A Diagnostic Algorithm for Evaluating Cases of Potential Macrocyclic Lactone-resistant Heartworm

Overview

Journal Parasit Vectors

Publisher Biomed Central

Specialties Parasitology
Tropical Medicine

Date 2017 Nov 17

PMID 29143642

Citations 5

Authors

Andrew R Moorhead

Christopher C Evans

Ray M Kaplan

Affiliations

Soon will be listed here.

Abstract

Background: The emergence of macrocyclic lactone resistance in canine heartworm poses a substantial threat to what is currently the only effective, FDA-approved available method of prevention. Further study of the biotypes is necessary to understand the mechanism of resistance and evaluate novel prevention options. Identifying cases of drug-resistant infection remains problematic, however, especially when poor compliance and insufficient testing are concerns. Furthermore, a definitive demonstration of resistance requires experimental infection and treatment, which is prohibitively costly.

Methods: With the aim of identifying likely cases of macrocyclic lactone-resistant heartworm and preventing their continued spread, we describe an algorithm for determining the likelihood of drug resistance and appropriate treatment strategies for each case.

Results: This algorithm relies on the microfilarial suppression test (MFST), which has been used previously as an efficient and discrete measure of suspected resistance. By standardizing this method in a format that is readily available to practitioners, it could become possible to preliminarily survey the emergence and spread of resistance.

Conclusion: Heartworm isolates identified through this method can be used in research to better understand macrocyclic lactone resistance so prevention strategies can be adapted.

Citing Articles

Strain-level variations of Dirofilaria immitis microfilariae in two biochemical assays.

Hampton N, Smith V, Brewer M, Jesudoss Chelladurai J PLoS One. 2024; 19(7):e0307261.

PMID: 39018313 PMC: 11253964. DOI: 10.1371/journal.pone.0307261.

Concern for and Macrocyclic Lactone Loss of Efficacy: Current Situation in the USA and Europe, and Future Scenarios.

Diakou A, Prichard R Pathogens. 2021; 10(10).

PMID: 34684273 PMC: 8541013. DOI: 10.3390/pathogens10101323.

Challenges and opportunities for the adoption of molecular diagnostics for anthelmintic resistance.

Kotze A, Gilleard J, Doyle S, Prichard R Int J Parasitol Drugs Drug Resist. 2020; 14:264-273.

PMID: 33307336 PMC: 7726450. DOI: 10.1016/j.ijpddr.2020.11.005.

Laboratory assays reveal diverse phenotypes among microfilariae of Dirofilaria immitis isolates with known macrocyclic lactone susceptibility status.

Jesudoss Chelladurai J, Martin K, Chinchilla-Vargas K, Jimenez Castro P, Kaplan R, Brewer M PLoS One. 2020; 15(8):e0237150.

PMID: 32760111 PMC: 7410292. DOI: 10.1371/journal.pone.0237150.

Perspectives on the utility of moxidectin for the control of parasitic nematodes in the face of developing anthelmintic resistance.

Prichard R, Geary T Int J Parasitol Drugs Drug Resist. 2019; 10:69-83.

PMID: 31229910 PMC: 6593148. DOI: 10.1016/j.ijpddr.2019.06.002.

References

McCall J . The safety-net story about macrocyclic lactone heartworm preventives: a review, an update, and recommendations. Vet Parasitol. 2005; 133(2-3):197-206. DOI: 10.1016/j.vetpar.2005.04.005. View

Bourguinat C, Keller K, Blagburn B, Schenker R, Geary T, Prichard R . Correlation between loss of efficacy of macrocyclic lactone heartworm anthelmintics and P-glycoprotein genotype. Vet Parasitol. 2011; 176(4):374-81. DOI: 10.1016/j.vetpar.2011.01.024. View

Bourguinat C, Keller K, Bhan A, Peregrine A, Geary T, Prichard R . Macrocyclic lactone resistance in Dirofilaria immitis. Vet Parasitol. 2011; 181(2-4):388-92. DOI: 10.1016/j.vetpar.2011.04.012. View

Geary T, Bourguinat C, Prichard R . Evidence for macrocyclic lactone anthelmintic resistance in Dirofilaria immitis. Top Companion Anim Med. 2011; 26(4):186-92. DOI: 10.1053/j.tcam.2011.09.004. View

Chandrashekar R, Beall M, Saucier J, OConnor T, McCall J, McCall S . Experimental Dirofilaria immitis infection in dogs: effects of doxycycline and Advantage Multi® administration on immature adult parasites. Vet Parasitol. 2014; 206(1-2):93-8. DOI: 10.1016/j.vetpar.2014.08.011. View

Pulaski C, Malone J, Bourguinat C, Prichard R, Geary T, Ward D . Establishment of macrocyclic lactone resistant Dirofilaria immitis isolates in experimentally infected laboratory dogs. Parasit Vectors. 2014; 7:494. PMC: 4228187. DOI: 10.1186/s13071-014-0494-6. View

Atkins C, Murray M, Olavessen L, Burton K, Marshall J, Brooks C . Heartworm 'lack of effectiveness' claims in the Mississippi delta: computerized analysis of owner compliance--2004-2011. Vet Parasitol. 2014; 206(1-2):106-13. DOI: 10.1016/j.vetpar.2014.08.013. View

McCall J, Arther R, Davis W, Settje T . Safety and efficacy of 10% imidacloprid+2.5% moxidectin for the treatment of Dirofilaria immitis circulating microfilariae in experimentally infected dogs. Vet Parasitol. 2014; 206(1-2):86-92. DOI: 10.1016/j.vetpar.2014.09.011. View

Bourguinat C, Lee A, Lizundia R, Blagburn B, Liotta J, Kraus M . Macrocyclic lactone resistance in Dirofilaria immitis: Failure of heartworm preventives and investigation of genetic markers for resistance. Vet Parasitol. 2015; 210(3-4):167-78. DOI: 10.1016/j.vetpar.2015.04.002. View

10.

Bowman D, Charles S, Arther R, Settje T . Laboratory Evaluation of the Efficacy of 10 % Imidacloprid + 2.5 % Moxidectin Topical Solution (Advantage® Multi, Advocate®) for the Treatment of Dirofilaria immitis Circulating Microfilariae in Dogs. Parasitol Res. 2015; 114 Suppl 1:S165-74. DOI: 10.1007/s00436-015-4522-z. View

11.

Maclean M, Savadelis M, Coates R, Dzimianski M, Jones C, Benbow C . Does evaluation of in vitro microfilarial motility reflect the resistance status of Dirofilaria immitis isolates to macrocyclic lactones?. Parasit Vectors. 2017; 10(Suppl 2):480. PMC: 5688452. DOI: 10.1186/s13071-017-2436-6. View

12.

McCall J, McTier T, Ryan W, Gross S, Soll M . Evaluation of ivermectin and milbemycin oxime efficacy against Dirofilaria immitis infections of three and four months' duration in dogs. Am J Vet Res. 1996; 57(8):1189-92. View