Cited by 36Parasitic Diseases Research and TreatmentHelminth infection and controlResearch on Leishmaniasis Studies

Geographic distribution of canine heartworm (Dirofilaria immitis) infection in stray dogs of eastern Romania

Open access
Ciucă, Lavinia, Musella, Vincenzo, Miron, Liviu D., Maurelli, Maria Paola, Cringoli, Giuseppe, Bosco, Antonio, Rinaldi, Laura·2016·Geospatial Health

Abstract

A survey was conducted in the eastern part of Romania to assess the prevalence and geographical distribution of Dirofilaria immitis in dogs. Plasma samples were collected from 458 stray dogs hosted in shelters in 8 counties and tested serologically for the presence of heartworm. In addition, 45 blood samples from dogs of a shelter in Galati city were examined by the modified Knott and multiplex polymerase chain reaction (PCR) techniques. The immmunological assay showed a heartworm infection prevalence of 8.9% in the dogs. Optical density results for positive samples ranged between 0.217 and 2.683. Geographical information systems (GIS) were used to produce overlays of distribution maps of D. immitis prevalence and predictive maps based on temperature suitability. High prevalence of D. immitis was found in the central East up to the northern border of the country, i.e. Galati county (60%), followed by the counties of Vaslui (12.0%) and Iasi (7.7%). Out of 45 samples examined using the Knott test, 23 were positive for circulating microfilariae (51.1%), while 19 dogs were positive for D. immitis and 4 for both D. immitis and D. repens with the multiplex PCR test. The high prevalence for D. immitis shown in dogs in the Southeast (Galati, 42.2%) also by multiplex PCR gave strong support to the results achieved by the serological tests. The present study confirms the ability of GIS to predict the distribution and epidemiology of dirofilariosis in different geographical territories as has been already demonstrated by the empirical epidemiological data obtained at the continental, national and intraregional levels.

AI snapshot

Written from the paper’s full text.

TL;DR

A 2013–2014 cross-sectional survey of 458 stray dogs in eight eastern Romanian counties found 8.9% *Dirofilaria immitis* seroprevalence by ELISA, with the highest prevalence in Galati county (60%). GIS mapping and temperature-suitability predictions matched the observed distribution, supporting GIS as a tool for heartworm risk assessment.

Key findings

  • ELISA on 458 shelter dogs found an overall *D. immitis* prevalence of 8.9% (41/458); positive optical density values ranged from 0.217 to 2.683. County-level prevalence was highest in Galati (60%, 30/50), followed by Vaslui (12%, 6/50) and Iasi (7.7%, 5/65); no positives were found in Suceava, Botosani, Neamt, Bacau, or Vrancea.
  • Among 45 dogs from a Galati city shelter, the modified Knott test found 23/45 (51.1%) positive for circulating microfilariae; multiplex PCR identified 19 dogs positive for *D. immitis* and 4 positive for both *D. immitis* and *D. repens*, giving a *D. immitis* PCR prevalence of 42.2% (19/45) in that subset.
  • Higher *D. immitis* prevalence was found in dogs over 2 years of age (P<0.05); the paper states no significant differences by sex or coat length (P>0.05), though Table 1 lists female 12.7% vs male 4.7% and short-coat 11.8% vs long-coat 4.1%.
  • GIS overlays and the HDU-based predictive model agreed with the observed distribution; the longest development period was in Bucharest (21 May–20 September).

Methods

  • Cross-sectional survey conducted between 2013 and 2014 using plasma from 458 stray dogs (245 females, 213 males; ages 9 months to 12 years) housed in shelters across 8 eastern Romanian counties; samples were tested for *D. immitis* antigen by commercial ELISA (PetCheck), with sex, age, and coat length recorded as potential risk factors.
  • An additional 45 EDTA blood samples from dogs in a Galati city shelter (28 females, 17 males; ages 2–10 years) were examined by modified Knott test and multiplex PCR targeting the 12S rDNA region.
  • Data were georeferenced at county level and mapped in ArcGIS 10.3, compared with the temperature-suitability HWD predictive model by Genchi et al.; univariate chi-squared tests were performed in SPSS.

Limitations

  • The paper does not include a formal limitations section. It notes that antigen tests may give false negatives in dogs with low parasitic burdens or infections with only male worms, which may explain a previous failure to detect cases in Iasi county.
  • Evident from the text: sampling was cross-sectional and restricted to stray dogs in shelters, molecular confirmation covered only 45 dogs from one Galati shelter, and spatial analysis was conducted at county level, limiting finer-scale inference.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.4081/gh.2016.499

Cites

37 of 37 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 9 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    No D. immitis infections were detected by serology in stray dogs from Botosani, Suceava, Neamt, Bacau, and Vrancea counties.

