The prevalence and trends of canine heartworm (Dirofilaria immitis) in Kuala Lumpur, Malaysia (1970-2018)

Malaysia is considered a hyperendemic area for canine heartworm (Dirofilaria immitis) due to its favorable climate for the completion of the parasite life cycle. This study provides an updated prevalence data on D. immitis in owned dogs from Kuala Lumpur, Malaysia and compares the trends of D. immitis in Malaysia. In the period between December 2017 and June 2018, 3.85% (5/130) dog blood samples tested positive for the presence of D. immitis antigen. A majority of the tested dogs (122/130) were not on rigorous heartworm prevention. After collating and analyzing information from 10 historical studies (1970-2017), we identified a significant decline in prevalence of D. immitis antigen in Malaysia, after the year 2000. Historically, the prevalence of D. immits antigen in owned dogs was significantly lower than the prevalence seen in stray dogs in Malaysia. This study demonstrates that D. immitis remains active in Kuala Lumpur, implying that accurate compliance of heartworm prevention is essential in Malaysia.