Dengue Vector Control Program Research Articles

Stage-specific insecticide susceptibility and life-table analysis of the dengue vector mosquitoes <em>Aedes aegypti</em> and <em>Ae. albopictus</em>

Vector resistance to insecticides is a significant challenge in the control of mosquito-borne diseases such as dengue. Analysis of the growth rate and survivorship of the immature stages of larvae has been important in formulating effective vector control strategies. The present study aimed to assess insecticide resistance in both larvae and adults of Aedes aegypti and Ae. albopictus, and the life tables of their immature stages.Mosquito eggs collected from Kurunegala and Colombo districts of Sri Lanka from January to March 2023 were reared under laboratory conditions. Larval bioassays were carried out with temephos (0.0125 ppm, 0.0625ppm and 0.125ppm) and, the adult bioassays were with pyrethroids (0.03% deltamethrin, 0.05% and 0.08% lambdacyhalothrin, 0.04% permethrin) and malathion (1%and 5%). Biochemical assays were used to evaluate the activity of insecticide-detoxifying enzymes and the insensitivity of the organophosphate target site acetylcholinesterase. Survivorship of immature stages under laboratory conditions and semi-field conditions i.e., bamboo stumps, tyres and clay pots, were studied using Kaplan-Meier survival analysis.Larvae and adults of both species from Kurunegala were susceptible to all the insecticides tested, whereas Colombo populations were resistant. Acetylcholinesterases were largely sensitive in all vector populations. Higher activities of esterases, glutathione s-transferases and monooxygenases were found in Colombo populations. Results indicated that Ae. aegypti larvae were more resistant to insecticides than Ae. albopictus larvae. Also, the mechanisms of insecticide resistance were well developed in adults than in larvae.Aedes aegypti larval development time (5 days) was significantly shorter than that of Ae. albopictus (9 days) under laboratory conditions. Survival probabilities of them were 76-80%. Egg hatching to adult emergence period was 8 days for Ae. aegypti and 13 days for Ae. albopictus. This period, under semifield conditions were; bamboo stumps 7-7.2 days, tyres 10-11.3 days, and clay pots 13.8-14 days with survival rates varied from 28.8 to 63% for both species. This study highlights stage specific response of dengue vectors to insecticides and survivorship of their immature stages in different habitats. This knowledge can be effectively used in future dengue vector control programmes.

Phytotelmata accounts for Aedes breeding places in Mantup Sub-district, Lamongan District, Indonesia

Abstract. Fauziyah S, Susanti SF, Hariyono H, Fazirrah V, Novitasari AE, Fadhilah N, Sucipto TH, Naw SW. 2023. Phytotelmata accounts for Aedes breeding places in Mantup Sub-district, Lamongan District, Indonesia. Biodiversitas 24: 4820-4828. Dengue infection still remains a public health problem in Indonesia, which is classified as a tropical country. Some environmental factors that contribute to the transmission of dengue infection are human migration, human activity, food supply, and climate change. The other type of breeding place is natural breeding habitats, called phytotelmata. This study aims to investigate the diversity of Aedes species in phytotelmata from Mantup Sub-district, Lamongan, East Java, Indonesia. The analytical observational study was conducted with a purposive sampling design. Mosquito larvae collection was carried out from February to March 2023 in Mantup Sub-district, an endemic region of dengue infection in Lamongan. Immature mosquitoes were reared in the laboratory till they merged into adult mosquitoes. This study found four groups of phytotelmata: leaf axils, bamboo joints, fallen leaves, and coconut shells. Leaf axils were the predominant type of phytotelmata (86.67%). Meanwhile, the lowest percentage was coconut shells and fallen leaves (3.33%). A total of 56 mosquito larvae consisting of 12 male Aedes aegypti, 21 female Ae. aegypti, 12 male Aedes albopictus, and 11 female Ae. albopictus were collected from 30 observation points. Eleven families of phytotelmata were found in this study. The predominant family was Araceae (33.3%), while the lowest were Agavaceae, Commelinaceae, Marantaceae, and Liliaceae (3.33%). Phytotelmata accounts for mosquito breeding places, which should be noticed and considered in dengue vector control programs.

