Search Results (2)

The components of blackfly (Diptera: Simuliidae) saliva secreted during feeding on humans and animals induce various pathological reactions manifested by skin lesions and systemic symptoms. In this study, we describe 43 cases of severe skin lesions induced by blackfly bites and analyze their potential causes. Based on the results of a survey of 418 patients, we identified periods with risk of blackfly attacks and their environmental determinants in the eastern part of the European Union. Especially strong inflammatory reactions after blackfly bites were reported in patients with concomitant cardiovascular diseases (mainly with venous insufficiency), metabolic diseases, and bacterial infections. Enhanced symptoms of simuliosis were also observed in other patients attacked by these insects only once or repeatedly. The greatest number of blackfly attacks in the study area is recorded from May to July, with a peak in June (38.73%) in the afternoon (37.10%) and evening (33.03%), when patients are in fields, forests, or their households. The case analysis indicates interactions of various factors in the development of severe inflammatory reactions in patients bitten by blackflies. Therefore, it is recommended that subjects exposed to the presence of blackflies during their work or rest should limit the length of their stay in a vulnerable environment during the highest seasonal and daily activity of these insects. It is also necessary to take measures to reduce the number of blackflies and popularize methods for prophylaxis of their attacks. Full article

Due to their mass occurrence in some environments and high aggressiveness, blackflies (Simulium spp.) represent the most bothersome arthropods attacking humans. In this study, we describe the medical effects of blackfly infestations in humans in southeastern Poland. Local and systemic reactions to blackfly bites were monitored in 418 patients (61.24% of females and 38.76% of males) of medical centers. Only skin lesions at the site of the bites were found in 88.52% of the patients, whereas accompanying systemic reactions were diagnosed in 11.48%. The most common signs observed in the area of the bites were pruritus (94.74%), burning (55.02%), edema (44.02%), and erythema (40.91%). The skin lesions, which were most often grouped small papules and papular and purpuric lesions with a varied range, typically persisted for several days, or for several weeks in some patients. Statistical analyses confirmed that the persistence of the skin lesions did not depend on the sex of the patients and the number of blackfly infestations. The systemic reactions to the components of the blackfly saliva were manifested by headache, increased body temperature, arthralgia, lymphadenopathy, and menstrual disorders in the females. The patients were most often attacked simultaneously by many blackflies on exposed parts of the body, mainly the upper limb, lower limb, head, and neck areas. The investigations indicate that blackflies are an important etiological factor of dermatitis and other symptoms in humans; hence, they should be considered in clinical diagnosis. Full article