scholarly journals Abundance and Seasonality of Aedes aegypti (Diptera: Culicidae) in Two Suburban Localities of South Mexico, With Implications for Wolbachia (Rickettsiales: Rickettsiaceae)-Carrying Male Releases for Population Suppression

Author(s):  
Azael Che-Mendoza ◽  
Abdiel Martin-Park ◽  
Juan Manuel Chávez-Trava ◽  
Yamili Contreras-Perera ◽  
Hugo Delfín-González ◽  
...  

Abstract We conducted a baseline characterization of the abundance and seasonality of Aedes aegypti (Linnaeus, 1762)—a vector of dengue, chikungunya, and Zika—in two suburban localities of Yucatan, Mexico, as the first step in the implementation of an integrated vector management (IVM) plan combining ‘traditional Aedes control’ (source reduction/truck-mounted ultra-low volume [ULV] spraying) and incompatible insect technique/sterile insect technique for population suppression in Yucatan, Mexico. Weekly entomological collections with ovitraps and BG-sentinel traps were performed in 1-ha quadrants of both localities for 1 yr. Three distinct periods/phases were identified, closely associated with precipitation: 1) a phase of low population abundance during the dry season (weekly average of Aedes eggs per ovitrap and adults per BG trap = 15.51 ± 0.71 and 10.07 ± 0.88, respectively); 2) a phase of population growth and greatest abundance of Aedes (49.03 ± 1.48 eggs and 25.69 ± 1.31 adults) during the rainy season; and finally 3) a phase of decline among populations (20.91 ± 0.97 eggs and 3.24 ± 0.21 adults) after the peak of the rainy season. Seasonal abundance and dynamics of Ae. aegypti populations suggest that it is feasible to develop and implement time-specific actions as part of an IVM approach incorporating integrating novel technologies (such as rear-and-release of Wolbachia-infected males) with classic (insecticide-based) approaches implemented routinely for vector control. In agreement with the local vector control program, we propose a pilot IVM strategy structured in a preparation phase, an attack phase with traditional vector control, and a suppression phase with inundative releases, which are described in this paper.

2021 ◽  
Vol 3 (2) ◽  
pp. 043-048
Author(s):  
Mohi Eldin Abdallah M Mohammed ◽  
Omar Yousof M Ali ◽  
Ashraf Abd El-Salam H Mangoud ◽  
Mutaman Ali A Kehail

Mosquitoes can act as vectors for many disease-causing viruses and parasites through carrying these organisms from person to person. The objective of this study was to evaluate the susceptibility of Aedes aegypti larvae to some insecticides in Jeddah Governorate. Mosquito larvae were collected from all the available breeding sites in Jeddah municipalities using standard larval collection kits. The diagnostic doses (LC50 and LC90) were calculated from the mortality and concentration data. The larvicides Pirimiphos methyl, Fenitrothion, Bifenthrin and Cypermethrin were tested against the larvae of Ae. aegypti mosquito. The results showed positive correlation between the concentrations under investigation and mortality% of the treated larvae. Cypermethrin gave strong effect against Ae. aegypti larvae (LD50 0.0015 ml/L) followed by Pirimiphos methyl (LD50 0.0020 ml/L), Bifenthrin (LD50 0.039 ml/L), and at last rank Fenitrothion (0.041 ml/L). The same trend was obtained in LD90s. Ae. aegypti in Jeddah was susceptible to Bifenthrin, Cypermethrin, Pirimiphos methyl and Fenitrothion. Further studies should be run to conduct an intensive and appropriate vector control program in Jeddah Governorate.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Marylene de Brito Arduino

The control of dengue relies on the elimination of vector breeding sites. This study identified the container categories most productive for A. aegypti within the framework of the São Paulo dengue vector control program (DVCP) in São Sebastião, a large city located on the state’s coast where dengue cases have occurred since 2001. Containers were inspected monthly for the occurrence of mosquito immature stages during two consecutive vector-breeding seasons in 2002–2004. Containers were classified by their material, use, and fixed or removable status. Pupal productivity differed significantly among container types, items made of metal and plastic, and boats being those with the highest relative contribution. Significant correlations between traditional indices of A. aegypti abundance (Container Index, House Index, and Breteau Index) and pupal productivity/demographic indices (Pupae/Container, Pupae/House, Pupae/ha, and Pupae/Person) ranged 0.56–0.65; correlations were not statistically significant for any combination involving the Pupae/Container index. The assessment of pupal productivity indices could be incorporated into the DVCP without any additional operational onus, allowing vector control managers to determine appropriate control actions targeting the most productive containers and sites. Further studies are needed to assess whether pupal productivity indices may be used as epidemiological indicators of risk of dengue transmission.


2015 ◽  
Vol 93 (6) ◽  
pp. 1231-1239 ◽  
Author(s):  
Kota Yoshioka ◽  
Jiro Nakamura ◽  
Lenin Pérez ◽  
Yuichiro Tabaru ◽  
Doribel Tercero ◽  
...  

