References

Anvari D, Narouei E, Daryani A The global status of Dirofilaria immitis in dogs: a systematic review and meta-analysis based on published articles. Res Vet Sci.. 2020; 131:104-116 https://doi.org/10.1016/j.rvsc.2020.04.002

Berlioz-Arthaud A Survey on Leptospirosis in the Pacific 2003. https://www.pphsn.net/wp-content/uploads/2017/12/Survey-lepto-Pacific.pdf

Bidaisee S, Macpherson CN Zoonoses and one health: a review of the literature. J Parasitol Res.. 2014; 2014 https://doi.org/10.1155/2014/874345

Carslake R, Hill K, Sjolander K, Hii S, Prattley D, Acke E A crosssectional survey of health management and prevalence of vector-borne diseases, endoparasites and ectoparasites in Samoan dogs. Aust Vet J.. 2017; 95:(12)462-468 https://doi.org/10.1111/avj.12647

Chadsuthi S, Bicout DJ, Wiratsudakul A Investigation on predominant Leptospira serovars and its distribution in humans and livestock in Thailand, 2010-2015. PLoS Negl Trop Dis.. 2017; 11:(2)2010-2015 https://doi.org/10.1371/journal.pntd.0005228

Curtis KM, Foster PC, Smith PS Performance of a recombinant LipL32 based rapid in-clinic ELISA (SNAP® Lepto) for the detection of antibodies against Leptospira in dogs. Int J Appl Res Vet Med.. 2015; 13:(3)182-189

Farnworth MJ, Blaszak KA, Hiby EF, Waran NK Incidence of dog bites and public attitudes towards dog care and management in Samoa. Animal Welfare.. 2012; 21:(4)477-486 https://doi.org/10.7120/09627286.21.4.477

Gubler DJ, Reiter P, Ebi KL, Yap W, Nasci R, Patz JA Climate variability and change in the United States. Environ Health Perspect.. 2001; 109:(Suppl 2)223-233 https://doi.org/10.1289/ehp.109-1240669

Guernier V, Goarant C, Benschop J, Lau CL A systematic review of human and animal leptospirosis in the Pacific Islands reveals pathogen and reservoir diversity. PLoS Negl Trop Dis.. 2018; 12:(5) https://doi.org/10.1371/journal.pntd.0006503

Izurieta R, Galwankar S, Clem A Leptospirosis: The ‘mysterious’ mimic. J Emerg Trauma Shock.. 2008; 1:(1)21-33 https://doi.org/10.4103/0974-2700.40573

Jackman J, Rowan AN Free-roaming dogs in developing countries: the benefits of capture, neuter, and return programs.

Lau CL, Watson CH, Lowry JH Human leptospirosis infection in Fiji: an eco-epidemiological approach to identifying risk factors and environmental drivers for transmission. PLoS Negl Trop Dis.. 2016; 10:(1)1-25 https://doi.org/10.1371/journal.pntd.0004405

Lizer J, Velineni S, Weber A, Krecic M, Meeus P Evaluation of 3 serological tests for early detection of Leptospira-specific antibodies in experimentally infected dogs. https://doi.org/10.1111/jvim.14865

Major A, Schweighauser A, Francey T Increasing incidence of canine leptospirosis in Switzerland. Int J Environ Res Public Health.. 2014; 11:(7)7242-7260 https://doi.org/10.3390/ijerph110707242

Meeyam T, Tablerk P, Petchanok B, Pichpol D, Padungtod P Seroprevalence and risk factors associated with leptospirosis in dogs. Southeast Asian J Trop Med Public Health.. 2006; 37:(1)148-153

Zoonotic Dirofilaria immitis and Dirofilaria repens infection in humans and an integrative approach to the diagnosis. https://doi.org/10.1016/j.actatropica.2021.106083

Miller MD, Annis KM, Lappin MR, Lunn KF Variability in results of the Microscopic Agglutination Test in Dogs with clinical leptospirosis and dogs vaccinated against leptospirosis. J Vet Intern Med.. 2011; 25:426-432 https://doi.org/10.1111/j.1939-1676.2011.0704.x

Montoya-Alonso JA, Carretón E, Corbera JA Current prevalence of Dirofilaria immitis in dogs, cats and humans from the island of Gran Canaria, Spain. Vet Parasitol.. 2011; 176:(4)291-294 https://doi.org/10.1016/j.vetpar.2011.01.011

Muñoz-Zanzi C, Mason MR, Encina C, Astroza A, Romero A Leptospira contamination in household and environmental water in rural communities in southern Chile. Int J Environ Res Public Health.. 2014; 11:(7)6666-80 https://doi.org/10.3390/ijerph110706666

Rissi DR, Brown CA Diagnostic features in 10 naturally occurring cases of acute fatal canine leptospirosis. J Vet Diagn Invest.. 2014; 26:(6)799-804 https://doi.org/10.1177/1040638714553293

Santoro M, Miletti G, Vangone L, Spadari L, Reccia S, Fusco G Heartworm disease (Dirofilaria immitis) in two roaming dogs from the urban area of Castel Volturno, southern italy. Front Vet Sci.. 2019; 6:1-4 https://doi.org/10.3389/fvets.2019.00270

