Morpho-molecular investigation of ectoparasitic infestation of companion animals in Sylhet city, Bangladesh.

Ticks (Ixodida) and Fleas (Siphonaptera) are considered among the most important arthropod of public health concern due to their ability to transmit vector-borne pathogens to humans. By sharing a common environment, vector-borne diseases constituted major setbacks to the development of a pet population in Bangladesh. This study aimed to determine companion animal-associated ticks and fleas based on morpho-molecular approaches. Between December 2021 and May 2022, 74 animals (62 cats and 12 dogs) were examined, of which 17 (27.4%) cats and 9 (75.0%) dogs had ectoparasitic infestations, with 35.1% overall prevalence. Morphometrical examination showed the ectoparasites in these animals were Ctenocephalides spp. (flea) and Riphicephalus spp. (tick). Genetic analysis using the mitochondrial markers i.e. Cytochrome c oxidase subunit 1 (cox1) revealed the presence of two flea species i.e., Ctenocephalides canis, Ctenocephalides felis, and one tick species Rhipicephalus sanguineus. Interviews of animal owners indicate that 35.14% of them had no concern about ectoparasitic infestation or ectoparasites-borne diseases. Our results indicated that fleas and ticks were the most common ectoparasites in companion animals of this area. The zoonotic nature of some ectoparasites can be regarded as a public health alert. The findings will assist epidemiologists and policymakers in offering customized guidance for upcoming monitoring and preventive tactics in this area.

An Update on Gastrointestinal Parasitic Infection in Captive Wild Animals in Bangladesh.

Gastrointestinal parasites cause health problems and even death in captive animals. These animals are more susceptible to parasitic infestations because of confinement and stress. The aim of the study is to describe parasitic causal agents in captive wild animals at the Bangladesh National Zoo, Chittagong Zoo, and Tilagarh Eco Park, in Sylhet. A total of 54 fecal samples were collected from the Bangladesh Zoo, Chittagong Zoo, and Tilagarh Eco Park from April 2022 to November 2022. Samples were collected from animals of the groups Aves (16), Reptiles (4), Artiodactyla (23), Perissodactyla (8), and Proboscidea (3). All samples were examined using a modified formalin ether sedimentation technique. Fecal examination consoled an overall occurrence of 61.1%. Out of 54 samples, 33 were positive for parasitic infection. The parasites observed were as follows: Ascarididae eggs (57.58%), Capillaria spp. (18.18%), Strongyloides spp. (9.09%), Trichuris spp. (6.06%), and mixed infection (9.09%). The order Reptiles had a 100% infection rate, while Aves had the lowest infection rate (50%). Only nematodes were detected in this study. Without showing evident, clinical signs and symptoms of disease, the prevalence of gastrointestinal parasites is high. This indicates a subclinical infection. This study shows that more epidemiological research and sanitation management programs, including regular antihelminthic therapy for controlling parasitic infection, should be adopted in zoos and ecoparks.

An update of intestinal helminth infections among urban slum communities in Bangladesh.

Aim: To assess the prevalence of intestinal helminth infections and associated risk factors among people living in urban slums in Bangladesh. Methods: A cross-sectional study was conducted across three clusters: Dhaka, Sylhet and Chattogram. In total, 360 individuals divided into two groups (school-aged children and adults) provided stool samples and completed a semi-structured questionnaire. Parasitological assessment was performed using the formol-ether concentration technique. Results: Overall, 31.7% (114/360) of participants had helminthiasis, with 13.3% (48/360) having mixed infections. Among the infected participants, school-aged children had a higher rate of infection (41.7%, 75/180) compared with adults (21.7%, 39/180). Ascaris lumbricoides was the predominant parasite, followed by hookworms, Trichuris trichiura, Hymenolepis nana, Enterobius vermicularis and Rhabditis sp. Parasitic infections were significantly associated with type of latrine used, direct exposure to soil, open defaecation, and presence of free-roaming animals. Conclusion: Despite continuous efforts to control helminthiasis, a substantial proportion of the study participants were infected with intestinal helminths. Ignorance of the roles of the environment and animals was influential, and had a negative impact on existing control interventions. An integrated public health and veterinary public health approach is required for sustainable control of intestinal helminthiasis.

Current Status of Fasciolosis of Goat in Sylhet, Bangladesh: An Integrated Morphomolecular Study.

