Prevalence and seasonal dynamics of gastrointestinal nematodes of domestic fowls (Gallus gallus domesticus) in Kashmir, India

Ascaridia galli, a common nematode in semiscavenging indigenous chickens in Bangladesh: epidemiology, genetic diversity, pathobiology, ex vivo culture, and anthelmintic efficacy

Ascaridia galli is the most common nematode in chickens. Ascaridia galli is highly prevalent in chickens reared in scavenging or semiscavenging systems. Here, we studied the epidemiology, pathology, genetic diversity, ex vivo culture protocol and anthelmintic sensitivity of A. galli prevalent in indigenous chickens in Bangladesh. Through morphological study and molecular analyses, the isolated worms were confirmed as A. galli. Of the chickens examined, 45.6% (178 out of 390) were found infected. The male and young chickens were significantly (P < 0.05) more prone to A. galli infection. Prevalence of the infection was significantly (P < 0.05) lower in the summer season. In heavy infections, A. galli blocked the small intestine. Marked inflammation, increased mucus production and petechial hemorrhages were evident in the small intestine, particularly in the duodenum. Also, there were desquamation and adhesion of the mucosal villi; degeneration, necrosis of the epithelial cells and goblet cell hyperplasia. The mucosal layer was infiltrated mainly with eosinophils and heterophils. We developed a hen egg white-based long-term ex vivo culture protocol which supported the survival and reproduction of A. galli for more than a week. Levamisole (LEV) and ivermectin (IVM) efficiently killed A. galli. However, albendazole (ABZ), mebendazole (MBZ), and piperazine (PPZ) did not kill the worms even at 120 μg/mL and 1mg/mL concentrations, respectively. Taken together, our results suggest that A. galli is highly prevalent in semiscavenging chickens in Bangladesh. Ascaridia galli can be easily maintained ex vivo in egg white supplemented M199 medium. LEV and IVM, but not ABZ, MBZ and PPZ, can be used for treating and controlling A. galli infections in chickens.

Ascaridia galli infection in chicken: Pathobiology and immunological orchestra

BACKGROUND

Ascaridia galli is the largest gut-dwelling helminth of chickens, which confers adverse effects on meat and egg production; thus, on the animal protein supply and the economy. Both adult and immature parasites affect gut health, but larval stages play a major role in pathology.

AIMS

Here, we present immunology and pathology of A. galli in chickens.

MATERIALS AND METHODS

Literatures were surveyed through online platforms such as PubMed, Google Scholar and Researchgate.

RESULTS

The larvae cause excessive mucus production, damage to the intestinal gland, hemorrhage, anemia, diarrhea, and malnutrition. The adult worms can cause death by intestinal obstruction and intussusception. Although both cellular and humoral immunity are involved in fighting against ascariasis, the role of naturally acquired immunity is poorly defined. In cellular immunity, Th-2 cytokines (IL-4, IL-5, IL-9, and IL-13), goblet cells (mucin), gut-associated lymphoid tissues, CD8α+ intraepithelial cells, TCRγδ + T cells, and TGF-β4 form a protective band. Type 2 immunity provides protection by forming a network of endogenous damage-associated molecular patterns, chitin, and parasitic antigens. Among antibodies, IgY is the most prominent in chickens and provides temporary humoral protection. During parasitic infection, infiltration of various immune cells is evident, especially in the intestinal epithelium, lamina propria, and crypts of the duodenum and jejunum. In chickens older than 12 weeks, gradual reduction of worm burden is more successful than the younger birds. Female chickens exert a short-lived but higher level of protection by passing IgY to chicks in the form of egg yolk antibodies. In laying conditions, immunity differs between breeds. This review provides an overview of the silent but inevitable pathological changes induced by A. galli and the interaction of host immunity with the parasite.

A high level estimation of the net economic benefits to small-scale livestock producers arising from animal health product distribution initiatives

Introduction

A fundamental challenge for charities that facilitate distribution of animal health products to small-scale livestock producers (SSPs) in low and middle income countries (LMICs) is identifying the products and market mechanisms that provide the greatest positive impact for SSPs and estimating their associated impact. This paper describes a pragmatic approach to modeling the impact of market-led product distribution initiatives based on estimating the net economic benefit of administration of animal health products.

Methods

The model estimates the economic impact of diseases at the individual animal level for poultry, small ruminants, and cattle. The economic impact of mortality and growth inhibition associated with disease are then estimated in conjunction with the losses averted or recovered by preventing or treating the disease. Economic benefit is estimated in 2014-2017 values and also adjusted to 2023 values. The flexible model structure allows for addition of new geographies, new products, and increased granularity of modeled production systems.

Results

Applied to the Global Alliance for Livestock Veterinary Medicines (GALVmed) product distribution initiatives conducted in Africa and South Asia (SA) between 2014 and 2017, the model estimates an adjusted total net economic benefit of 139.9 million USD from sales of vaccines and poultry anthelminthics in these initiatives. Within SSA, the greatest net economic benefit was realized from East Coast fever and Newcastle disease vaccines, while in SA, peste des petits ruminants and Newcastle disease vaccines had the greatest net economic benefits. This translated to an adjusted $37.97 of net economic benefit on average per SSP customer, many of whom were small poultry producers.

