The effectiveness of five mosquito traps at sampling anopheline mosquitoes was compared with landing/biting (L/B) collections in western Thailand. Traps evaluated included a CDC style light trap (CDC LT) with dry ice, the American Biophysics Corporation (ABC) standard light trap (ABC LT) with dry ice and octenol, the ABC counterflow geometry (CFG) trap with dry ice and octenol, the ABC mosquito magnet (MM) trap with octenol, and the Nicosia and Reinhardt Company Mosquito Attractor Device (N&R trap). Mosquito numbers captured in landing-biting collections were 5.2, 7.0, 7.3, 31.1, and 168.8 times greater than those collected in the ABC LT, MM, CDC LT, CFG, and N&R traps, respectively, for Anopheles minimus Theobald, the predominant malaria vector in the region. Similar results were obtained for the secondary malaria vectors Anopheles maculatus Theobald and Anopheles sawadwongporni Rattanarithikul & Green. Only Anopheles kochi Doenitz was collected in significantly greater numbers in the CDC LT, ABC LT, and MM traps compared with L/B collections. Although none of the traps were as effective as L/B collections, the ABC LT, MM, and CDC LT were the best alternatives to human bait for the collection of anopheline malaria vectors in Thailand.

BackgroundSampling for adult mosquito populations is a means of evaluating the efficacy of vector control operations. The goal of this study was to evaluate and identify the most efficacious mosquito traps and combinations of attractants for malaria vector surveillance along the Thai-Myanmar border.MethodsIn the first part of the study, the BG-Sentinel™ Trap (BGS Trap) and Centers for Disease Control and Prevention miniature light trap (CDC LT) baited with different attractants (BG-lure® and CO2) were evaluated using a Latin square experimental design. The six configurations were BGS Trap with BG-lure, BGS Trap with BG-lure plus CO2, BGS Trap with CO2, CDC LT with BG-lure, CDC LT with BG lure plus CO2, and CDC LT with CO2. The second half of the study evaluated the impact of light color on malaria vector collections. Colors included the incandescent bulb, ultraviolet (UV) light-emitting diode (LED), green light stick, red light stick, green LED, and red LED.ResultsA total of 8638 mosquitoes consisting of 42 species were captured over 708 trap-nights. The trap types, attractants, and colored lights affected numbers of female anopheline and Anopheles minimus collected (GLM, P < 0.01). Results revealed that BGS Trap captured many anophelines but was significantly less than the CDC LT. The CDC LT, when baited with BG-lure plus CO2 captured the greatest number of anopheline females with a catch rate significantly higher than the CDC LT baited with BG-lure or CO2 alone (P < 0.05). The number of anopheline females collected from the CDC LT baited with CO2 was greater than the CDC LT baited with BG-lure (646 vs 409 females). None of the alternative lights evaluated exceeded the performance of the incandescent light bulb in terms of the numbers of anopheline and An. minimus collected.ConclusionWe conclude that the CDC LT augmented with an incandescent light shows high potential for malaria vector surveillance when baited with CO2 and the BG-lure in combination and can be effectively used as the new gold standard technique for collecting malaria vectors in Thailand.

We investigated the efficacy of a liquid larvicide, Natular 2ECt (spinosad), applied with ultra-low volume sprayer as a residual application during the dry season in southeastern Thailand against 4 medically important species-Aedes aegypti, Ae. albopictus, Anopheles dirus, and An. minimus. We found that this larvicide could be applied as a residual to dry areas known to collect water and potentially still be effective after rains or irrigation, which could increase the flexibility and efficiency of an integrated vector management program targeting these species. This investigation also demonstrated, for the 1st time, efficacy of spinosad against An. minimus and An. dirus.

. This study describes the natural history of dengue virus (DENV) infection in rhesus monkeys exposed to the bites of DENV-infected Aedes aegypti mosquitoes. Dengue virus–infected mosquitoes were generated by either intrathoracic inoculation or by oral feeding on viremic blood meals. Each of the six rhesus monkeys that were fed upon by intrathoracically infected mosquitoes developed non-structural protein 1 (NS1) antigenemia and an IgM response; viremia was detected in 4/6 individuals. No virological or immunological evidence of DENV infection was detected in the three monkeys exposed to mosquitoes that had been orally infected with DENV. These results demonstrate the utility of mosquito-borne challenge of rhesus monkeys with DENV.

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