Table 5.

Reviewed intervention for outdoors occupation.

Intervention	Advantages	Disadvantages
Chemoprophylaxis (Miller et al., 1999; Behrens et al., 2010; Li et al., 2015)	‣ Available for malaria. ‣ Several types of prophylaxis available to choose from. ‣ Effective when the risk of acquiring infection is high (McBride, 2010). ‣ Cost per person per year for malaria prevention: US$0.53–5.97 (Conteh et al., 2021).	‣ Possible reaction in users (Behrens et al., 2010). ‣ Needs repeated use (Deller and Russell, 1967). ‣ Not for prolonged use (McBride, 2010). ‣ Difficult to adhere (Kitchener et al., 2003). ‣ Intolerance (Kain et al., 2001; Boggild et al., 2007; Gawthrop and Ford, 2009). ‣ Linked to increased parasite resistance (Mika et al., 2008). ‣ Delays disease onset but not infection (Miller et al., 1999).
Insecticide-treated clothing (Soto et al., 1995; Kimani et al., 2006; Kittayapong et al., 2017; Klein et al., 2018; Obwaller et al., 2018)	‣ Prevents bites from all major vectors. ‣ Application lasts for months. ‣ No need for reapplication. ‣ Can also kill vectors, providing possible mass protection if deployed to camps. ‣ Cost per person per year: US$5 (Tozan et al., 2014).	‣ Reaction in some users, but uncommon (Young and Evans, 1998; Sharma et al., 2009). ‣ Efficacy reduced with time and washing (Orsborne et al., 2016; Kittayapong et al., 2017). ‣ There is a limited number of chemicals proved to be safe for treatment while these chemicals are resistant to some vectors. ‣ People may not wear treated clothing for long (Crawshaw et al., 2017). ‣ People may remove clothing when working in hot climates, e.g. tropical forests (Lightburn et al., 2002).
Topical repellents (Klein et al., 2018)	‣ Readily available. ‣ Can be used on exposed skin if long clothing not worn. ‣ Cost per person per year: US$3.80 (Agius et al., 2020).	‣ Needs daily regular reapplication (Gryseels et al., 2015; Crawshaw et al., 2017). ‣ Poor adherence (Gryseels et al., 2015). ‣ Mosquitoes may be diverted to unprotected people (Moore et al., 2007; Maia et al., 2013).
Indoor residual spraying (Jeffree et al., 2018)	‣ Readily available. ‣ Highly effective against malaria (WHO, 2019b), dengue (Vazquez-Prokopec et al., 2017) and visceral leishmaniasis (Rijal et al., 2019); may also be effective against peridomestic cutaneous leishmaniasis (González et al., 2015). ‣ Cost per person per year: US$5.33 in Africa (Yukich et al., 2022).	‣ Must be applied by a trained person (Malaria Consortium, 2021; Sadasivaiah et al., 2007). ‣ Useable only indoors. ‣ Logistically challenging. ‣ Suitable only for semi-permanent settlements (Messenger et al., 2023).
Immunisation/vaccination (Brown et al., 1990)	‣ Prevents disease from developing or reduces severity. ‣ Protects around the clock and long term. ‣ Can be bundled with other vaccination programmes. ‣ Herd immunity: If enough people are immunised against an infection, it is more difficult for it to be spread to those not immunised. ‣ Vaccination helps reduce the social and psychological toll of illness on people and reduce the burden on hospitals and healthcare systems. ‣ Vaccine cost effectiveness similar for leishmaniasis (Bacon et al., 2013), malaria (Galactionova et al., 2017) and dengue in high-burden areas (Perera et al., 2019; Espana et al., 2021; Suwantika et al., 2021).	‣ No available human vaccine for leishmaniasis (Zutshi et al., 2019); leishmaniasis vaccines in development (Claborn, 2010); canine vaccine available (Velez and Gallego, 2020). The first vaccine introduced is only for children and has to be used with other preventive methods (WHO, 2021c). ‣ Malaria has complex stages of the life-cycle but R21, the second malaria vaccine, targets the sporozoite stage only (WHO, 2023b). ‣ Licensed quadrivalent vaccine CYD-TDV available; indicated to people aged 9–45 years and residents of endemic regions with laboratory-confirmed previous dengue infection (Torres et al., 2019); not prequalified by WHO but approved in 19 countries (WHO, 2018; CDC, 2021a). ‣ Vaccine for all four dengue virus strains needed to prevent cross-reaction (CDC, 2022a). ‣ High cost and low uptake.
Spatial repellents (volatile pyrethroids, spatial emanators)	‣ Protect multiple users in a space (Tambwe et al., 2021a). ‣ Multiple modes of action contribute to community and personal protection, i.e. inhibit blood-feeding, incapacitate, kill and reduce mosquito fertility (Bibbs and Kaufman, 2017; Tambwe et al., 2021b). ‣ Reduce malaria in Southeast Asia (Syafruddin et al., 2020) and Africa (WHO, 2023c) and dengue (Morrison et al., 2022). ‣ Cost: US$3 per household per year.	‣ Regular replacement needed (Stevenson et al., 2018; Syafruddin et al., 2020). ‣ Proper disposal needed. ‣ Low temperature and high wind can reduce efficacy (Choi et al., 2016). ‣ Users may not know when the spatial repellent has worn out. ‣ Requires some degree of compliance.
Attractive targeted sugar bait	‣ Attracts and kills mosquitoes and sand flies (Müller and Galili, 2016). ‣ Mortality up to 97% recorded (Fiorenzano et al., 2017). ‣ Can be used both indoors and outdoors against both male and female mosquitoes (Maia et al., 2018b). ‣ Can be used with multiple active ingredients for insecticide resistance management (NʼGuessan et al., 2007; Asidi et al., 2012). ‣ Minimal impact on non-target organisms (Müller et al., 2010; Khallaayoune et al., 2013; Müller and Galili, 2016).	‣ Community-based intervention; mosquitoes may be killed in the vicinity away from the user and the user may not perceive the benefits (Maia et al., 2018b). ‣ May affect non-target insects when disposed of, including pollinators. ‣ Difficult to protect the baits for long periods from dust and rain (Müller and Galili, 2016). ‣ Cost has not been calculated. ‣ No evidence of clinical efficacy although trials ongoing.
Wolbachia endosymbionts	‣ Can infect wide range of mosquitoes (Popovici et al., 2010; Vavre and Charlat, 2012). ‣ Drive into the population through cytoplasmic incompatibility, reducing need to reapply (Werren and Bartos, 2001). ‣ Have reduced dengue, chikungunya and Zika in multiple settings (Ant et al., 2022). ‣ ‣Cost-effective for endemic urban areas (Brady et al., 2020).	‣ Community trust and acceptance of a mosquito-release program takes time (Ong, 2021). ‣ Sometimes Wolbachia endosymbionts are lost, and more releases are needed (Ant et al., 2022).
Gene drive using non-Mendelian inheritance to modify mosquitoes for population suppression or replacement with refractory strains (Alphey et al., 2020; Leung et al., 2022)	‣ Expected to prevent the target infections from spreading, which will lower human morbidity and mortality, provided engineered mosquitos are present at sufficiently high frequencies (James, 2005).	‣ Mosquitoes or parasites may evolve mechanisms to evade to genetic constructs (Wedell et al., 2019). ‣ Possible unknown consequences of incorporation of genetic material into unintended populations or species (Wedell et al., 2019). ‣ Public distrust of genetic modification (Collins, 2018). ‣ Research still in early stages.