Author:
Negron Veronica,Saleh Meriam N.,Sobotyk Caroline,Luksovsky Joe L.,Harvey Tatiani V.,Verocai Guilherme G.
Abstract
Abstract
Background
Current recommendations for diagnosis of Dirofilaria immitis infection in dogs rely on the detection of antigen produced largely by adult females coupled with the visualization of microfilariae (mf) in the circulation via a microfilaria detection test (MFDT). It is hypothesized that qPCR assays used in parallel with antigen detection tests will perform better in detecting mf than modified Knott’s test (MK), when combined with antigen detection. This study compares probe-based qPCR and MK techniques for mf detection used in parallel with the DiroCHEK® antigen test to screen for heartworm infection in shelter dogs.
Methods
Matching blood and serum samples were collected from 300 shelter dogs in Brazos and Harris counties, Texas, USA. Blood was assessed for the presence of mf via MK and the presence of D. immitis DNA by a species-specific probe-based qPCR assay. Serum samples were tested for the presence of heartworm antigen using DiroCHEK® before and after immune complex dissociation (ICD) via heat treatment. In addition, the performance of each diagnostic test was evaluated via Chi-square test, Cochran’s Q test, and post hoc analysis.
Results
Qualitatively, MK detected mf in 22.0% (66/300) of samples, 55 of which were morphologically identified as D. immitis and 11 as Acanthocheilonema reconditum. The range of heartworm mf was 28 to 88,803 mf/ml (median: 6627.5). Real-time PCR detected D. immitis DNA in 20.7% (62/300) of samples. Heartworm antigen was detected in 24.7% (74/300) of samples pre-ICD, and in 29.3% (88/300) post-ICD. When comparing tests, the Chi-square and McNemar’s tests showed that the difference between positive and negative proportions was statistically significant. The Cochran test showed the difference in the distributions of cases and non-cases was significant when individual tests were combined (χ2 = 62.3, df = 3, P < 0.0001) and when parallel methods were combined (χ2 = 43.1, df = 4, P < 0.0001).
Conclusion
Considering individual and combined test performances, practicality, and efficient use of bench time, this heartworm-specific probe-based qPCR method is a viable option as a mf detection test to be used in parallel with antigen tests for canine heartworm infection in diagnostic and research settings.
Graphical Abstract
Publisher
Springer Science and Business Media LLC
Subject
Infectious Diseases,Parasitology
Reference32 articles.
1. Simón F, Siles-Lucas M, Morchón R, González-Miguel J, Mellado I, Carretón E, et al. Human and animal dirofilariasis: the emergence of a zoonotic mosaic. Clin Microbiol Rev. 2012;25:507–44. https://doi.org/10.1128/cmr.00012-12.
2. Genchi C, Kramer LH. The prevalence of Dirofilaria immitis and D. repens in the Old World. Vet Parasitol. 2020;280:108995. https://doi.org/10.1016/j.vetpar.2019.108995.
3. Nelson CT, McCall JW, Jones S, Moorhead A: Current canine guidelines for the prevention, diagnosis, and management of the heartworm (Dirofilaria immitis) Infection in dogs. Edited by Wilmington. https://www.heartwormsociety.org/veterinary-resources/american-heartworm-society-guidelines: American Heartworm Society; 2018.
4. Sobotyk C, Nguyen N, Negrón V, Varner A, Saleh MN, Hilton C, et al. Detection of Dirofilaria immitis via integrated serological and molecular analyses in coyotes from Texas, United States. Int J Parasitol Parasites Wildlife. 2022;18:20–4. https://doi.org/10.1016/j.ijppaw.2022.03.012.
5. Dantas-Torres F, Otranto D. Dirofilariosis in the Americas: a more virulent Dirofilaria immitis? Parasit Vectors. 2013;6:288. https://doi.org/10.1186/1756-3305-6-288.
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