The literature search was conducted in the ScienceDirect and EBSCOhost databases from 18 October until 1 December 2023. The following keywords were used when searching for the relevant articles: "construction worker*" OR "construction industr*" AND "mosquito*" AND "control*". All retrieved articles were imported into Google Sheet library, and a library de-duplication was implemented using Microsoft Excel.

The inclusion criteria for this study were as follows: (1) full publication in the English language; (2) articles were published from 2014 onwards; (3) original articles including cohort, case-control, and cross-sectional investigating the associated factors with mosquito control among construction workers. Meanwhile, the exclusion criteria include the following: mixed method and qualitative studies, as well as non-original articles, such as conference proceedings, perspective, commentary, opinion, reports, systematic reviews, and meta-analyses, were excluded from this study.

Two independent reviewers were in charge of screening the titles and abstracts of the retrieved materials against the inclusion and exclusion criteria. The articles identified during the main screening were kept, and the full-text article was thoroughly reviewed independently by a third reviewer according to the inclusion and exclusion criteria. The fourth reviewer was assigned to resolve any arising disagreements between each of reviewers.

The Mixed Method Appraisal Tool (MMAT) was employed to evaluate the quality of articles selected in this study. The MMAT approach includes five core quality criteria for each of the selected articles and focuses on methodological criteria [10]. Basically, an independent reviewer extracts the data, and another independent reviewer then assesses the data. Eligible articles were analysed in detail using the content analysis method without any statistical tests.

This section describes the outcome of the critical appraisal and data extraction of the four studies, focusing on the standard mosquito control practices among construction workers. The studies included in this review showed significant factors on mosquito control among construction workers, which can be divided into three main factors: (i) mosquito-related knowledge, (ii) Mosquito prevention measures, and (iii) Larval Source Management (LSM).

The quality appraisal of all four quantitative non-randomised studies in this systematic review was conducted using the MMAT based on five main criteria [10]. Details of the MMAT assessment for the selected studies are reported in Table 3.

Knowledge of mosquitoes and their disease-carrying capability was found to be significantly associated with mosquito control practices among construction workers [11]. The findings can be related to a study performed in Tibet in 2014, which found that mosquito-related knowledge was significantly associated with mosquito control practice (p < 0.01) [15]. This relationship was also noted in another study in China in 2023 that showed dengue fever knowledge had a direct positive effect on mosquito control behaviour (p < 0.01) [16]. This finding further emphasises the government’s approach to educating and training the community in dengue and its related knowledge, specifically Communication for Behavioural Impact (COMBI). However, the extent of COMBI and its impact needs to be further reviewed since a study in Hulu Langat, Selangor, Malaysia, claimed that COMBI only influenced respondents during its implementation weeks, and the incidence of dengue cases was not reduced [17]. Furthermore, certain construction site approaches can be initiated to address this factor, specifically in the construction industry.

One of the study also showed that female workers (β = -0.281, P = 0.001) were associated with higher malaria knowledge scores [11]. This finding correlates with a recent systematic review that concluded women can be successfully engaged in vector control programmes at the community level [18]. This finding highlighted the need to boost women’s involvement in the construction industry. Since the construction industry is currently dominated by males, reducing this domination may improve mosquito control practices at construction sites [19].

Having experienced malaria within 1 year (β = 0.276, p < 0.001) was associated with higher malaria knowledge scores. This finding is in accordance with Kolb’s Experiential Learning Cycle, which states that concrete experience will be reflected and then conceptualised before being experimented to try its success [20]. While it is unethical to expose humans to malaria for experimental purposes, it is more beneficial to provide sufficient training to ensure effective mosquito control practices among construction industry employees.

Furthermore, those preferring modern medicine (β = 0.283, p = 0.001) had higher malaria knowledge scores compared to their counterparts. This may be attributed to the relatively advanced health education in India [21]. A similar approach can be used to address the relentless dengue problem in Malaysia.

This review found that individual preventive measures were significantly associated with malaria infection. Specifically, using mosquito nets every night (p = 0.016) and spraying insecticide indoors every day (p = 0.047) was negatively associated with malaria infection. Conversely, cleaning up vegetation around self-owned homes every month had a positive association (p = 0.028) with malaria infection. This may be explained by the potential risk of mosquito bites among those who were involved in the cleaning process, which could lead to malaria infection [12].

