Asia-Pacific Serological Survey of Canine Heartworm Disease Based on In-Clinic SNAP Heartworm RT and SNAP 4Dx Plus Test Results, 2013–2017
J. Braff1; L.W. Chang2; R. Chandrashekar1; J.S. Buch1
Introduction
Canine heartworm, caused by infection with mosquito-borne Dirofilaria immitis, poses a significant health risk for dogs throughout the world. Although chemoprophylactic medications can reduce the incidence of this serious disease, heartworm continues to be prevalent in many parts of the Asia-Pacific region.
Objectives
The goal of this observational study was to evaluate Asia-Pacific regional geographic and temporal variation in canine heartworm antigen test results over a five-year period.
Methods
Canine heartworm antigen test results spanning a period of five years (2013–2017) were obtained from an international database of SNAP® Heartworm RT and SNAP® 4Dx® Plus Test results from veterinary clinics. Repeat test results for a single patient and data from countries with less than one hundred available results were excluded. Data was included from at least 520 locations across twelve Asia-Pacific countries.
Results
Table 1. Heartworm (HW) positive results by country
|
Country
|
Test count
|
HW positive
|
HW Pos % (95% CI)
|
|
Australia
|
9,469
|
53
|
0.6 (0.4–0.7)
|
|
China
|
432
|
4
|
0.9 (0.3–2.4)
|
|
Hong Kong
|
27,952
|
1,514
|
5.4 (5.2–5.7)
|
|
India
|
2,369
|
25
|
1.1 (0.7–1.6)
|
|
Japan
|
253,229
|
3,573
|
1.4 (1.4–1.5)
|
|
Malaysia
|
6,192
|
568
|
9.2 (8.5–9.9)
|
|
Myanmar
|
515
|
76
|
14.8 (11.8–18.1)
|
|
Philippines
|
950
|
67
|
7.1 (5.5–8.9)
|
|
Singapore
|
18,528
|
488
|
2.6 (2.4–2.9)
|
|
South Korea
|
9,810
|
903
|
9.2 (8.6–9.8)
|
|
Taiwan
|
131,729
|
13,526
|
10.3 (10.1–10.4)
|
|
Thailand
|
18,563
|
561
|
3.0 (2.8–3.3)
|
|
Total
|
479,738
|
21,358
|
4.5 (4.4–4.5)
|
Conclusions
Results from this study indicate that the proportion of positive heartworm antigen test results varies greatly by country. These findings underscore that dogs within the Asia-Pacific region are at risk for heartworm infection and the importance of regular screening and use of preventatives to mitigate this risk.