Comparing the ability of molecular diagnosis and CAP-inhibition in identifying the really causative venom in patients with positive tests to Vespula and Polistes species.

BACKGROUND: Cross-reactivity among Hymenoptera venoms is an important issue when prescribing venom immunotherapy (VIT). Using all venoms eliciting a positive response results in treatment excess and unjustified cost increase. The first in vitro method that helped to identify the really causative venom was RAST-inhibition, but in latest years also molecular allergy (MA) diagnostics, that detects specific sIgE to single venom allergens, was introduced. We compared the two methods in patients with double sensitization to Vespula spp. and Polistes spp. METHODS: Fifty-four patients with anaphylactic reactions to Hymenoptera stings and positive results to skin tests and sIgE measurement with whole venom from Vespula spp. and Polistes dominula were included in the study. Sera from all patients were analyzed by CAP-inhibition (Thermo Fisher Scientific, Uppsala, Sweden) and MA diagnostics with recombinant Ves v 1, Ves v 5 and Pol d 5. RESULTS: By the data obtained from MA technique, VIT would have been prescribed to 7 patients for Polistes, to 6 for Vespula, and to 41 for both venoms. With the data from CAP inhibition, it would have been a prescription to 15 patients for Polistes, to 28 for Vespula, and to 11 for both venoms. A good concordance between the results of MA and CAP-inhibition was found only when the value in kU/l of Ves v 5 were about twice those of Pol d 5, and vice versa. CONCLUSIONS: These findings suggest that in the choice of the venom to be used for VIT CAP-inhibition remains a pivotal tool, because the significance of in vitro inhibition is definite and provides a diagnostic importance higher than MA in patients with positive tests to both Vespula and Polistes spp.

Management of Double Sensitization to Vespids in Europe.

Wasp allergy with a diagnostic profile of double sensitizations to vespid venom is a frequent clinical problem in areas where different genera of wasps are present. Identification of the insect responsible for serious reactions poses a diagnostic challenge as the only effective treatment to date is immunotherapy based on the specific venom. In southern Europe, the double sensitization to Vespula and Polistes venoms is highly frequent. It has been shown that the major allergenic proteins (Phospholipase A1 and Antigen 5) share sequences across the different genera and species, which would be the cause of cross-reactivity. Additionally, the minor allergens (Dipeptidyl-peptidases, Vitellogenins) have been found to share partial sequence identity. Furthermore, venom contains other homologous proteins whose allergenic nature still remains to be clarified. The traditional diagnostic tools available are insufficient to discriminate between allergy to Vespula and Polistes in a high number of cases. IgE inhibition is the technique that best identifies the cross-reactivity. When a double sensitization has indeed been shown to exist or great uncertainty surrounds the primary sensitization, therapy with two venoms is advisable to guarantee the safety of the patient. In this case, a strategy involving alternate administration that combines effectiveness with efficiency is possible.

Field Method for Testing Repellency of an Icaridin-Containing Skin Lotion against Vespid Wasps.

Vespid wasps are ecologically beneficial predators of insects but their stings also pose a human health risk. Current control methods based on killing vespids are suboptimal. Here, the repellent effect against Vespula vulgaris of a 20% icaridin skin lotion was evaluated under field conditions. An experimental setup was designed in which six artificial skin pieces (10 × 10 cm) were video-recorded for 1 h, to count each min the numbers of flying and feeding vespids. Prior to monitoring, five pieces were successively smeared with 2 mg of cream per cm², in 30 min intervals, from t = -120 min to 0. The sixth sheet remained untreated to serve as a control. One milliliter of an attractant, fruit jam, was deposited on each of the six surfaces at t = 0. The control surface was free of any flying or feeding vespid during an average period of 25 min, whereas the other five surfaces (treated at t = -120, -90, -60, -30, and 0 min) remained vespid-free for 39, 40, 45, 49, and 51 min, respectively. The skin lotion remained significantly active for at least 2 h. The experimental methodology is adjustable and allows the study of repellents against vespids in semi-natural conditions.

When can immunotherapy for insect sting allergy be stopped?

BACKGROUND: Stings by Hymenoptera (honey bees, vespids, ants) can cause systemic allergic reactions (SARs). Venom immunotherapy (VIT) is highly effective and reduces an allergic patient's risk of a recurrent SAR to less than 5-20%. The risk of a recurrent SAR to a re-sting decreases the longer VIT is continued. The recommended duration of VIT is at least 3 to 5 years. RISK FACTORS: Risk factors for recurrent SARs to a sting after stopping VIT have been identified and discussed: Recommendations concerning stopping VIT: For patients without any of the identified risk factors, VIT should be continued for 5 rather than 3 years. In patients with definite risk factors, a longer duration of VIT has to be discussed before stopping it. In mast cell disorders, VIT for life is recommended. Because of the residual risk of SARs after VIT, all patients are advised to carry an epinephrine autoinjector indefinitely and to continue to take measures to avoid Hymenoptera stings.

Notes on social wasps of the group of Mischocyttarus(Omega) punctatus (Ducke), with description of six new species (Hymenoptera, Vespidae, Polistinae)

ABSTRACTA revision of the taxonomic status and an identification key for wasp species of the genus Mischocyttarus related to M. punctatus (Ducke, 1904) are presented here. Six new species are proposed (M. tayrona Silveira sp. nov.; M. anchicaya Silveira sp. nov.; M. caxiuana Silveira sp. nov.; M. verissimoi Silveira sp. nov.; M. rodriguesi Silveira sp. nov.; M. ryani Silveira sp. nov.), raising to nine the number of species in the M. punctatus group. The highest diversity of the group concentrates in northern South America, in Andean areas and Amazonia. New information concerning the very peculiar nests of these wasps is also given.