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

May combine two claims.

Filarioid nematode DNA was detected in eight additional Culex pipiens specimens, in both the thorax and abdomen, but the sequences could not be unambiguously assigned to a previously defined species.

“Filarioid nematode DNA was also detected in eight additional Cx. pipiens specimens also in both the thorax and the abdomen, but analysis of sequence data did not allow unambiguous assignment of any of the obtained sequences to a previously defined species.”

May combine two claims.

The seasonal distribution of Culex pipiens showed a strong influence of climate, with a monophasic distribution from May to August, coincident with an average monthly temperature of 26 °C and low relative humidity of 40%.

“The data gained during the two consecutive seasons showed a strong influence of climate on the abundance of Cx. pipiens , with a clear monophasic distribution from May to August, which was coincident with the average monthly temperature (26 °C) and low relative humidity (40%), typically observed for this bioclimatic area.”

May combine two claims.

Culex theileri, Aedes caspius, and Anopheles maculipennis s.l. were collected in this study but were not infected with Dirofilaria spp.

“Cx. theileri , Ae. (Och.) caspius and An. maculipennis s.l have also been collected in this study, albeit not infected with Dirofilaria spp., demanding further studies to ascertain their role in its transmission in this region of Spain.”

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

Cx. pipiens is an endemic species and highly abundant in the surveyed area.

“Being Cx. pipiens an endemic species and highly abundant in the surveyed area”

May combine two claims.

In this study, haplotype H1 was detected in two mosquitoes infected with filarioid nematodes and identified as Cx. pipiens f. pipiens by CQ11.

“In this study, the haplotype H1 was detected in two mosquitoes (infected with filarioid nematodes) identified as Cx. pipiens f. pipiens by CQ11.”

May combine two claims.

The analysis of ITS-2 sequences indicated the presence of haplotype H2 as well as hybrid forms in mosquitoes with filarioid DNA.

“Moreover, the analysis of ITS-2 sequences also indicated the presence of haplotype H2 as well as hybrid forms in mosquitoes with filarioid DNA.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Dirofilaria immitis is present in Spain, with prevalences ranging from 0.8% to 36.7% in dogs along the Iberian Peninsula, and 19%-39% in the Balearic and Canary Islands.

“D. immitis is present in Spain, with prevalences ranging from 0.8% to 36.7% in dogs along the Iberian Peninsula, and 19%-39% in the Balearic and Canaries islands (reviewed by Diosdado et al., 2016).”

• cites Diosdado et al., 2016Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

All PCR products were sequenced on both strands.

“All PCR products were sent to purify and sequence on both strands”

Probably not a substantial claim: may not pass S3 (load-bearing).

In neighbouring Portugal, Culex pipiens revealed a higher Dirofilaria immitis infection rate (0.5%).

“In neighbouring Portugal, Cx. pipiens revealed a higher D. immitis infection rate (0.5%) ( Ferreira et al., 2015)”

• cites Ferreira et al., 2015 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Convergence was monitored with Tracer v1.6, confirming that ESS values of all estimated parameters were above 200.

“Convergence was monitored with Tracer v1.6, confirming that ESS values of all the estimated parameters confirmed to be above 200.”

Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

The hypothesis that Cx. pipiens f. pipiens may play a role as a competent vector requires further confirmation, especially because of the limited number of infected specimens.

“This hypothesis requires further confirmation, specially accounting the limited number of infected specimens.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Positive controls (DNA from molestus and pipiens forms) were included in the PCR assays.

“Positive controls (i.e. DNA from molestus and pipiens forms) were included in the PCR assays.”

Classified as probably not a substantial claim.

After blood meal digestion, larval development to the infective L3 stage in Malpighian tubules and migration to the head-thorax may have occurred in the gravid Cx. pipiens f. pipiens in which D. immitis was detected.

“holds the possibility that after blood meal digestion, larval development to the infective L3 stage in Malpighian tubules and migration to the head-thorax, may have occurred ( Anderson, 2000).”

• cites Anderson, 2000Not checked yet

  Not checked in the free run.

• AssumptionRests on an assumption: Detection of D. immitis DNA in the head-thorax of a gravid Cx. pipiens f. pipiens indicates that larval development and migration to the head-thorax occurred, rather than residual blood-meal DNA.