    “The present study showed negative results in some counties, such as Botosani, Suceava, Neamt, Bacau and Vrancea.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Stray dogs hosted in shelters in the eight sampled counties are representative of the stray dog population in eastern Romania.
    • Rests on an assumption: The commercial ELISA test kit used accurately detects D. immitis infection in dogs.
  • Findingown data

    There was no significant difference in D. immitis seroprevalence between dogs with short and long coats (P>0.05).

    “there were no significant differences between dogs with short or long coat (P>0.05).”
    • Also stated in: § n l y Discussion · plain
      “There were no significant differences between dogs with short or long coat (P>0.05), as also found by Vieira et al. (2014).”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Stray dogs hosted in shelters in the eight sampled counties are representative of the stray dog population in eastern Romania.
    • Rests on an assumption: The commercial ELISA test kit used accurately detects D. immitis infection in dogs.
  • Findingown data

    Multiplex PCR detected both D. immitis and D. repens in 4 of the 45 dogs from Galati city.

    “19 dogs were positive for D. immitis and 4 for both D. immitis and D. repens with the multiplex PCR test.”
    • Also stated in: § Results · plain
      “Nineteen dogs were positive for D. immitis and 4 were positive for both D. immitis and D. repens according to the PCR test (Table 2).”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Stray dogs hosted in shelters in the eight sampled counties are representative of the stray dog population in eastern Romania.
  • Findingown data

    D. immitis seroprevalence was higher in dogs over 2 years of age than in younger dogs (P<0.05).

    “The D. immitis prevalence was higher in dogs over 2 years of age (P<0.05) but there were no significant differences between dogs with short or long coat (P>0.05).”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Stray dogs hosted in shelters in the eight sampled counties are representative of the stray dog population in eastern Romania.
    • Rests on an assumption: The commercial ELISA test kit used accurately detects D. immitis infection in dogs.
  • Findingown data

    The prevalence of D. immitis in dogs in Galati county by multiplex PCR was 42.2%.

    “The high prevalence for D. immitis shown in dogs in the Southeast (Galati, 42.2%) also by multiplex PCR gave strong support to the results achieved by the serological tests.”
    • Also stated in: § Results · boosted
      “The high prevalence for D. immitis in dogs in the Southeast (Galati county, 42.2%) was confirmed by multiplex PCR providing strong support to the results achieved by the serological tests.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Stray dogs hosted in shelters in the eight sampled counties are representative of the stray dog population in eastern Romania.
  • May combine two claims. 4
  • Classified as probably not a substantial claim. 5
  • May combine two claims.

    Interpretationcitation

    The low-level prevalence of D. immitis in Iași county is important because D. immitis may serve as a reservoir of infection for other animals in low-incidence areas.

    “However, also the low-level prevalence in Iași county revealed in our study is important because, as reported by Miro et al. (2013), D. immitis may serve as a reservoir of infection for other animals in low-incidence areas.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Miro et al. (2013)

      Not checked in the free run.

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

    Premisecitation

    Dirofilariosis in animals and humans is being detected more and more frequently in the Mediterranean countries.

    “Dirofilariosis in animals and humans is being detected more and more frequently in the Mediterranean countries (Genchi et al., 2005).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Genchi et al., 2005

      Not checked in the free run.

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

    Premisecitation

    The intermediate hosts and vectors of D. immitis are different species of culicid mosquitoes of the genera Culex, Aedes and Anopheles.

    “The intermediate hosts and vectors are different species of culicid mosquitoes of the genera Culex, Aedes and Anopheles (Cancrini and Kramer, 2001).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Cancrini and Kramer, 2001

      Not checked in the free run.

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

    Premisecitation

    The presence of canine and human Dirofilaria infections in the Balkan Peninsula suggests that climate, ecology factors and mosquito abundance are suitable for full development and transmission of the infection.

    “The presence of canine and human Dirofilaria infections in the Balkan Peninsula suggests that climate, ecology factors and mosquito abundance are suitable for the full development and transmission of the infection (Tasić-Otaševi et al., 2015).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Tasić-Otaševi et al., 2015

      Not checked in the free run.

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

    Premisecitation

    D. immitis is one of the most pathogenic parasites of dogs and has an increasing distribution, possibly due to climatic changes and animal and human movements.

    “Cardiopulmonary dirofilariosis or heartworm disease (HWD) is caused by D. immitis, which is the one of the most pathogenic parasites of dogs with an increasing distribution, possibly due to climatic changes as well as animal and human movements (Genchi et al., 2011).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Genchi et al., 2011

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    The high prevalence of D. immitis in southeastern Romania could be explained by the presence of floodplains and confirmed vector species.