Utilization of Digital Health Applications in Implementing the Dengue Vector Control Program

<div><table cellspacing="0" cellpadding="0" align="left"><tbody><tr><td align="left" valign="top"><p><em>One House One Larva Monitor Movement is a dengue vector control program of the Ministry of Health which has been promoted since 2016. However, there are still several areas that have not been successful in implementing this movement, one of which includes the City of Padang. The purpose of this study was to examine the importance of using digital applications in implementing dengue vector control programs. This research is a research with qualitative methods using the case study genre through a constructivist approach. The location of the qualitative research was carried out at the Padang City Health Office, in the working areas of the Nanggalo Health Center, Pagambiran Health Center, and Rawang Health Center which were designated as research areas. This research was conducted in 2023 with informants including the person in charge of the dengue fever program at the Padang City Health Service, the person in charge of the dengue fever program at the Community Health Center, and the larva monitoring coordinator. The results of the study indicate that efforts to control dengue vectors through the One House One larva monitor Movement are still not running as they should. This movement can only run when larva monitor performs its main tasks and functions in accordance with the provisions. For this reason, it is necessary to carry out coaching and supervision efforts. However, there are several obstacles that require the design of a comprehensive and integrated digital health application to improve the health information system to improve the performance of larva monitors.</em></p><p><em> </em></p></td></tr></tbody></table></div><p><strong><em>Keyword: DHF, Digital Health, Vector Dengue</em></strong></p>

Effectiveness of Indoor Residual Spraying as A Method of Controlling Dengue Fever in Communities: A systematic review

Background: Dengue remains a significant public health issue in the Western Pacific Region. In the absence of a vaccine, vector control is the mainstay for dengue prevention and control. This study aimed to explore the effectiveness of Indoor Residual Spraying as A Method of Controlling Dengue Fever in Communities. Subjects and Method: A systematic review was conducted by searching articles from PubMed, ResearchGate, Science Direct, Google Scholar, and EBSCO is an article published from 2013 to 2023. The keywords were “dengue hemorrhagic fever” OR “DHF” AND “community” OR “family” AND “disaster” AND “IRS” OR “indoor residual spraying”. The inclusion criteria were a Cross-sectional study. The articles were selected by PRISMA flow diagram method. Results: A total of 9 studies were included in this review. All of the studies stated that IRS can have both an immediate and sustained effect on reducing adult and immature A. aegypti populations and should be considered as an adult mosquito control strategy by dengue vector control programs also IRS led to 86-96% reduction in dengue cases in sprayed premises, compared to unsprayed controls. Conclusion: IRS significantly reduces the malaria burden in high-transmission settings. Keywords: dengue hemorrhagic fever, DHF, family, community. Correspondence: Titik Anggraeni. School of Health Sciences Estu Utomo Boyolali, Central Java, Indonesia. Jl. Tentara Pelajar 7, Mudal, Boyolali, Central Java, Indonesia. Email: titik.anggraeni146@gmail.com. Mobile: +62 858-6729-2673.

EVALUASI PROGRAM PENGENDALIAN VEKTOR DBD DI PUSKESMAS MEDOKAN AYU KOTA SURABAYA TAHUN 2022

There were 111 cases of dengue fever in Surabaya in 2021 with the highest cases being at the Medokan Ayu Health Center with 13 cases. Based on data from the Medokan Ayu Health Center, there were 25 cases of dengue fever in 2021, and this increased to 28 cases from January to May 2022. The purpose of this study was to evaluate the implementation of the dengue vector control program at the Medokan Ayu Health Center, Surabaya City in 2022.
 The design of this research is descriptive and was conducted in April-July 2022. The total sample used was 22 people who had suffered from DHF in the working area of ​​the Medokan Ayu Public Health Center.
 The results of the interviews that have been conducted obtained 13 people with sufficient criteria and 9 people with good standart, those can be seen the implementation of the DHF vector control program at the Medokan Ayu Health Center is efficient. Of the 9 vector control activity variables, the Medokan Ayu Health Center only carried out 7 DHF vector control activities.
 The conclusion from the research that has been conduct is that the implementation of the dengue vector control program at the Medokan Ayu Health Center has been efficient. However, several variables scored less than the respondents, including counseling activities, eradicating mosquito nests, and fogging. Suggestions for Medokan Ayu Health Center and society to help each other in implementing the dengue vector control program.

