Addressing Needs of Foreign Schoolchildren to Combat a Global Epidemic of Dengue Virus Infection: Transnational and Trans-Sectoral Initiatives

Summary

This study highlights the demand for conducting outreach to foreign demographics in countries affected by infectious diseases. The increasing global burden of mosquito-borne Dengue virus infection suggests that local health education efforts need to include the population’s foreign segments. Communicating information in their mother tongue and empowering them with knowledge of local diseases and preventive measures is essential when foreign residents cannot fully understand the local language(s). This paper presents an example of transnational and trans-sectoral initiatives in anti-dengue education, which involved 1,105 Japanese schoolchildren in Singapore. Paying attention to cross-cultural, language, and other elements, an academic from a university, a medical doctor from Japan, and a medical entomologist from a Singapore governmental agency collaborated. Lessons included the importance of building capacity among schoolteachers in order to engage schoolchildren. Conducting outreach to foreign residents will be increasingly important when a new technology is introduced as a preventive measure or when scientific evidence must be communicated to combat a global epidemic. Otherwise, key messages might remain unnoticed and ineffective in motivating people to take necessary action. Transnational and trans-sectoral collaboration could be a solution to sustain outreach efforts for public health.

Graphical Abstract/Art Performance

The code of this chapter is 01101001 01110011 01110101 01010110 01110010.

It’s a global pandemic. It’s quite clear that the disease… has evolved. There just is more dengue in the world.

Duane Gubler

1 Introduction

1.1 Public Education Initiatives in the New Decade

The ongoing COVID-19 pandemic has reminded all governments of the critical importance of proactively formulating and executing public health strategies to prevent and control emerging infectious diseases, including new and unprecedented ones. The challenge is how to convey information on health risks to and obtain understanding and compliance from the community at risk. Authorities are now tasked to disseminate more complicated and technical information to the general public more frequently than ever to prevent and control epidemics. Governmental capacities and capabilities to make provisions based on scientific evidence may play a vital role in delivering effective public messages to engage the community.

Today, public health education poses a renewed challenge to governments, scientists, and people in many parts of the world where multi-lingual, multi-cultural, and multi-ethnic residents live. Globalization has accelerated population movement across national, language, and cultural borders. More countries now see the increasing presence of foreign residents among their total population. Therefore, it is important to highlight that public health leadership in controlling and preventing infectious diseases should include foreigners and visitors.

Considerable attention has been paid to the importance of community engagement in infectious disease management, but rather less research has been devoted to the foreign segments of populations in endemic countries. Engaging foreign residents, visitors, and nationals is essential to improve overall public health measures, especially when combatting a global epidemic. Hence, there is a need to explore outreach efforts to deal with potential language barriers, cultural sensitivities, and other elements.

Educating foreign residents and visitors is important for a host country to strengthen its overall infectious disease management. Likewise, improving the public health of own nationals staying in endemic areas is essential for a country that desires to reduce imported cases. However, what can be prescribed to achieve these goals with limited resources? This paper reviews academia’s initiatives from Japan and a government agency in Singapore to address foreign schoolchildren’s needs to combat a global epidemic of dengue. Such transnational and trans-sectoral collaboration may provide further insights for health authorities and scientists elsewhere.

1.2 Global Burden of Mosquito-Borne Dengue on the Rise

Dengue is a mosquito-borne disease associated with increasing health and economic risk globally. Rapid urbanization, increased movement of goods and people, transnational travel, and climate change are among factors that increase dengue risk. The World Health Organization (WHO) estimates 100 to 400 million cases newly infected with dengue each year, with almost half of the global population at risk. The international health authority also notes that the disease has spread to new parts of the world, putting all regions at risk. The numbers of dengue cases reported to WHO in 2000 and 2019 were 505,430 and 4.2 million, respectively, recording a more than eight-fold surge over the last two decades. Reported fatalities also increased from 960 in 2000 to 4,032 in 2015 [1].