Management-initiated practices, which include free distribution of mosquito nets, living in a dormitory with a bathroom, living in a single-person dormitory, living in a clean and sanitary environment, vegetation effectively controlled camp-wide or housing type, were measured in the study in a 1-year duration. However, the results showed that management-initiated practices were insignificantly associated with the infection risk [12]. Hence, this finding warrants further explanation as recall bias may be excluded, given that these activities should have been easy to remember correctly. Although mosquito nets were used every night, the insignificant correlation between the free distribution of mosquito nets and the infection rate indicates that free resources should be used regularly to ensure their effectiveness. In addition, maintaining a good housing area and a clean environment is insufficient to avoid the risk of malaria infection. Instead, self-awareness and worksite behaviour of construction workers are more critical in guaranteeing a safer place to work with minimal risk of malaria infection [12]. Such efforts must be implemented together with individual preventive measures to decrease the incidence of mosquito-borne diseases.

Other factors that require further assessment is the durability of the freely distributed nets. A study in Chad showed that less than one-third of the freely distributed nets were in serviceable conditions after an average of 14 months [22]. Further evidence is needed regarding the effective use of mosquito nets and its association with specific factors that influence the fabric integrity, such as washing frequency, proximity to water for washing, location of kitchen, type of cooking fuel, and low net maintenance [23]. These factors may contribute to the declining effectiveness of the nets, thus explaining the persistent case of mosquito-borne diseases.

LSM refers to the management of aquatic habitats (water bodies) that are potential larval habitats for mosquitoes to prevent the complete growth cycle of immature mosquitoes [24]. For instance, study that employed LSM is significantly reduce the detection of immature mosquitoes in the intervention sites using BTI larvicide compared to control sites [14]. However, health authorities were required to seek approval to enter these construction sites, which makes this approach challenging to be practically applied. Such obstacles can be overcome through legal channels by making it compulsory for construction sites to carry out specific mosquito control measures and facilitating health inspectors in obtaining site visit permits.

Nevertheless, the BTI method has limited effect against Aedes albopictus, which can develop strong resistance to B. thuringiensis, thus rendering it unsustainable [25] Furthermore, B. thuringiensis toxic proteins were relatively weak to kill off the mosquitoes [26].

Alternatively, the construction industry may consider implementing vector control by releasing Wolbachia-carrying mosquitoes at construction sites to control the proliferation of mosquitoes. Through this technique, the Wolbachia-carrying mosquito population will transmit the Wolbachia bacteria to uninfected mosquitoes, causing sterility of mosquitoes, thus reducing their offspring [27]. The release of Wolbachia-carrying mosquitoes at construction sites is expected to be more acceptable since the community responded negatively to the release of Wolbachia-carrying mosquitoes in its initial phase, as previously reported [28].

Another effective alternative is the use of insecticide paint [29]. However, the suitability of this method need to be asssess particularly for a rapidly changing building structure, such as construction sites. Nevertheless, a field trial of insecticide paint in Africa revealed encouraging results in the first three months [30]. However, further study of its effectiveness in the humid and tropical Malaysian environment should be conducted.

Successful mosquito control is less achievable using a single approach. Instead, Integrated Vector Management (IVM) combining LSM and practical mosquito prevention measures with other methods is more effective in achieving significant outcomes [31]. As such, employers and employees need to work hand in hand, as recent reports on management-initiated mosquito prevention practices have proven to be unsuccessful if individual measures were not taken concurrently.

Moreover, employers must continue to provide a safe working and living environment for their employees, as the surrounding environment is an integral part of the Epidemiology Triad that affects how a disease spreads. Therefore, preserving the working and living environment should be prioritised, either by the Occupational Safety and Health (OSH) unit or an additional supervisory unit. Continuous employee education should also be in place, as knowledge was significantly associated with mosquito control practice. Besides, employers may consider additional incentives for employees who comply with the proposed preventive measures.

Once the employer has outlined the mosquito prevention measures, employees need to comply with the guidelines. Past evidence showed that employer provision without employees’ involvement would not produce a significant outcome [12]. Hence, individual mosquito prevention measures must be concurrently practised to ensure a higher rate of success. Other novel mosquito control measures, such as the release of Wolbachia-carrying mosquitoes, insecticidal paint, or other methods, should also be considered.

As with any research, this systematic review is not without limitations. Primarily, the impact of publication bias in this systematic review must be acknowledged, as grey literature was excluded. Furthermore, language bias should also be considered as the search strategy resulted in literature sourced from several countries where English is not the primary language (India, Africa, Equatorial Guinea, and China), but only articles published in English were included. Despite these limitations, this systematic review presented new insights regarding the knowledge, practice, and policy-related factors associated with mosquito control practices among construction workers, which may serve as a valuable guideline for improving service delivery strategies of the dengue control programme in Malaysia.