Bovine hypodermosis: prevalence and economic significance in southern Punjab, Pakistan

Study of medicinal plants used in ethnoveterinary medical system in riverine areas of Punjab, Pakistan

BACKGROUND

The use of medicinal plants to treat various veterinary illnesses has been practiced for millennia in many civilizations. Punjab is home to a diverse ethnic community, the majority of whom work in dairy farming, agriculture, and allied professions and have indigenous practices of treating animal illnesses using native flora. This study was designed to (1) document and preserve information about the applications of medicinal plant species in ethnoveterinary remedies among inhabitants of Punjab, Pakistan, and (2) identify popular plants for disease treatment by quantitative analysis of the obtained data and to assess the pharmacological relevance of these species.

METHODS

To collect data from informants (N = 279), questionnaires and semi-structured interviews were used. The ethnoveterinary data were analyzed using principal component analysis, relative frequency citation, fidelity level, relative popularity level, and rank order priority.

RESULTS

A total of 114 plant species utilized in the ethnoveterinary medicinal system were found, which were divided into 56 families and used to treat 16 different illnesses. The Poaceae family, with 16 species, was the most common in the region. The most commonly employed growth form in herbal preparation was herb (49%). The most used part in ethnoveterinary remedies was leaves (35%), while powder was the most commonly used way for preparing ethnoveterinary remedies (51 applications). According to principal component analysis, the most typically used species in the research region were grasses. Five grasses (Arundo donax, Desmostachya bipinnata, Eleusine indica, Hordeum vulgare, and Pennisetum glaucum) showed a 100% FL value when used to treat diuretics, helminthiasis, digestive problems, fever, cough, worm infestation, indigestion, galactagogue, oral infections, and genital prolapse. The maximum value of disease cured level (DCL%) was recorded at 87.6% for endo- and ecto-parasitic ailments in the study area.

CONCLUSION

This study demonstrates that medicinal plants play an important part in satisfying farmers' animal healthcare demands, making it a feasible practice. The study also provides a wealth of knowledge regarding ethnoveterinary methods for further planning and application, providing an option for farmers who cannot afford allopathic therapy.

Epidemiological Surveillance of Hypodermosis in Cattle from Romania

Hypodermosis, or warble fly, is an endemic parasitic disease, common in countries from the northern hemisphere. The use of effective insecticides has decreased the frequency of this parasitic disease, with untreated cattle remaining to act as reservoirs. This study focused on assessing the status of hypodermosis in northwestern Romania by means of clinical examination (skin inspection and palpation performed in order to identify nodules) conducted on a number of 11.741 cattle. The study was carried out from March until June 2021. The identified larvae were subject to molecular assays for species identification and genotyping, followed by comparison with data available in the GenBank database. The average prevalence rate of parasitism caused by Hypoderma spp. was 0.31%, with values ranging from a minimum of 0.11% to a maximum of 1.32%. The dominant age group among positive animals was the 1-3 years old category and in terms of breed distribution, most positive cases were seen in cows belonging to an indigenous breed: Bruna de Maramures. April was the most prolific month in terms of nodule count/animal. The species identified in our study by means of molecular assays was H. bovis with two haplotypes: HB3 and HB8.

Comparative Analysis of Different ELISA Methods for the Serodiagnosis of Przhevalskiana silenus Infestation in Goats

Przhevalskiana silenus (warble fly) grubs cause myiasis in goats, in mountainous and semi-mountainous areas and different regions in Pakistan, and cause substantial losses to livestock. The palpation method for detecting warble flies generally neglects the infestation intensity; therefore, the development of a reliable and efficient diagnostic technique is extremely necessary. This study compared three indirect enzyme-linked immunosorbent assay (ELISA) methods for detecting anti-P. silenus antibodies using the hypodermin C (HyC) purified from Hypoderma spp. Larvae collected in cattle (local isolate, Microbiology Laboratory, PMAS-Arid Agriculture University, Rawalpindi), the crude antigen from the first instar stage of P. silenus, and a commercial Bovine Hypodermosis Antibody ELISA kit (IDEXX Laboratory), for accurately estimating the seroprevalence of goat warble fly infestation (GWFI) in the Pothwar plateau, Punjab, Pakistan. The ELISA with the crude antigen of P. silenus proved very sensitive and specific, 91% and 93%, respectively. The optical density exhibited a monthly variation, and the antibody titer began increasing from June, continually increased from July to December, and gradually decreased thereafter until March. The study confirmed the endemic status of GWFI in the Pothwar region and identified that ELISA based on the crude antigen of P. silenus was a more sensitive and specific immunodiagnostic method for determining seroprevalence, and could be employed for initiating nationwide eradication campaigns.

