Operations Strategy

NEA's key strategy in dengue control is to tackle the root of the problem, which is to deny Aedes mosquitoes the place to breed (i.e. source reduction). This approach has been endorsed by WHO[1].

NEA adopts a multi-pronged approach to control dengue. The main thrusts in our approach are:

a. preventive surveillance and control;

b. public education & community involvement;

c. enforcement; and

d. research.

Preventive Surveillance and control

Through data gathered during field surveillance and with the aid of the Geographical Information System, NEA conducts daily mosquito surveillance operations. The information enables NEA to move quickly into areas to do source reduction (i.e. remove/destroy breeding grounds found). These are important steps to prevent possible dengue transmission.

NEA's operations strategies are:

a. Active surveillance in areas prone to dengue and/or where there is high mosquito population.

b. Breaking the source of transmission as quickly as possible when cases (both suspected and confirmed) and clusters of cases emerge.

(a) NEA's Pest Control Efforts (Manpower)

  • Currently NEA has 850 officers carrying out dengue inspection on full time basis. Dedicated teams have been formed to carry out regular auditing, inspections and enforcement in each of the 87 constituencies.

  • These teams, being familiar with the areas under their charge, are able to identify and pre-empt potential problematic areas quicker and more effectively.

(b) Integrated Efforts with Other Agencies/Organizations

NEA works with various land agencies as well as private organizations and associations to ensure that there is a coordinated approach in keeping the mosquito population and dengue cases low. Some of the agencies NEA has worked with include:

  1. i. Construction Sites
    • Since 2001, an Environmental Control Officer (ECO) Scheme had been introduced in construction sites. Under the Scheme, construction sites are required to engage a part time or full time ECO depending on the cost of the development.
    • These NEA-trained ECOs are responsible for maintaining the pest and mosquito control works within the construction sites.
  2. ii. Schools
    • Since 1999, a programme was introduced to train Operation Managers of schools on dengue prevention.
    • Through the training, these Managers have a deeper knowledge of mosquito control and are able to audit the performance of their pest control operators more effectively
    • NEA also worked closely with the schools to put in place a comprehensive mosquito control programme.
  3. iii. Town Councils
    • In Sep 2005, NEA had assisted TCs to kick-start a dedicated mosquito control programme. The dedicated programme focuses the dengue control efforts on source reduction.
    • Under the programme, TCs engage a pest control operator (PCO)[2] to carry out weekly search-and-destroy operation.
    • Apart from providing technical specifications for dengue control works, NEA also provided some financial assistance for these programmes.
    • TC officers were also trained as Estate Environmental Officers so as to equip them with the necessary mosquito control knowledge and skills to supervise the performance of pest control operators.
    • Regular meetings with TCs are held to assess and review the dengue situation within their respective TC areas.
  4. iv. Inter-Agency Dengue Task Force
    • The Chief Executive Officer of NEA chairs the Inter-Agency Dengue Task Force (IADTF) comprising of 27 government agencies and private associations.
    • Through IADTF, NEA leads other government agencies to similarly enhance their mosquito control programmes.
    • This collaboration has enhanced the communication and coordination on dengue control efforts among various agencies. Since then, the mosquito control regimes of the various government agencies had been strengthened. Each agency has put in place a tighter and more comprehensive source reduction regime in their mosquito control contracts with pest control operators.
    • Furthermore, permanent solutions to eliminate potential sources of stagnant water like repairs to infrastructure, sealing up of cracks, backfilling of land, and removal of roof-gutters are carried out on a regular basis.

(c) Intensive Source Reduction Exercises (ISREs)

  • As NEA officers carry out routine surveillance checks every day, additional pre-emptive Intensive Source Reduction Exercises (ISREs) are carried out ahead of the warmer months to pre-empt the rise in dengue fever cases, which usually occurs around June to October.

  • ISREs consist of coordinated, pre-emptive search and destroy operations carried out to remove mosquito breeding habitats (including potential habitats), hence suppressing the rise in mosquito population during warmer months.

  • NEA, together with land agencies, town councils, as well as their pest control operators, carried out coordinated search and destroy operations in the agencies’ premises and public areas including residential estates. Potential breeding habitats were also identified for necessary follow-up action.

(d) Notice to Enter Premises

In order to protect public health and to prevent the spread of the Aedes mosquito-borne dengue fever, NEA has the powers, under the Control of Vectors and Pesticides Act (CVPA) to enter vacant premises to check for mosquito breedings. However, NEA will only do this if the situation warrants it, such as when

  1. i. there is a cluster of dengue fever cases in an area and the owner cannot be contacted; and

  2. ii. there are strong indications that there is mosquito breeding within the premises and the owner cannot be    contacted.

  3. Upon notification of a dengue cluster, NEA officers will be deployed to carry out intensive search and destroy operations at outdoor as well as indoor areas within the cluster area. All premises will have to be checked at least once during the cluster period. If residents are not at home, our officers will adopt the following steps to gain access to the premises

    • ■  Firstly, officers will attempt a second visit at night between 7 – 10pm or during the weekend. In addition, a call    letter would have been sent to your household, and you can call NEA to make an appointment for an    inspection.

    • ■  If NEA officers are unable to enter the premises during the first round of inspection , a legal Notice to Enter Premises Under Section 35 of the CVPA will be pasted on the door of the    premises to inform the owner/ occupier of the specific date and time that NEA officers will inspect the    premises. An Explanatory Letter which explains the purpose of the Notice (in four languages) will be slipped    under the door of the premises. If the owner/ occupier cannot be at home during the scheduled date and time    given in the Notice, they should call NEA to arrange for a mutually convenient time for an inspection. In the    interest of safety of the residents around the unoccupied house, the resident or home occupier must respond    within two days. Meanwhile, NEA officers will also try to contact the owner/ occupier through their neighbours    or local Resident's Committee.

    • ■  If there are still dengue fever cases in the area after all other premises in the cluster had been cleared and    NEA assesses the vacant premises may be a breeding site, NEA will, as a final resort, serve a Notice of Entry    under Section 36 of the CVPA to the owner/ occupier. It will keep the Police, Town Council and local    Resident's Committee informed of our intended into the premises entry.

    We would like to assure everyone that NEA will only invoke Section 36 of the CVPA to gain access to vacant premises as a last resort, after all other means of ownership search and contacting the owner/ occupier have been exhausted, and only if the situation warrants it (such as in the case of continued rise in dengue cases in a known cluster). Entries into homes will be supervised in the presence of senior NEA officers, as well as Town Council representatives

[1] The WHO notes: "in order to achieve sustainability of a successful DF/DHF vector control programme, it is essential to focus on larval source reduction and to have complete cooperation with non-health sectors, such as non-governmental organizations, civic organizations and community groups, to ensure community understanding and involvement in implementation. There is therefore a need to adopt an integrated approach to mosquito control by including all appropriate methods (environmental, biological and chemical) that are safe, cost-effective and environmentally acceptable. A successful, sustainable Aegypti control programme must involve a partnership between government control agencies and the community."

[2] The PCOs will carry out audits on common areas such as common corridors, linkways, gutters, bus shelters, bin centres and roof tops of HDB blocks as part of preventive surveillance. If there is active transmission of dengue cases in a particular location, the PCOs will thermal fog the area, including corridors of all floors of HDB blocks and surrounding ground areas to kill all possible infective adult mosquitoes. As an additional precautionary measure, the PCOs will help NEA check places where there are heavy concentration of people, e.g. town centres with bus interchanges/MRT stations. This will reduce any possible breeding in such heavily populated areas. In this way, Aedes mosquitoes cannot have breeding spots to populate and infect new generations to further transmit the virus.