Entomological Surveillance of the Invasive Aedes Species at Higher-Priority Entry Points in Northern Iran: Exploratory Report on a Field Study

Abstract

Background Arboviral diseases such as dengue, Zika, and chikungunya are transmitted by Aedes aegypti and Ae albopictus and are emerging global public health concerns. Objective This study aimed to provide up-to-date data on the occurrence of the invasive Aedes species in a given area as this is essential for planning and implementing timely control strategies. Methods Entomological surveillance was planned and carried out monthly from May 2018 to December 2019 at higher-priority entry points in Guilan Province, Northern Iran, using ovitraps, larval collection, and human-baited traps. Species richness (R), Simpson (D), evenness (E), and Shannon-Wiener indexes (H̕) were measured to better understand the diversity of the Aedes species. The Spearman correlation coefficient and regression models were used for data analysis. Results We collected a total of 3964 mosquito samples including 17.20% (682/3964) belonging to the Aedes species, from 3 genera and 13 species, and morphologically identified them from May 2018 to December 2019. Ae vexans and Ae geniculatus, which showed a peak in activity levels and population in October (226/564, 40.07% and 26/103, 25.2%), were the eudominant species (D=75.7%; D=21.2%) with constant (C=100) and frequent (C=66.7%) distributions, respectively. The population of Ae vexans had a significant positive correlation with precipitation (r=0.521; P=.009) and relative humidity (r=0.510; P=.01), whereas it was inversely associated with temperature (r=−0.432; P=.04). The Shannon-Wiener Index was up to 0.84 and 1.04 in the city of Rasht and in July, respectively. The rarefaction curve showed sufficiency in sampling efforts by reaching the asymptotic line at all spatial and temporal scales, except in Rasht and in October. Conclusions Although no specimens of the Ae aegypti and Ae albopictus species were collected, this surveillance provides a better understanding of the native Aedes species in the northern regions of Iran. These data will assist the health system in future arbovirus research, and in the implementation of effective vector control and prevention strategies, should Ae aegypti and Ae albopictus be found in the province.

Entomological surveillance of invasive Aedes mosquitoes in Mazandaran Province, northern Iran from 2014 to 2020

“…echinus , and Ae. pulchritarsis were also detected in higher priority entry points in Gilan Province, northern Iran 39 . So far, 12 species have been included in new Checklist of Iranian Aedes 40 Aedes vexans , known as the floodwater mosquito, is widely scattered in eastern Asia, North America, Western Africa, and much of Pacific Oceania 41 .…”

Malaria Vector Bionomics: Countrywide Surveillance Study on Implications for Malaria Elimination in India

“…The migration of various malaria vectors across neighboring areas, ecological transitions, and colonization of new habitats through evolutionary adaptation to eco-climatic changes have been documented in numerous instances in India [ 9 ]. An entomological surveillance study [ 10 ] was conducted to monitor the Aedes invasion in the Guilan Province of Iran, which boasts several ports of entry. Although no specimens of Aedes aegypti or Aedes albopictus were collected, the importance of such regular surveillance was acknowledged [ 10 ].…”

“…An entomological surveillance study [ 10 ] was conducted to monitor the Aedes invasion in the Guilan Province of Iran, which boasts several ports of entry. Although no specimens of Aedes aegypti or Aedes albopictus were collected, the importance of such regular surveillance was acknowledged [ 10 ]. Similarly, in India, the Indian Council of Medical Research’s (ICMR) Vector Control Research Centre is conducting a study to explore the relationship between human and mosquito mobility and its implications for the control of mosquito-borne infections.…”