Background: Allergy toVespa affinisvenom is common in the Asia Pacific region. Venom preparations for diagnosis are not commercially available for this species.Methods: The prominent allergens inV. affinisvenom were identifiedusing immunochemical methods. Use of ImmunoCAP ofVespula vulgariscrude venom/its components and a passive basophil activation test (BAT) in the diagnosis of patients who had anaphylaxis toV. affinisvenom (n = 30) were also accessed. The IgE double-positivity rates (positive to both hornet and honeybee) in ImmunoCAP and the passive BAT were determined.Results: High IgE reactivity was seen with the five allergens inV. affinisvenom; 96% (29/30) for 34 and 24 kDa, 93% (28/30) for 45 kDa and 90% (27/30) reactivity for the 100 and 80 kDa respectively. IgE cross-reactivity was low with ImmunoCAP usingV. vulgarisvenom (43%; 13/30) and Ves v1 (3%; 1/30), but relatively high with Ves v5 (73%; 22/30). All patients (100%) were positive toV. affinisvenom in passive BAT. In ImmunoCAP, a high double-positivity rate (76%; 23/30) was detected while no double-positivity was detected in passive BAT.Conclusions: High IgE reactivity for five allergens ofV. affinispoints to the potential of using these allergens in component resolved diagnosis (CRD). The passive BAT has shown its importance as a promising diagnostic tool with high accuracy. It would be particularly useful in cases with doubtful double-positive results of other diagnostic tests.

Background: Allergy toApis dorsata(Giant Asian Honeybee) venom is the commonest insect allergy in Sri Lanka and South East Asia. However, laboratory diagnosis is difficult as the pure venom and diagnostic reagents are not commercially available.Objective: This study assessed the use of four recombinant allergens ofA. melliferavenom and the passive basophil activation test in the diagnosis ofA. dorsatavenom anaphylaxis.Methods: Serum IgE levels to four recombinant allergens ofA. mellifera, rApi m 1, 2, 5 and 10 were assessed and compared with serum IgE to the crude venom ofA. melliferaorV. vulgarisby Phadia ImmunoCAP, in patients who developed anaphylaxis toA. dorsatastings. Basophil activation in response to venom ofA. dorsataorV. affiniswas assessed using a passive basophil activation test. Association of the severity of the reaction with basophil activation was compared.Results: rApi m 1 and 10 combinedly had significant correlation (r = 0.722; p < 0.001) with the crude venom ofA. mellifera(Western honeybee) and a higher positivity rate of 90% (27/30). Whereas, IgE reactivity to rApi m 2 or 5 had significant correlation (p = 0.02 and p = 0.005 respectively) withV. vulgariscrude venom. All 30 (100%) were positive toA. dorsatavenom in passive BAT; 70% (21/30) had over 80% activation, 96.7% (29/30) had over 60% activation and 100% had over 50% activation. Percentage activation of basophils in patients who had mild or moderate reactions (n = 20) was significantly low (p = 0.02) from that of patients who had severe reactions (n = 10).Conclusions: rApi m 1 and 10 when combined was sensitive for the diagnosis ofA. dorsataallergy. This combination had the lowest cross-reactivity rate withVespula vulgaris. The passive BAT is highly sensitive inA. dorsataallergy. The basophil reactivity was significantly higher in severe anaphylaxis compared to mild/moderate anaphylaxis. This finding should be further explored in further studies.

Dengue is among the deadliest insect-borne diseases circulating in Sri Lanka. Most of the infections that are diagnosed early are manageable. However, delays in diagnosis may cause fatalities. We evaluated the dengue NS1 antigen card and NS1 SD kit for early diagnosis of dengue using samples from 116 RT-PCR-positive patients admitted within 5 days of the fever onset. RT-PCR tests were performed as standard tests. IgM and IgG ELISA tests were carried out to identify primary and secondary infections. Of the 116 patients who tested positive for dengue using PCR, 48 were positive using NS1 antigen card and 45 were positive using NS1 SD. Patients with 100 copies or higher viral load showed a higher sensitivity in both antigen card and NS1 SD. Of 34 primary infections evaluated, 23 were positive by NS1 antigen card, while the positivity was 21 by NS1 SD. Of the 30 secondary infections evaluated, 15 were positive by NS1 antigen card while 14 by NS1 SD. Our findings showed that while the rapid tests are convenient and much easier to use than PCR, they are less sensitive and need improvement. Until then, clinical diagnosis should have more emphasis on the early diagnosis of dengue.