The word ‘dengue’ is originally from the Swahili denga and was incorporated into a West Indian Spanish expression (“fastidiousness”), meaning the stiffness of the neck and shoulders of patients [2]. The causative agent is the Dengue virus (DENV). Following a bite by a dengue-infected female Aedes mosquito, it usually takes 4–10 days for one to develop symptoms.

DENV is a virus made up of a single-stranded RNA genome. It is defined as a member of the Flaviviridae family with four serotypes: DENV-1, DENV-2, DENV-3, and DENV-4, which are antigenically but not serologically related. Infection with one serotype is understood to result in serotype-specific life-long immunity with partial and brief cross-immunity to the other serotypes. As presented by dengue hemorrhagic fever and dengue shock syndrome, the risk of progressing into severe forms of the disease is believed to be associated with secondary infection with other serotypes.

Although vaccines for other flaviviruses, including Yellow Fever and Japanese encephalitis, became available sooner, the need to incorporate all four serotypes into a single formulation has complicated vaccine development for DENV infection. The dengue vaccine licensed in December 2015 was later reported—as shown in the position paper published by WHO in September 2018—to carry a higher risk of severe disease in seronegative individuals at the time of vaccination [3]. Given the absence of a safe dengue vaccine, it is essential to deploy other prevention tools, e.g., sustainable vector control, including source reduction.

The female Aedes (Stegomiya) mosquito is responsible for transmitting viruses such as dengue. The daytime feeding female Aedes aegypti (Linnaeus) mosquito is the primary vector of DENV. It is found in suburban and urban environments. The Aedes aegypti mosquito is endophilic; that is, she bites, rests, and lays her eggs mainly in artificial or human-made containers indoors. Once in contact with water, the eggs might hatch but can also survive for months under dry conditions. The vector has adapted to human dwellings and is anthropophilic, possessing a high preference for human blood.

The secondary vector of DENV is the Aedes albopictus (Skuse) mosquito, also a daytime feeder and commonly known as the Asian tiger mosquito. It is native to Southeast Asia and is distributed in rural to urban vegetated environment. The female Aedes albopictus mosquito tends to be more exophilic and can bite, rest, and lay her eggs outdoors as well.

Dengue can present as asymptomatic, mild/subclinical, or with severe symptoms. Dengue and severe dengue are two categories classified by WHO. Two or more symptoms can accompany dengue during the febrile phase: severe headache, rash, vomiting, nausea, swollen glands, muscle/joint pains, and orbital pain. Severe dengue can be characterized by warning signs, such as repeated vomiting, blood in vomit, bleeding gums, serious abdominal pain, rapid breathing, anxiety, and exhaustion. Without proper medical care or delayed medical attention, severe dengue can result in complications, such as severe bleeding, plasma leakage, organ impairment, fluid accumulation, and respiratory distress. With anti-viral drugs under development, only symptomatic therapy is available for dengue or severe dengue.

In 2020, rising numbers of dengue cases were reported in Bangladesh, Brazil, Cook Islands, Ecuador, India, Indonesia, Maldives, Mauritania, Mayotte (Fr), Nepal, Singapore, Sri Lanka, Sudan, Thailand, Timor-Leste, and Yemen [1].

1.3 The Study Site: Singapore

The tropical island city-state, the Republic of Singapore, is situated about 137 km (85 miles) north of the Equator (taking place between latitudes 1° 09′ N and 1° 29′ N and longitudes 103° 36′ E and 104° 25′ E), across the Malay Peninsula. Singapore comprises the main island and small islands (Jurong Island, Western Islands, North-Eastern Islands, and Southern Islands). The territory is divided into five regions: Central, West, North, North-East, and East. The main island is separated from Peninsular Malaysia to the north by a road and rail causeway of Johor Strait, and its coastline is 203 km (roughly 48 km East–West and 25 km North–South).

