Arboviral diseases are viral diseases transmitted by mosquitoes of the Aedes genus and are constantly spreading throughout the world, constituting a significant threat to public health.
In Africa, there is very little data on the epidemiological situation of Aedes-borne diseases and programs for monitoring these diseases are very limited. In the Democratic Republic of the Congo (DRC), several epidemics of yellow fever, dengue fever, chikungunya and Zika cases have been reported. In particular, in Kinshasa, the dengue and chikungunya viruses have previously been detected in patients with undifferentiated fevers and several studies have shown entomological transmission indices above the criteria and standards of the World Health Organization (WHO).
The aim of our study is to implement and evaluate different strategies to control Aedes mosquitoes at different stages of their life cycle in the city of Kinshasa.
In particular, a before-and-after interventional study will be piloted and tested in the health zone of Kinshasa, with the aim of providing preliminary evidence of the impact of vector control tools.
Interventions will be implemented in 400 households for each arm for 12 months. Before, after and during the interventions, entomological surveys will be conducted in 160 households in each arm to define the density of the vectors. Mosquitoes will be tested for the possible presence of arbovirus RNA (dengue, chikungunya, Zika, yellow fever). During the pre-intervention period, a serological survey for the same diseases transmitted by the Aedes mosquito will be conducted on a sample of 450 people included in two health centers of reference for the health zone of Mont Ngafula 1. A questionnaire will also be administered before and after the intervention implementation to assess the community's knowledge, attitudes and practices towards Aedes mosquito vector control and Aedes-borne diseases.
The integration of the data collected within the scope of this study will provide an assessment of the feasibility and impact of the tested methods on entomological indicators, as well as determining the exposure and knowledge of Aedes-borne diseases in the Mont Ngafula 1 area.
Belong to a household in one of the 4 health areas selected as study arms
From 18 years of age to consent for household enrollment and participation in the serosurvey
Consenting
Not belong to a household in one of the 4 health areas selected as study arms
Under 18 years of age
Non-consenting
From 18 years of age
Parallel
Community-based environmental management
BehavioralThis intervention will be performed by the local community, who will have been previously informed and trained on the appropriate environmental management methods for the control of the Aedes mosquito. It will be based on the following elements: i) identification and removal of all artificial sources of reproduction of the Aedes mosquito inside and around the house (i.e. covering abandoned containers and/or storage containers to avoid water accumulation); ii) regular collection and disposal of household waste; iii) identification and resolution of all artificial sources of reproduction of the Aedes vector in or around the house (i.e. natural cavities such as tree holes will be filled to prevent water accumulation). This intervention will be carried out as a single intervention in Arm 1, in combination with a larvicidal intervention in Arm 2 and in combination with the intervention against the adult stage of the Aedes mosquito in Arm 3.
Vector control against immature stages of Aedes
Other interventionLarvicidal control will be carried out through pyriproxifen-based autodissemination stations combined with Beauveria bassiana, implemented according to the manufacturer's recommended procedures.
Vector control against the mature stages of Aedes
Other interventionThe control of the adult Aedes mosquitoes will be carried out through mass trapping using BG-GAT traps implemented according to the manufacturer's recommended procedures. In each household, three traps will be deployed.
Adult mosquito collection - Entomological Indicator
Adult mosquitoes will be collected outdoor using Prokopack mosquito aspirator in 50 households at the center of each of the 4 study arms and using BG-Sentinel traps in 10 households at the center of each of the 4 study arms. Adult mosquitoes obtained through BG-GAT traps in Arm 3 will also be collected.
Mosquito larval survey - Entomological Indicator
Larval surveys will be carried out in 100 households at the center of each of the 4 study arms. Immature mosquitoes obtained through the auto-dissemination stations in Arm 2 will also be collected.
Epidemiological indicator
A sero-survey prospectively including 450 consenting subjects will be carried out in two hospitals in the health zone of Mont Ngafula 1, Kinshasa. The blood sample will be tested for antibodies against the main arboviruses (Yellow Fever, Dengue, Chikungunya, Zika). De-identified socio-demographic data will be collected.
Knowledge, attitudes, and practices.
A survey on knowledge, practices and behaviors regarding Aedes-borne diseases, Aedes mosquitoes and vector control will be proposed to 100 subjects for each study arm, for a total of 400 participants.
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Institute of Tropical Medicine, Belgium
Lead sponsor
Institut National de Recherche Biomédicale. Kinshasa, République Démocratique du Congo
Collaborator