First molecular characterization of hypodermin genes of Hypoderma bovis and serodiagnosis of bovine hypodermosis with recombinant hypodermin C antigen and a synthetic peptide containing its linear B-cell epitope

Hypodermins A (HA), B (HB), and C (HC) of warble flies are modulatory antigens involved in host inflammation and immune responses during migration of the warble fly larvae through host connective tissues. In the current study, molecular characteristics of the genes encoding HA, HB, and HC were revealed from cDNA constructs of third-instar larvae of Hypoderma bovis. The open reading frame (ORF) of each hypodermin gene was amplified with modified gene-specific primers, and the resulting PCR products were cloned into pGEM-T Easy Vector to produce recombinant plasmids (rHA, rHB, and rHC). The ORF sequences of rHA, rHB, and rHC genes are 705 bp, 771 bp, and 783 bp long and encode proteins of 234, 256, and 263 amino acids with predicted sizes of 25.74 kDa, 27.79 kDa, and 28.51 kDa, respectively. The rHC gene was subcloned into the pET 100/D-TOPO Expression Vector, and the recombinant HC was purified using affinity chromatography. Western blotting indicated that rHC was recognized by the sera of cattle naturally infested with H. bovis. The rHC and a synthetic peptide (sHC) containing its linear B cell-specific epitope were evaluated as serological markers in indirect ELISA (iELISA) for the diagnosis of bovine hypodermosis. Both sHC and rHC iELISAs had sensitivity values equal to or higher than 90 % and specificity values of 100 %. A total of 200 serum samples from cattle in the Central Anatolia Region of Turkey were also analyzed by rHC and sHC-iELISAs to reveal the seroprevalence of bovine hypodermosis. The results of both iELISAs were consistent with one another and revealed a hypodermosis prevalence of 62 %. Our study provides the first data on molecular characterization of hypodermin genes of H. bovis and indicates the efficacy of recombinant antigen and peptide-based iELISA for serodiagnosis of bovine hypodermosis.

Effect of Mixed Invasions of Hypoderma bovis and Ostertagia ostertagi in Cattle on Milk Yield and Contents in Polish Dairy Farms

Wide distribution of ecto- and endoparasites in cattle is a serious problem in the sustainability of a farm, due to the negative impact on animals' health and productivity. The aim of this study was to determine the presence of antibodies against Ostertagia and Hypoderma in udder milk samples and the comparison of milk yield and content of the basic components of milk in ELISA-positive and ELISA-negative cows. Milk samples were collected from 148 lactating cows from 3 herds. Antibody detection was performed using specific ELISAs for Ostertagia ostertagi and Hypoderma bovis. Milk yield and content of protein, fat, and dry matter were studied in samples from each individual cow 11 times per year at 4 week intervals. The extensiveness of dual parasitic invasions in individual herds, estimated on the basis of udder milk testing with the ELISA test, varied and amounted to 3.22%, 11.36%, and 4.76% in the three studied herds, respectively. No antibodies were found in 61.2%, 22.7%, and 57.1% of the milk samples from the cows in each herd. The milk yield of ELISA-positive cows was significantly lower in comparison to the efficiency of ELISA-negative cows and amounted to 294 kg and even to 3672 kg of milk per year, per cow. No significant differences were found between the fat and protein contents of milk between ELISA-positive and -negative cows for both parasites.

Cytokine expression in bovine PBMC cultures stimulated with Hypoderma lineatum antigens

Hypoderma antigens are involved in host inflammation and immune response, conditioning larvae survival. In this study, peripheral blood mononuclear cell (PBMC) cultures from Hypoderma sensitized and unsensitized cattle were performed to determine the effect of H. lineatum antigens and incubation time (18, 24, 48 h) on IFN-γ, TNF-α, IL-10 and IL-4 mRNA gene expression determined by RT-qPCR. TNF-α and IL-4 gene expression were higher in Hypoderma previously sensitized PBMCs, suggesting that a mixed Th1/Th2 response may play a significant role in host defence reactions against Hypoderma exhibited by previously infested cattle. Incubation time had a significant effect on IL-10 and TNF-α gene expression, which decreased over time. Regarding to H. lineatum antigens, the crude larval extract and the purified fraction hypodermin B (HB) produced a significant reduction of the mRNA expression levels of the proinflammatory cytokine, IFN-γ; moreover, the HB had a stimulating effect on the mRNA gene expression of the anti-inflammatory cytokine IL-10, demonstrating that the parasite would modulate the host defence mechanisms by avoiding harmful immune responses that would limit its survival into the host tissues.

