Consequently, current strategies for control of filarial nematode diseases include elimination of their symbiotic Wolbachia via the simple doxycycline antibiotic, rather than directly killing the nematode with often more toxic antinematode medications. Disease prevention Naturally existing strains of Wolbachia have been shown to be a route for vector control strategies because of their presence in arthropod populations, such as mosquitoes. Due to the unique traits of Wolbachia that cause cytoplasmic incompatibility, some strains are useful to humans as a promoter of genetic drive within an insect population. Wolbachia-infected females are able to produce offspring with uninfected and infected males; however, uninfected females are only able to produce viable offspring with uninfected males. This gives infected females a reproductive advantage that is greater the higher the frequency of Wolbachia in the population. Computational models predict that introducing Wolbachia strains into natural populations will reduce pathogen transmission and reduce overall disease burden. An example includes a life-shortening Wolbachia that can be used to control dengue virus and malaria by eliminating the older insects that contain more parasites. Promoting the survival and reproduction of younger insects lessens selection pressure for evolution of resistance. In addition, some Wolbachia strains are able to directly reduce viral replication inside the insect. For dengue they include wAllbB and wMelPop with Aedes aegypti, wMel with Aedes albopictus. and Aedes aegypti. A trial in an Australian city with 187,000 inhabitants plagued by dengue had no cases in four years, following introduction of mosquitoes infected with Wolbachia. Earlier trials in much smaller areas had been carried out, but the effect in a larger area had not been tested. There did not appear to be any environmental ill-effects. The cost was A$15 per inhabitant, but it was hoped that it could be reduced to US$1 in poorer countries with lower labor costs. The "strongest evidence yet" to support the Wolbachia technique was found in its first randomized controlled trial, conducted between 2016 and 2020 in Yogyakarta, an Indonesian city of about 400,000 inhabitants. In August 2020, the trial's Indonesian lead scientist Adi Utarini announced that the trial showed a 77% reduction in dengue cases compared to the control areas. Wolbachia has also been identified to inhibit replication of chikungunya virus (CHIKV) in A. aegypti. The wMel strain of Wolbachia pipientis significantly reduced infection and dissemination rates of CHIKV in mosquitoes, compared to Wolbachia uninfected controls and the same phenomenon was observed