This compact and highly developed country in South-East Asia exhibits several situational factors that expose the population to the threat of infectious diseases, including dengue. The first factor is the inherent weather resulting from the geographical location. Singapore is situated in a tropical climate zone, suitable for the propagation of pathogens. It is hot, humid and rainy, throughout the year. Inter-monsoon periods, typically accompanied by afternoon thunderstorms, separate two distinct monsoon seasons (December to early March, and June to September): the North-East Monsoon and the South-West Monsoon, respectively. In 2018, Singapore’s air temperature showed 31.6 °C (daily max.) and 25.4 °C (daily min.); the 24-h mean relative humidity was 79.6%; the annual rainfall was 1,708.2 mm. Aside from flash floods, Singapore is generally protected from natural disasters, e.g., earthquakes and tropical cyclones. However, in addition to abundant rainfall, Singapore’s hot and humid climate provides optimal conditions for breeding.

The second factor is the dense population of the city-state, sometimes described as an urban regional hub. The main island is built up of residential, commercial, and industrial zones. As of 2019, Singapore’s area is 725.7 km²; the total population is estimated to be 5.7 million, including 4 million Singapore residents (Chinese, Malays, Indians, and Others). The population density of 7,866/km² is high, and foreign residents represent 29.8% of the total population.

The third factor is the transnational mobility of people, as seen in tourist arrivals and residents’ frequent travels in cosmopolitan Singapore. In 2018, the international visitor arrivals recorded 18.5 million; outbound departures of Singapore residents exceeded 10.3 million. When national borders of the South-East Asian hub for business and travel are open, the importation of infectious diseases, including mosquito-borne infections, is inevitable. Urban Singapore is actually situated in a dengue-endemic region, where Aedes mosquito vectors abound.

1.4 Dengue Virus Infection in Singapore

Singapore has dealt with dengue for decades (Fig. 1). The country reported 40,496 cases during a two-year outbreak from 2013 to 2014 (22,170 in 2013 and 18,326 in 2014) [4]. While Singapore has a national dengue control program incorporating extensive mosquito control measures and stringent public health education, dengue was ranked the third-highest, after hand, foot, and mouth disease and sexually transmitted infections, among Singapore’s infectious disease notifications in 2018.

Fig. 1

(Modified from [4])

Reported dengue and severe dengue in Singapore from 1999 to 2018

In 2018, a total of 3,283 laboratory-confirmed dengue cases were reported in Singapore, comprising 3,257 dengue and 26 severe dengue cases. The total reported cases included 215 imported cases from Indonesia, Malaysia, India, and Thailand. The Singapore resident incidence rate among local cases was the highest in 45 to 54 years, followed by 15 to 24 years. Ethnic-specific incidence distribution of local dengue in 2018 showed: Chinese (54.3%), Malay (9.6%), Indian (4.9%), Others (6.6%), and foreigners (24.6%). Results of positive dengue samples serotyped in 2018 indicated that DENV-2 was the dominant serotype [4].

Nearly 80% of people in Singapore live in public housing flats managed by the Housing and Development Board (HDB) of Singapore (Fig. 2); 16% in private condominiums and other apartments; with the remaining in landed properties and other types of housing, according to the General Household Survey 2015. When classified according to housing types, the highest incidence rate of indigenous dengue reported cases was 129.3 per 100,000 population at landed properties, including shophouses, representing 13.9% of all housing types where the infection was identified. The majority of cases, as high as 71.4% of the local cases, were reported at HDB flats, followed by 14.25% at condominiums [4].

Fig. 2

A typical HDB Block in Singapore

Since DENV infection is mosquito-borne, the Ministry of Health (MOH) handles the surveillance of human cases, while the National Environment Agency (NEA), a statutory board under the Ministry of Sustainability and the Environment (MSE), is responsible for environmental aspects, including surveillance, control, and research of the vector mosquitoes, as well as public communications and education. NEA’s active leadership in the national anti-dengue efforts was visible after 2006 in deploying an inter-governmental approach and promoting its 3P partnership that is “people (community, volunteers, and Grassroots organizations), the Private sector (service providers and professional associations), and the Public sector (government agencies).”