PENGENDALIAN DEMAM BERDARAH DENGUE DENGAN OVITRAP DAN MOSQUITO TRAP DI BEBERAPA DAERAH DI INDONESIA

The Dengue Fever (DF)/Dengue Hemorrhagic Fever (DHF) is still a major public health problem in Indonesia. Indonesia of DHF cases in 2019 increased compared to the previous year, which was 138.127 cases with an Incidence Rate (IR) of 51.53 per 100.000 population. The vectors of dengue virus are Aedes aegypti, Aedes albopictus, Aedes polynesiensis, and Aedes scutellaris mosquitoes. Prevention of dengue transmission relies mainly through vector control. The use of traps such as ovitrap and mosquito trap has the potential to be applied and integrated with other methods. Ovitrap and mosquito trap usage information is expected to be applied in the community and can assist in the dengue vector control program. The data in this article were secondary data from several research results that had been published and were field experiment. Ovitrap and mosquito trap are able to trap Aedes and non-Aedes mosquitoes. The effectiveness of the trap can be increased through the use of attractants from plant-based ingredients in the form of straw soaking water, mixture of brown sugar and yeast, mixture of granulated sugar and yeast, and chili extract. Ovitrap and mosquito trap with attractants from plant-based ingredients were quite effective in reducing the density of Aedes mosquitoes, besides that it safer for humans and non-target animals.

Knowledge Regarding Dengue Vector Control Among the Community of Tehsil Sahiwal, Sargodha

Dengue virus infection is a vector borne illness which causes epidemics and urges for serious policies and steps to devise control stretegies Objectives: The objectives of the study are to assess the knowledge regarding dengue vector control among community of Tehsil Sahiwal, District Sargodha Methods: It was a cross-sectional study conducted in community of Tehsil Sahiwal of District Sargodha. A total of 384 residents were enrolled in this study by simple random sampling technique. A pre-tested questionnaire was used to ask knowledge related questions regarding dengue vector control program. Data was analyzed by SPSS version 20.0. Tables and figures were used to present the data Results: Mean age of the respondents was 37.35 + 11.67 years, out of these 69.8% were males and remaining were females, 69.8% respondents were males, 38.1% were matric and above, 51.1% were working in private firms and 62.2% respondents had family monthly income less than 20,000 rupees. Among respondents, 53.9% had overall good knowledge and 46.1% had poor knowledge. 25.0% acquired information from television and 35.1% from health personnel counseling. Among 177 respondents who had overall poor knowledge, 24(6.3%) had good attitude and 153 (39.8%) had poor attitude. The result was found statistically significant (P=0.000) Conclusions: Knowledge of the residents regarding dengue vector control program was satisfactory (53.9%).

Implementasi Usaha Kesehatan Sekolah (UKS) dalam Pengendalian Demam Berdarah di Kecamatan Pangandaran

Anak sekolah/madrasah merupakan bagian dari elemen masyarakat yang berpeluang besar sebagai salah satu agent perubahan. Selain itu, anak sekolah/madrasah memiliki risiko terhadap penularan DBD. Melihat peluang tersebut maka pada tahun 2014 Kementerian Kesehatan membuat petunjuk teknis (Juknis) pelaksanaan Jumantik-PSN anak sekolah/madrasah. Hal ini didasari oleh terbitnya Surat Keputusan Bersama (SKB) empat menteri pada tahun yang sama. Implementasi program tesebut berkaitan erat dengan kemampuan pemerintah daerah dalam memaksimalkan sumber daya serta sarana dan prasarana yang tersedia. Tujuan dari penelitian ini adalah untuk mengevaluasi kegiatan UKS/M dalam mengimplementasikan program pengendalian vektor DBD sesuai Petunjuk Teknis Jumantik-PSN anak sekolah tahun 2014. Jenis penelitian ini adalah evaluasi implementasi dengan desain mixed method, menggabungkan metode kuantitatif dengan kualitatif. Sampel penelitian adalah sebanyak 44 sekolah/madrasah Hasil penelitian menunjukkan bahwa Angka Bebas Jentik (ABJ) sekolah di Kecamatan Pangandaran adaah 75% dan hal ini menunjukkan adanya risiko penularan DBD di sekolah. Kegiatan UKS/M belum mendukung dalam pengendalian penyakit DBD. Hambatan implementasi program ini meliputi faktor pengetahuan SDM, anggaran, fasilitas serta Komunikasi lintas sektor. Sedangkan faktor pendukungnya adalah sikap positif pelaksana program serta tersedia sarana teknis pelaksanaan. Hasil penelitian menyimpulkan bahwa Program Jumantik-PSN anak sekolah belum terimplementasi dengan baik dan benar.
 Kata kunci: Jumantik, PSN, UKS/M, sekolah/madrasah, implementa

