Kajian Entomologi dalam Mendukung Pengendalian Malaria melalui Program Flying Health Care (FHC) di Kabupaten Yahukimo, Provinsi Papua

Flying Health Care is one of the programs of the Ministry of Health to accelerate the elimination of malaria in an integrated manner, especially in the Yahukimo Regency. The purpose of this activity is to describe the role of entomological aspects in malaria control efforts. The data includes cases of malaria, mosquitoes and Anopheles larvae, breeding place, and vector control efforts. Data was collected by observation, survey, and secondary data analysis. The results of the study show that malaria cases rank first out of 10 diseases in health facilities. Malaria cases were more common occurred at the age of 10-19 years, male and near to health facilities. Breeding places in the form of swamps and puddles in the environment around patients with water depths ranging from 5-30 cm. There is no entomological data at the district level or at Puskesmas Aplim. Ongoing vector control efforts are in the form of distributing insecticide-treated mosquito nets. Insecticide mosquito nets have not been fully distributed to the community, this is constrained by the existing infrastructure in health care facilities. Vector control efforts should be supported by the results of entomological surveys and it is important to do socialization on how to use and maintain mosquito nets at the time of mosquito net distribution.

The Potential for a Released Autosomal X-Shredder Becoming a Driving-Y Chromosome and Invasively Suppressing Wild Populations of Malaria Mosquitoes

Sex-ratio distorters based on X-chromosome shredding are more efficient than sterile male releases for population suppression. X-shredding is a form of sex distortion that skews spermatogenesis of XY males towards the preferential transmission of Y-bearing gametes, resulting in a higher fraction of sons than daughters. Strains harboring X-shredders on autosomes were first developed in the malaria mosquito Anopheles gambiae, resulting in strong sex-ratio distortion. Since autosomal X-shredders are transmitted in a Mendelian fashion and can be selected against, their frequency in the population declines once releases are halted. However, unintended transfer of X-shredders to the Y-chromosome could produce an invasive meiotic drive element, that benefits from its biased transmission to the predominant male-biased offspring and its effective shielding from female negative selection. Indeed, linkage to the Y-chromosome of an active X-shredder instigated the development of the nuclease-based X-shredding system. Here, we analyze mechanisms whereby an autosomal X-shredder could become unintentionally Y-linked after release by evaluating the stability of an established X-shredder strain that is being considered for release, exploring its potential for remobilization in laboratory and wild-type genomes of An. gambiae and provide data regarding expression on the mosquito Y-chromosome. Our data suggest that an invasive X-shredder resulting from a post-release movement of such autosomal transgenes onto the Y-chromosome is unlikely.

Philosophy of Technoscience: From Cis-Continental to Trans-Continental

The previous chapters explored how four (interacting and overlapping) continental approaches (dialectics, dialectical materialism, psychoanalysis and phenomenology) offer hints and guidance for coming to terms with the revolutionary dynamics and disruptive impact of contemporary technoscience. Hegelian dialectics provides a conceptual scaffold for developing a comprehensive view of the terrestrial system and even for addressing the Cambrian explosion currently unfolding in laboratories around the globe, as a result of technoscientific developments such as synthetic biology and CRISP-Cas9. Dialectical materialism likewise offers a conceptual framework for addressing the rapidly aggravating disruption of the metabolism between nature and global civilisation, and the ongoing convergence of biosphere and technosphere, exemplified by the synthetic cell. Francophone psychoanalysis, closely aligned with dialectical thinking, adds to our understanding of the specificity of technoscience, both as a practice and as a discourse, where technoscientific research emerges as a questionable vocation driven by a desire to control, but at the same time ostensibly out of control. The dialectical methodology of psychoanalysis was exemplified with the help of case histories, moreover, involving Majorana particles, gene drives, malaria mosquitoes and nude mice. The latter represent technoscientific commodities, exemplifying the assembly-line production of human-made organisms (the commodification of life as such). Subsequently, we demonstrated how Heideggerian phenomenology entails important methodological hints for understanding technoscientific artefacts against the backdrop of technoscience as a mobilising force and as a global enterprise. And finally, we outlined how Teilhard’s views on the genesis of consciousness, self-consciousness and hyperconsciousness retrieve the historical (dialectical) dimension of phenomenology, thus allowing us to assess the present as a global unfolding of the noosphere.

Evaluating the contribution of aestivation to the persistence of malaria mosquitoes through the Sahelian dry season using stable isotopes

Data suggests the malaria vector Anopheles coluzzii persists in the Sahel by dry-season aestivation though evidence is scant. We have marked Anopheles mosquitoes using deuterium (2H) to assess the contribution of aestivation to persistence of mosquitoes through the seven-month dry season. If local aestivation is the only way A. coluzzii persists, the frequency of marked mosquitoes should remain stable throughout, whereas finding no marked mosquitoes would be evidence against aestivation. Larval sites were spiked with 2H at the end of the 2017 wet season in two Sahelian villages in Mali. We monitored 2H-enriched populations until the onset of rains. By the end of the enrichment period, 33% of A. coluzzii mosquitoes were clearly marked. Expectedly, 2H levels in marked mosquitoes degraded over time, resulting in a partial overlap of the marked and non-marked 2H distributions. We utilized three methods to estimate the fraction of marked mosquitoes in the population. Seven months after enrichment, 7% of the population had 2H values above the highest pre-enrichment value. An excess of 21% exceeded the 3rd quartile of the pre-enrichment population. A finite mixed population model showed 2.5% represented a subpopulation of marked mosquitoes with elevated 2H, compatible with our predictions. We provide evidence that aestivation is a major persistence mechanism of A. coluzzii in the Sahel, contributing at least 20% of the adults at the onset of rains, suggesting A. coluzzii utilizes multiple persistence strategies enabling its populations rapid buildup, facilitating subsequent malaria resurgence. These may complicate vector control and malaria elimination campaigns.