In 2018, NEA inspected over one million premises–comprising residential premises, construction sites, schools, dormitories, factories, and other premises. The top five Aedes aegypti mosquito breeding habitats found in 2018 were: “domestic containers, flower pot plates/trays, ornamental containers, closed perimeter drains and scupper drains of housing estates.” The top five Aedes albopictus mosquito breeding habitats in 2018 were: “domestic containers, flower pot plates/trays, discarded receptacles, closed perimeter drains and ornamental containers” [4]. The prevention and control of dengue rely on effective and sustainable mosquito control measures. Community engagement is critical for the governmental sector to enhance dengue control and prevention measures.

The dengue outbreak in Singapore in 2020 is the worst ever recorded in Singapore’s history. The official report shows the cumulative number of reported dengue cases in 2020 (Sept 7, 2020) to be over 28,300, with 21 deaths. At the height of the COVID-19 pandemic (55,395 confirmed cases and 27 fatalities as of Aug 12, 2020) [5], the Singapore Government also strived to draw the public’s attention to dengue.

Several factors are suspected of having been associated with the increased number of dengue cases in 2020. For the prevention of COVID-19, Singapore adopted a strict “Circuit Breaker” period between April and May, where the entire nation was mandated to stay home. During the two months, compared with the preceding two months, NEA detected five times the number of mosquito breeding habitats (with Aedes mosquito larvae identified) in residential areas (homes and common passageways) twice the usual number at construction sites. Furthermore, the first four months of 2020 saw the risk of a serotype switching from DENV-2 to DENV-3–the latter to which the population of Singapore has very low immunity. The Government urged the People (residents) and the Private sector (contractors and business owners) to prevent Aedes mosquitoes’ breeding and help combat dengue.

1.5 Dengue Health Threats Among Children in Singapore

While the incidence rate per 100,000 residents in Singapore was lower in the 5–14 year age group (37.2), compared to >56.8 for other age groups in 2018 [4], researchers in Singapore found that the dengue seroconversion rate in children aged six years and above increased with the onset of attendance at school [6]. An elevated risk of dengue infection among younger individuals with relatively low immunity was noted [7]. Another study highlighted an increased risk of acquiring dengue infection from viremic children, who had symptoms mild enough to allow attendance at school [8]. As children stay at school for a long time daily, the school environment represents a risk for dengue transmission [9].

2 The Transnational and Trans-Sectoral Prescription for Anti-Dengue Efforts

2.1 The Japanese Residents: A Demographic Segment Difficult to Conduct Outreach to in Singapore

While foreign residents comprised more than a quarter of the total population, there were 36,963 Japanese residents (excluding permanent residents) in Singapore as of October 2015, representing an increase of 42% in only four years [10]. The Japanese population in Singapore is, therefore, a rapidly growing demographic. Because there is no available data on reported cases of dengue in Singapore stratified by nationality, dengue infection among Japanese residents remains unknown. However, knowledge of dengue among this segment was thought to be insufficient.

A study reported that only 51.7% of the subjects (259 Japanese patients at a Japanese health clinic in Singapore) were concerned that either they or their family members would contract dengue between December 2014 and January 2015. The same study suggested that NEA's frequently disseminated anti-dengue information and public education might not have reached Japanese residents, even after over one year of stay in Singapore. For example, 25.9% rarely or never turned over their pails and water storage containers when not used [11]. These activities were included in the anti-dengue messages disseminated locally by NEA at that time (Fig. 3). In contrast, a study conducted in 2007 among 472 Singapore households reported that 93.4% turned over their pails when not used [12].

Fig. 3

The anti-dengue measures recommended and disseminated by NEA

A questionnaire conducted among Japanese adult residents of Singapore in January 2015 revealed insufficient knowledge of the dengue mosquito vector as a daytime biter among the respondents. Furthermore, 87.6% of the respondents answered that they were “not aware” or “do not know much about anti-dengue activities at their residential areas” (unpublished). As most Japanese nationals in Singapore reside in privately owned condominiums, they may have limited awareness that community-based activities, such as regular dengue prevention exercises and an annual nationwide anti-dengue campaign, are usually conducted at public residential estates or community clubs. A follow-up study on 89 Japanese residents in Singapore, conducted in January 2016, revealed heavy dependency on the Japanese language when seeking information regarding infectious disease outbreaks [13]. Although NEA conducts public communication and education in all the four official languages of Singapore (Malay, English, Chinese, and Tamil), Japanese residents remained unable to benefit from real-time outbreak information or educational opportunities offered by the Singapore government.