    “Therefore, this could be an explanation for the high prevalence in the southeastern Romania as detected in this study.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    HWD is still prevalent in dogs in large areas despite the availability of reliable diagnostic tools and effective prophylaxis.

    “In spite of the availability of reliable diagnostic tools and effective prophylaxis, HWD is still prevalent in dogs in large areas (McCall et al., 2008).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites McCall et al., 2008

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Dirofilaria spp. have spread towards eastern and north-eastern European countries, but only limited epidemiological information is available from there.

    “Dirofilaria spp.have spread towards the eastern and north-eastern European countries, but only limited epidemiological information is available from there (Genchi et al., 2009(Genchi et al., , 2011)).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Genchi et al., 2009

      Not checked in the free run.

    • cites Genchi et al., 2011

      Not checked in the free run.

8 of 8
  • The paper relies on this without support.

    Stray dogs hosted in shelters in the eight sampled counties are representative of the stray dog population in eastern Romania.

    “Plasma samples were collected from 458 stray dogs hosted in shelters in 8 counties and tested serologically for the presence of heartworm.”
    “The mean prevalence of D. immitis was 8.9% and the OD results for the positive samples ranged from 0.217 to 2.683.”
  • The paper relies on this without support.

    The commercial ELISA test kit used accurately detects D. immitis infection in dogs.

    “At least 2 mL of blood from each of the 458 analysed dogs was collected in a plasma separator tube and stored at -20°C until tested for the presence of D. immitis antigen using a commercial ELISA test kit based on heartworm antigen (HA) available from PetCheck ® (Westbrook, ME, USA) according to the manufacturers' instructions.”
    “The immmunological assay showed a heartworm infection prevalence of 8.9% in the dogs.”
2 of 2

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Sex difference is reported as nonsignificant despite the stated counts

    Major

    Table 1 reports 31 positives among 245 females and 10 among 213 males. A chi-squared test on those counts gives approximately P=0.003, contradicting the reported P>0.05.

  • Coat-length difference is reported as nonsignificant despite the stated counts

    Major

    Table 1 reports 34 positives among 289 short-coated dogs and 7 among 169 long-coated dogs. A chi-squared test on those counts gives approximately P=0.006, not P>0.05.

2 of 2

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Coman S, Bacescu B, Coman T, 2007. Epidemiological and paraclinical aspects in dirofilariosis in dogs. In: Proceedings of the First European Dirofilaria Days, 22-25 Feb 2007, Zagreb, Croatia, p.

Cited by

Sorted by citations

Authors
Ciucă, L., Musella, V., Miron, L. D., Maurelli, M. P., Cringoli, G., Bosco, A., & Rinaldi, L.
Affiliations
  • "Ion Ionescu de la Brad" Iasi University of Life Sciences (RO)
  • Magna Graecia University (IT)
  • University of Naples Federico II (IT)
Corresponding author
  • Ciucă, Lavinia
  • Musella, Vincenzo
  • Miron, Liviu D.
  • Maurelli, Maria Paola
  • Cringoli, Giuseppe
  • Bosco, Antonio
  • Rinaldi, Laura
Venue
Geospatial Health
Published
2016-11-21
Volume
11
Issue
3
Pages
499-499
ISSN
  • 1827-1987 (ISSN-L)
  • 1970-7096
OpenAlex
W2559281245
Cited by
35
References
37
Citations by year
2025: 5 · 2024: 5 · 2023: 7 · 2022: 4 · 2021: 3 · 2020: 2 · 2019: 4 · 2018: 4 · 2017: 1
FWCI
2.75
Type
journal article
Language
en
Open access
Locations
  • Geospatial health (publishedVersion, cc-by-nc)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
  • INFM-OAR (INFN Catania) (submittedVersion, cc-by-nc)
Funders
European Social Fund (2007–2013, POSDRU/159/1.5/S/132765)
Topics
  • Health Sciences › Medicine › Infectious Diseases › Parasitic Diseases Research and Treatment
  • Health Sciences › Veterinary › Small Animals › Helminth infection and control
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Research on Leishmaniasis Studies
Keywords
Dirofilaria immitis, canine heartworm disease, stray dogs, geographic distribution, infection prevalence, serological diagnosis, multiplex PCR, Dirofilaria repens, temperature suitability, Eastern Romania
MeSH terms
Animals, Dirofilaria immitis, Dirofilariasis, Dog Diseases, Dogs, Romania, Prevalence

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-09.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-09.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review