Maria Assunta Cafiero

Prevalence and key figures for the poultry red mite Dermanyssus gallinae infections in poultry farm systems

Recent surveys and sample collection have confirmed the endemicity of Dermanyssus gallinae in poultry farming worldwide. The reduction in number and efficacy of many acaricide products has accentuated the prevalence rates of this poultry ectoparasite observed more often in non intensive systems such as free-range, barns or backyards and more often in laying hens than in broiler birds. The lack of knowledge from producers and the utilisation of inadequate, ineffective or illegal chemicals in many countries have been responsible for the increase in infestation rates due to the spread of acaricide resistance. The costs for control methods and treatment are showing the tremendous economic impact of this ectoparasite on poultry meat and egg industries. This paper reviews the prevalence rates of this poultry pest in different countries and for different farming systems and the production parameters which could be linked to this pest proliferation.

Acaricide Residues in Laying Hens Naturally Infested by Red Mite Dermanyssus gallinae

In the poultry industry, control of the red mite D. gallinae primarily relies worldwide on acaricides registered for use in agriculture or for livestock, and those most widely used are carbamates, followed by amidines, pyrethroids and organophosphates. Due to the repeated use of acaricides - sometimes in high concentrations - to control infestation, red mites may become resistant, and acaricides may accumulate in chicken organs and tissues, and also in eggs. To highlight some situations of misuse/abuse of chemicals and of risk to human health, we investigated laying hens, destined to the slaughterhouse, for the presence of acaricide residues in their organs and tissues. We used 45 hens from which we collected a total of 225 samples from the following tissues and organs: skin, fat, liver, muscle, hearth, and kidney. In these samples we analyzed the residual contents of carbaryl and permethrin by LC-MS/MS. Ninety-one (40.4%) samples were positive to carbaryl and four samples (1.7%) were positive to permethrin. Concentrations of carbaryl exceeding the detection limit (0.005 ppm) were registered in the skin and fat of birds from two farms (p<0.01), although these concentrations remained below the maximum residue limit (MRLs) (0.05 ppm) (p<0.01). All organs/tissues of hens from a third farm were significantly more contaminated, with skin and muscle samples exceeding the MRL (0.05 ppm) (p<0.01) of carbaryl in force before its use was banned. Out of 45 chickens tested, 37 (82.2%) were found to be contaminated by carbaryl, and 4 (8.8%) by permethrin. The present study is the first report on the presence of pesticides banned by the EU (carbaryl) or not licensed for use (permethrin) in the organs and tissues of laying hens, which have been treated against red mites, and then slaughtered for human consumption at the end of their life cycle.

A gallery of the key characters to ease identification of Dermanyssus gallinae (Acari: Gamasida: Dermanyssidae) and allow differentiation from Ornithonyssus sylviarum (Acari: Gamasida: Macronyssidae)

BackgroundDermanyssus gallinae (poultry red mite) is a major threat for the poultry industry and is of significant interest for public health. Identification of D. gallinae can be difficult for scientists not familiar with mite morphology and terminology especially when trying to use identification keys. Moreover, this species may easily be confused with another dermanyssoid mite, Ornithonyssus sylviarum (northern fowl mite), which often shares the same hosts and environment.MethodsSpecimens of D. gallinae were collected at poultry farms in the Puglia and performed for light and scanning electron microscopy observations, identification and micrographs. Moreover specimens of O. sylviarum were collected separately macerated and mounted on slides for light microscopy observations, identification and pictures.ResultsThe micrographs used in this study, based on LM and SEM observations, highlight the following important identifying characters of D. gallinae: the prominent shoulders of the dorsal shield and the jagged edges of the shield reticulations, the position of setae j 1, s 1 and the epigynal pores, and the presence on tibia IV pl of one seta. Additional micrographs highlighting the shape of the dorsal (abruptly narrowed posteriorly) and epigynal (narrowly rounded posteriorly) shields and the chelicera (elongate, with distinct digits) of O. sylviarum enable its differentiation from D.gallinae.ConclusionThe photographic support provided here (both LM and SEM pictures) can be considered a practical tool for scientists who are not well acquainted with the morphology of D.gallinae, and who are involved with classical and molecular systematics, veterinary and human health aspects of poultry red mites.