2.2 Dengue Incidence at a Japanese Primary School in Singapore

During an outreach seminar on tropical infectious diseases conducted for Japanese adult residents in Singapore, a Japanese primary school teacher requested for an educational activity to be carried out at his school. He shared his concern on dengue incidence at a campus earlier and reported cases among schoolchildren. The first author, a university lecturer in Japan researching mosquito-borne infectious diseases in South-East Asia, thus proposed outreach classroom activities targeting Japanese schoolchildren in Singapore in consultation with Japan's Embassy in Singapore. Having obtained approval from the primary school to conduct the dengue outreach exercise as a classroom activity under the school curriculum, teaching materials were made in the Japanese language to increase dengue awareness in this population demographic. However, one indispensable element to include is the contents of local health education that reflect the situation of disease and vector in Singapore to encourage the practice of anti-dengue measures.

NEA responded to the request from the Japanese academic for academia-government trans-sectoral collaboration. The Singapore government agency was fully supportive in providing local educational materials and giving the help of a medical entomologist from its research facility. Additionally, live exhibits of mosquitoes were made available for the outreach exercise, as are usually displayed at NEA events. As mosquitoes’ breeding is illegal in Singapore, residents, including the Japanese schoolchildren, seldom contact live mosquito larvae, pupae, or adults–and especially not up-close. Therefore, such exhibits were considered educational and invaluable in assisting the schoolchildren with viewing and understanding the life cycle of mosquitoes. Thus, our transnational and trans-sectoral collaboration complemented cross-cultural and bilingual capacities and necessary resources essential for the outreach efforts. All the stakeholders involved had a common purpose: strengthening the local health promotion activities to prevent and control dengue.

2.3 The First Dengue Outreach Exercise at a Japanese Primary School in Singapore

When both foreign children and their parents cannot fully understand the local language(s), they require additional assistance in obtaining information about local diseases. The anti-dengue outreach exercise, “Let’s beat dengue fever,” was thus conducted at a Japanese primary school in Singapore from 25 to Jan 26, 2016, with facilitation from Japan's Embassy in Singapore. The purpose was to disseminate and improve the knowledge of dengue symptoms and preventive measures through an impactful classroom activity. The three main messages conveyed during the activity were: i, tell your parents on the day if mosquitoes bite you; ii, protecting yourself from mosquito bites can protect you from dengue; iii, do not make any places that can collect stagnant water in and near your home/school, to stop mosquitoes from breeding.

A total of 1,105 schoolchildren aged between 7 and 12 attended the classroom activity (Table 1), divided into five independent sessions (each lasting 45 min). One session was conducted for grades 5 and 6 at a large event room of the urban campus. One session was also conducted for grades 1 to 2, 3 to 4, and 5 to 6 at the gymnasium of the semi-urban campus. Each session was divided into four parts: talks, posters, videos, and exhibits (Graphical Abstract). All the sessions were administered by a Japanese academic researching Singapore’s anti-dengue measures, a Japanese physician specializing in infectious diseases, and a medical entomologist from NEA–a Singapore government agency.

Table 1 The number of schoolchildren at two campuses

The Japanese school principal at each campus introduced the authors to the schoolchildren. An introductory talk (10 min) highlighted the symptoms of dengue and the Aedes mosquito vector's characteristics (Fig. 4). The talk covered each page of an educational booklet distributed locally by NEA, entitled ‘Do the Mozzie Wipeout: Our lives. Our fight’, which had been translated into Japanese by the first author. The influences of climate change and environmental parameters on vector-borne diseases were also elaborated on to explain the roles individuals can play in dengue prevention and control.

