Table 1 Interventions tested in the SFS

1.BiteBarrier (new) (BB-new)

(R1, R2)

Passive transfluthrin-based VPSR, previously unused and unopened. Two BiteBarrier units were hung on opposing sides of the intervention temporary open structure, two hours prior to onset of collections. The same BiteBarrer units were used for the eight replicates

Additional product information: BiteBarrier, formerly known as PIRK, PIC Corp, is composed of two 25 × 25 cm sheets (4 sheets total), and is intended for hanging inside rooms. BiteBarrier is transfluthrin-based (98.68%), an odorless active ingredient manufactured by Envu, known for its excellent safety profile in mammals [73]. Depending on their exposure levels to this active ingredient, transfluthrin can effectively prevent mosquito biting and induce mosquito mortality [17, 74]. 11/21/2024 11:36:00 AM

No devices hung. Collectors wore short sleeves and short trousers, with a net jacket and covered shoes. Both legs (knee to ankle) exposed

2.BiteBarrier (aged 20 days) (BB-20)

(R1)

BiteBarrier was ‘aged’ for twenty days. This process involved hanging the BiteBarrier sheets on the morning of ‘ageing’ day one using hangers and clips in a shaded, outdoor structure located away from human circulation and protected from wind, temperature fluctuations (acceptable temperature range 23.9–32.3 ºC), and sun exposure. The BiteBarrier units were left in the same location for twenty days. Each BiteBarrier were separated from one another by at least one meter. On the morning of day 21, the BiteBarrier units were removed and individually carefully wrapped each in aluminum foil and stored in the refrigerator at 4 ºC. Aged BiteBarriers had to be used within the following two to three days to be considered as ‘aged 20 days’). The same aged BiteBarriers were used for the eight replicates

3.BiteBarrier (aged 30 days) (BB-30)

(R2)

BiteBarrier was ‘aged’ for thirty days by being hung in the same location at both institutes using the same ageing method as for BB-20, and were retrieved at day 31 for trial use. The same aged BiteBarriers were used for the eight replicates

4.Fuyi Sin Olor (Fuyi)

(R1)

Active transfluthrin-based VPSR, in the form of a hand-held, aerosol with pulsation spray can. To apply in the temporary open structure, the applier stood in the middle of the open structure, and sprayed once each of the four corners of the structure towards the eaves, over 0.5 m (~ 1.64 feet) away from the substrate. Application of Fuyi Sin Olor in the open structure was done once only per night, five minutes before onset of the HLCs

Additional product information: Fuyi Sin Olor is composed of 3.05% transfluthrin and is manufactured by SC Johnson & Son, Inc, Racine, WI, USA

5.SumiOne (new)

(R2)

Passive metofluthrin-based VPSR, previously unused and unopened. Two SumiOne units were hung on opposing eaves of the intervention temporary open structure, two hours prior to onset of collections. The same SumiOne units were used for the eight replicates

Additional product information: The SumiOne passive emanator device is comprised of a methacrylate polymer net impregnated with 10% w/w (ca. 0.217 g) of the synthetic, volatile pyrethroid metofluthrin (manufactured by Sumitomo Chemical Company Ltd., Tokyo, Japan). The formulation is currently registered in various formulations in Australia, Singapore, Malaysia, and Thailand. The device’s impregnated net is contained within a 95 × 160 mm plastic holder, intended for hanging inside rooms, against a wall. Metofluthrin is characterized by its elevated volatility, low mammalian toxicity, and important lethal/KD effects on mosquitoes [75]

6.Etofenprox-treated ranger uniform (0 washes)

(EtoR-0)

(R1)

Long-sleeved and round collar shirt and long trousers made of 50% cotton and 50% nylon textile, worn with a net jacket. Uniforms were treated by hand, using the etofenprox spray application bottles (700 mL spray bottles (7.0% etofenprox) with a calibrated nozzle. The etofenprox was applied according to manufacturer’s instructions: the bottle was held 15–20 cm away from the garment to allow spraying on fabric for a treatment level of 2.0 g/m². Using slow, sweeping motion, the garments were evenly coated for approximately 30 s on each side. Garments were air dried for 2 h by being hung outside. Unwashed

