Inflammatory reaction to the human bot‐fly, Dermatobia hominis, in infested and reinfested mice

Abstract

Abstract. Two groups of mice were infested with first stage larvae of the human bot-fly, Dermatobia hominis (Linnaeus Jr) (Diptera: Oestridae). In the first group, skin biopsies were carried out 1, 3, 5, 7, 10 and 18 days after infestation. The second group was also infested but had all the larvae removed 5 days after infestation. The mice in the latter group were reinfested 4 weeks later and skin biopsies were carried out 1, 3, 5, 7, 10 and 18 days after reinfestation. In the first group, an inflammatory reaction began slowly, the neutrophils being the main inflammatory cells, eosinophils being scarce. The reaction progressed with time, developing a necrotic halo around the larvae containing inflammatory cells surrounded by fibroblasts. The inflammation invaded the adjacent tissue. In the second group, the inflammatory reaction was intense on the day immediately after reinfestation, the pattern being changed by the presence of a large number of eosinophils. Activated fibroblasts surrounding the necrotic area around the larvae appeared 3 days after reinfestation in the second group and 7 days after infestation in the first group. The results demonstrated that the previous contact with the antigens elicited the early arrival of eosinophils, probably through the chemotactic factors liberated by mast cells in the anaphylactic reaction.

Histological and immunohistochemical characterization of Hypoderma lineatum (Diptera: oestridae) warbles

“…They are characterized by the existence of a chronic, proliferative dermatitis in the internal dermis with variations in the cell populations present in the infiltrate according to the different types of lesion. During the penetration phase, and associated with the first instar, an inflammation characterized by abundant neutrophils and eosinophils in the skin is recognized (Lello and Rosis, 2003;López et al, 2005;Oryan and Bahrami, 2012). However, in our study, inflammation has been predominantly mononuclear where neutrophils have not been recorded.…”

Lymphadenopathy and Expression of Nodal Mast Cells and Eosinophils in the Myiasis by Human Bot Fly

“…They are also important in protective immune responses against pathogens. In myiasis, high numbers of mast cells associated with the presence of warbles have been reported mainly from the skin for D. hominis infestations in a previous study (Pereira et al 2001) and by Lello and Rosis (2003) and from the naso-sinusal mucosae in those due to Oestrus ovis (L.) (Jacquiet et al 2005). It has been suggested that immediate hypersensibility in the naso-sinusal mucosae of sheep and goats is induced by excretory-secretory products of O. ovis larvae (Dorchies 1997, Jacquiet et al 2005.…”

Painful, slow developing abscesses. Furuncular miyasis due to double skin infestation by Dermatobia hominis

“…In repeatedly infested hosts the inflammatory reaction is more rapid and gets stronger with an early involvement of eosinophils. 6 Collagen degradation is seen secondary to larval enzymatic destruction. The cavity around the larva may be epithelialised, and rupture may be associated with a foreign body reaction.…”