Fig. 4

An introductory talk held at a large event room at the Japanese School in Singapore

Additionally, Singapore’s dengue alert color codes in red, yellow, and green were explained (Fig. 5). The schoolchildren were asked to report any mosquito bites to their parents to seek early healthcare if needed. After that, they were divided into groups of 20 to 30 schoolchildren–each group accompanied by a teacher–to take turns viewing educational posters, exhibits, and videos, for about 25 min in total (Fig. 6).

Fig. 5

Singapore’s dengue alert color codes

Fig. 6

Groups of 20–30 schoolchildren took turns to view posters

Two posters provided by NEA for the outreach exercise had also been translated into Japanese. The first showed the Aedes mosquito life cycle and its relation to the environment. The second highlighted relevant mosquito control tools to target each stage of the vector life cycle. Two versions of translations were required to address different stages in learning the mother tongue: one using only the Japanese kana syllabary for the first to third graders, and the other with a mixture of kana syllables and the more complex kanji (Chinese) characters for the fourth to sixth graders.

The schoolchildren were particularly excited by the opportunity to view up-close NEA’s live mosquito exhibits–eggs, larvae, pupae, female and male Aedes albopictus, and male Aedes aegypti adult mosquitoes. Many eagerly volunteered to place their hands inside a box full of male mosquitoes, learning that male mosquitoes do not bite and are thus incapable of transmitting disease (Fig. 7). Also, an NEA Gravitrap was displayed to encourage interest among the young audience (Fig. 8). The trap uses hay-infusion water as an olfactory cue, as well as a non-repellent sticky inner lining to attract and trap gravid female Aedes mosquitoes. 64,000 Gravitraps have been placed in residential areas throughout Singapore to provide information on Aedes mosquito populations and the risk of dengue in all areas islandwide.

Fig. 7

Many volunteered to place their hands inside a box full of male Aedes aegypti mosquitoes, which cannot bite or transmit disease

Fig. 8

NEA’s Gravitrap at residential areas nationwide

NEA’s educational cartoon videos were also shown to encourage the schoolchildren to advocate environmental management, prevent or minimize mosquito propagation, with two additional take-home messages. These were the importance of frequently changing the water in flower vases and flowerpot plates; and not discarding empty bottles, cans, or containers in open spaces–all common potential mosquito breeding habitats. The classroom activities to learn about mosquito-borne infectious diseases were designed to encourage the schoolchildren's advocacy at school and home. A brief Q&A time was set aside for each group. After that, the schoolchildren returned to their classrooms to fill in the after-class quizzes.

2.4 Results of After-Class Quizzes

As a part of the classroom activity, the schoolchildren participated in review quizzes after the respective sessions. We obtained the answers with no personally identifiable information from each teacher responsible for each cohort. As shown in Table 2, the reported compliance for “tell a parent if bitten by a mosquito” was 95.8% among the first graders. This compliance declined slightly for the second and third graders. Similarly, the younger the schoolchildren, the higher the compliance reported among the fourth to sixth graders, which suggests the importance of providing the older children with knowledge of self-protection from mosquito bites (Table 3).

Table 2 Results of quizzes administered after each outreach session for schoolchildren in the first, second and third grades at the Semi-urban campus, SU, semi-urban campus

Table 3 Results of quizzes administered after each outreach session for schoolchildren in the fourth, fifth, and sixth grades at the Semi-urban campus and Urban campuses. Questions and choices of answers for the fourth to sixth graders differed from those for the first to third graders. SU, semi-urban campus; U, urban campus

As expected, the older the schoolchildren among first to third graders, the higher the number of children who reported that they had “understood the talk” (Table 2). The younger children might have better accepted a topic such as dengue after seeing the visual materials.

Between 88.6% and 99.2% of the fourth to sixth graders chose correctly that they “try not to be bitten by mosquitoes” as a means of avoiding dengue. Between 88.6% to 100% of them selected “try not to create places with stagnant water near home or school” as a method to prevent breeding mosquitoes (Table 3). However, follow-up studies are needed to ascertain if they alert their parents when bitten by mosquitoes or discard rubbish properly to prevent creating mosquito breeding habitats.

