Hubungan Frekuensi Gen Knock-Down Resistance (KDR) V1016G, V410L, dan F1534C dengan Tingkat Resistensi Populasi Aedes aegypti di Denpasar, Bali

 ABSTRACT Insecticides are used to reduce the number of Aedes aegypti mosquitoes, a vector of the dengue virus that causes dengue hemorrhagic fever in Indonesia, including in Bali. However, in recent years, the resistance of the Ae. aegypti mosquito to insecticides has been reported in Bali. In addition, Ae. aegypti is also identified to be resistant to several types of insecticides whose resistance mechanism is not yet clear. Several studies have stated that the KDR genes are one of the causes of resistance to pyrethroid insecticides. Therefore, a study was conducted to determine the frequency of the KDR genes in the Ae. aegypti population in Denpasar, Bali which had been previously shown resistance to permethrin (type of pyrethroid). Forty-three females Ae. aegypti specimens from bioassay testing using permethrin stored in tubes containing 100% ethanol were used in this study. Each mosquito is put in a different tube. The mosquito DNA was then extracted. Three KDR genes, V1016G, V410L, and F1534C, were analyzed using the quantitative-PCR melt curve method at the Biomolecular Laboratory, FKIK Unwar. In this study, the mutation frequency of 1016G was 98%, 410L was 50%, and 1534C was 3.4%. The 410L mutant gene was shared by all specimens, although only in one allele (heterozygous). Of the 43 specimens, 39 had homozygous mutant V1016G, heterozygous V410L, and wild typehomozygous F1534C. It indicated that the frequency of the 1016G and 410L mutant genes is quite high, while the 1534C gene is low. The combination of the KDR 1016G and 410L genes was the most dominant found in permethrin-resistant Ae. aegypti specimens. Therefore, it is assumed that these two KDR genes play a role in forming permethrin resistance in Ae. aegypti. ABSTRAK Insektisida digunakan untuk menurunkan jumlah nyamuk Aedes aegypti yang merupakan vektor virus dengue penyebab penyakit demam berdarah dengue di Indonesia, termasuk di Bali. Namun, dalam beberapa tahun terakhir, resistensi nyamuk Ae. aegypti terhadap insektisida dilaporkan sudah terjadi di Bali. Selain itu, Ae. aegypti juga dilaporkan resisten terhadap beberapa jenis insektisida yang mekanisme terjadinya resistensi belum diketahui. Beberapa penelitian menyebutkan bahwa gen KDR menjadi salah satu penyebab terjadinya mekanisme resistensi terhadap insektisida golongan peritroid. Oleh sebab itu, dilakukan penelitian untuk mengetahui frekuensi gen KDR pada populasi Ae. aegypti di Denpasar, Bali yang sebelumnya telah terbukti memiliki resistensi permetrin (insektisida golongan peritroid). Sebanyak 43 spesimen Ae. aegypti betina hasil dari pengujian bioassay yang tersimpan dalam tabung yang berisi etanol 100% digunakan dalam penelitian ini. Tiap nyamuk dimasukkan dalam tabung yang berbeda. Selanjutnya dilakukan ekstraksi DNA nyamuk. Tiga jenis gen KDR, yaitu V1016G, V410L, and F1534C, dianalisis dengan metode quantitative-PCR melt curve di Laboratorium Biomolekuler FKIK Unwar. Dalam penelitian ini ditemukan frekuensi mutasi 1016G sebesar 98%, 410L 50%, dan 1534C sebesar 3,4%. gen mutan 410L dimiliki oleh seluruh spesimen walaupun hanya pada salah satu alel (heterozigot). Dari 43 spesimen yang diteliti, terdapat 39 spesimen yang memiliki profil genotip V1016G homosigot mutan, V410L heterosigot, dan F1534C homosigot wild type. Sehingga dapat disimpulkan bahwa frekuensi gen mutan 1016G dan 410L cukup tinggi, sedangkan gen 1534C rendah. Kombinasi gen KDR  1016G dan 410L paling dominan ditemukan pada spesimen Ae. aegypti resisten permetrin. Kedua gen KDR diasumsikan berperan dalam pembentukan resistensi permetrin pada Ae. aegypti.  