Molecular Characterization of Hypoderma SPP. in Domestic Ruminants from Turkey and Pakistan

The aim of this study was to determine the morphological and molecular characterization of Hypoderma spp. in cattle and yak from provinces in Turkey and Pakistan. In total, 78 Hypoderma larvae were collected from slaughtered animals in Turkey and Pakistan from October 2015 to January 2016. Thirty-eight of these 78 Hypoderma larvae were morphologically classified as third instar larvae (L3s) of Hypoderma bovis, 37 were classified as Hypoderma lineatum, and 3 were classified as suspected or unidentified. The restriction enzyme TaqI was used to differentiate the Hypoderma spp. by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). According to the sequences and the PCR-RFLP results, all larval samples from cattle from Turkey were classified as H. bovis, except for 1 sample classified as H. lineatum. All Hypoderma larvae from Pakistan were classified as H. lineatum from cattle and as Hypoderma sinense from yak. This study provides the first molecular characterization of H. lineatum (cattle) and H. sinense (yak) in Pakistan based on PCR-RFLP and sequencing results.

An overview on different aspects of hypodermosis: Current status and future prospects

Livestock plays a vital role in economic development of a nation and is being used in agriculture for draft power, production of farmyard manure as well as milk and meat production. Bovine hypodermosis is the top culprit among all parasitic infections across the world. Hypodermosis is an endemic disease in the mountainous areas/plain areas and is regularly observed in the northern hemisphere of the globe affecting cattle, deer, yaks and buffaloes. There is a wide variation in geographical distribution of Hypoderma spp. during the years 1945-2015. The manuscript includes a geospatial study that tries to maps the global distribution of hypodermosis in different areas of the world in order to detect hotspots or endemic areas that may be a potential source for disease spread. This information's are very useful to predict the potential high risk areas that are prone to disease outbreak. The present review aims to evaluate the global distribution, molecular discrimination, diagnostics and vaccination of hypodermosis, focusing on its current status and future perspectives towards the management of the disease and its control strategies.

Bovine hypodermosis--a global aspect

Cattle hypodermosis (warble fly infestation) is a notorious veterinary problem throughout the world. Larvae of Hypoderma species cause a subcutaneous myiasis of domesticated and wild ruminants. This disease is caused by, Hypoderma bovis, Hypoderma lineatum in cattle whereas, Hypoderma diana, Hypoderma actaeon, and Hypoderma tarandi, affect roe deer, red deer, and reindeer, respectively. Adults of the cattle grub are commonly known as heel flies, warble flies, bomb flies or gad flies. The biology of hypodermosis is complex because it passes through ecto- as well as endoparasitic stages in the life cycle. The parasitic stage of hypodermosis lasts about 1 year in domesticated as well as in the wild animals, while in the adult stage, a free-living fly lasts only for few days. The diagnosis of hypodermosis is of prime importance for planning treatment and the eradication program. Generally, there are two methods that are routinely used for diagnosis of hypodermosis, i.e., the direct clinical examination and immuno diagnosis by the use of pooled serum and/or milk sample. For the control of hypodermosis, different preparations are available and their use in most of the countries is limited to an individual level but never cover the whole cattle population of a country. Re-infestation in the herd occurs due to the untreated animals that remain the reservoir of the disease. The disease causes huge economic losses in animal production due to the effect of this disease on meat, milk, and the leather industry. It can also affect the general health status as well as the immune system of the body of the diseased animals. As regards the control measures of the disease, different methods have been efficiently practiced and consequently this disease is controlled at national level in many European countries.

Cutaneous myiasis caused by Hypoderma lineatum

Cutaneous myiasis is a temporary parasitic infestation of the skin of domestic and wild animals and occasionally of humans by the larvae of flies. Larvae of many flies from various geographic areas can cause myiasis: in Central and South America, human cutaneous myiasis is mainly caused by the larvae of Dermatobia hominis; in Africa, by the larvae of Cordylobia anthropophaga; in the northern hemisphere (North America, Europe, Africa and Asia), by the larvae of Hypoderma spp. A case of cutaneous myiasis in a 47-year-old woman, co-author of the present report, is described. She returned to Slovenia from a three-week trip to Ladakh in Northern India. The parasite, nested in tumor-like swelling about 1-2 cm in diameter and 0.5 cm high in her neck, was removed. The parasite was identified by its morphological characteristics as the larva of Hypoderma lineatum. After the removal of the larva, which was yellowish-white, oval-shaped and about 6 mm long and 1.5 mm wide, the lesion healed in two weeks without further treatment. Clinical and laboratory staff will need to be alert in the future, not only to myiasis caused by Dermatobia and Cordylobia larvae from tropical and subtropical areas but also to Hypoderma larvae from the Himalayan area from where the patient returned to Slovenia.