2.5 Schoolyard On-Site Inspection

The teachers listened to us attentively when we pointed out the potential mosquito breeding habitats to look out for in the vicinity of school premises during a ground survey at the campus. Five dengue cases (including two among schoolchildren) were reported here in 2015. We also advised the teachers to take precautionary measures against mosquitoes if construction work was carried out near the school. This is because construction sites tend to harbor many places with stagnant water–ideal spots for mosquitoes to breed in. As a matter of fact, construction was being carried out next to the swimming pool at the time of inspection.

Flowerpot plates had been removed in response to advice from NEA inspectors, who visited the campus after reported cases the previous year. We additionally drew the teachers’ attention to the pails and water storage containers that had been put on upside down. The teachers were surprised to hear that the container rims could easily collect rainwater and that eggs laid by Aedes mosquitoes could hatch in less than a day under optimal conditions in tropical Singapore.

3 Lessons Learnt from the First Outreach Exercise

Important lessons garnered from the classroom exercise included: foreign schools would benefit from the supply of more information, particularly on self-protection and effective mosquito control measures locally. It is also vital to build capacity among teachers in communicating the dengue risk when engaging schoolchildren and parents.

We spent over 60 min with the teachers after the sessions at each campus. These consultation hours revealed that many of them were eager to learn more about the local disease situation, correct ways to apply repellent, habits of Aedes mosquitoes, and places to watch out for regarding mosquito breeding inside and outside the school building.

It is felt like a duty to protect the schoolchildren from dengue was expressed by the teachers. Some parents, understandably, expect the school to provide their children with a safe and dengue-free environment; empowering the teachers with knowledge of the disease and the mosquito vector is essential. Building their capacity to communicate the dengue risk to schoolchildren is also indispensable because the teachers can regularly remind the schoolchildren about anti-dengue activities. Although our previous educational seminars were offered to Japanese adult residents in Singapore, to homemakers and businesspersons, more targeted activities for schoolteachers could be desirable.

Our transnational and trans-sectoral approach worked efficiently and effectively for outreach to the Japanese schoolchildren while ensuring that all dengue prevention and control messages propagated were in line with those disseminated by the Singapore Government. Country-specific scientific findings were also presented. For example, the Aedes mosquito life cycle duration of seven days under optimal conditions may be more commonly experienced in Singapore’s tropical climate rather than in Japan’s temperate climate. Additionally, the Aedes mosquito's rapid and easy dispersal is much greater than previously thought and could be a local-specific feature in highly urbanized and built-up Singapore [14].

Transnational parties can better administer Anti-dengue education in the age of globalization involving foreign population segments. Such initiatives may be encouraged by governments in both the host and origin countries. Offering foreign schoolchildren opportunities to learn about mosquito-borne infectious diseases while living in an endemic region can empower them and encourage their advocacy in both the host country and their own country upon repatriation. Trans-sectoral collaboration could be a key to sustaining efforts in global health education, such as anti-dengue initiatives.

4 Science Communication for Community Engagement: Project Wolbachia–Singapore

Although comprehensive vector control to prevent and control mosquito-borne infectious diseases has been carried out in Singapore, traditional source reduction of finding and removing mosquito breeding and habitats is becoming increasingly difficult. New technologies are deemed necessary to complement existing vector control measures. Many years were invested in laying the foundation to adopt a novel vector control technology, including carrying out a prior comprehensive risk assessment. NEA has carried out extensive laboratory and field research studies to assess the feasibility and effectiveness of using male Wolbachia-carrying Aedes aegypti mosquitoes to reduce the wild-type Aedes aegypti mosquito population in Singapore. The Wolbachia-Aedes suppression approach was assessed to be the most suitable for Singapore’s local context.