Simón F, Morchón R, González-Miguel J, Marcos-Atxutegi C, Siles-Lucas M

Sykes JE, Hartmann K, Lunn KF, Moore GE 2010 ACVIM small animal consensus statement on Leptospirosis: diagnosis, epidemiology, treatment, and prevention. J Vet Intern Med.. 2011; 25:(1)1-13 https://doi.org/10.1111/j.1939-1676.2010.0654.x

Tangkanakul W, Smits HL, Jatanasen S, Ashford DA Leptospirosis: an emerging health problem in Thailand. Southeast Asian J Trop Med Public Health.. 2005; 36:(2)281-288

Tonga statistics at a glance. In: Census of Population and Housing.. 2016; https://tongastats.gov.to/census-2/population-census-2/(accessed

Traub RJ, Irwin P, Dantas-Torres F Toward the formation of a companion animal parasite council for the tropics (CAPCT). https://doi.org/10.1186/s13071-015-0884-4

Victoriano AFB, Smythe LD, Gloriani-Barzaga N Leptospirosis in the Asia Pacific region. BMC Infect Dis.. 2009; 9 https://doi.org/10.1186/1471-2334-9-147

Vieira AL, Vieira MJ, Oliveira JM, Simoes AR, Diez-Banos P, Gestal J Prevalence of canine heartworm (Dirofilaria immitis) disease in dogs of central Portugal. Parasite.. 2014; 21 https://doi.org/10.1051/parasite/2014003

Villanueva SYAM, Ezoe H, Baterna RA Serologic and molecular studies of Leptospira and leptospirosis among rats in the Philippines. Am J Trop Med Hyg.. 2010; 82:(5)889-898 https://doi.org/10.4269/ajtmh.2010.09-0711

Winzelberg S, Tasse SM, Goldstein RE Evaluation of SNAP® Lepto in the diagnosis of leptospirosis infections in dogs: twenty two clinical cases. Int J Appl Res Vet Med.. 2015; 13:(3)193-198

Wynwood SJ, Graham GC, Weier SL Leptospirosis from water sources. Pathog Glob Health.. 2014; 108:(7)334-338 https://doi.org/10.1179/2047773214Y.0000000156

Leptospira spp. and Dirofilaria immitis in dogs in Tonga: a pilot study

02 April 2023
8 mins read
Volume 14 · Issue 3
Table 1. Gender and age distribution of dogs tested for prevalence of Leptospira spp. and D. immitis

Abstract

Dogs are common in Tonga and exist in a close relationship with humans, both as free-ranging pets and guard dogs for domestic properties. Little is known about pathogens present in these animals, and this pilot study aimed to develop a methodology to identify the presence of zoonotic pathogens Leptospira spp. and Dirofilaria immitis (the causative agent of heartworm), in a sample of 82 dogs voluntarily presented to a spey/neuter clinic, using blood samples and point-of-care tests. No positive tests were returned for Leptospira spp. or D. immitis, despite the presence of Leptospira spp. having previously being identified in Tonga.

The Kingdom of Tonga’s main island of Tongatapu has a human population of 74611 (Tonga Department of Statistics, 2016), and an estimated canine population of 17 122 dogs, giving a dog:human ration of 1:4 (G Aguilar, unpublished data, 2018), similar to other developing countries such as Nepal, Indonesia and the Philippines (Jackman and Rowan, 2007; Traub et al, 2015). The close physical relationship that dogs have with humans in Tonga, as both pets and guard dogs, inherently increases the risk of disease transmission, since more than 60% of known infectious diseases are zoonotic (Bidaisee and Macpherson, 2014).

This pilot study considers two specific zoonotic pathogens - Leptospira spp. and Dirofilaria immitis - in dogs in the Kingdom of Tonga. Leptospirosis has been identified in 13 Pacific nations, including Tonga (Guernier et al, 2018). However, under-reporting of this disease is common, and it is known to mimic other diseases (Izurieta et al, 2008; Victoriano et al, 2009). Cattle, swine, dogs and rats are common reservoirs for Leptospira spp., and shed leptospires in urine. In countries with tropical climates, such as the Philippines and Thailand, 68-92% of rats were found to carry antibodies for leptospires (Tangkanakul et al, 2005; Villanueva et al, 2010). Dogs infected with Leptospira spp. typically present with fever, jaundice, vomiting, diarrhoea, intravascular disseminated coagulation, renal failure, haemorrhages and death. Infection may occur via direct or indirect exposure, where rivers, soil and water reservoirs may be contaminated by urine of carrier animals (Victoriano et al, 2009; Guernier et al, 2018). Spikes in infection rates in humans are often noted following cyclones with secondary flooding, and projected changes in the world’s climate are expected to increase the frequency of these severe weather events (Gubler et al, 2001; Lau et al, 2016). Clinical signs in humans range from a mild flu-like illness, to severe complications including acute renal failure and pulmonary haemorrhagic syndrome. The latter is associated with high fatality rates (Guernier et al, 2018).

Register now to continue reading

Thank you for visiting The Veterinary Nurse and reading some of our peer-reviewed content for veterinary professionals. To continue reading this article, please register today.