Kdr type mutations and enhanced GST based insecticide resistance in dengue vector mosquitoes Aedes aegypti and Aedes albopictus

Pyrethroid resistance has imposed a severe threat to the control programmes of dengue vectors Aedes aegypti and Ae. albopictus in Sri Lanka. Present study investigated the resistance status and underlying mechanisms of these mosquitoes in six provinces of Sri Lanka. Mosquitoes were collected from Badulla (Uva Province), Batticaloa (Eastern), Colombo (Western), Jaffna (Northern), Kandy (Central) and Kurunegala (Northwestern). Adults were exposed to discriminating dosages of permethrin, deltamethrin, λ-cyhalothrin, cyfluthrin and DDT according to WHO guidelines. Survivals from bioassays were tested for kdr type mutations. Elevation of insecticide metabolizing enzymes and insensitivity of acetylcholinesterases, the target site of organophosphates and carbamates, were also tested. A total of 4875 mosquitoes (2687 Ae. aegypti, 2188 Ae. albopictus) were subjected to bioassays. All the populations had high resistance to DDT though it has not been used in the country for more than four decades. In general, Ae. aegypti populations showed more resistance towards pyrethroids. Glutathione S-transferase (GST) activities were enhanced in most of the populations with no enhancement of carboxylesterase and monooxygenase activities. Acetylcholinesterases were not altered in both species. Aedes aegypti showed high resistance to pyrethroids, mainly due to three kdr type mutations; V1016I, S989P and F1534C found in the voltage gated sodium channel which is the target site of pyrethroids and DDT. Both species were highly resistant to DDT mainly through a GST based mechanism. In the absence of elevated esterase-based and insensitive AChE mechanisms, organophosphates and carbamates can be recommended as alternatives for future dengue vector control programmes in Sri Lanka.

Association among ecological and behavioural attributes, dengue vector and disease control: a cross-sectional study of the city of Dhaka, Bangladesh.

BackgroundThis study examines vector density, the prevailing knowledge, awareness, attitudes and practice (KAAP) of community members regarding dengue disease and their willingness to pay (WTP) for vector control in Dhaka, Bangladesh.MethodsA population-based, cross-sectional study design was followed: (i) an entomological survey was carried out in 727 randomly selected households in 12 wards, representing four urban ecological zones and (ii) a survey of 330 household heads was conducted to study their KAAP. The χ2 test and multinomial logistic regression (MLR) were applied to investigate factors associated with WTP and other variables.ResultsThe Stegomyia indices significantly vary among the urban zones, revealing that the paved and built areas with concentrated public/commercial services have the highest mosquito density. Most respondents (93.9%) knew about dengue and its severity (90.3%); however, many of them were unaware (79.3%) about the types of mosquitoes causing dengue. MLR modelling reveals that average spending per month for mosquito control, household income and knowledge about the effects of land use and seasonality on dengue were significantly associated with the WTP for controlling the dengue vector.ConclusionsConcerted efforts should be made to increase awareness about dengue transmission and develop community-based sustainable dengue vector control programmes involving both the public and private sectors.

Barriers to Engaging Communities in a Dengue Vector Control Program: An Implementation Research in an Urban Area in Hanoi City, Vietnam.

The dengue situation in the urban setting of Hanoi city, Vietnam, is emerging, focusing on inner districts. Previous studies showed that a dengue vector control program in Hanoi was not effective because of the lack of adequate engagement of the local government authorities, health sector, and community. This implementation research aimed to explore barriers to implementing community engagement in a dengue vector control program in an urban district of Hanoi city. Ten in-depth interviews and 14 focus group discussions were conducted at Lang Thuong, Khuong Thuong, Tho Quan, and Kim Lien wards in Dong Da district, Hanoi city. Data collection was implemented from April to June 2017. All discussions were recorded and transcribed verbatim. Data were analyzed using the content analysis approach. Secondary data from the dengue vector control program reports were used to support the qualitative evidence. We found that the barriers to implementing effective community engagement were as follows: 1) lack of interest and an attitude of dependency on action from the health sector of local people's committee, 2) lack of enthusiasm of mass organizations and community leaders, 3) overburdened workloads and lack of communication skills from health sector, 4) low awareness and readiness from community, 5) lack of detailed policy guidelines and low enforcement of related policy, and 6) limited budget. Recommended actions should be made to improve the community engagement in the current resource-limited context of Vietnam by both top-down and bottom-up approaches.