Discussion

While the model currently estimates impacts from mortality and growth inhibition in livestock, there is the potential to extend it to cover impacts of further initiatives, including interventions targeted at diseases that impact production of milk, eggs, and reproduction.

The first record of Heterakis gallinarum as a cause of fatal nodular typhlitis in golden pheasants (Chrysolophus pictus) in India

Background

Heterakidosis is one of the most prevalent parasitic diseases in birds, the caecae of a variety of wild and domestic birds are infected with these nematodes. In pheasants, nodular typhlitis is a lethal disease caused mainly by infection with Heterakis isolonche alone or in conjunction with Heterakis gallinarum. H. gallinarum has long been recognized to infect birds with low pathogenicity, with only a few fatal cases previously reported.

Case description

This paper describes a case of fatal nodular typhlitis due to H. gallinarum in a male and female pair of adult golden pheasants (Chrysolophus pictus) from a zoological garden in Uttar Pradesh, India.

Findings/treatment and outcome

The caecum had multiple serosal and mucosal nodules, the majority of which were found to contain various stages of parasites embedded in the center along with the free forms in the caecal contents. Histopathologically, these nodules were generally represented by granulomas centered on necrotic parasite debris, with the occasional reactive fibrous hyperplastic tissue reaction. Based on the morphology and nematode-specific internal transcribed spacer (ITS) ITS1-5.8 rRNA-ITS2 region-based PCR, the nematode was identified as H. gallinarum. The presence of H. gallinarum was further confirmed by sequencing the ITS region followed by phylogenetic analysis. According to the author's best knowledge, this is the first instance of H. gallinarum being linked to nodular typhlitis in pheasants in India.

Conclusion

Our findings confirm that H. gallinarum, other than H. isolonche, can induce severe nodular typhlitis with a fatal outcome in pheasants.

First report of gastrointestinal nematodes and coccidia parasites from free-range chickens in Mafeteng district, Lesotho

Free-range chickens are an integral part of poultry production in many developing countries. In the Mountain Kingdom of Lesotho, the majority of the population own free-range chickens, which serve a variety of purposes including being a source of meat, eggs and use for cultural rituals amongst others. However, there is lack of scientific studies on occurrence of parasitic infections on free-range chickens in Lesotho. The aim of this study was to document common gastrointestinal parasites infecting free-range chickens in four villages of Mafeteng District in Lesotho. A total number of 462 pooled faecal samples were collected from various households in HaKubutu (n = 114), HaMatjeka (n = 120), HaMpalipali (n = 120) and Thabang Villages (n = 108) which were subjected to microscopic examination using McMaster technique. The prevalence of gastrointestinal parasite infection was as follows: Eimeria tenella (12.8%), Ascaridia galli (10.4%) and Heterakis gallinarum (5%). The prevalence for H. gallinarum and Ascaridia galli were comparatively higher during the hot-wet season (7.1% and 2.8% respectively) than the cold-dry season (3.2% and 1.9% respectively) and varied significantly (P < 0.05). For E. tenella, the oocysts per gram were slightly higher in the cold-dry season than the hot-wet season. Polymerase chain reaction only amplified DNA from six (29%) adult A. galli worms of which two amplicons were successfully sequenced. The obtained cytochrome C oxidase subunit 1 partial gene sequences displayed 98-100% identity with South African A. galli isolates. This is the first scientific study on prevalence and molecular characterization of nematodes and coccidia species infecting free-range village chickens in Lesotho. The findings can be used to review management of gastrointestinal nematodes and protozoal parasites of free-range chickens in Lesotho.

Prevalence of gastrointestinal parasites in three groups of domestic poultry managed under backyard system in the Savanna subregion, Department of Sucre, Colombia

Objective:

To identify the prevalence of gastrointestinal parasites that affect the backyard poultry system in the Savanna region, Department of Sucre, Colombia.

Materials and Methods:

Fecal samples were collected from 860 native birds, both hens (Gallus domesticus), ducks (Anas platyrhynchos domesticus), and turkeys (Meleagris gallopavo), regardless of age and sex. Samples were processed using direct techniques with ZnSO₄ and indirect methods such as modified Sloss. Data were presented as frequencies, and the nonparametric odds ratio test was used for two independent samples.

Results:

A total of 77.3% (665/860) of the birds were infected with one or more species of gastrointestinal parasites. Among the nematodes, Capillaria spp. (45.6%), Ascaridia galli (18.4%), Heterakis gallinarum (59.4%), Syngamus trachea (38.9%), Tetrameres spp. (25.2%), and Strongylus spp. (12.2%) were recorded. The cestodes were Choanotaenia infundibulum (22.6%), Davainea proglottina (42.3%), Raillietina spp. (58.3%), and Hymenolepis spp. (54.7%), while only Eimeria spp. (90%) was recorded as protozoa.

Conclusions:

The study showed a high incidence of gastrointestinal parasite infestations, the most common species being Hymenolepis spp., Eimeria spp., Raillietina spp., and Heterakis gallinarum.