A large variety of ectoparasites parasitizing on livestock, dogs, and rodents are documented throughout the world, of which several are proven vectors for major (including zoonotic) diseases affecting humans and/or livestock. However, there remains a significant lack of knowledge in regard to the ectoparasite fauna in remote regions of the developing world, such as southeastern Bangladesh, and an urgent need to investigate this fauna to improve diagnostic options. In the course of the present study, more than 5,300 ectoparasites were collected by flag dragging and handpicking of livestock, dogs, and rodents in the District of Bandarban (Chittagong Hill Tracts) in southeastern Bangladesh. Three tick species were identified: Haemaphysalis bispinosa (flagging, cattle, goats, and dogs), Rhipicephalus microplus (cattle, goats), and Rhipicephalus sanguineus (dogs, goats, and flagging). H. bispinosa was the dominant tick species on mammalian hosts as well as on vegetation. Furthermore, Ctenocephalides canis (dogs, goats) and Linognatus sp. (goat) were found. Overall, 73 rodents of eight different species (e.g., Mus musculus, Rattus sikkimensis, Bandicota bengalensis, and Niviventer sp.) hosted a variety of ectoparasites such as mites (Laelaps nuttali, Laelaps echidninus, Lyponissoides sp. and Ornithonyssus bacoti), fleas (Xenopsylla cheopis), and one myiasis-causing dipteran species. Monitoring the ectoparasite burden of livestock and other mammals is urgently needed in order to control ectoparasites associated with social and economic burden (e.g., reduced milk production, weight loss). Several zoonotic diseases can be transmitted by ectoparasites in this area, where the majority of the population live in basic housing conditions and in direct contact with livestock, dogs, and rodents.

Rodents are a key mammalian group highly successful in adapting to a variety of environments throughout the world and play an important role in many zoonotic cycles. Within this project, the gastrointestinal and extraintestinal parasite fauna of 76 rodents (Muroidea and Sciuridae) was determined in the District of Bandarban (Chittagong Hill Tracts) in Southeastern Bangladesh. Gastrointestinal and extraintestinal parasites were examined with macro- and microscopical tools (e.g. Ziehl-Neelsen Staining) at a field site in Bandarban. A wide variety of parasites were found in rodent hosts, including protozoa-Giardia sp. (n = 8), Cryptosporidium sp. (n = 1), Entamoeba sp. (n = 8), Trichomonadida (n = 4), Isospora sp. (n = 1), trematodes (Echinostoma sp.; n = 3), cestodes-Hymenolepis nana (n = 1), Hymenolepis diminuta (n = 3), Hymenolepis sp. (n = 2), Taenia taeniaeformis-Larven (n = 4), Catenotaenia sp. (n = 1), Taenia sp. (n = 1), nematodes-Heterakis spumosa (n = 4), Heterakis sp. (n = 1), Aspiculuris tetraptera (n = 2), Capillaria hepatica (n = 2), Capillaria sp. (n = 3), Syphacia sp. (n = 2), Strongyloides sp. (n = 10), Trichostrongylus sp. (n = 2) and Trichuris sp. (n = 1)-and acanthocephalans (Moniliformis moniliformis; n = 2). Several of the examined parasites are of zoonotic importance via direct or indirect transmission (e.g. C. hepatica) and may affect humans.

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.