Habitat Aedes Pradewasa dan Indeks Entomologi di 11 Kabupaten/Kota Provinsi Sumatera Selatan

Dengue fever and dengue haemorrhagic fever still becomes public health problems in South Sumatera Province with all of its regencies/cities have infested with Aedes aegypti. This research aimed to determine Aedes entomological indices and its breeding habitats. The research located at 11 regencies/cities, where in every regencies/cities determined two clusters (village) based on incidence rate in the last three years. Survey of preadult mosquito was carried out inside and outside areas of 1181 houses using single larva method with modification. The survey found that the dengue vector indices for house index, breteau index, and container index were at range 22,6% - 60,6%, 26,4 – 154,1 and 8,0% - 36,2% respectively. The most dominant water holding containers found infested with pre-adults mosquito were cement tanks (33,4%), followed by buckets (18,2%) and drums (14,7%). Inside houses, larva or pupae found dominants in cement tanks (44,3%), buckets (19,5%) and drums (13,9%), while outside of the house were used containers (20,7%), followed by drums (16,7%), buckets (15,0%) and used tires (11,9%). Statistical analysis by chi-square test showed a significant relationship between infested of Aedes pre-adults with characteristic of containers (colours, volume, location found and containers). Larval survey by visiting houses should carry out routinely and integrated into dengue vector control program.

Effectiveness of a novel long-lasting pyriproxyfen larvicide (SumiLarv\xae2MR) against Aedes mosquitoes in schools in Yangon, Myanmar

BackgroundMosquito-borne diseases are prevalent in Myanmar, with the number of dengue cases showing a significant increase in recent years. Dengue vectors have developed resistance to insecticides and currently used larvicides show only short-term effectiveness. As a result, an alternative larvicide is urgently needed. The present study evaluated the larvicidal effectiveness of long-lasting pyriproxyfen resin discs (SumiLarv®2MR) against dengue virus vectors in schools in Hlaing Thar Yar Township, Yangon.ResultsThe proportion of Aedes mosquito-infested containers was significantly reduced in the schools applied with the larvicide (OR: 0.24, 95% CI: 0.12–0.48) while there was little reduction noted in the control schools (OR: 0.97, 95% CI: 0.55–1.72). The density of infested containers was also significantly reduced in the intervention schools (Beta: -1.50, 95% CI: -1.98– -1.04), but there was no significant reduction in density in the control schools (Beta: -0.19, 95% CI: -0.53–0.14). The proportion of adult emergence was less than 20% in the treated water collected from the intervention schools for six months, while the proportion was over 90% in the untreated water. In addition, eight-month-old SumiLarv®2MR resin discs were still 100% effective when tested in the laboratory. More than 50% of the discs disappeared from treated containers within two months of intervention.ConclusionsSumiLarv®2MR was effective in reducing Aedes-infested containers at least six months after its application in schools. This new pyriproxyfen formulation has great potential for improving the current dengue vector control program in Myanmar.

High Levels of Resistance in A Culex quinquefasciatus Population to the Insecticide Permethrin in Filariasis Endemic Areas in Central Java

Resistance among Culex mosquitoes to various insecticides has been reported in many countries. However, there have been no studies of the resistance status of Culex in Indonesia. There is a need for such studies to develop a database for use in vector control management. This study aimed to investigate the insecticide resistance status of C. quenquefasciatus , which is the primary vector of filariasis, to aid the planning of a vector control management program. In the present study, Culex quinquefasciatus larvae were collected from five districts/municipalities where filariasis is endemic in Central Java. The larvae were reared to adult stage, and insecticide susceptibility testing was then conducted according to standard bioassay procedures of the World Health Organization (WHO). The results of the bioassays showed that C. quinquefasciatus had a high level of resistance against 0.75% permethrin, with mortality rates ranging from 4.8 to 21.6%. The lowest resistance was found among mosquitoes collected from Grobogan district. This may be explained by the district’s remote geographical location. The high level of resistance found in the present study may be caused by exposure to local insecticides, which have been applied for many years as part of a dengue vector control program. These insecticides may also have contaminated the breeding sites of C. quinquefasciatus mosquitoes. Better vector control management is needed to help prevent the development and spread of resistance. Such management should include routine insecticide surveillance and insecticide alternation.

