Container Preference of the Asian Tiger Mosquito (Aedes albopictus) in Kathmandu and Lalitpur Districts of Nepal

Abstract

In various countries the Asian Tiger Mosquito (Aedes albopictus) is a known vector of dengue and chikungunya viruses and other pathogens, but its ecology and role in disease transmission in Nepal has not been studied yet. Here, we report on an investigation of the seasonal distribution of potential artificial breeding habitats of A. albopictus in urban areas of the Kathmandu and Lalitpur districts of Nepal. Larval collections were performed from April 2009 to March 2010 simultaneously in all the wet containers present in and around the houses of the study areas. Altogether 1873 water containers in Kathmandu district and 1807 in Lalitpur district were searched in 12 months, out of which 107 (5.7%) and 129 (7.1%), respectively, were found positive for A. albopictus breeding. Within the urban agglomeration of both districts, the breeding was found to vary between localities. Immature stages of A. albopictus were recorded in pre-monsoon, monsoon and post-monsoon seasons as 1.9%, 6.7% and 5.6%, respectively, in wet containers in Kathmandu district. In Lalitpur district, A. albopictus larvae were detected in 4.6%, 7.6% and 7.1% of the wet containers in the pre-monsoon, monsoon and post-monsoon, respectively. The breeding preference ratio during all seasons was highest for discarded tires lying outdoors in both Kathmandu and Lalitpur districts. Among nine container types searched and examined, 95% of discarded tires were found positive for A. albopictus larvae and pupae, followed by metal drums (2%) and plastic drums (1.25%). Continued and increased urbanization and vehicle movement in Kathmandu and Lalitpur districts have resulted in increased amounts of non-biodegradable containers such as tires around human dwellings, thereby creating ideal breeding habitats for A. albopictus.

Risk Factors for the Presence of Chikungunya and Dengue Vectors (Aedes aegypti and Aedes albopictus), Their Altitudinal Distribution and Climatic Determinants of Their Abundance in Central Nepal

“…aegypti and Ae . albopictus larvae and adults had been recorded up to the Middle Mountain region in Kathmandu Valley (∼1,350 m asl) [ 9 , 10 , 13 , 25 ] and their eggs (but not confirmed) up to the High Mountain region in central Nepal [ 25 ]. Our present study confirmed that those eggs were likely to have been either Ae .…”

“…Each selected house was geo-referenced using a portable global positioning system (GPS) device (Garmin eTrexH) and all accessible artificial larval developmental sites such as discarded tires, metal drums, plastic drums, other metal containers, plastic buckets, flower pots, mud pots, cement tanks, tree holes, rocks and other plastic containers in indoor and outdoor locations were inspected using dippers, as described elsewhere [ 10 , 13 , 28 , 29 ]. The equipment used for collecting Aedes spp.…”

“…aegypti and Ae . albopictus has already been reported from different areas of the Middle Mountain region, including Kathmandu Valley, average altitude 1,350 m above sea level[asl] [ 9 , 10 , 13 , 14 ]. Autochthonous cases of DF along with the circulation of all four DENV serotypes were first reported in 2006 during an outbreak that mostly affected urban areas of the Terai lowlands [ 12 ], and an autochthonous case from Nepal’s capital city Kathmandu was first reported during an epidemic in 2010 [ 15 ].…”

A Mosquito Workshop and Community Intervention: A Pilot Education Campaign to Identify Risk Factors Associated with Container Mosquitoes in San Pedro Sula, Honduras

“…These studies highlight the importance of community engagement and targeted elimination of types of water-holding containers responsible for higher production of invasive Aedes mosquitoes. The types of container present in an area varies greatly depending on geography and cultural practices [36,39,40,41]. Therefore, identifying the most prevalent and problematic containers in an area is a necessary step in controlling container mosquitoes.…”

Incidence of dengue and chikungunya viruses in mosquitoes and human patients in border provinces of Vietnam

“…were searched for mosquito larvae and pupae. Potential sites were inspected using dippers, as previously described [ 22 , 23 ]. All collected larvae and pupae were placed into labeled plastic vials containing RNAlater®.…”