Epidemiological information and proper identification of Fasciola species present in Bangladesh are important for control. This study was aimed at determining the prevalence of liver fluke infection of goats in Sylhet, Bangladesh, and identifying those using integrated morphometric and molecular techniques. A total of 260 slaughtered goats (Capra hircus) were examined, and flukes were collected from infected liver using sterilized forceps. Fasciolosis prevalence in goats was 35.38% (92/260) across all age and sex categories. Female goats were found more infected (37.14%, 65/175) than male goats (31.76%, 27/85), while infection rate was found higher in young animals (37.91%, 69/182) compared to adults (29.48% 23/78). Infection rate was observed higher in rainy season (52.96%, 45/85), followed by winter (27.38%, 26/95) and summer (26.25%, 21/80). Collected flukes were examined by light microscopy after being stained with Semichon's acetocarmine, and sequences of mtDNA Cox1 genes were obtained. Ten adult flukes were measured, 38.72 ± 3.37 mm in length and 11.8 ± 1.9 mm in width. Based on morphometric features especially branching of the testis and body length/body width ratios (3.28 ± 0.42), the flukes were primarily identified as Fasciola gigantica. Amplicon sequences were compared by BLAST and the cox1 sequences showed 97.1-99.3% similarity with the reference sequences (F. gigantica and Fasciola sp.) from GenBank. In this study, we found a considerable prevalence of fascioliasis in goats, and F. gigantica was solely identified with variation. To control these parasites and prevent potential public health risks, appropriate control techniques must be developed.

Faunal diversity of ticks in animals and environment in eastern Bangladesh.

Tick and tick-borne diseases cause significant impediments to livestock health and production; however, information on the tick fauna is significantly limited in Bangladesh. This study was aimed to investigate tick fauna in Sylhet sub-district of Bangladesh targeting animal hosts and environment. A total 1427 ticks were collected by using blunt forceps, hand picking and dragging techniques from host body and environment during October 2018 to March 2019. Identification was made using morpho-taxonomical keys. Eight species from three separate genera of tick, namely Rhipicephalus(≈Boophilus) microplus, Rhipicephalus decoloratus, R. annulatus, R. sanguineus, Haemaphysalis intermedia, H. bispinosa, H. leachi, and Amblyomma variegatum were identified. Rhipicephalus spp. was dominant in the hosts whereas, Haemaphysalis spp. was the most prevalent in the environment. This study for the first-time enlisted ticks in two different ecological settings in Sylhet, Bangladesh. Further investigations should be made to evaluate the burden and control the associated socio-economic risk.

Morphometrical and Molecular Characterization of Oesophagostomum columbianum (Chabertiidae: Oesophagostominae) and Haemonchus contortus (Trichostrongylidae: Haemonchinae) Isolated from Goat (Capra hircus) in Sylhet, Bangladesh.

This study was aimed at describing two (2) intestinal nematodes from naturally infected native breed of goats (Capra hircus) in Bangladesh, identified as Oesophagostomum columbianum (Curtice, 1890) Stossich 1899 and Haemonchus contortus (Rudolphi, 1803) Cobb, 1898. The identification was made based on morphometric features and was confirmed by amplifying internal transcribed spacer (ITS) and cytochrome c oxidase (cox1) gene. Well-developed lateral alae, distinct cervical papillae anteriorly to esophageal expansion, and male spicule length (0.73-0.79 mm, n = 2) were characteristically observed in O. columbianum. At the same time, male spicule length (0.40-0.46 mm, n = 2) and position of female vulvar flap (4.30-4.54 mm from posterior end, n = 3) were observed in H. contortus. DNA sequence homology of the ITS and cox1 gene of both specimens revealed the same results, showing similarity to the GenBank sequences of O. columbianum (GenBank No. KC715827; JX188470) and H. contortus (GenBank No. KJ724377; HQ389229). Phylogenetic analysis computed by maximum livelihood (ML) from the ITS nucleotide sequences revealed that the O. columbianum and H. contortus isolates identified in this study were clustered in the same clade with isolates from China and Iran, respectively. This study, for the first time, illustrates the characteristics of O. columbianum and H. contortus in Bangladesh, combining both morphological and molecular data. The universal primer-based polymerase chain reaction (PCR) protocol could be an economical and efficient option for researchers from poor resource settings for precise identification of nematodes. The information generated in this study may contribute to formulating effective control strategies against these nematodes.

Molecular diagnosis of bovine tuberculosis in bovine and human samples: implications for zoonosis.

AIM: To develop emerging diagnostic technique for bovine tuberculosis and to identify its potential risk factors. MATERIALS & METHODS: Bacterial genomic DNA was isolated from bovine milk and human sputum samples and subjected to PCR using specific primer pairs. PCR results were validated using bacteriological cultures. RESULTS: PCR amplification of the targeted DNA fragment of Mycobacterium bovis was successful in 12.33% (37/300) of the bovine samples. Interestingly, 500-bp DNA fragment was also amplified in 6.67% (6/90) of the sputum indicating the possibility of zoonotic transmission. Rearing of livestock in household, unpasteurized milk consumption and smoking were identified as potential risk factors. CONCLUSION: Results of the study may add value to bovine tuberculosis eradication campaigns to achieve the One Health initiative.