Additional product information: Etofenprox (Perimeter ETO Insect Guard formulation) is an insecticide manufactured by Mitsui Chemicals and formulated exclusively by Pine Belt Processing, a wholly owned subsidiary of Warmkraft, Inc. Etofenprox is approved by the United States Environmental Protection Agency (US EPA) specifically designed for treating clothing worn by the US military [76]

Untreated uniforms with boot footwear, with a net jacket. Trousers were not rolled up to the knees in order to preserve the functionality of the ranger uniform

7.Etofenprox-treated ranger uniform (20 washes)

(EtoR-20)

(R1)

Same intervention as for EtoR-0, except washed 20 times. To wash the clothing twenty times, washing and drying were repeated once per day, every day, for 20 days. Clothing was washed by washing machine, on the cold setting, using soap flakes. Washed clothing was air dried by being laid out flat on tarps in the shade

8. Etofenprox-treated civilian clothing (short-sleeved shirts and short trousers) (0 washes)

(Eto-Sh-0)

(R1)

Short-sleeved t-shirt and short trousers (knee-length), worn with a net jacket. Clothing made of 100% cotton. Same etofenprox treatment method as for EtoR-0 and EtoR-20

Matched civilian clothing (100% cotton),       short-sleeved t-shirt and short trousers,     with  a net jacket and closed shoes

9.Etofenprox-treated civilian clothing (short-sleeved shirts and short trousers) (20 washes)

(Eto-Sh-20)

(R1)

Same intervention as Eto-Sh-0, except washed 20 times. The same washing method as for EtoR-20 was applied

10.Etofenprox-treated ranger uniform with 20% picaridin (0 washes)

(EtoR-0-Pi)

(R1)

Same uniform and etofenprox treatment as for EtoR-0 and EtoR-20. A 20% picaridin (191 g/L) topical repellent (OFF! Tropical Strength Insect Repellent Spray, SC Johnson & Son Pty Ltd) was applied 1 ml/600 cm² so total ml to exposed hands of the collector conducting the HLCs and wearing the treated clothing. Prior to each collection shift, the collector applied the topical repellent evenly to the hands, as these were the only areas of the body not covered by the treated uniform

Untreated uniforms with boot footwear, along with net jacket. Trousers were not rolled up to the knees in order to preserve the functionality of the ranger uniform

11.Etofenprox-treated ranger uniform with 20% picaridin (20 washes)

(EtoR-20-Pi)

(R1)

Same intervention as for EtoR-0-Pi, except uniform washed 20 times (same wash methods as for EtoR-20 and EtoC-20)

12.Etofenprox-treated civilian clothing (short-sleeved shirts and short trousers (knee-length)) with 20% picaridin (0 washes)

(Eto-Sh0-Pi)

(R1)

Same civilian clothing and etofenprox treatment as for Eto-Sh-0 and Eto-Sh-20. 20% Picaridin topical repellent was applied at 1 ml/600 cm² to all exposed skin of the collector conducting the HLCs and wearing the treated clothing. Prior to each collection shift, the collector applied the topical repellent evenly to the areas of the body not covered by the treated clothing or net jacket

Matched civilian clothing (100% cotton), short-sleeved t-shirt and short trousers, with a net jacket and closed shoes

13.Etofenprox-treated civilian clothing (short-sleeved shirts and short trousers (knee-length)) with 20% picaridin (20 washes)

(Eto-Sh20-Pi)

(R1)

Same intervention as for Eto-Sh0-Pi, except civilian clothing washed 20 times (same wash methods as for EtoC-20 and EtoR-20)

14.Etofenprox-treated civilian clothing (short-sleeved shirts and long trousers) with 20% picaridin (0 washes)

(EtoCL-0)

(R2)

Same intervention as for Eto-Sh0-Pi, except collectors wore long trousers instead of short trousers

Matched civilian clothing (100% cotton), short-sleeved t-shirt and long trousers, with a net jacket and closed shoes

15. Combined interventions

(BBEtoPI)

(R2)

Two BiteBarrier units were hung on opposing eaves of the intervention temporary open structure, two hours prior to onset of collections. The same BiteBarrier units were used for the eight replicates. At the same time, the collector also applied intervention EtoCL-0