the cytochromec oxidase subunit 1 (D. repens ) and 16S rRNA gene fragment (D. immitis ). Results The average of the yearly sum of potentialDirofilaria spp. transmission days between 2010 and 2015 ranged from 90 to 140 days with an increasing gradient from the North to the South of Moldova. Positive mosquito pools forD. repens were found countrywide at 13 of the 25 trapping sites and in 17 of the 22 screened mosquito taxa (26.51% of all 347 tested pools), whileD. immitis was detected only at 4 of the trapping sites (Center and South) in 4 different mosquito species (8.65% of all 347 tested pools). Highest infection rates (EIR) per 100 specimens for bothDirofilaria species were found inAn. maculipennis (s.l .) (D. repens : EIR = 4.91;D. immitis : EIR = 2.01), whereas the most frequent mosquito taxonCx. pipiens (s.l .)/torrentium had significantly lower infections rates (D. repens : EIR = 0.88;D. immitis : EIR = 0.47). Conclusions The temperature conditions in Moldova are suitable for transmission ofDirofilaria spp. within the entire country, which is supported by a wide distribution ofDirofilaria spp.-positive mosquitoes with high infection rates. The low number of reported human cases most likely does not reflect the current epidemiological situation of dirofilariasis in Moldova.