Dermanyssus gallinae in non-avian hosts: A case report in a dog and review of the literature

Growth kinetics and population density of a laboratory colony of the poultry red mite (Dermanyssus gallinae) established in Japan

The poultry red mite (PRM), Dermanyssus gallinae, is a hematophagous ectoparasite that significantly threatens the poultry industry, not only through blood-feeding but also as a vector for deadly pathogens. With the growing challenge of acaricidal resistance, the demand for alternative control measures is urgent. However, effective PRM research, particularly in acaricidal efficacy and new drug discovery, hinges on the availability of reliable laboratory colonies. In this study, we successfully established a stable PRM laboratory colony, originally isolated from the field in 2021 and maintained under controlled conditions at the Research Institute for Animal Science in Biochemistry and Toxicology (RIAS). We investigated the growth kinetics and population dynamics of the laboratory colony within a Styrofoam-based maintenance box (SBMB) containing chicks. PRM propagation was tracked over 28 days, with mites collected every seven days. The average bulk weight of the mites in the trap increased from 4.3 ± 1.2 mg on day 7 to 201.4 ± 56.5 mg on day 28, despite seasonal variations, indicating optimal conditions for population growth. The collected mites spanned various blood-feeding developmental stages such as protonymph, deutonymph, and adult stages, enabling comprehensive assessments of molting and egg-laying efficiency. Our findings confirm that the laboratory colony of PRM can be stably maintained, providing a reliable source of PRMs for further experimental research aimed at advancing control strategies against this pervasive pest.

One health approach to study human health risks associated with Dermanyssus gallinae mites

Despite the significant health risks associated with Dermanyssus gallinae infestations in humans, they are often overlooked. This study investigated a household case of D. gallinae infestation and explored the resulting clinical manifestations and risk of infection in family members. Microfluidic PCR was employed for high-throughput screening of pathogens in collected mites and blood samples from both chickens and family members. Morphological and molecular examinations confirmed the identity of the mites as D. gallinae sensu stricto (s.s.), with evidence indicating recent blood feeding. Results indicated that the mites exclusively harbored various pathogens, including Bartonella spp., Ehrlichia spp., Apicomplexa, and Theileria spp. Blood samples from family members and poultry tested negative for these pathogens, suggesting a potential reservoir role for D. gallinae. The study further identified haplotypes of D. gallinae, classifying them into D. gallinae s.s., cosmopolitan haplogroup A. Serological analysis revealed elevated IgE seroreactivity against mite proteins in the family member with bite lesions. Antibodies against Bartonella spp. were detected in this individual, indicating exposure to the pathogen. In summary, this study sheds light on the clinical manifestations, pathogen detection, and genetic characterization of D. gallinae infestations, underscoring the necessity of adopting comprehensive approaches to manage such infestations effectively.

Short-time cold atmospheric pressure plasma exposure can kill all life stages of the poultry red mite, Dermanyssus gallinae, under laboratory conditions

In the present study, the acaricidal effects of cold atmospheric pressure plasma treatment on poultry red mites of different developmental stages have been investigated under laboratory conditions using a dielectric barrier discharge system. A total of 1890 poultry red mites and 90 mite eggs, respectively, were exposed to the plasma under various parameter settings with a single plasma pulse generated using the gas mixture of the ambient air at atmospheric pressure. The results showed that all developmental stages of the poultry red mite could be killed by cold atmospheric pressure plasma treatment. Plasma exposure to mite eggs resulted in a complete 100% hatch inhibition regardless of the parameter settings. Post-exposure mortality rates of larvae, nymphs and adults showed significant differences after utilization of plasma at 10 W for 1.0 s. In addition, the mortality rate increased with progressing time after plasma exposure. An average mortality rate of 99.7% was observed after 12 h in all mites exposed to plasma, regardless of the selected plasma parameter, developmental stage, and nutritional status of the mites. Cold atmospheric pressure plasma has an acaricidal effect on all developmental stages of Dermanyssus gallinae, suggesting that it could be developed to an effective method for the control of poultry red mites in laying hen husbandry.

Evaluation of the in vitro acaricidal activity of Chinese herbal compounds on the poultry red mite (Dermanyssus gallinae)

The poultry red mite Dermanyssus gallinae is an economically important pest in poultry farms worldwide, but an effective treatment option is lacking. The current study determined the effectiveness of six Chinese herbal medicines [Syzygium aromaticum (clove), Hibiscus syriacus (Hibiscus), Illicium verum (star anise), Leonurus artemisia (motherwort), Cinnamomum cassia (cinnamon), and Taraxacum sp. (dandelion)] against D. gallinae. Alcohol extracts were prepared via the solvent extraction method and the phenol, flavonoid, and tannin contents were determined. These active components were highest in S. aromaticum and lowest in H. syriacus, I. verum. No tannin content was detected in L. artemisia. All extracts showed contact toxicity against D. gallinae at a test concentration of 1 g/mL, with S. aromaticum and L. artemisia resulting in 100% mortality. S. aromaticum, L. artemisia, and I. verum showed the best efficacy (LC₅₀ 0.159, 0.200, and 0.292 g/mL, respectively). Different combinations of extracts showed an additive effect of I. verum LC₉₀ + L. artemisia LC₉₀. The acaricidal efficacy of this combination was tested against different developmental stages of D. gallinae, being most efficacious against nymphal and larval D. gallinae, with a corrected mortality rate of 100%. However, inhibition of egg hatching was only 53.69%. Taken together, these results highlight I. verum LC₉₀ + L. artemisia LC₉₀ as a promising compound with severe contact toxicity against D. gallinae. Given the wide cultivation of these species and their extensive use in foodstuffs and cosmetics as flavors and fragrances, they could be a cheap, readily available ecofriendly alternative to pesticides currently used in poultry farms.

