Residual efficacy of deltamethrin applied to foliage against Malaysian Aedes aegypti (L.) and Aedes albopictus (Skuse)

@#The spraying of insecticide on foliage to provide an insecticidal barrier may serve as part of the vector control measures to combat the increasing threat of Aedes-borne diseases. The effectiveness of insecticide barrier spraying was evaluated by assessing the residual efficacy of deltamethrin sprayed on foliage against Malaysian Ae. aegypti (L.) and Ae. albopictus (Skuse). In this semi-field study, landscape plants grown within the vicinity of the Institute for Medical Research (IMR), Malaysia, were treated with deltamethrin suspension concentrate (SC) with the dosage of 30 mg/m2 and 50 mg/m2 in three rounds of spraying. Deltamethrin residual activity on treated and untreated leaves was investigated using standard WHO cone bioassays. Wild Aedes populations at both deltamethrin-treated and untreated plant clusters were monitored by ovitrap surveillance. Ovitrap monitoring revealed that the mean number of Ae. albopictus larvae at deltamethrin-treated were significantly lower than the mean number of larvae of the same species at the untreated plant cluster. Cone bioassay results showed that the insecticide remained effective for up to 4 weeks (> 80% mortality), but the insecticide residual activity was affected by rainfall. These results suggest that insecticide barrier spraying is a promising tool and may be used along with other mosquito control tools such as indoor residual spray and space spraying to reduce the dengue burden.

Pharmaceutical sector in transition--a cross sectional study in Vietnam.

Increasing efforts are being made to improve pharmaceutical sector performance in low- and middle-income countries. An essential tool for such work is an objective and standard method of assessment which can be used to promote evidenced based National Drug Policy development and implementation. The average drug expenditure per capita has steadily increased in Vietnam and at the time of this study a National Drug Policy was being developed. This study assessed the Vietnamese pharmaceutical sector 1991-1994, focusing on the standard of the drug quality control system, availability of drugs and rational use of essential drugs in the private and public sectors by means of standardised indicators. The results from this study show that the quality control system is impaired and does not have capacity to quality control all drugs on the market. The availability of essential drugs is good whereas essential drugs are poorly prescribed, injections common and there is a high average number of drugs per prescription, both in the public and private sectors. Violations are common and enforcement of regulations weak. On top of this there is an active commercial advertising and marketing of drugs. These findings identify priorities for action to improve the present situation where the development and implementation of the Vietnamese National Drug Policy will be of major importance.