Aedes aegypti mosquitoes had been collected at field of some Northern provinces between 2001 and 2004 for studies of their susceptibility to insecticides. It was seen that: all of tested mosquitoes dropped immediately 100% and 100% killed after 24 hours. The results showed that all tested mosquitoes were highly susceptible to insecticides, such as permethrin, lambda cyhalothrin, and malathion from 2001-2004 in Northern region. The provinces participate in the test was up fro 5-7. Using the insecticides to kill Aedes aegypti by ULV spraying was effective in Northern provinces in Vietnam. It is adviced to send mosquitoes and lavae in June and July when the density of mosquitoes and lavae is high. Therefore, expanding studies to other provinces throughout the country to identify susceptibility of Aedes aegypti to insecticides is very necessary for Dengue Hemorrhagic Fever vector control.
Culicidae ; Insecticides

The spatial repellency with metofluthrin impregnated strips were hung in 15 households at Do Son, Hai Phong. The results showed that the density of mosquitoes reduced by 18 weeks after hanging strips. People agree that this was one of the safe, effective and simple method to control mosquitoes.
Culicidae ; Cyclopropanes

The study was conducted in Khanh Trung commune, Khanh Vinh district of Khanh Hoa province to assess the mosquito infection two years after DEC administration. Seventeen species of mosquito belonging to 5 genera have been found of which the main vector Wuchereria bancrofti was predominant. Indoor collection of Culex quinquefasdatus at daytime and nighttime was 3.5 and 2.3 individuals/house, respectively. Cx. vishnui was mainly found on the cattle sheds with an average density of 4.6 individuals/shed. A total of 578 mosquitoes of five species (Cx. quinqllefasciatus, An. vaglls, Cx. tritaeniorhynchus, Cx. vislznui, Cx. fuscocephalus) were dissected. None of them were positive with microfilaria.
Culicidae ; Albendazole

100% of mosquito batches were collapsed after 30 minutes exposing to test paper and dead after 24 hours following up. This indicates that the mosquito in test places is very sensitive to permethrin and lambda cyhalothrin and these chemicals are effective in killing mosquito during outbreaks. The number of locals where involved in evaluating the sensitivity of mosquito to chemicals are increasing. These are provinces where the insects surveillance systems are available.
Pesticides ; Culicidae

Freshly fed or half gravid An.sundaicus collected in An Thoi Dong commune, Can Gio district, Ho Chi Minh city were brought to the insectary of NIMPE for colonizing. Larvae were fed by a combination of 4gr bread powder + 4 shrimp powder + 2gr bean powder + 0.001gr vitamine B1. Larvae were contained at the conditions: a density of 0.3 larvae/cm2 of the surface water. Water for rearing was taken form the field with the salinity of 0.6 – 0.8%. Room temperature of 27 – 31oC, humidity of 60 – 90%. At these conditions, the image period took the time of 5 – 17 days. From the 8th generation (F8), mosquitoes were found to take free matting in the cage of 30 x 30 x 30 cm
Laboratories ; Culicidae ; diagnosis ; Diptera

To evaluate the effectiveness in malaria vector control of residual spraying with Solfac WP10 at dose of 50mg ai/m2 and bednet impregnated with Solfac EW050 at a dose of 50mg ai/m2, based on bioassays, side effects. The results showed that: in pilot doses, the residual effect with Solfac 10WP produced the residual effect for 6 months on the walls made of wood with the bioassay mortality of 70.60%; for 2 months on the wall made of brick with the bioassay mortality of 61.63%. The residual effect of Solfact EW 050 on polyester bednet is 4 months after 2 washes, with the bioassay mortality of 73.6%. House spraying with Solfac WP10 and bednet impregnation with Solfac EW 050 at a dose of 50mg/ ai/m2 to prevent malaria due to mosquito were found to cause light side effects
malaria ; Antimalarials ; disease ; Culicidae

From Sept.2001 to Oct.2002, in diverse studied and control villages of 2 communes Iakor and Iatiem of ChuSe district, GiaLai province, an investigation was performed. In Iakor, 50mg/m2 solfac EW050 soaked mosquito bednets, and in Iatiem, 50mg/m2 solfac WP10 maintaining sprayed mosquito bednets were supplied for use. On the wooden or bamboo wall surface, insecticide effect was maintained for 6 months, on brick wall for 1month and on soaked net for 11 months. In the permanent resident sites of mosquitoes, no An. minimus and An.dirus, main vectors, were detected after the trial, but some other such as An.aconitus and An. jeyporiensis were still detected
Malaria ; Culicidae ; Insecticides

An evaluation of the current coverage and diminished rate of mosquito nets usage for malaria control plays an important role in malaria control planning. A survery was carried out between 1995 and 2003 in 15 hamlets of five communes of 3 malaria endemic districts in Thua Thien – Hue province. A high rate of bed-net usage was found in the surveyed hamlets. In average, the coverage reached the rate of 2.0 ± 0.3% nets per person. However a considerable rate of damaged nets (4.7 ± 1.2%) was also recorded in the surveys. Further surveys and studies should be conducted to determine the ways the bed-nets go down and get diminished for planning of more appropriate malaria control measures
Malaria ; Culicidae ; Mosquito Control

A research was conducted in 2001 and 2002 to evaluate the efficacy of remaining spray by using Permethrin 50EC to kill both kinds of vectors: Xenopsylla cheopis and Anopheles minimus, responsible for plague and malaria transmission, respectively. The results showed that Permethrin 50EC at the concentration of 0.5g/m2 was highly effective to kill Xenopsylla cheopis and Anopheles minimus and remained effective for 4 months
Anopheles ; Permethrin ; Culicidae

In September – December 2001 period, from 4987 female Culex mosquitoes collected in Cat Que commune, Hoai Duc district, Ha Tay province, 4 viral species were isolated by clone C6/36 cells of Vero and Aedes albopictus. Among them, 2 species were alpha virus, 01VN61 virus was isolated from Culex tritaeniorhynchus and 01VN62 virus from Culex gelidus, both strains were adapted to 1-2 days age mice. By sequencing technique on E1 gene and 3 NCR gene area, 01VN62 virus was identified as Safiyama virus, a virus of alpha virus
Alphavirus ; Culicidae ; Culex