Risk of dengue, Zika, and chikungunya transmission in the metropolitan area of Cucuta, Colombia: cross-sectional analysis, baseline for a cluster-randomised controlled trial of a novel vector tool for water containers

Abstract

Background Arbovirus diseases such as dengue, Zika, and chikungunya are a public health threat in tropical and subtropical areas. In the absence of a vaccine or specific treatment, vector management (in this case the control of the primary vector Aedes aegypti) is the best practice to prevent the three diseases. A good understanding of vector behaviour, ecology, human mobility and water use can help design effective vector control programmes. This study collected baseline information on these factors for identifying the arbovirus transmission risk and assessed the requirements for a large intervention trial in Colombia. Methods Baseline surveys were conducted in 5,997 households, randomly selected from 24 clusters (neighbourhoods with on average 2000 houses and 250 households inspected) in the metropolitan area of Cucuta, Colombia. The study established population characteristics including water management and mobility as well as larval-pupal indices which were estimated and compared in all clusters. Additionally, the study estimated disease incidence from two sources: self-reported dengue cases in the household survey and cases notified by the national surveillance system. Results In all 24 study clusters similar social and demographic characteristics were found but the entomological indicators and estimated disease incidence rates varied. The entomological indicators showed a high vector infestation: House Index = 25.1%, Container Index = 12.3% and Breteau Index = 29.6. Pupae per person Index (PPI) as an indicator of the transmission risk showed a large range from 0.22 to 2.04 indicating the high transmission risk in most clusters. The concrete ground tanks for laundry –mostly outdoors and uncovered- were the containers with the highest production of Aedes mosquitoes as 86.3% of all 17,613 pupae were identified in these containers. Also the annual incidence of dengue was high: 841.6 self-reported cases per 100,000 inhabitants and the dengue incidence notified by the National surveillance system was 1,013.4 cases per 100,000 in 2019. Only 2.2% of the households used the container water for drinking. 40.3% of the study population travelled during day (when Aedes mosquitoes bite) outside their clusters. Conclusions: The production of Aedes aegypti mosquitoes occurred almost exclusively in concrete ground tanks for laundry (lavadero) which are the primary intervention target. The baseline study provides important evidence for the design and implementation of a cluster randomized intervention trial in Colombia.

Occurrence of arbovirus infections in two riverine populations in the municipality of Humaitá, Amazonas, Brazil

“…Although many studies affirm that women are at a higher risk for arbovirus infection, since they spend longer periods at home, considering the domestic habits of the Aedes aegypti vector 32 , 33 , this study demonstrated a higher prevalence of previous infections with the DENV in men (p < 0.018) ( Table 5 ). This can be justified by the fact that infections did not occur in rural households but in urban areas, with trips to the local towns being mostly undertaken by men and, for cultural reasons, women remaining at home to perform chores and take care of children.…”

Mosquito Salivary Antigens and their Relationship to Dengue and P. <em>vivax </em>Malaria

“…However, this association was not observed with Pvs25, suggesting that expression of Pvs230 may be associated with exposure to mosquito bites from both Anopheles and Aedes mosquitoes. Previous entomological data from this region indicate that Anopheles and Aedes mosquitoes are prevalent in the area 45,46 . However, a limitation of this study is that the gSG6-P1 and the Nterm34kDa peptides we evaluated as markers of mosquito exposure have not been extensively validated for their correlation with mosquito abundance 47,48,49 , and we did not collect specific mosquito data from the sites in our study which could be used to confirm exposure to these mosquito species.…”

A Poisson Cokriging Modeling of Co-circulation of Mosquito-borne Diseases in Colombia

“…ZIKV high-risk concentrated in southern areas characterized by crowded living conditions, limited access to safe water, and strained healthcare centers, creating favorable conditions for the rapid ZIKV transmission. Moreover, the rural municipalities in this area frequently experience standing water deposits such as laundry tanks and provisional water containers, facilitating mosquito breeding and hindering effective vector control efforts [36]. Hotspots of DENV were also identified in the northern central region, primarily containing rural municipalities with limited access to public, educational, and health services.…”