Experts shed more light on mosquito behaviour

Intermittent rain and hot weather can cause an increase in mosquito breeding and their population as well as hasten their life cycle, say experts. The Head of the Entomology Unit at the Institute for Medical Research, Dr Lee Han Lim, said these conditions were conducive for the mosquitoes to breed and the larva would not be washed away as there was no regular heavy rain. He said the hot weather helped to make the breeding process more efficient because it would shorten the life cycle of the mosquito. "If heavy rain happens often, dengue will not occur frequently because the Aedes mosquitoes are not able to breed productively, but, if intermittent rain happens, then the condition will be conducive for the insect to breed. "Mosquitoes need time to breed - at least two to three weeks - and a certain period to transmit the dengue (virus)," he told Bernama on the sidelines of the launch of the Malaysian Society of Parasitology and Tropical Medicine (MSPTM) Golden Jubilee and the Sixth Asean Congress of Tropical Medicine and Parasitology, here, Thursday. The three-day congress, organised by the MSPTM in conjunction with the anniversary celebration, was attended by 420 people from 43 countries. Carrying the theme 'Global Challenges in Tropical Diseases: Bridging Gaps and Building Partnerships', the congress aims to provide real-world experience from speakers and peers with the current challenges facing Malaysia and other countries the world over due to the changing dynamics of disease transmission and epidemiology in the tropics. Among the tropical diseases discussed at the congress were dengue and malaria. Dr Lee said that as there was no effective dengue vaccine yet, the co-operation of the community and the participation of non-governmental organisations (NGOs) in dengue prevention became all the more vital. Furthermore, non-health organisations such as property developers and architects could ensure that the design and structure of buildings did not inadvertently provide breeding grounds for the Aedes mosquito. "Based on our research, dengue is related to vector control; so the community must take care of the cleanliness of the surrounding areas. "On our part, we will conduct more research to control the mosquito population and hope that the best vaccine will be successfully produced," he said. Similar views were shared by the deputy director-general of health (public health), Datuk Dr Lokman Hakim Sulaiman. He said the current large number of dengue cases demanded that the community must be alert and strictly ensure that their surroundings are clean and free of the Aedes mosquito breeding grounds. Dr Lokman said the hot weather was conducive for the spread of tropical diseases such as dengue because the Aedes mosquito gets easily hungry during such weather and bite humans more often. "The people should enhance their knowledge and awareness about tropical diseases such as dengue and malaria. This will help them take the necessary action to check the diseases," he said. Meanwhile, the research consultant at the Parasitology Department, Faculty of Medicine, Universiti Malaya, Datin Dr Indra Vythilingam, said the Human Landing Catch (HLC) technique had to be employed, where a tube was used to collect the mosquitoes. For Indra, who is an expert on malaria, said people who had travelled to malaria- endemic places, forests and recreational areas for example, should go for a medical check-up as soon as possible if they fell ill and inform the doctor where they had been because there were drugs to treat the disease. Unless the doctor was given such information, he or she might not suspect that the patient was suffering from malaria.