Probably not a substantial claim: may not pass S3 (load-bearing).

Elsewhere, Cx. pipiens s.l. has been found as a competent vector for D. immitis.

“However, elsewhere, Cx. pipiens s.l. has been found as a competent vector for this parasite ( Capelli et al., 2013).”

• cites Capelli et al., 2013 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

Negative controls (no DNA template) were performed for each extraction procedure.

“Negative controls (no DNA template) were performed for each extraction procedure.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Humans are only accidental hosts for Dirofilaria immitis as the parasite cannot develop to the adult stage.

“Humans are only accidental hosts as the parasite cannot develop to the adult stage (dead-end host)”

• cites Pampiglione and Rivasi, 2001Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Other mosquito species have been found infected with Dirofilaria throughout Europe, with infection rates ranging from 0.17% to 1.13% for Culex theileri.

“Other mosquito species, have been found infected throughout Europe, such as Cx. theileri in the Canary islands ( Morchón et al., 2011), Madeira island (Santa-Ana et al., 2006), and mainland Portugal (Ferreira et al., 2015), with infection rates that range from 0.17% to 1.13%.”

• cites Morchón et al., 2011Not checked yet

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• cites Santa-Ana et al., 2006 sourceNot checked yet

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• cites Ferreira et al., 2015 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The incrimination of vectors of Dirofilaria in Spain has so far led to the detection of Dirofilaria immitis DNA in the abdomen of two Culex pipiens (haplotype H1) in Salamanca and in Culex theileri in the Canary Islands, and no mature infections have been found.

“The incrimination of vectors of Dirofilaria in Spain has led so far to the detection of D. immitis DNA in the abdomen of two Culex pipiens (haplotype H1) in Salamanca (western Spain) and in Cx. theileri in the Canary Islands, and no mature infections have been found, as no DNA was detected in the head-thorax of the analysed specimens ( Morchón et al., 2007 and Morchón et al., 2011).”

• cites Morchón et al., 2007 sourceNot checked yet

  Not checked in the free run.

• cites Morchón et al., 2011Not checked yet

  Not checked in the free run.

May combine two claims.

The pipiens form of Culex pipiens is anautogenous, eurygamous, and preferably ornithophilic, while the molestus form is autogenous, stenogamous, and preferably mamophilic.

“The socalled pipiens form is characterized as being anautogenous, eurygamous, and preferably ornithophilic, while the molestus form is autogenous, stenogamous and preferably mamophilic.”

• cites Gomes et al., 2015 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

Editing of the COI alignments was done using GUIDANCE, selecting columns with confidence levels above 0.9.

“Editing of the COI alignments was done using GUIDANCE, selecting columns with confidence levels above 0.9.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Canine dirofilariosis is a major veterinary health problem in tropical, subtropical and temperate regions of the world.

“Canine dirofilariosis is a major veterinary health problem in tropical, subtropical and temperate regions of the world (Simón et al., 2012)”

• cites Simón et al., 2012 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

In neighbouring Portugal, canine dirofilariosis is endemic with an overall national seroprevalence of 2.1%-15.1%.

“In neighbouring Portugal, canine dirofilariosis is endemic with an overall national seroprevalence of 2.1%- 15.1% ( Alho et al., 2014 and Vieira et al., 2015).”

• cites Alho et al., 2014 sourceNot checked yet

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• cites Vieira et al., 2015 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

In cats, seroprevalence values of 11.4% and 18.1% were detected in Barcelona and the Canary Islands, respectively.

“In cats, seroprevalence values of 11.4% and 18.1% were detected in Barcelona and the Canary Islands, respectively ( Montoya-Alonso et al., 2014 and Montoya-Alonso et al., 2015).”

• cites Montoya-Alonso et al., 2014 sourceNot checked yet

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• cites Montoya-Alonso et al., 2015 sourceNot checked yet

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May combine two claims.

The detection of Dirofilaria immitis in a single Culex pipiens specimen indicates a low prevalence in this species (0.16%), in line with previous reports from mainland Spain, although with a higher infection rate (0.3%).

