Black Fly Bites Research Articles

Analyses of cDNA and recombinant protein for a potent vasoactive protein in saliva of a blood-feeding black fly, Simulium vittatum.

A cDNA was cloned from the salivary glands of a blood-feeding black fly Simulium vittatum. The encoded protein has been given the name Simulium vittatum erythema protein or SVEP, because of its ability to increase blood perfusion in skin capillaries, resulting in the well-characterized erythema of black fly bites. The full-length cDNA contains 548 base pairs which encode 152 amino acid residues of the nascent protein. Post-translational processing produces a mature, secreted protein of 133 residues with a molecular mass of 15.4 kDa. Recombinant SVEP (rSVEP) was produced in a baculovirus expression system and purified by a one-step reversed-phase HPLC procedure. Analyses of physical properties and biological potency demonstrated fidelity of rSVEP to the native protein. Recombinant SVEP relaxed rabbit aorta preparations when preconstricted with 2 micromol l-1 phenylephrine or 25 mmol l-1 K+ but not with 60 mmol l-1 K+. Further, the rSVEP-induced relaxation response of phenylephrine-constricted aorta was inhibited by glibenclamide (10 micromol l-1), suggesting that at least part of its action to relax smooth muscle may result from the opening of ATP-dependent K+ channels. SVEP is a novel salivary-gland-derived vasoactive protein that may be essential for blood feeding by black flies and could potentially enhance transmission of filarial parasites.

B30 ブユ刺咬に即時型アレルギー反応を示した症例のブユ抗原に対する IgE 抗体

B30 ブユ刺咬に即時型アレルギー反応を示した症例のブユ抗原に対する IgE 抗体

Environmental risk factors in endemic pemphigus foliaceus (Fogo selvagem)

Abstract Endemic pemphigus foliaceus or Fogo selvagem (FS) is an epidermal organ-specific autoimmune disease mediated by autoantibodies. Individuals at risk are peasants who live and work on farms located in the interior of certain endemic states of Brazil. This case-control study compares a group of 52 FS patients with 52 patients suffering from other dermatoses admitted and followed at the hospital for pemphigus (Hospital do Penfigo) in the city of Goiania, state of Goias. Patients and controls matched 1:1 by age, sex, and occupation were examined by two dermatologists at the time of admission and asked to respond to a prepared questionnaire. This questionnaire concerned current and past (1 and 5 years) exposure to environmental risk factors. The following risk factors were assessed: black fly bites, presence of rodents at home, exposure to cereal dust, exposure to fumes or dust released by tree and shrub removal, and exposure to insecticides. Relative risks were estimated from tabulated data by the odds ratio and tested for significance by the chi-square test. The 95% confidence interval for the odds ratio was also calculated for each of the risk factors. The only risk factor showing an odds ratio significantly different from one was exposure to simuliidae bites (odds ratio 4.7, p

Environmental Risk Factors in the Endemic Pemphigus Foliaceus (Fogo Selvagem)

Endemic pemphigus foliaceus or Fogo selvagem (FS) is an epidermal organ-specific autoimmune disease mediated by autoantibodies. Individuals at risk are peasants who live and work on farms located in the interior of certain endemic states of Brazil. This case-control study compares a group of 52 FS patients with 52 patients suffering from other dermatoses admitted and followed at the hospital for pemphigus (Hospital do Penfigo) in the city of Goiania, state of Goias. Patients and controls matched 1:1 by age, sex, and occupation were examined by two dermatologists at the time of admission and asked to respond to a prepared questionnaire. This questionnaire concerned current and past (1 and 5 years) exposure to environmental risk factors. The following risk factors were assessed: black fly bites, presence of rodents at home, exposure to cereal dust, exposure to fumes or dust released by tree and shrub removal, and exposure to insecticides. Relative risks were estimated from tabulated data by the odds ratio and tested for significance by the chi-square test. The 95% confidence interval for the odds ratio was also calculated for each of the risk factors. The only risk factor showing an odds ratio significantly different from one was exposure to simuliidae bites (odds ratio 4.7, p less than 0.001). This study reinforces the hypothesis that chronic exposure to black fly antigens may precipitate IgG4 antibody formation in predisposed individuals. These antibodies in turn may cross-react with epidermal antigens and cause acantholysis and the clinical expression of the disease known as FS.

ブユアレルギーに関するアンケート調査

ブユアレルギーに関するアンケート調査

ブユ刺咬症の疫学調査成績

The epidemiological study was made on the cases of black fly bites in the campus of a certain college of Kanagawa prefecture during the period from February 1976 to January 1977,where many students had been suffered from various skin lesions by black fly bites and six kinds of black flies including the dominant species of Simulium aokii were identified from the nearby stream. The patients of 85 individuals were recorded among 200 students in total during one year survey. Black fly bites were observed in all seasons, but most of the bites occurred in three months from May to July. Most of the bites were inflicted around sunrise or sunset, especially from 3 to 5 p.m. Most of the bites occurred in the fields such as the farm or the lawn around the campus but a few cases were recognized indoor such as the green house or the passage of the school building. The sites of bites were present mainly at the upper or lower extremities. Many lesions and accompanying manifestations produced by black fly bites were recognized. Redness as primary lesions was classified into four types : erythema, point-sharp erythema, erythema nodosum and urticarial rash. These reactions occurred within 15min in most cases but the occurrence of 24hrs later was also observed. While, erythema nodosum and urticarial rash developed into secondary lesions including eczematous purulence or necrosis. In this study, severe cases including fever, nausea, headache, lymphnode swelling or general malaise were recognized. Their manifestations may suggest the participation of allergic reaction for the toxin of black flies. The duration of the scar of black fly bites was common in 4 or 5 days, but also in one year or so.

Field evaluation of deet-treated mesh jacket against black flies (Simuliidae).

A cotton-polyester mesh jacket treated with technical N-N-diethylmetatoluamide (deet) was evaluated as a personal protective measure in the prevention of black fly bites. In addition, the jacket was evaluated as to skin irritability, and acceptability with respect to comfort and convenience after continual wear. The deet-impregnated mesh jacket offered significant protection from black flies as measured by statistical comparisons between the number of bites received by individuals wearing treated and non-treated jackets. Of the participants queried, 96.03% stated that the deet-treated jacket produced no skin irritability. With respect to comfort and convenience, a range of 21.9% to 83.2% acceptance was recorded for the jacket.

Blood Parameters in Leucocytozoon smithi Infected Poults Fed Clopidol

Poults naturally infected with L. smithi demonstrated a significant (P < 0.01) decrease in arterial PO2 (mm. Hg) during the second and third weeks after exposure to black fly bites. Poults fed Clopidol (0.0125%) during the exposure period and subsequent experimental periods showed very little parasitemia and no significant reduction in arterial PO2.

A Field Study of the Effect of Black Fly Bites on Egg Production of Laying Hens

SINCE field data pertaining to the effect of arthropods on laying hens are scarce (Biester and Schwarte, 1948), it was thought that an outbreak of black flies attacking a flock of laying hens in South Alabama in April, 1951, was worth investigating and reporting. Nearly every year epidemics of black flies are reported by poultrymen from various parts of the state in April and May, particularly in the Black Belt Area. In the past these flies have played an important and devastating role in transmitting leucocytozoon disease of turkeys. Although black flies have been known to attack chickens, they have not been considered a serious problem of chicken flocks in Alabama in recent years.The outbreak reported here occurred at the farm of R. A. Wible, Monroeville, Alabama. Under attack was a small flock of 40 White Leghorn hens confined to individual laying cages. A few flies were seen annoying …