Morpho-histometric evaluations of pre-pubertal, pubertal and post-pubertal vesicular gland of indigenous bulls of Bangladesh / Evaluaciones morfohistométricas de la glándula vesicular prepuberal, púberal y postpuberal de bovinos nativos de Bangladesh

The present observation was aimed to evaluate the gross and histometric parameters of the vesicular glands of indigenous bulls. Twenty-eight bulls of three age groups were selected from the local market: the pre pubertal group A (<1 year n=4), pubertal group B (1.5­2.5 years, n=16) and post pubertal or adult group C (above 3 years, n=8). The weight, length (anterio-posterior), width (latero-medial) and the thickness (dorso-ventral) of the both left and right vesicular glands were recorded separately after slaughter of each animal. The left and right vesicular gland shows significantly different (p<0.01), in weight and length in every group. Left vesicular glands were slightly higher than the right in all parameters. The lobules of the gland showed folded mucosa, lined with pseudostratified columnar epithelium. Three types of cells were identified in the epithelium containing A, B and C cell. Type A cells were tall columnar cells having distinct cell boundaries with the oval, round or elongated nucleus. Type B cells were located in the basal lamina having round or oval nucleus with indistinct cell boundaries. Type C cells were narrow columnar cells interspersed between A cells with darkly stained cytoplasm. Lamina propria consisted of loose connective tissue surrounded the alveoli, tubules and some solid end pieces. The numbers of secretory end pieces were variable. The diameters of luminated or non-luminated acini of the glandular end pieces and ducts were increased gradually and significantly (p<0.01) with the advancement of age. The epithelial height of the duct and alveoli were increased with the advancement of age, but no significantly differences among them. Tunica adventitia and muscularis grew with the advancement of age while the interstitial tissue shrunk equally. Above all parameters help to conclude that the vesicular glands of the pubertal indigenous bulls were more functional.

El presente estudio tuvo como propósito evaluar los parámetros macroscópicos e histométricos de las glándulas vesiculares de toros autóctonos. Veinticuatro toros fueron seleccionados en el mercado local y agrupados según la edad en: grupo prepuberal A (<1 año; n=4), grupo puberal B (1.5­2,5 años; n=16) y postpuberal o adulto C (por sobre 3 años; n=8). Se registró el peso, longitud (antero-posterior), ancho (latero-medial) y espesor (dorso-ventral) de las glándulas vesiculares izquierda y derecha por separado, después de sacrificado cada animal. Las glándulas vesiculares izquierda y derecha presentaron diferencia significativa (P<0,01) en cuanto al peso y longitud en cada grupo. Las glándulas vesiculares izquierdas fueron ligeramente mayores en relación a la derecha en todos los parámetros. Los lóbulos de la glándula mostraron una mucosa plegada, cubierta con epitelio columnar pseudoestratificado. Se identificaron tres tipos de células en el epitelio, conteniendo células de tipo A, B y C. Las células de tipo A eran células columnares altas con núcleos ovalados, redondos o alargados. Las células de tipo B se localizaron en la lámina basal, presentando un núcleo redondo o oval con límites celulares indistintos. Las células de tipo C eran células columnares estrechas intercaladas entre las células de tipo A, presentando un citoplasma oscuro. La lámina propia estaba constituida por tejido conectivo laxo, rodeada de alvéolos, túbulos y algunas piezas terminales sólidas. El número de extremos de secreción fue variable. El diámetro de los acinos con luz y sin luz de las piezas terminales y conductos glandulares aumentaron de manera gradual y significativa con el avance de la edad (P<0,01). La altura del epitelio del conducto y alvéolos aumentó con el avance de la edad, pero sin diferencias significativas entre ellos. Las túnicas adventicia y muscular aumentaron con el avance de la edad, mientras que el tejido intersticial se retrajo de manera proporcional. A partir de todos los parámetros analizados, se puede concluir que las glándulas vesiculares de los toros del grupo puberal fueron las más funcionales.

Surveillance of avian influenza virus type A in semi-scavenging ducks in Bangladesh.

BACKGROUND: Ducks are the natural reservoir of influenza A virus and the central host for highly pathogenic avian influenza (H5N1), while domestic ducks rearing in semi-scavenging system could serve as re-assortment vessels for re-emerging new subtypes of influenza viruses between birds to human. Avian influenza virus (AIV) surveillance in Bangladesh has been passive, relying on poultry farmers to report suspected outbreaks of highly pathogenic H5N1 influenza. Here, the results of an active surveillance effort focusing on the semi-scavenging ducks are presented. RESULT: A total of 2100 cloacal swabs and 2100 sera were collected from semi-scavenging ducks from three wintering-sites of Bangladesh during three successive winter seasons, December through February in the years between 2009 and 2012. Virus isolation and identification were carried out from the cloacal swabs by virus propagation in embryonated hen eggs followed by amplification of viral RNA using Avian influenza virus (AIV) specific RT-PCR. The overall prevalence of avian influenza type A was 22.05% for swab samples and 39.76% ducks were sero-positive for avian influenza type A antibody. Extremely low sero-prevalence (0.09%) of AIV H5N1 was detected. CONCLUSIONS: Based on our surveillance results, we conclude that semi-scavenging ducks in Bangladesh might play important role in transmitting Avian Influenza virus (AIV) type A. However, the current risk of infection for humans from domestic ducks in Bangladesh is negligible. We believe that this relatively large dataset over three winters in Bangladesh might create a strong foundation for future studies of AIV prevalence, evolution, and ecology in wintering sites around the globe.