Knowing that community engagement is a critical factor for the implementation of Project Wolbachia–Singapore, NEA carried out thorough and extensive impactful engagement activities for several years, well in advance of the first field release. Comprehensive consultation was held with the study sites’ residents, general members of the People sector, the medical and scientific professionals, and the Public sector. The outreach efforts focused on community engagement to raise awareness of the Wolbachia-Aedes suppression technology in the form of more than 100 talks, seminars, workshops, conferences, and public engagement sessions [15]. Explanations covered areas such as: “how the technology works”; “why it is the most suitable for Singapore”; “the technology is safe and natural”; “male mosquitoes do not bite or transmit disease”; and “the project only targets Aedes aegypti mosquitoes” [16].

NEA has released male Wolbachia-Aedes mosquitoes at various local study sites in phases since October 2016. The Phase 4 Field Study, conducted from November 2019 to July 2020, involved 56,000 households in 553 HDB blocks in two residential locations. As a result of the ongoing releases of male Wolbachia-Aedes mosquitoes, NEA achieved an unprecedentedly long period of one year of suppressing the urban Aedes aegypti mosquito population to a low level that posed a low dengue risk at the study sites. Besides reducing the Aedes aegypti mosquito population by 90% at the two release sites, the preliminary case–control analysis presented a 65 to 80% reduction in reported dengue cases in 2019, at sites with releases compared to at control sites with no releases [16].

NEA researchers have also reported reducing Zika virus and Chikungunya virus infections in mosquitoes after having introgressed wMel strain of Wolbachia into a Singapore Aedes aegypti mosquito [17]. As NEA works on Project Wolbachia's progression - Singapore in size and complexity, towards possible large-scale nationwide releases in the future, targeted and accurate science communication for the community, inclusive of foreign residents and visitors, will become even more imperative. This approach is critical when results and highly technical plans are to be introduced to the community.

5 Conclusions

This study indicates the importance of including foreign segments of the population in any local efforts to prevent infectious diseases of global concern. There is a demand for outreach activities among the foreign segment of demographics in countries affected by infectious diseases, such as dengue. Disseminating information in their mother tongue and empowering them with knowledge of local diseases and preventive measures is essential when foreign residents cannot fully understand the local language(s).

Outreach to foreign residents will be increasingly important when a new technology needs to be introduced or when technical, scientific evidence must be presented to control public health threats, such as infectious disease outbreaks. Thus, we have concluded that it is important to empower foreign residents with knowledge of self-protection measures and potential mosquito breeding habitats in Singapore. Encouraging them to put knowledge to practice is equally crucial to improve the overall effort for dengue prevention.

This study's limitations include data that were restricted to Japanese residents as a foreign demographic in Singapore. However, the study shed light on the insufficient knowledge and compromised compliance of public health measures by a foreign segment of the resident population, despite a comprehensive national dengue control program led by an active and responsible governmental agency.

As the Japanese demography tends to rely heavily on the Japanese language at home and abroad, it is essential to conduct outreach activities to the Japanese community in dengue-endemic regions. Otherwise, key messages might remain missed or neglected, no matter how widely they are distributed online or displayed at public places nationwide (Figs. 9 and 10). Increasing their knowledge of the disease and its vector and preventative measures would hopefully encourage them to carry out anti-dengue activities at home, at school, and in the community, for their own protection and that of others.

Fig. 9

An example of an NEA flyer with a key message disseminated online

Fig. 10

An example of an NEA poster displayed at public places

Transnational collaboration is vital, and trans-sectoral collaboration could be vital in sustaining efforts to combat a global epidemic. We have presented our Japan-Singapore and academic-government initiatives in anti-dengue outreach initiatives in Singapore. Living at a time when the world has faced enormous challenges due to the COVID-19 pandemic, the authors hope that similar efforts could be reviewed, replicated, or resumed elsewhere to address the specific needs of foreign segments of resident populations.

Core Messages

• Mosquito-borne Dengue virus infection is an alarming public health risk globally.

• The effects of traditional vector control strategies such as source reduction are diminishing.

• Authorities are now tasked to communicate more detailed and technical information to prevent global epidemics.

• Transnational and trans-sectoral collaboration addresses cultural and language challenges in science communication.

• Building capacity among teachers in communicating the dengue risk is essential to engage schoolchildren and parents.