No abstract

The sterilization process using gamma irradiation is a crucial component in a program using sterile insect technique (SIT) to control Aedes aegypti. Unfortunately, there is no efficient standard protocol for sterilizing mosquitoes that can produce a high level of sterility while maintaining mating ability and longevity. Therefore, we conducted a study of the critical factors necessary to develop such a standard protocol. In this study, male Ae. aegypti pupae, as well as adults aged 1 d and 3 d, were irradiated using a Gamma-cell 220 irradiator doses of 0, 20, 40, 60, 70, 80, and 100 Gray (Gy). In addition, male Ae. aegypti in the pupal and adult stage aged 1 d were irradiated at a dose of 70 Gy at various temperatures. Changes in emergence rates, longevity, sterility, and mating competitiveness were recorded for each combination of parameters. Results showed that an increase of irradiation dose leads to a rise of induced sterility at all developmental stages, while simultaneously reducing emergence rate, survival, and mating competitiveness. Higher temperatures resulted in increased levels of sterility, reduced longevity, and did not affect the ability to mate. This study found that an irradiation dose of 70 Gy at a temperature between 20.00 and 22.30°C administered in the pupal stage induced a high level of sterility (around 98%), while maintaining mating competitiveness and longevity.

Filariasis as part of the neglected tropical disease is one of the health problems in the world. Filariasis divided into onchocerciasis (river blindness) and lymphatic filariasis or elephantiasis. This disease caused by filarial nematode parasites Onchocerca volvulus, Wuchereria bancrofti, Brugia malayi and Brugia timori. Filariasis transmitted by several mosquito genera as the vector. Indonesia as endemic filariasis, agreed on plays a role on World Health Organization (WHO) global filariasis elimination in 2020. Sterile insect technique (SIT) is a potential method which can be applied to filariasis elimination program by controlling the mosquito population. Basic principles of SIT involve mass rearing of species target, sterilization process using gamma-rays and releasing sterile male insect into a target area. SIT combined with other methods under one management as Area-wide Integrated Pest Management (AW-IPM) to increasing effectiveness and successful filariasis elimination program in Indonesia. Filariasis elimination program in Indonesia has several challenges and needed public participation to achieve program goals. Key words : filariasis, Indonesia, sterile insect technique (SIT) ABSTRAKFilariasis sebagai bagian dari penyakit tropis yang terbengkalai merupakan salah satu masalah kesehatan di dunia. Filariasis dibagi menjadi onchocerciasis dan filariasis limfatik atau kaki gajah. Penyakit ini disebabkan oleh parasit nematoda filarial Onchocerca volvulus, Wuchereria bancrofti, Brugia malayi dan Brugia timori. Filariasis ditularkan oleh beberapa genera nyamuk sebagai vektor. Indonesia sebagai endemik filariasis, sepakat memainkan peran dalam eliminasi filariasis global yang diagendakan oleh world health organization (WHO) pada tahun 2020. Teknik serangga mandul (TSM) adalah metode potensial yang dapat diterapkan pada program eliminasi filariasis dengan mengendalikan populasi nyamuk. Prinsip dasar SIT melibatkan pembiakan populasi target secara massal, proses sterilisasi menggunakan sinar gamma dan melepaskan serangga jantan steril ke daerah sasaran. TSM dapat dikombinasikan dengan metode lain di bawah satu manajemen terpadu, yaitu area-wide integrated pest management (AW-IPM) untuk meningkatkan efektivitas dan keberhasilan program eliminasi filariasis di Indonesia. Program eliminasi filariasis di Indonesia memiliki beberapa tantangan dan kebutuhan partisipasi masyarakat untuk mencapai tujuan program.

Given the facts that Indonesia has suitable environment condition to survival, reproduction and development of the principal mosquito vector for dengue virus, Aedes aegypti, the transmission of dengue virus does routinely occur every year. The sterile insect technique (SIT) as one of the techniques in area-wide integrated pest management (AW-IPM) has been developed to control Aedes aegypti population since 2004. The first 5 years of the program (2004)(2005)(2006)(2007)(2008)(2009)) was focused on mass rearing facility establishment. The lab-work study for the entomological data and field trials were performed in 2010-2014. In 2014-2019, the program was addressed to enhance the mass rearing facility to increase sterile male production and strengthening the networking throughout the involvement in the regional and interregional program coordinated by International Atomic Energy Agency (IAEA). The main future challenge of the SIT program against Aedes aegypti is developing the capacity building and strong commitment of all stakeholders i.e. the Ministry of Health, the universities, the research institutes and the public. In the future work plan, the pilot project design to proof the concept of the SIT is strongly recommended to obtain a firm, unbiased and strong results as the consideration for the decision maker to create the Aedes control program in Indonesia.Journal homepage: http://aij.batan.go.id