2019 ◽  
Vol 53 ◽  
pp. 29 ◽  
Author(s):  
Gerson Laurindo Barbosa ◽  
Mariana De Oliveira Lage ◽  
Valmir Roberto Andrade ◽  
Antônio Henrique Alves Gomes ◽  
Jose Alberto Quintanilha ◽  
...  

OBJECTIVE: To evaluate whether sites with large amount of potential breeding sites for immature forms of Aedes aegypti, called strategic points, influence in the active vector’s dispersion into properties in their surroundings. METHODS: We selected four areas in the municipality of Campinas, three of them with strategic points classified as high, moderate, and low risk according to infestation and a control area, without strategic points. Between October 2015 and September 2016, we monthly installed oviposition traps and evaluated the infestation by Ae. aegypti in all properties of each selected area. To verify if there was vector dispersion from each strategic point, based on its location, we investigated the formation of clusters with excess of eggs or larvae or pupae containers, using the Gi spatial statistics. RESULTS: The amount of eggs collected in the ovitraps and the number of positive containers for Ae. aegypti did not show clusters of high values concerning its distance from the strategic point. Both presented random distribution not spatially associated with the positioning of strategic points in the area. CONCLUSIONS: Strategic points are not confirmed as responsible for the vector’s dispersion for properties in their surroundings. We highlight the importance of reviewing the current strategy of the vector control program in Brazil, seeking a balance from the technical, operational, and economic point of view, without disregarding the role of strategic points as major producers of mosquitoes and their importance in the dissemination of arboviruses in periods of transmission.


PLoS ONE ◽  
2011 ◽  
Vol 6 (1) ◽  
pp. e16066 ◽  
Author(s):  
Delenasaw Yewhalaw ◽  
Fantahun Wassie ◽  
Walter Steurbaut ◽  
Pieter Spanoghe ◽  
Wim Van Bortel ◽  
...  

2020 ◽  
Author(s):  
Gilmar Ribeiro ◽  
Cristiane Medeiros Moraes de Carvalho ◽  
Renato Freitas de Araújo ◽  
Fernanda Cardoso Lanza ◽  
Diego Lopes Paim Miranda ◽  
...  

Abstract Background: This study presents a descriptive analysis of the occurrence of synanthropic triatomine species in the state of Bahia, before and after the implementation of the vector control program. Methods: Occurrence and number of collected specimens in the municipalities were analyzed in two periods: (A) 1957 to 1971, before systematic vector control actions; and (B) 2006 to 2019, after the certification of interruption of Chagas disease transmission by Triatoma infestans. Results: In total, 17 species were recorded during period A and 21 during period B. Panstrongylus megistus was the most frequent species in period A (42%), while Triatoma pseudomaculata (42%) and T. sordida (38%) were more frequent in period B. In period A, T. infestans was found in 26 (9%) municipalities, and in period B it was found in 7 (2%). During period B, most triatomines (88%) were captured at the peridomestic habitats, with a predominance of T. sordida (85%). Species with greatest relative abundance within the household were T. sordida (49%), T. brasiliensis (27%), and T. pseudomaculata (15%). Conclusions: We have observed a clear reduction in the occurrence of P. megistus and T. infestans and an increase in the relative abundance and geographical distribution of T. sordida and T. pseudomaculata after 40 years of the vector-control program. High frequency of other triatomine species in the municipalities of the state of Bahia and a great abundance of T. sordida in recent years, highlight the need to reinforce permanent entomological surveillance actions for Chagas disease.


2021 ◽  
Author(s):  
Sylvie Manguin ◽  
Vincent Foumane ◽  
Jean-Claude Toto ◽  
Franck Martinaud ◽  
Maria Adelaide Dos Santos ◽  
...  

Abstract Background: A long-term village scale vector control program was implemented in eight villages around the Balombo town (Benguela Province, Angola) to compare the efficacy of four methods of vector control inside houses including long-lasting deltamethrin insecticide treated nets (PermaNet© 2.0 model or P.2.0); association of P.2.0 and deltamethrin Insecticide Treated Plastic Sheeting (ITPS)-Zero Fly© model; deltamethrin ITPS-Wall Lining model alone; and 2 rounds of lambdacyhalothrin Inside Residual Spraying followed by installation of ITPS.Methods: Cross sectional parasitological surveys (CSS) were done every two months. Thick blood films (TBF) were microscopically examined at the Medical Department of the Angolese Sonamet company in Lobito and a sample of them were double-checked in Yaoundé. Plasmodium species determination, parasitaemia and gametocytes presence, and evolution in time were analyzed.Results: A total of 190 CSS was done between 2007 and 2011, Plasmodium spp. were observed in 5,431 of the 21,804 TBF done. Plasmodium malariae alone was observed in 22 TBF (0.4%) and mixed infections P. falciparum and P. malariae in 44 TBF (0.8%).Conclusion: The very low frequency of P. malariae could explain the fact it is usually not reported in classical point prevalence surveys. Our study confirms the presence of this species in Angola, which must be known due to its special clinical impact, quartan fever, kidney failure, chronicity, symptomless carriers, persistence for several years with long term recrudescence and reported cases of resistance to classical ACTs. The prevalence of P. malariae decreased after implementation of vector control methods.


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