Dengue in Bali: Clinical characteristics and genetic diversity of circulating dengue viruses

A high number of dengue cases are reported annually in Bali. Despite the endemicity, limited data on dengue is available for Bali localities. Molecular surveillance study was conducted to explore the clinical and virological characteristics of dengue patients in urban Denpasar and rural Gianyar areas in Bali during the peak season in 2015. A total of 205 adult dengue-suspected patients were recruited in a prospective cross-sectional study. Demographic and clinical information were obtained, and dengue screening was performed using NS1 and IgM/IgG ELISAs. Viral RNA was subsequently extracted from patients’ sera for serotyping using conventional RT-PCR and Simplexa Dengue real-time RT-PCR, followed by genotyping with sequencing method. We confirmed 161 patients as having dengue by NS1 and RT-PCR. Among 154 samples successfully serotyped, the DENV-3 was predominant, followed by DENV-1, DENV-2, and DENV-4. Serotype predominance was different between Denpasar and Gianyar. Genotyping results classify DENV-1 isolates into Genotype I and DENV-2 as Cosmopolitan Genotype. The classification grouped isolates into Genotype I and II for DENV-3 and DENV-4, respectively. Clinical parameters showed no relationship between infecting serotypes and severity. We observed the genetic diversity of circulating DENV isolates and their relatedness with historical data and importation to other countries. Our data highlights the role of this tourist destination as a potential source of dengue transmission in the region.

Dengue is the most significant mosquito-borne viral disease affecting humans. Up to one third of the world population is at risk of dengue virus (DENV) infection, transmitted through the bite of Aedes mosquitoes. Bali, a well-known international tourist destination, is regularly ravaged by dengue disease. This disease impacts the health of both local people and visitors thus imposing a heavy economic burden. Bali has a constant flow of travelers and labors that contribute to the spread of DENV infection. Detailed characterization of DENV from Bali is limited; most reports are from travel-acquired cases. Here, we study dengue clinical and virological aspects in local Balinese people. We presented the clinical spectrum of the disease and the virological characteristics, observing the circulation of genetically diverse endemic virus strains including strains which are closely related to imported viruses in neighboring countries. The circulation of a lineage of DENV-2 proposed to cause outbreak in the past is also identified. Our study provides data on the genetic of circulating DENV in Bali which are useful for further applications, such as to monitor the virus transmission and outbreak investigation in the region.

Development of Culturally Appropriate Educational Material to Improve Home Case Management of Diarrhea in Rural Lombok, Indonesia

Indonesia is a country of many different ethnic groups and cultural norms. Despite this fact, most health education materials in Indonesia have been designed for an overall national audience. These materials rarely take into account local cultural perceptions and ideas about disease causation and appropriate treatment. Once materials are developed, they are rarely pretested to ensure that they are understood and accepted by the communities for which they are intended. We believe that educational messages and illustrations should be based on thorough research and analysis, not only of the health problem, but also of the perceptions, beliefs, and cultural practices of the target audience.

In order to develop a culturally sensitive health education campaign on appropriate home case management of diarrhea, we first conducted formative research with mothers of young children and health care providers in West Lombok, Indonesia. This research showed that the people recognize four different types of diarrhea according to signs and symptoms and perceived etiology. Based on the results of the formative research, a flipchart was designed incorporating five messages. The flipchart was then revised on the basis of two pretests. The pretest results showed that visual messages about child health, the course and treatment of diarrheal diseases, and the preparation of oral rehydration solutions were often misinterpreted or not considered in accordance with local cultural norms. Most of the respondents understood the messages but felt that several of the illustrations did not accurately reflect their ways of living. After changes were made, the materials were easily understood and accepted by respondents. To maximize the benefit of educational materials, the national health education sector should be more flexible in the adaptation of materials to local customs and perceptions.

Home treatment of acute diarrhoea in Bali, Indonesia

To determine how acute diarrhoea is managed at home, 75 structured interviews were conducted with mothers of children under two years of age who were admitted to hospitals or health centres in Denpasar district, Bali. Most mothers did not follow the guidelines for home case management established by the World Health Organization (WHO) Control of Diarrhoeal Diseases (CDD) Programme. Sixty eight percent of the mothers reported giving oral rehydration therapy (ORT) to their children with diarrhoea, and over half of these children were given home made salt-sugar-solutions (SSS). However, only 12% of the mothers were able to properly make the SSS. Over two thirds of the mothers reduced or stopped the intake of bottled milk and solid food during the episode. Forty-five percent of breast-feeding mothers increased the frequency of feeding. Over half of the mothers gave drugs to their children, 90% of which were obtained from the physicians or health post personnel. These results indicate that more effective ways to implement the proper home-case management of diarrhoea are needed.