Optimized conditions for the packaging and transportation of sterile males are crucial factors in successful SIT programs against mosquito vector-borne diseases. The factors influencing the quality of sterile males in packages during transportation need to be assessed to develop standard protocols. This study was aimed to investigate the impact of compaction, temperature, and duration factors during packaging and transportation on the quality of gamma-sterilized male Ae. aegypti. Aedes aegypti males were sterilized at a dose of 70 Gy, compacted into Falcon tubes with densities of 40, 80, and 120 males/2 mL; and then exposed to temperatures of 7, 14, 21, and 28 °C. Each temperature setup was held for a duration of 3, 6, 12, 24, and 48 h at a 60 rpm constant vibration to simulate transportation. The parameters of mortality, flight ability, induced sterility, and longevity were investigated. Results showed that increases in density, temperature, and duration significantly increased mortality and reduced flight ability and longevity, but none of the factors significantly affected induced sterility. With a mortality rate of less than 20%, an escaping rate of more than 70%, considerable longevity, and the most negligible effect on induced sterility (approximately 98%), a temperature of 7 °C and a compaction density of 80 males/2 mL were shown to be optimized conditions for short-term transportation (no more than 24 h) with the minimum adverse effects compared with other condition setups.

No abstract

Aedes aegypti is currently emerging as a main vector of Dengue, Zika, and Chikungunya transmission. Chemical control was reported to be less effective due to the resistance of this mosquito to some types of insecticides. Therefore, another vector control is needed which is most appropriate to be used, i.e. the sterile insect technique (SIT). Information about optimum range dispersal sterile male Aedes aegypti for optimalization SIT program are needed. This study was designed to determine the dispersal pattern and population estimation of Aedes aegypti sterilized with gamma rays using mark-release-recapture (MRR) method. After the male Aedes aegypti (pupal stage) was irradiated with 70 Gy of gamma rays, the mosquitoes were then marked with Rhodamine-B and released into the study site. MRR experiments were carried out in Batan Indah residential area, and the Aedes aegypti were released in center of the site. Mosquitoes were recaptured at 28 points spread over the Batan Indah Residence for 2, 4, 6, and 8 days after release by using BG-Sentinel Traps. The result showed that the population of Aedes aegypti in the site was estimated to be 5.402 (1.347-14.636; CI 95 %) with the furthest spread distance was 119 meters from the release point. This study also showed that the MRR experiment can be used to estimate the population size and dispersal pattern of Aedes aegypti movement in a given locality. The result of present study provide better understanding for optimalization mosquito-borne disease prevention based on SIT programs.

Abstract. Ernawan B, Surniyantoro HNE, Sugoro I, Tambunan USF. 2019. A mutant variant of Nix gene on γ-irradiated Aedes aegypti as a male-determination factor. Biodiversitas 20: 893-899. This study was aimed to examine the effect of γ-irradiation on the Nix gene sequence as a male-determination factor on Ae. aegypti. The novelty of the present study is the investigation on the gene mutation level of the deoxyribonucleic acid as an impact of ionizing radiation exposure. Males Ae. aegypti at the pupal stage were sterilized by applying 70 Gy γ-rays in varies dose-rates, i.e., 300, 600, 900, 1200 and 1500 Gy/h utilizing panoramic irradiator and males group without γ-irradiation as controls. Adult males that emerged from the pupal stage were assessed for the Nix gene sequence using a Real-Time Polymerase Chain Reaction method and were sequenced using Clustal Omega and Bioedit software, respectively. The results indicated that mutation occurred in Nix gene sequences were categorized as a point mutation. The change of Nix gene sequences was occurred between the nitrogenous base of guanine to adenine (G>A), thymine to adenine (T>A) and cytosine to adenine (C>A) in certain sequence numbers. There were six and nineteen on the forward-strand and reverse-strand of the Nix gene, respectively, due to γ-irradiation treatment. We conclude that γ-irradiation exposure causes point mutation on the Nix gene of males Ae. aegypti.