Chlamydia psittaci infection in canaries heavily infested by Dermanyssus gallinae

Dermanyssus gallinae is a haematophagous ectoparasite responsible for anemia, weight loss, dermatitis and a decrease in egg production. Dermanyssus gallinae may play a role in the modulation of the host immune system, maybe predisposing the host to some bacterial infections such as chlamydiosis. This is an important zoonosis. Humans are exposed to Chlamydia psittaci through inhalation of the agent dispersed from the infected birds. In this study, a syndrome observed in an aviary of canaries was investigated. A heavy infestation by D. gallinae was reported. Simultaneously, a C. psittaci infection was molecularly confirmed in the canaries. Combined therapy was applied successfully. The association of C. psittaci with the examined mites has been confirmed. Therefore, we think that D. gallinae have played a role in the spreading of C. psittaci infection among the canaries. Moreover, D. gallinae could have played an important role predisposing the canaries to the development of chlamydiosis, by inducing anemia and debilitation. The control of mites in the aviaries may represent a crucial step for the prevention of important infection such as chlamydiosis in birds and humans.

Why dermanyssosis should be listed as an occupational hazard

The red mite, Dermanyssus gallinae (Acarina: Mesostigmata), is a temporary blood-sucking ectoparasite of poultry and other avian species, with a worldwide distribution. It can occasionally bite mammals, including humans, and cause dermatitis. Medical textbooks frequently cite itching and cutaneous lesions resulting from red-mite bites as a normal occurrence in subjects working in close conjunction with poultry. In fact, D. gallinae is one of the most common pests and a major cause of economic loss in the poultry industry, with a farm prevalence of up to 90%.1 In the literature, red-mite dermatitis (RMD) is generally regarded as an urban hygiene issue. Not only …

Phylogenetic relationship between Dermanyssus gallinae populations in European countries based on mitochondrial COI gene sequences.

Phylogenetic analysis of Dermanyssus gallinae mites originating from UK, France and Italy was performed using partial amplification of the mitochondrial COI gene. Results showed that UK samples reveal the greatest variation and diversity and are linked to one of the French populations highlighting North–South genetic transitions in European red mite populations. Intra-farm variations between mite samples highlighted the diversity between national populations and possibly its origin from the different chemical strategies used in each country.

An urban outbreak of red mite dermatitis in Italy

The outbreak involved three adults (two women and one man) and a child living in two apartments in the same building in a city in southern Italy. At the end of March, the married couple (living in the second-floor apartment of the three-story building) noted small, light-colored and/or brownish crawling arthropods on the cordless phone in the bedroom. Because they experienced itching in and around the ear whenever they used the phone, they sprayed it with a commercial insecticide designed to kill ants. After several days, the itching returned. During early April, their 2-yearold daughter developed intensely pruritic skin lesions. The symptoms initially involved the posterior auricular and parietal regions of the head, as well as the neck and extremities, but rapidly generalized. The child slept in the same room as her parents, who noted similar eruptions, first involving the ankles and feet, and then the legs, arms, and trunk. The lesions were accompanied by intense, especially nocturnal, pruritus. Two weeks after the onset of the symptoms, the child was examined by her pediatrician who prescribed cortisone and antimicrobials. The treatment was ineffective. At the end of April, the family left home for a 1-week holiday, and the skin lesions healed almost completely. The pruritic dermatitis returned after one night at home, and actively motile arthropods were found on the bedroom furniture. De-infestation was performed. On May 8th, the mother collected a small brownish parasite from the child’s bed, and a second parasite was accidentally crushed against the pillowcase, producing a blood spot (Fig. 1). Alarmed by the presence of ‘‘blood-feeding insects,’’ the mother also collected parasites from the cordless phone, although they were clearly different in size and color, and took them to the Laboratory of Entomology of the Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata (IZS), Foggia, Italy. On May 9th, the IZS staff found a pigeon’s nest under the gutter between the balconies of the two apartments. Diffuse skin lesions were visible on most of the child’s body (Fig. 2), and the parents showed a few lesions involving the extremities. The owner of the top-floor apartment, a 69-year-old woman, was also found to be afflicted with a generalized, pruritic dermatitis (Fig. 3). On several occasions, she found ‘‘tiny, light-colored, rapidly crawling insects’’ on the television and alarm clock in her bedroom. Her physician prescribed cortisone and tranquilizers. The mites collected from the nest and surrounding areas were identified as Dermanyssus 1119 Figure 1 Blood spot caused by a fed Dermanyssus gallinae (red poultry mite) crushed against the pillowcase