Evaluation of the Acaricidal Effectiveness of Fipronil and Phoxim in Field Populations of Dermanyssus gallinae (De Geer, 1778) from Ornamental Poultry Farms in Italy

The poultry red mite Dermanyssus gallinae is the most important blood-sucking ectoparasite in egg-laying hen facilities. The aim of this study was to evaluate the in vitro acaricidal activity of different concentration of authorized (phoxim, ByeMite®, 500 mg/mL) and unauthorized (fipronil, Frontline® 250 mg/100 mL spray) molecules on 14 field isolates of D. gallinae collected from different ornamental poultry farms from different Italian regions. The sensitivity test was performed by contact exposure to four concentrations of each insecticide diluted at 1:5 (10,000-2000-400-80 ppm for phoxim, 500-100-20-4 ppm for fipronil) on a filter paper. The effectiveness of the treatment was significantly (p < 0.0001) associated with the dose of the pesticide used. Considering the mean lethality, phoxim has greater efficacy compared to fipronil (p < 0.001). A great variability of lethality rate was observed with the increase in fipronil dilution; conversely, for phoxim, some outliers were observed, particularly in one farm, suggesting the hypothesis that a certain degree of resistance in the mite population could occur possibly as a consequence of the continual contact with the molecule. This underlines the importance of the use of licensed products administered at correct dosages and the need for alternative molecules to avoid the onset of drug resistance phenomena.

Zoonotic Episodes of Scabies: A Global Overview

Zoonotic scabies (ZS), also referred to as "pseudoscabies", is considered a self-limiting disease with a short incubation period and transient clinical skin signs. It is commonly thought that Sarcoptes scabiei mites from animals are unable to successfully reproduce and persist on human skin; however, several ZS case reports have mentioned the persistence of symptoms and occasionally mites for weeks. The aim of this review was to collect and organize the sparse literature explicitly referring to S. scabiei zoonotic transmission, focusing on the source of the outbreak, the circumstances leading to the transmission of the parasite, the diagnosis including the identification of the Sarcoptes "strain" involved, and the applied treatments. A total of 46 articles, one conference abstract and a book were collected describing ZS cases associated with twenty animal hosts in five continents. Dogs were by far the most common source among pet owners, while diverse livestock and wildlife contributed to the caseload as an occupational disease. Genetic epidemiological studies of ZS outbreaks are still limited in number, but tools are available to fill this knowledge gap in the near future. Further research is also needed to understand the apparent heterogeneity in the morbidity, disease severity and timing of the response to treatment among people infected with different animal-derived strains.

Risk Factors for Bovine Cysticercosis in North-West Italy: A Multi-Year Case-Control Study

Simple Summary

Bovine cysticercosis is a parasitic disease caused by Cysticercus bovis, the larval stage of the human tapeworm Taenia saginata, which is the causative agent of human taeniasis, a foodborne parasitic disease caused by the consumption of infected raw or undercooked beef meat. Although commonly asymptomatic, bovine cysticercosis has an important impact worldwide, causing huge economic losses to the meat industry due to carcass condemnation or downgrading. Given the lack of epidemiological case-control surveys carried out in Italy, the present survey’s aim was to assess the presence of farm-level risk factors for bovine cysticercosis in an endemic area in North-West Italy. The results of our survey show a significant association between the detection of bovine cysticercosis cases at slaughter and farm proximity to picnic spots, closeness of wastewater treatment plant effluents, presence of employees along with the family members and loose-housing systems. These findings highlight the need for enforced food chain information and surveillance strategies and the crucial role that hygiene-related campaigns would play to educate both the general public and farm operators on the transmission pathways of T. saginata.

Abstract

Taenia saginata is the causative agent of bovine cysticercosis, a zoonotic parasitic disease with a worldwide distribution. Bovine cysticercosis is considered to be an important food safety issue responsible for human taeniasis and a major economic concern since infected carcasses undergo condemnation, freezing and downgrading. The aim of the current investigation was to assess the presence of farm-level risk factors for bovine cysticercosis in an endemic area in North-West Italy. A questionnaire was designed to collect information relating to several farm structural features, as well as management practices, environmental characteristics and attitudes of farmers. The questionnaire was administered in two separate time intervals by direct interview to previously selected case and control farms. Overall, 32 case farms and 131 control farms were included between 2005 and 2011 and 50 case farms and 192 control farms were included between 2014 and 2020. The present survey showed a significant association between the detection of bovine cysticercosis cases at slaughter and farm proximity to picnic spots, closeness of wastewater treatment plant effluents, loose-housing systems and presence of employees along with the family members, highlighting the need for targeted awareness raising policies.