A new paradigm for Aedes spp. surveillance using gravid ovipositing sticky trap and NS1 antigen test kit.
BACKGROUND
Dengue remains a serious public health problem in Southeast Asia and has increased 37-fold in Malaysia compared to decades ago. New strategies are urgently needed for early detection and control of dengue epidemics.


METHODS
We conducted a two year study in a high human density dengue-endemic urban area in Selangor, where Gravid Ovipositing Sticky (GOS) traps were set up to capture adult Aedes spp. mosquitoes. All Aedes mosquitoes were tested using the NS1 dengue antigen test kit. All dengue cases from the study site notified to the State Health Department were recorded. Weekly microclimatic temperature, relative humidity (RH) and rainfall were monitored.


RESULTS
Aedes aegypti was the predominant mosquito (95.6%) caught in GOS traps and 23% (43/187 pools of 5 mosquitoes each) were found to be positive for dengue using the NS1 antigen kit. Confirmed cases of dengue were observed with a lag of one week after positive Ae. aegypti were detected. Aedes aegypti density as analysed by distributed lag non-linear models, will increase lag of 2-3 weeks for temperature increase from 28 to 30 °C; and lag of three weeks for increased rainfall.


CONCLUSIONS
Proactive strategy is needed for dengue vector surveillance programme. One method would be to use the GOS trap which is simple to setup, cost effective (below USD 1 per trap) and environmental friendly (i.e. use recyclable plastic materials) to capture Ae. aegypti followed by a rapid method of detecting of dengue virus using the NS1 dengue antigen kit. Control measures should be initiated when positive mosquitoes are detected.
Selangor State Health Department, State Vector Borne Disease Control Unit, 29 Jalan Bayu Tinggi, 41200, Klang, Selangor, Malaysia.|Department of Parasitology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603, Kuala Lumpur, Malaysia.
Sai Ming
SM
Lau
Department of Pathobiology and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia.
Tock H
TH
Chua
Department of Parasitology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603, Kuala Lumpur, Malaysia.
Wan-Yussof
WY
Sulaiman
Department of Parasitology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603, Kuala Lumpur, Malaysia.
Sylvia
S
Joanne
Department of Parasitology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603, Kuala Lumpur, Malaysia.
Yvonne Ai-Lian
YA
Lim
Department of Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 506030, Kuala Lumpur, Malaysia.
Shamala Devi
SD
Sekaran
Julius Centre, Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603, Kuala Lumpur, Malaysia.
Karuthan
K
Chinna
Selangor State Health Department, State Vector Borne Disease Control Unit, 29 Jalan Bayu Tinggi, 41200, Klang, Selangor, Malaysia.|Perak State Health Department, Jalan Panglima Bukit Gantung Wahab, 30590, Ipoh, Perak, Malaysia.
Balan
B
Venugopalan
Department of Parasitology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603, Kuala Lumpur, Malaysia. indra.vythilingam@gmail.com.
Indra
I
Vythilingam
D000330:Aedes / Q000502:physiology* / Q000821:virology*; D000818:Animals; D003716:Dengue Virus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D007159:Immunologic Tests; D007303:Insect Vectors / Q000502:physiology* / Q000821:virology*; D008296:Malaysia; D008297:Male; D010058:Oviposition; D013696:Temperature; D017361:Viral Nonstructural Proteins / Q000032:analysis* / Q000235:genetics / Q000276:immunology
D017361:Viral Nonstructural Proteins
Aedes mosquito; Dengue NS1 kit; GOS traps; Surveillance