Avian mite dermatitis: an Italian case indicating the establishment and spread ofOrnithonyssus bursa(Acari: Gamasida: Macronyssidae) (Berlese, 1888) in Europe

Evaluation of the in vitro acaricidal activity of ethanol extracts of seven Chinese medicinal herbs on Ornithonyssus sylviarum (Acari: Macronyssidae)

Ornithonyssus sylviarum (Acari: Macronyssidae) is a common ectoparasite that feeds on the blood of poultry. Following infestation, this mite will cause symptoms such as weight loss, anemia, and decreased egg production. To explore green and safe drugs for the prevention and treatment of O. sylviarum, this study evaluated the effects of ethanol extracts of seven Chinese medicinal herbs-Leonurus artemisia (motherwort), Illicium verum (star anise), Cinnamomum cassia (cinnamon), Hibiscus syriacus, Artemisia argyi (Chinese mugwort), Taraxacum sp. (dandelion), and Syzygium aromaticum (clove)-on O. sylviarum at different life stages. The results showed that different methods of administration affected the acaricidal efficacy of these plant extracts on O. sylviarum. After 6 h of administration with the fumigation method, the acaricidal efficacy of S. aromaticum on adults, nymphs and larvae of O. sylviarum reached 100%. 30 min after administration with the infiltration method, S. aromaticum, H. syriacus and L. artemisia showed acaricidal effects on adults and nymphs of O. sylviarum reaching 100%. In another experiment evaluating the inhibition of egg hatching of O. sylviarum with alcohol extracts of these seven herbs, at 48 h after treatment, A. argyi and C. cassia showed inhibition rates of 19.4%. The results of this study indicate that S. aromaticum induced mortality at all stages of O. sylviarum, whereas A. argyi was found to be the most effective at inhibiting the mite's egg hatching among the seven herbs. These herbs can therefore be used as potential substitutes for chemical pesticides to prevent and control O. sylviarum. These results provide practical knowledge for the control of O. sylviarum.

First record of Ornithonyssus bursa (Berlese, 1888) (Mesostigmata: Macronyssidae) parasitizing invasive monk parakeets in Santiago, Chile

Myiopsitta monachus is an invasive psittacine with wide distribution due to the pet trade. Its large communal nests and synanthropic nature contribute to its successful colonization of cities, from where it seems to be expanding in range and numbers. This is relevant with regard to pathogens that invasive species may harbor, especially when host populations thrive. We aimed to identify an abundant mite found in invasive monk parakeet chicks that had been collected in Santiago during 2017 and 2018. Through morphological and molecular identification of the 18S ribosomal RNA gene, we confirmed the presence of Ornithonyssus bursa. This was the first report of this mite in Chile. This mite is common in native and invasive monk parakeet populations and may affect other birds, including domestic fowl. Further, this mite bites people and can be a potential vector of pathogens such as bacteria or viruses. We conclude that this parasite was likely introduced with the parakeet and discuss possible ecological, health and economic consequences of this new potential pest.

Case Report: Human Dermatitis Linked to Ornithonyssus bursa (Dermanyssoidea: Macronyssidae) Infestation in Portugal

Ornithonyssus bursa (Berlese, 1888), also known as the tropical fowl mite, is a blood-feeding ectoparasite of domestic and wild birds. It is considered a serious pest to poultry in warm and tropical climates and has been reported to attack humans, causing gamasoidosis. Avian-mite dermatitis may be difficult to recognize and misdiagnosed as bites from other arthropods. The present report describes two cases of human dermatitis linked to O. bursa infestation. Both cases occurred in an apartment in a residential area in Oeiras, Portugal, where two members of the same family presented with pruritic erythematous skin eruptions disseminated over their body over a period of 4 months. The lesions were located mostly in the pelvic, gluteal, coccygeal, and perineal regions, and also on the neck, wrists and torso. On inspecting the mattresses and the covers of the bedrooms, three mites ~1 mm long by 0.5 mm wide were found. The three specimens were identified as O. bursa. Investigations tracing back the source of infestation, revealed that the mites were carried over from chickens raised 45 km away (Sesimbra, Setúbal) that, after being slaughtered for consumption, had been transported by car to the apartment in Oeiras. The chickens were farmed in an open backyard henhouse that allowed free access to several species of wild birds, including pigeons (Columba livia), turtle doves (Streptopelia decaocto), and sparrows (Passer domesticus). Recent reports suggest that O. bursa may be established in Mediterranean countries, increasing the risk of gamasoidosis. This is the first record linking O. bursa infestation of chickens with human dermatitis in continental Portugal. More research is needed to assess the extent of poultry infestation and evaluate the possible implications for the poultry industry, as well as for human health in Portugal.

Clinical gamasoidosis and antibody response in two patients infested with Ornithonyssus bursa (Acari: Gamasida: Macronyssidae)

Blood-feeding ectoparasites constitute a growing burden for human and animal health, and animal production worldwide. In particular, mites (Acari: Gamasida) of the genera Dermanyssus (Dermanyssidae) and Ornithonyssus (Macronyssidae) infest birds and cause gamasoidosis in humans. The tropical fowl mite, Ornithonyssus bursa, is commonly found in tropical and subtropical countries but rarely reported in Europe. In this research we characterized the first two cases in Spain of clinical gamasoidosis diagnosed in patients infested with O. bursa, and investigated the IgE, IgM and IgG antibody response to mite proteins and the carbohydrate Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal) involved in the tick-bite associated alpha-Gal syndrome (AGS). The results suggested that O. bursa is establishing across Mediterranean countries, and may increase the risk for gamasoidosis. The immune antibody response to mite proteins was higher for IgM and similar for IgE and IgG antibodies between patients and non-allergic control individuals exposed to mite or tick bites. The anti-α-Gal antibody levels were similar between patients and controls, a result supported by the absence of this carbohydrate in mites. These results suggested that mite bites do not correlate with antibody response to acarine proteins or α-Gal, and are not associated with the AGS.