RESUMO
Aedes aegypti is the main vector of the dengue virus in Colombia. Some factors have been associated with its presence; however, in the local context, it has not been sufficiently evaluated. The present study seeks to identify the socioeconomic, environmental, and behavioral factors associated with the presence and abundance of A. aegypti in urban dwellings in the municipality of Castilla la Nueva. A cross-sectional cohort study was conducted in houses in the urban area of the municipality of Castilla la Nueva, where 307 houses were sampled by systematic random sampling during May 2018. A multifactorial survey was used to measure the socioeconomic, environmental, and behavioral factors as explanatory variables. The infestation and relative abundance were established by the presence of larval stages and ovitraps. The associated factors for the presence and abundance of A. aegypti were identified using negative binomial and logistic regression models. A positive housing infestation of 33.2% was identified by direct inspection and 78.5% with ovitraps. The main factors positively associated with the presence and abundance of A. aegypti were one-story homes (PR = 2.26; 95% CI: 1.31-3.87), the storage of water for domestic use (PR = 1.91; 95% CI: 1.18-3.09), and local conditions such as disorganized backyard (PR = 79.95; 95% CI: 10.96-583.24) and the proportion of shade greater than 50% of the backyard (PR = 62.32; 95% CI: 6.47-600.32). And, it is negatively associated with residential gas service (PR = 0.3; 95% CI: 0.16-0.58) and self-administered internal fumigation (PR = 0.37; 95% CI: 0.2-0.69). The presence and abundance of A. aegypti were explained by interrelated socioeconomic, environmental, and behavioral factors where local conditions and habits such as the organization of the patio, knowledge about vector biology, and cleaning containers are identified as main topics for future prevention strategies for the transmission of dengue in the local and national context.
RESUMO
Aedes spp. are considered the main vectors of dengue (DENV), Zika (ZIKV) and chikungunya (CHIKV) viruses in the world. Arbovirus detection in Aedes mosquitoes can alert authorities to possible outbreaks, reducing the impact of these diseases. The purpose of this study was to perform an operational strategy for virological surveillance of DENV, ZIKV and CHIKV in adult Aedes aegypti and Aedes albopictus mosquitoes captured at different key-sites in an endemic urban area of the Northeast Region of Brazil, with the prospect of discussing its role as part of an alert system for outbreaks in critical areas. Residential and non-residential premises located in areas of recent of transmission of these arboviruses were selected for adult mosquito collection in the rainy season (July) of 2018. A total of 1068 adult mosquitoes were collected: 946 Culex quinquefasciatus (88.6%), 118 Ae. aegypti (11.0%), two Ae. albopictus (0.2%) and two Aedes taeniorhynchus (0.2%). Among the premises surveyed, recycling points (Nâ¯=â¯48, 40.7%), municipal schools (Nâ¯=â¯36, 30.5%) and junkyards (Nâ¯=â¯31, 26.2%) were the places with the highest frequency of adult Ae. aegypti. Health units (including primary health care facilities and one hospital) (Nâ¯=â¯23; 19.5%) together with residential premises (Nâ¯=â¯11; 9.3%) presented the lowest frequencies. Total RNAs of the samples were extracted from Aedes mosquitoes and a nested reverse transcription (RT) polymerase chain reaction (PCR) assay for detecting and typing DENV, ZIKV and CHIKV was performed. From the 37 Aedes spp. pools analyzed (35 Ae. aegypti, one Ae. albopictus and one Ae. taeniorhynchus), seven were positive for DENV-3, including three pools containing Ae. aegypti females, one containing an Ae. aegypti engorged female and three comprised of Ae. aegypti males. The positive pools were composed of mosquitoes collected in public schools, health units, junkyards, recycling points and residential premises. Our findings reinforce the importance of continuous virological surveillance in Aedes mosquitoes, as a useful tool for detecting arboviruses circulation in vulnerable areas, even in low infestation seasons.
Assuntos
Aedes/virologia , Vírus Chikungunya/isolamento & purificação , Vírus da Dengue/isolamento & purificação , Zika virus/isolamento & purificação , Adulto , Animais , Doenças Endêmicas/estatística & dados numéricos , Feminino , Humanos , Masculino , Mosquitos Vetores/virologiaRESUMO
Aedes albopictus is registered for the first time in Roraima, Brazil. From June 2006 to May 2007, three pupae and ten larvae of Ae. albopictus were collected, during routine surveillance work in three urban neighborhoods in the city of Boa Vista. Two larvae reached adulthood as females. Although Ae. albopictus is not presently considered of primary importance in dengue transmission, its occurrence could favor a linkage between urban and forest cycles of yellow fever and other arboviruses in Brazil.
Aedes albopictus é registrado pela primeira vez no estado de Roraima, Brasil. Entre junho de 2006 e maio de 2007 foram coletadas três pupas e dez larvas, duas das quais chegaram à fase adulta, durante atividades de vigilância rotineiras em três bairros urbanos da cidade de Boa Vista. Embora essa espécie não seja incriminada como vetor primário do dengue, a sua presença pode favorecer a ligação entre os ciclos silvestre e urbano da febre amarela e de outras arboviroses no Brasil.