Coxiella-like endosymbiont associated to the "Anatolian brown tick" Rhipicephalus bursa in Southern Italy.

Several different ticks have been reported to harbor microbes related to Coxiella burnetii, the agent of the Q fever. Rhipicephalus bursa is an important vector of tick-borne diseases in livestock in Mediterranean area; it is also abundant in ovi-caprine farms with C. burnetii infection, in Southern Italy. 60 females of Rh. bursa (15 pools) and 40 their eggs (2 pools) were screened for C. burnetii by a conventional PCR targeting the insertion sequence IS1111 and by Loop mediated isothermal amplification assay (LAMP) targeting com1 gene. One of 15 tick pools (1/15) and both egg pools (2/2) were found positive by LAMP assay and negative by PCR targeting IS1111 gene. 16S rRNA gene was amplified by PCR from the LAMP-positive pools, amplicons were sequenced and found 95% similar to the corresponding sequences from C. burnetii. This let us to hypothesize the presence of a new Coxiella-like endosymbiont associated with Rh. bursa which could be vertically transmitted, described here for the first time. The lack of detection of IS1111 in Coxiella endosymbiont of Rh. bursa could be related to the possible absence of the Pathogenicity island of C. burnetii, to which IS1111s are associated.

Characterization of Dermanyssus gallinae (Acarina: Dermanissydae) by sequence analysis of the ribosomal internal transcribed spacer regions.

In the present work mites previously identified as Dermanyssus gallinae De Geer (Acari, Mesostigmata) using morphological keys were investigated by molecular tools. The complete internal transcribed spacer 1 (ITS1), 5.8S ribosomal DNA, and ITS2 region of the ribosomal DNA from mites were amplified and sequenced to examine the level of sequence variations and to explore the feasibility of using this region in the identification of this mite. Conserved primers located at the 3’end of 18S and at the 5’start of 28S rRNA genes were used first, and amplified fragments were sequenced. Sequence analyses showed no variation in 5.8S and ITS2 region while slight intraspecific variations involving substitutions as well as deletions concentrated in the ITS1 region. Based on the sequence analyses a nested PCR of the ITS2 region followed by RFLP analyses has been set up in the attempt to provide a rapid molecular diagnostic tool of D. gallinae.

Outbreaks of Dermanyssus gallinae (Acari, Mesostigmata) Related Dermatitis in Humans in Public and Private Residences, in Italy (2001-2017): An Expanding Skin Affliction

Avian mite dermatitis is a skin affliction of mammals, including humans caused by bites of nidicoulous, haematophagous mites in the suborder Mesostigmata, which naturally parasitize birds. The red-mite, Dermanyssus gallinae is the most common species implicated in episodes of dermatitis in city-dwellers, worldwide. Symptoms manifest in the form of pruritic, erythematous papules on exposed/covered body areas. We report 20 urban outbreaks of red-mite dermatitis occurring in Southern Italy from 2001 to 2017 (June) and diagnosed through parasitological identification by veterinarian entomologists. The patients, a total of 54 subjects, were infested in their homes/ workplaces by both mites emigrating indoors from deserted nests of sinantropic birds close to the infested edifices and from pet canaries. Red-mites may be the explanation of cases of pruriginous dermatitis of obscure origin in citydwellers. The applying of the One Health approach is crucial for diagnosis, treatment and prevention of dermatitis by epizoonotic ectoparasites.