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https://asia.nikkei.com/Business/Science/Southeast-Asia-warned-of-insecticide-resistant-dengue-mosquitoes?utm_campaign=GL_asia_daily&utm_medium=email&utm_source=NA_newsletter&utm_content=article_link&del_type=1&pub_date=20230207123000&seq_num=24&si=44594 Southeast Asia warned of insecticide-resistant dengue mosquitoes Japan's National Institute of Infectious Diseases finds new genetic mutation Aedes aegypti mosquitos are known as a vector of the Zika virus, as well as yellow fever and dengue fever. (Photo courtesy of Shinji Kasai) NORIAKI KOSHIKAWA, Nikkei staff writerFebruary 5, 2023 09:30 JST TOKYO -- A team of researchers led by Shinji Kasai, director of the Department of Medical Entomology at Japan's National Institute of Infectious Diseases, has warned about an increasing number of insecticide-resistant mosquitoes in Southeast Asia. The warning comes after the team found a new genetic mutation that makes Aedes aegypti mosquitoes -- also known as yellow fever or dengue mosquitoes -- more resistant to common insecticides. Aedes aegypti mosquitoes are known as a vector of the Zika virus, as well as yellow fever and dengue fever. More than 80% of Aedes aegypti mosquitoes in Vietnam and Cambodia were found to have this genetic mutation, necessitating review of mosquito control methods and increased caution about a proliferation of insecticide-resistant mosquitoes. The team led by Kasai collected mosquitoes in Vietnam and elsewhere and examined how they were resistant to commonly used "pyrethroid" insecticides. The study showed that even when the concentration of insecticides was raised to 10 times the level that can kill ordinary mosquitoes, about 80% of mosquitoes collected in Hanoi survived. Kasai's team identified a new genetic mutation called L982W, which makes mosquitoes more resistant to common insecticides. Between 78% and 99% of mosquitoes in three cities -- Hanoi in the north of Vietnam and Ho Chi Minh City in the south, as well as the Cambodian capital Phnom Penh across the border -- had this genetic mutation. Including L982W, four genetic mutations have so far been found to show resistance to insecticides. The percentage of mosquitoes with two of the four genetic mutations reached 91% in Phnom Penh, showing how resistance is strengthening there. According to Kasai's team, there is a possibility that insecticide-resistant mosquitoes spread from Cambodia to neighboring Vietnam. Although no mosquitoes with the L982W genetic mutation were found in Laos, Thailand and China, the mosquitoes might be gradually spreading across Indochina and to other regions in Asia. Even in Japan, there are concerns about Aedes aegypti mosquitoes taking hold, as regions in the country where they can survive winter are expanding due to warming temperatures. Kasai stressed the need to closely examine how insecticide-resistant mosquitoes are spreading across Indochina and how to reduce the use of pyrethroid insecticides, or use them with other mosquito control methods.

One woman got a few good sugesstions leh http://singaporeseen.stomp.com.sg/singapor...d=63982#comment

saw some ultrasonic electronic mosquito repellent at homefix. looks like a good idea but does this device work? anyone tried them? seems made in UK so wondering if it works for local mosquito. thanks.

SINGAPORE — The first Zika cluster in Singapore this year has been detected, after three cases of locally transmitted Zika virus infection have been confirmed near Serangoon Gardens, the National Environment Agency (NEA) said on Friday (13 September). All three cases are residents in the Hemsley Avenue vicinity. The Zika cluster was notified on Friday. Residents and stakeholders are urged to maintain vigilance and continue to eliminate mosquito breeding habitats, as there could still be asymptomatic or mild, undiagnosed cases which might result in further transmission of the virus if there are mosquitoes in the area. The Zika cluster is in close proximity to an 8-case dengue cluster at Bridport Ave / Cowdray Ave / Huddington Ave / Portchester Ave / Tavistock Ave, which was notified on 20 August. The NEA has commenced vector control operations in the area since the dengue cluster was notified. As of Friday, five breeding habitats in the dengue cluster area – comprising one in a home and four in common areas/other premises – have been detected and destroyed. Indoor spraying of insecticides and outdoor misting have been carried out at the premises. Thermal fogging will be carried out in the outdoor areas to eradicate any adult mosquitoes. NEA officers and community leaders will conduct outreach in the vicinity to distribute Zika information leaflets and insect repellents to households to raise general awareness of Zika, and advise on the steps to prevent mosquito breeding. The last reported Zika case in Singapore was early last year, when a patient was infected with the virus.