Combination of gravid ovipositing sticky trap and NS1 antigen test: New paradigm for dengue vector surveillance in Selangor Malaysia / Lau Sai Ming

• Main Author: Lau, Sai Ming
• Format: Thesis
• Published: 2018
• Subjects: R Medicine (General); RA0421 Public health. Hygiene. Preventive Medicine
• Online Access: http://studentsrepo.um.edu.my/9189/7/sai_ming.pdf; http://studentsrepo.um.edu.my/9189/
• Institution: Universiti Malaya

Dengue fever is a serious public health problem in tropical countries and has increased 37 folds in Malaysia compared to decades ago. Selangor, the most developed and populated state in Malaysia has contributed about 50% cases in the country. Vector control has been the hallmark for surveillance and control of dengue. However, there is no correlation between Aedes index and dengue cases. Thus, new proactive paradigms are necessary for vector surveillance which would help in the prevention of dengue epidemics in the country. This two-year study was conducted in dengue epidemic urban area of Selangor; where GOS trap (Gravid Mosquito Ovipositing in Sticky Trap) was used to capture gravid Aedes mosquitoes. All Aedes mosquitoes were tested with NS1 rapid antigen test kit. All dengue cases from the study site reported to the Ministry of Health were recorded. Microclimatic data such as rainfall, temperature and humidity were recorded weekly. Aedes aegypti was the predominant mosquito (95.6%) caught in GOS traps, 23% (43/187) pools of mosquitoes were positive for virus dengue using the NS1 antigen kit. Confirmed cases were observed with a lag of one week after positive Ae. aegypti were detected. Aedes aegypti density as analyzed by distributed lag non-linear models, will increase lag of 2-3 weeks for temperature increase from 28 to 30oC; and lag of three weeks for increased rainfall. In conclusion, the combined use of GOS trap and NS1 antigen kit to detect dengue virus in mosquitoes can be used as a new tool for dengue vector surveillance. It seems to be a proactive method where control action can be activated when positive mosquitoes are obtained. However, a randomized control trial needs to be conducted to prove that this paradigm will indeed reduce dengue epidemics.