“The detection of D. immitis in a single Cx. pipiens specimen is indicative of the nematode low prevalence in this species (0.16%), in line with previous reports from mainland Spain, although with a higher infection rate (0.3%) ( Morchón et al., 2007).”

• cites Morchón et al., 2007 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

Dirofilariosis is endemic in the Mediterranean region, affecting southern European countries including Portugal, Spain, France and Italy.

“Dirofilariosis is endemic in the Mediterranean region, affecting southern European countries including Portugal, Spain, France and Italy (Genchi et al., 2005 and Morchón et al., 2012).”

• cites Genchi et al., 2005 sourceNot checked yet

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• cites Morchón et al., 2012 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

At least 70 species of mosquitoes are considered potential vectors of Dirofilaria.

“with at least 70 species of mosquitoes being considered as potential vectors (Cancrini et al., 2006).”

• cites Cancrini et al., 2006 sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Detection of filarioid DNA in mosquitoes revealed nematode infections between June and August, coinciding with temperatures favourable for Culex pipiens abundance and parasite development.

“Detection of filarioid DNA in these mosquitoes revealed nematode-infections between June and August, coinciding with the time of average temperatures that are favourable for Cx. pipiens higher abundances and parasite development in the vector”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Diverse Filarioidea nematodes may be widely distributed in Europe, in a large range of hosts.

“reports such as these do suggest that diverse Filarioidea nematodes may be widely distributed in Europe, in a large range of hosts.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Boothe et al. (2015) reported detection of filarioid nematodes in 3.8% of blood-fed Cx. pipiens.

“while Boothe et al. (2015) reported detection of filarioid nematodes in 3.8% of blood-fed Cx. pipiens.”

• cites Boothe et al. (2015) sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Haplotype H1 may be genetically ascribed to Cx. pipiens f. pipiens, while haplotype H2 is an intermediate form or hybrid.

“These studies suggested that haplotype H1 may be genetically ascribed to Cx. pipiens f. pipiens while haplotype H2 as an intermediate form or hybrid.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Previous studies have reported detection of unknown species of filarioid nematodes in mosquitoes collected in Hungary and Germany.

“Previous studies have already reported the detection of unknown species of filarioid nematodes in mosquitoes collected in Hungary (Kemenesi et al., 2015), Germany (Czajka et al., 2012)”

• cites Kemenesi et al., 2015 sourceNot checked yet

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• cites Czajka et al., 2012 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Cx. quinquefasciatus is a competent vector for transmission of D. immitis, as shown by experimental infections.

“both Lai et al. (2000) and Carvalho et al. (2008) have provided compelling evidence for the vector competence of Cx. quinquefasciatus , a member of the same complex, for the transmission of D. immitis by means of experimental infections.”

• cites Lai et al. (2000) sourceNot checked yet

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• cites Carvalho et al. (2008) sourceNot checked yet

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Classified as probably not a substantial claim. May combine two claims.

Analysis of nuclear rDNA ITS-2 sequences allows validation of the classification and haplotype characterization of mosquitoes.

“According to Bargues et al. (2006) and Morchón et al. (2007), the analysis of nuclear rDNA ITS-2 sequences allows validation of the classification and haplotype characterization of mosquitoes.”

• cites Bargues et al. (2006) sourceNot checked yet

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• cites Morchón et al. (2007) sourceNot checked yet

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Probably not a substantial claim: may not pass S2 (checkable).

The possible role of Cx. pipiens as vector could have a clear impact on human and veterinary health that must be taken into consideration to establish control measures for dirofilariosis.

“its possible role as vector could have a clear impact on human and veterinary health that must be taken into consideration to establish control measures for dirofilariosis.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Cardiofilaria pavlovskyi has been previously reported in birds in Spain.

“Curiously, this species has also been previously reported in birds in Spain by López-Caballero (1982).”

• cites López-Caballero (1982)Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Genetic analysis of mosquito populations solely based on ITS-2 sequences is not devoid of analytical limitations.

“Despite its usefulness, genetic analysis of mosquito populations solely based on such a strategy is not devoid of analytical limitations, which could be overcome via combination with microsatellite analyses in future studies ( Gomes et al., 2013).”

• cites Gomes et al., 2013 sourceNot checked yet

  Not checked in the free run.