Indigenous Dirofilaria immitis in Bangladesh

Abstract

Dirofilaria immitis is a parasite of domestic and wild canids and felids in tropical, subtropical and temperate regions throughout the world. The canine heartworm (D. immitis) is the causative agent of canine and feline cardiopulmonary dirofilariasis. This parasite is known to cause a zoonotic disease, namely human pulmonary dirofilariasis. D. immitis is known to be endemic in several South and Southeast Asian countries (e.g. India and Malaysia), but there has previously been no information about the presence of this pathogen in Bangladesh. We present a case of canine dirofilariasis caused by D. immitis in rural southeastern Bangladesh. A male filaroid nematode (95 mm in length and 1.94 mm in width) was identified in the heart of a dog. Species classification was performed by microscopy and molecular tools. Sequence analysis revealed a 100 % identity within the mitochondrial cytochrome c oxidase I (CO1) gene to two Chinese and one Australian D. immitis samples. Usually, dogs stay outside overnight with a high risk to get infected with D. immitis via nocturnal mosquito vectors, which may lead to high prevalences of this pathogen in the canine population and thus increase the risk of human infections with this neglected parasitic disease.

Human Dirofilaria repens infection of the zygomatico-temporal region

“…It is generally believed that the increase of human nematodes caused by dirofilariae is caused by the climate change that leads to higher temperatures allowing the microfilaria to survive. On the other hand, the enormous increase of worldwide tourism potentiates the chance of human exposure to infected carnivores in regions with epidemical infections (Fuehrer et al, 2013. These infections may become apparent in patients after returning to their home countries in colder parts of the world where dirofilariasis is unknown.…”

“…Thus, the definite diagnosis of this zoonosis relies on adequate microbiological or molecular biological investigations. Dirofilariasis of the head and neck region affects predominantly the orbital region (Pampiglione and Rivasi, 2000, Akst et al, 2004, Fuehrer et al, 2013.…”

A broad insight onto the distribution pattern of Dirofilaria immitis in community dogs in Nepal

“…Results of the present study documented the occurrence of D. immitis infection in community dogs from Nepal demonstrating that the parasite is circulating among native dogs living in the Indo-Nepal border. With the exception of previous reports from mainland and northeast India [12,[23][24][25] or Bangladesh [26], no epidemiological data was available from the study area. Interestingly, the prevalence of the infection herein reported is relatively higher than that reported from the eastern Indian boundaries [12,[23][24][25][26], and whether this is due to the different climatic conditions, activity of arthropod vectors or availability of a larger population of stray dogs is yet to define.…”

Human subcutaneous dirofilariasis in Assam

“…[24] Earlier we have reported 3 cases of human ocular dirofilariasis cases from Dibrugarh and Tinsukia districts of Eastern Assam presenting as peri-orbital as well as subconjunctival cyst caused by D. repens . [4] These 3 sub cutaneous cases are also reported from Dibrugarh and Sibsagar districts from Eastern Assam within a period of 6 months in 2011.…”