Habitat Aedes Pradewasa dan Indeks Entomologi di 11 Kabupaten/Kota Provinsi Sumatera Selatan

Dengue fever and dengue haemorrhagic fever still becomes public health problems in South Sumatera Province with all of its regencies/cities have infested with Aedes aegypti. This research aimed to determine Aedes entomological indices and its breeding habitats. The research located at 11 regencies/cities, where in every regencies/cities determined two clusters (village) based on incidence rate in the last three years. Survey of preadult mosquito was carried out inside and outside areas of 1181 houses using single larva method with modification. The survey found that the dengue vector indices for house index, breteau index, and container index were at range 22,6% - 60,6%, 26,4 – 154,1 and 8,0% - 36,2% respectively. The most dominant water holding containers found infested with pre-adults mosquito were cement tanks (33,4%), followed by buckets (18,2%) and drums (14,7%). Inside houses, larva or pupae found dominants in cement tanks (44,3%), buckets (19,5%) and drums (13,9%), while outside of the house were used containers (20,7%), followed by drums (16,7%), buckets (15,0%) and used tires (11,9%). Statistical analysis by chi-square test showed a significant relationship between infested of Aedes pre-adults with characteristic of containers (colours, volume, location found and containers). Larval survey by visiting houses should carry out routinely and integrated into dengue vector control program.

Detection of Insecticide Resistance in Aedes Aegypti to Organophosphate in Pulogadung, East Jakarta

Dengue Hemorrhagic Fever (DHF) is a major public health problem in Indonesia. Jakarta is a capital city with the highest number of dengue patients. Among sporadic endemic areas in Jakarta, Pulogadung, a district of East Jakarta, is one of endemic areas of this disease. The primary strategy for the control of DHF is based on reducing population densities of the main mosquito vector Aedes aegypti. Organophosphate is an insecticide that has been used for more than 25 years in dengue vector control program. The long term used and sublethal dosage of this insecticide can induce resistance. This laboratory study used microplate test and ELISA reader to determine the increase of alfa- esterase activity in Aedes aegypti larvae for detecting the resistance to organophosphate. Resistance pattern of Ae aegypti to organophosphate insecticide in RW 01 Pulogadung was shown to be: 23% high resistant, 33% medium resistant and 44% sensitive. This result was highly related to local community behavior where we found that the use of insecticide spray by the people was very low (8.8% of the sample). We found that the people who used insecticide spray were only 8.8% of the sample. Therefore, organophosphate still can be used in this area to control the Dengue Hemorrhagic Fever in the future. Based on resistance pattern of Ae aegypti to organophosphate insecticide in RW 01 Pulogadung, we can conclude that organophosphate still can be used in this area to control the Dengue Hemorrhagic Fever in the future .

Coexistence of Aedes aegypti and Aedes albopictus in Jinghong City, Yunnan Province: A Survey of Aedes aegypti Invasion

We conducted this study to confirm that Aedes aegypti has invaded and colonized in Xishuangbanna, Yunan province, China. And we conducted a larval survey for dengue mosquito vectors, Ae. aegypti and Ae. albopictus, to assess on possible competition for breeding sites between these both species in urban environment in Jinghong city. The study was carried out at least once a month in February and March, November and December, and three times for each month from April to October in 2014 in five communities in the municipality of Jinghong city. No less than 50 houses were surveyed each time in one place. We collected immature stages of mosquitoes from all types of breeding sites in houses and their premises. Morphological species identification was carried for Ae. aegypti and Ae. albopictus. Both species occurred in all surveyed areas. Aedes aegypti has occupied a considerable composition (67.75%) since the uncertain time of its first invasion to Jinghong city. Aedes aegypti was predominant species indoor (74.19%), but also presented in surrounding environment (25.81%); while Ae. albopictus favored the outdoor environment (54.55%) as well as in houses (45.45%). We gave the preference water containers (tires) for dengue vectors, described different distribution in different investigated places, and showed with monthly variance by indices of BI and CI. We gave our rational explanation for the variance with raining in this area, Aedes keep a high density value during the rainy season. For both dengue vectors, the possibility cannot be excluded that the invasion of Ae. aegypti in the city might lead to a decrease or elimination of Ae. albopictus in houses and dwellings. Furthermore, we also found that both dengue vectors have already occupied the breeding sites in houses and their premises with water container in Jinghong city, and both should be managed during dengue epidemic season. These findings from this study are relevant for dengue vector control programs

