Implementation and Evaluation of Vector Control Methods in Kinshasa: The Case of Aedes

Официальное название

Implementation and Evaluation of Vector Control Methods in Kinshasa: The Case of Aedes, Vectors of Arboviruses.

Обзор

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.

Подробное описание

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 the last 30 years, the frequency and extent of Aedes-borne epidemics have increased significantly and the main vectors, Aedes aegypti and Aedes albopictus, have expanded their geographical distribution worldwide.

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). However, vector control activities for Aedes are not carried out regularly outside of epidemic periods and the need for targeted strategies remains essential.

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. Furthermore, the integration of a serological survey on diseases transmitted by the Aedes vector will strengthen our knowledge on the circulation of these diseases in the area, for which the data in the literature remain fragmentary until now.

In particular, a before-and-after interventional study will be piloted and tested in the health zone of Mont Ngafula 1, Kinshasa, which is characterized by ecological diversity and a known history of arbovirus circulation. In this pilot study, with the aim of providing preliminary evidence of the impact of vector control tools, there are four arms: i) community-based environmental management approach, ii) community-based environmental management and vector control against immature stages of Aedes (pyriproxifen-based autodissemination stations), iii) community-based environmental management and vector control against the mature stages of Aedes aegypti (mass trapping using BG-GAT - Gravid Aedes Traps), iv) control arm without implementation of vector control interventions. These 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. The knowledge, attitudes and practices of the subjects belonging to the households enrolled in the study will be collected using an electronic questionnaire before and after the intervention. 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, for a better definition of the next measures to be adopted in the fight against vectors, tailored to the specific context of the the DRC.

Вмешательства

• Поведенческое Community-based environmental management
  This 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 h
• Другое Vector control against immature stages of Aedes
  Larvicidal control will be carried out through pyriproxifen-based autodissemination stations combined with Beauveria bassiana, implemented according to the manufacturer's recommended procedures.
• Другое Vector control against the mature stages of Aedes
  The 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.

Первичные конечные точки

• Adult mosquito collection - Entomological Indicator [Срок оценки: Six collections in total: 1 at baseline, 4 during the intervention (one per trimester), 1 three months after completion of the intervention.]
• Mosquito larval survey - Entomological Indicator [Срок оценки: Six collections in total: 1 at baseline, 4 during the intervention (one per trimester), 1 three months after completion of the intervention.]
• Epidemiological indicator [Срок оценки: Once : before/at beginning of intervention]

Вторичные конечные точки (1)

• Knowledge, attitudes, and practices. [Срок оценки: Twice in total: at the beginning of the study and three months after completion of the intervention.]

Критерии участия

At household level:

Критерии включения

• 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

Критерии исключения

• Not belong to a household in one of the 4 health areas selected as study arms
• Under 18 years of age
• Non-consenting

At health facility level:

Критерии включения

• From 18 years of age
• Resident of the health zone of Mont Ngafula 1
• Consenting

Критерии исключения

• Under 18 years of age
• Not resident in the health zone of Mont Ngafula 1
• Seriously ill and hospitalized, requiring transfusion, presence of blood clotting disorders, allergies resulting from injections, adverse events associated with previous blood sampling, pregnancy
• Non-consenting

Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.

Здоровые добровольцы: Да

Дизайн исследования

Распределение

Рандомизированное

Модель

Параллельные группы

Маскирование

Открытое

Основная цель

Профилактика

Центры проведения

Democratic Republic of the Congo · 1 центр

• Institut National de Recherche Biomédicale, INRB — Kinshasa

Публикации

• Mbanzulu KM, Wumba R, Mukendi JK, Zanga JK, Shija F, Bobanga TL, Aloni MN, Misinzo G. Mosquito-borne viruses circulating in Kinshasa, Democratic Republic of the Congo. Int J Infect Dis. 2017 Apr;57:32-37. doi: 10.1016/j.ijid.2017.01.016. Epub 2017 Jan 30. PMID 28153792
• Proesmans S, Katshongo F, Milambu J, Fungula B, Muhindo Mavoko H, Ahuka-Mundeke S, Inocencio da Luz R, Van Esbroeck M, Arien KK, Cnops L, De Smet B, Lutumba P, Van Geertruyden JP, Vanlerberghe V. Dengue and chikungunya among outpatients with acute undifferentiated fever in Kinshasa, Democratic Republic of Congo: A cross-sectional study. PLoS Negl Trop Dis. 2019 Sep 5;13(9):e0007047. doi: 10.1371/j PMID 31487279
• Selhorst P, Makiala-Mandanda S, De Smet B, Marien J, Anthony C, Binene-Mbuka G, De Weggheleire A, Ilombe G, Kinganda-Lusamaki E, Pukuta-Simbu E, Lubula L, Mbala-Kingebeni P, Nkuba-Ndaye A, Vogt F, Watsenga F, Van Bortel W, Vanlerberghe V, Arien KK, Ahuka-Mundeke S. Molecular characterization of chikungunya virus during the 2019 outbreak in the Democratic Republic of the Congo. Emerg Microbes Infec PMID 32787529
• Willcox AC, Collins MH, Jadi R, Keeler C, Parr JB, Mumba D, Kashamuka M, Tshefu A, de Silva AM, Meshnick SR. Seroepidemiology of Dengue, Zika, and Yellow Fever Viruses among Children in the Democratic Republic of the Congo. Am J Trop Med Hyg. 2018 Sep;99(3):756-763. doi: 10.4269/ajtmh.18-0156. Epub 2018 Jul 5. PMID 29988000
• Weetman D, Kamgang B, Badolo A, Moyes CL, Shearer FM, Coulibaly M, Pinto J, Lambrechts L, McCall PJ. Aedes Mosquitoes and Aedes-Borne Arboviruses in Africa: Current and Future Threats. Int J Environ Res Public Health. 2018 Jan 28;15(2):220. doi: 10.3390/ijerph15020220. PMID 29382107

Идентификаторы

NCT: NCT06981442 · 1778/24

Первоисточники (государственные реестры)

• ClinicalTrials.gov (NIH, США)

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