Immunomodulating effects and hypersensitivity reactions caused by Northeast Indian black fly salivary gland extract

Abstract

The genus Simulium, black fly (Diptera), comprises 41800 species worldwide, of which 67 species under six subgenera have been well studied in India. While at the extreme, black fly bites can cause onchocerciasis or river blindness, the majority of clinical observations indicate mainly severe pain and continuous itching at bite sites. This investigation experimentally observed that black fly salivary extract (BFSE) causes unique biologic effects including immunomodulation, anti-coagulation, and hypersensitivity reactions in Wistar rats. Salivary glands from black flies were isolated, extracted in saline, and then &800 ng extract (BFSE) subcutaneously injected into rats. To evaluate potential immunosuppressive activity of the BFSE, serum levels of interleukins [IL]-6 and -10 and tumor necrosis factor [TNF]-a were assayed. To assess the BFSE impact on coagulation, activated partial thromboplastin time (aPTT), prothrombin time (PT), and bleeding time, as well as generation of coagulation activated factors I, IX, and X were analyzed. Anaphylaxis induction was monitored via electrocardiogram (ECG) and measures of blood pressure and rectal temperature. The data showed that BFSE treatment resulted in a significantly prolonged aPTT, PT, and bleeding time and reversibly inhibited generation of coagulation activated factors I, IX, and X. The extract also led to a prolonged (up to 48 h) suppression of serum IL-6, IL-10, and TNFa production. While these results suggest that BFSE possesses anti-thrombotic, anti-coagulant, and immunomodulatory activities, importantly, they also indicate that the extract has a capacity to induce anaphylaxis and acute cardiotoxicity.

Human-landing rate, gonotrophic cycle length, survivorship, and public health importance of Simulium erythrocephalum in Zaragoza, northeastern Spain

“…As vectors of disease agents (leucocytozoonosis, human onchocerciasis, mansonellosis, bovine onchocerciasis and the virus that causes vesicular stomatitis) [1], they also cause intolerable nuisances because of their abundance and habit of swarming and biting [1]. Blackflies introduce salivary molecules into the biting lesion, which are responsible for severe allergic reactions [2, 3]. In Spain, blackfly populations have expanded recently.…”

Kawasaki Disease with Retropharyngeal Edema following a Blackfly Bite

“…A blackfly bite usually causes local pain, swelling, and redness; however, the bite can also cause a systemic reaction (blackfly fever) that precipitates headaches, fever, nausea, vomiting, malaise, and generalized lymphadenopathy [ 11 , 12 ]. Blackfly salivary secretions contain a wide range of physiologically active molecules that can induce local immunomodulation and anticoagulation and local and systemic hypersensitivity reactions in humans [ 13 ]; however, patients with severe blackfly hypersensitivity reactions have rarely been reported. Orange et al [ 14 ] reported a patient with recurrent episodes of presumed cellulitis after blackfly bites who subsequently developed two episodes of delayed hypersensitivity reactions to these bites, including Guillain-Barré syndrome (GBS) and nephrotic syndrome (NS).…”

Who Bites Me? A Tentative Discriminative Key to Diagnose Hematophagous Ectoparasites Biting Using Clinical Manifestations

“…It is accompanied by headache, nausea, fever, and swollen lymph nodes. A severe anaphylactic reaction is a less common manifestation that may require hospitalization [61].…”

“…Various clinical presentations are described (edematous, erythematous-edematous, erysipeloid, inflammatory-indurative, phlegmonoid, and hemorrhagic), but the itching, localized swelling, inflammation eruptions of pruritic papules, vesicles, intense pruritus, and erythematous wheals are common symptoms, resulting from a hypersensitive reaction to black fly bites [62] (Figure 2, Table 2). The Simulium dermatitis is a concern with a high risk of anaphylaxis and acute cardiotoxicity in hypersensitive individuals [61].…”