Meeting the Challenges of the COVID-19 Pandemic for Operational Adaptations of a Cluster Randomized Controlled Trial of Dengue Vector Control in Malaysia | BMC Public Health

Trial design

The Intervention Project for Dengue Epidemiology Malaysia (iDEM) is a cluster randomized controlled trial that aims to assess the effectiveness of integrated vector management (IVM) on the incidence of dengue fever in urban Malaysia. . A cluster is defined as a residential area made up of neighboring buildings that share the same facilities such as parking lots, food court, grocery store, playground, and community halls.

The full trial protocol has been published previously [23]. In short, this IVM strategy combines (1) targeted outdoor residual spraying (TORS) with K-Othrine Polyzone, (2) deployment of In2Care mosquito traps as self-dissemination devices (ADD), and (3) Active Community Engagement (EC) Activities. The latter is carried out by community engagement officers specially trained for the purposes of the trial, each responsible for a defined number of clusters.

Community engagement activities take place in management offices and community halls during weekdays, weekends or evenings. They consist of meetings with the community in the study areas to explain the purpose of the study. In parallel, volunteers are identified to inform health workers in the field of potential vandalism and the need to replace ovitraps or ADDs. Communities are asked to cooperate when spraying and not to interfere with ADD equipment installed in their environment. We expect these regular meetings to build public understanding and trust, which would support the continued compliance of participating clusters and their collaboration with field workers during response cycles. During CE visits, banners, posters and brochures are distributed to explain the objectives of the study and the role of the community during and after the deployment of the intervention.

A total of 280 clusters located in the Federal Territory of Kuala Lumpur and Putrajaya were randomly allocated to receive either the combination of proactive vector control and vector control activities or only the routine vector control activities.

The trial was to last two years and include six cycles of intervention. The TORS was to be conducted every four months in all clusters in the intervention areas. The ADDs were distributed in the ground floors, the first floors, the upper floors and evenly between the intermediate floors at the start of the intervention and had to be maintained every two months. ADD services consist of ensuring that there is still an adequate amount of active ingredients, adding water inside the container, saving and then replacing damaged ADDs. Intervention cycles were planned to be sequential over the study period (Fig. 1). Community engagement events were planned as an ongoing activity throughout the life of the trial.

Fig. 1

Schedule of the iDEM project before and after the start of the COVID-19 pandemic

Implementation of the test

Our operational activities, including the implementation of TORS and ADDs, started on February 10, 2020, just weeks before the implementation of non-pharmaceutical interventions to contain the spread of COVID-19 in Malaysia. Due to MCOs and requirements to minimize face-to-face contact with participants, the trial was completely halted for a two-week period, from March 23 to April 5, 2020, to prepare the documents required by the service of execution (Malaysian Royal Police, Ministry of Health and National Security Council of Malaysia). These documents were: an SOP for community engagement steps during the pandemic; an SOP for operators and personnel to perform TORS and quality control assessments, and maintain ADDs; and an SOP for entomological data collection staff in control and response clusters.

The pandemic has forced the research and implementation team to consider how best to ensure the continuity of the trial and its procedures. The solutions had to be adaptable to the different situations of the pandemic while preserving the safety of field workers, the continuity of vector control interventions and the activities of the CE.

With strong support from the Institute for Medical Research (IMR), a division of the Malaysian Ministry of Health, a clearance letter was provided by the Director of IMR to the Field Operations Team to declare the need for their work to continue trial related vector control activities, i.e. ADD and TORS deployment.

Major challenges and solutions deployed

The first issue was the safety of workers in the field while carrying out their work during the pandemic, and this was ensured by equipping them with full personal protective equipment (PPE) and following the rules of the 3Ws and 3Cs . A formal training session was conducted in small groups on how to properly use and dispose of PPE. Additionally, field workers were tested for COVID-19 as soon as symptoms appeared or high-risk contacts were detected. Moreover, they benefited from the vaccination once it was available in the country. All field workers, 9 research assistants and 22 supervisors and operators have completed both doses of COVID-19 vaccine.

The second most important issue was to adapt the implementation plan of the vector control activities, i.e. to maintain the planned turnover for 6 cycles of TORS application every four months and the ADD services every two months. [23]. Due to the pandemic and the lack of budget, we had to consider the option of stopping the intervention after only 4 cycles. The trial protocol was written in accordance with the SPIRIT statement, and no interim analysis or early termination of the trial was planned. Also, the publication and dissemination of the results over only four cycles, instead of the six cycles initially planned, could have affected the power of the study and the credibility of the results. Maintaining a two-year intervention trial was also essential to manage the high temporal variability of dengue. Thanks to the operational changes adopted, we were able to maintain the original six cycles, as shown in the lower panel of Fig. 1.

During the MCO, vector control activities were carried out with a limited number of field agents in each cluster. The field team had to be divided into small teams, each with 6-8 operators, rather than the original plan with up to 18-24 operators in a given cluster. The RMCO began on June 7, 2020, allowing the Field Operations team to continue in a larger group while adhering to the aforementioned SOPs.

From January 2021 to May 2021, Malaysia experienced an increasing wave of COVID-19 cases across the country. In response to the increase in cases, the government has implemented another MCO following the same rules as MCO 1.0. In three iDEM response clusters with a high number of COVID-19 cases, or under the instruction of an Enhanced Movement Control Order (EMCO), ADD services and entomological data collection activities have been postponed for a period of four to six weeks until clearance is obtained from the Malaysian National Security Council. Obtaining clearance was based on the number of positive COVID-19 cases in the area.