The impact of indoor residual spraying of deltamethrin on dengue vector populations in the Peruvian Amazon

Dengue is an important public health problem in the Amazon area of Peru, resulting in significant morbidity each year. As in other areas of the world, ultra-low volume (ULV) application of insecticides is the main strategy to reduce adult populations of the dengue vector Aedes aegypti, despite growing evidence of its limitations as a single control method. This study investigated the efficacy of deltamethrin S.C. applied through indoor residual spraying (IRS) of dwellings in reducing A. aegypti populations. The residual effect of the insecticide was tested by monthly bioassays on the three most common indoor surfaces found in the Amazon area: painted wood, unpainted wood and brick. The results showed that in an area with moderate levels of A. aegypti infestation, IRS dramatically reduced all immature indices the first week after deltamethrin IRS application and the adult index from 18.5 to 3.1, four weeks after intervention (p<0.05). Even though housing conditions facilitated reinfestation with A. aegypti (100% of the houses have open roof eaves, 31.5% lack sewage systems, and 60.4% collected rain in open containers), indices remained low compared to baseline 16 weeks after insecticide application. Bioassays showed that deltamethrin S.C. caused mortalities >80% 8 weeks after application on all types of surfaces. The residual effect of the insecticide was greater on brick than on wooden walls (p<0.05). Our results demonstrate that IRS can have both an immediate and sustained effect on reducing adult and immature A. aegypti populations and should be considered as an adult mosquito control strategy by dengue vector control programs.

Cost of Dengue Vector Control Activities in Malaysia.

Dengue fever, an arbovirus disease transmitted by Aedes mosquitoes, has recently spread rapidly, especially in the tropical countries of the Americas and Asia-Pacific regions. It is endemic in Malaysia, with an annual average of 37,937 reported dengue cases from 2007 to 2012. This study measured the overall economic impact of dengue in Malaysia, and estimated the costs of dengue prevention. In 2010, Malaysia spent US$73.5 million or 0.03% of the country's GDP on its National Dengue Vector Control Program. This spending represented US$1,591 per reported dengue case and US$2.68 per capita population. Most (92.2%) of this spending occurred in districts, primarily for fogging. A previous paper estimated the annual cost of dengue illness in the country at US$102.2 million. Thus, the inclusion of preventive activities increases the substantial estimated cost of dengue to US$175.7 million, or 72% above illness costs alone. If innovative technologies for dengue vector control prove efficacious, and a dengue vaccine was introduced, substantial existing spending could be rechanneled to fund them.

Assessment ofAedes aegyptiPupal Productivity during the Dengue Vector Control Program in a Costal Urban Centre of São Paulo State, Brazil

The control of dengue relies on the elimination of vector breeding sites. This study identified the container categories most productive forA. aegyptiwithin the framework of the São Paulo dengue vector control program (DVCP) in São Sebastião, a large city located on the state’s coast where dengue cases have occurred since 2001. Containers were inspected monthly for the occurrence of mosquito immature stages during two consecutive vector-breeding seasons in 2002–2004. Containers were classified by their material, use, and fixed or removable status. Pupal productivity differed significantly among container types, items made of metal and plastic, and boats being those with the highest relative contribution. Significant correlations between traditional indices ofA. aegyptiabundance (Container Index, House Index, and Breteau Index) and pupal productivity/demographic indices (Pupae/Container, Pupae/House, Pupae/ha, and Pupae/Person) ranged 0.56–0.65; correlations were not statistically significant for any combination involving the Pupae/Container index. The assessment of pupal productivity indices could be incorporated into the DVCP without any additional operational onus, allowing vector control managers to determine appropriate control actions targeting the most productive containers and sites. Further studies are needed to assess whether pupal productivity indices may be used as epidemiological indicators of risk of dengue transmission.