New Cytogenetic Photomap and Molecular Diagnostics for the Cryptic Species of the Malaria Mosquitoes Anopheles messeae and Anopheles daciae from Eurasia

The Eurasian malaria vector Anopheles messeae is a widely spread and genetically diverse species. Five widespread polymorphic chromosomal inversions were found in natural populations of this mosquito. A cryptic species, Anopheles daciae, was differentiated from An. messeae by the presence of several nucleotide substitutions in the Internal Transcribed Spacer 2 (ITS2) region of ribosomal DNA. However, because of the absence of a high-quality reference cytogenetic map, the inversion polymorphisms in An. daciae and An. messeae remain poorly understood. Moreover, a recently determined heterogeneity in ITS2 in An. daciae questioned the accuracy of the previously used Restriction Fragment Length Polymorphism (RFLP) assay for species diagnostics. In this study, a standard-universal cytogenetic map was constructed based on orcein stained images of chromosomes from salivary glands for population studies of the chromosomal inversions that can be used for both An. messeae and An. daciae. In addition, a new ITS2-RFLP approach for species diagnostics was developed. Both methods were applied to characterize inversion polymorphism in populations of An. messeae and An. daciae from a single location in Western Siberia in Russia. The analysis demonstrates that cryptic species are remarkably different in their frequencies of chromosomal inversion variants. Our study supports previous observations that An. messeae has higher inversion polymorphism in all autosomes than the cryptic species An. daciae.

Naturally Occurring Compounds With Larvicidal Activity Against Malaria Mosquitoes

Female Anopheles mosquitoes transmit Plasmodium parasites that cause human malaria. Currently, vector control is the most widely deployed approach to reduce mosquito population and hence disease transmission. This relies on use of insecticide-based interventions including Long-lasting Insecticide-treated Nets (LLINs) and Indoor Residual Spraying (IRS) where scale-up has contributed to a dramatic decline in malaria deaths and morbidity over the past decade. Challenges to their effective use include the emergence and spread of insecticide resistance by malaria vector populations coupled with the inability to curb outdoor transmission. Under these situations, use of larvicides through larval source management (LSM) can complement these existing measures. The need to minimize environmental impact and effect on non-target organisms has spurred interest in the development of eco-friendly larvicides of natural origin. Here, we review literature published in the last five years to highlight compounds of natural origin found to exhibit larvicidal activity against malaria mosquitoes. Specifically, the larvicidal activity of different classes of compounds is discussed including their effect on non-target organisms. Additionally, we provide suggestions for future research into mosquito larvicides including the use of chemical synthesis to improve the bioactivity of known natural compounds.

Flight-tone mediated circadian control of audibility in mating swarms of Anopheles mosquitoes

Mating swarms of malaria mosquitoes form every day at sunset throughout the tropical world, they typically last less than 30 minutes. Activity patterns must thus be highly synchronized between the sexes. Moreover, males must be able to identify the few sporadically entering females by detecting the females' faint flight tones. We here show that the Anopheles circadian clock ensures a tight synchrony of male and female activity and - importantly - also retunes the males' acoustic detection system: by lifting their own flight tones at dusk, males actively enhance the audibility of females. The reported phenomenon of 'harmonic convergence' is a random by-product of the mosquitoes' flight tone variance. Intriguingly, flight tones of individual mosquitoes occupy narrow, partly non-overlapping, frequency ranges, suggesting that the audibility of individual females varies across males.

A genetically encoded anti-CRISPR protein constrains gene drive spread and prevents population suppression

CRISPR-based gene drives offer promising means to reduce the burden of pests and vector-borne diseases. These techniques consist of releasing genetically modified organisms carrying CRISPR-Cas nucleases designed to bias their inheritance and rapidly propagate desired modifications. Gene drives can be intended to reduce reproductive capacity of harmful insects or spread anti-pathogen effectors through wild populations, even when these confer fitness disadvantages. Technologies capable of halting the spread of gene drives may prove highly valuable in controlling, counteracting, and even reverting their effect on individual organisms as well as entire populations. Here we show engineering and testing of a genetic approach, based on the germline expression of a phage-derived anti-CRISPR protein (AcrIIA4), able to inactivate CRISPR-based gene drives and restore their inheritance to Mendelian rates in the malaria vector Anopheles gambiae. Modeling predictions and cage testing show that a single release of male mosquitoes carrying the AcrIIA4 protein can block the spread of a highly effective suppressive gene drive preventing population collapse of caged malaria mosquitoes.

The relationship between house height and mosquito house entry: an experimental study in rural Gambia

Most malaria infections in sub-Saharan Africa are acquired indoors, thus finding effective ways of preventing mosquito house entry should reduce transmission. Since most malaria mosquitoes fly less than 1 m from the ground, we tested whether raising buildings off the ground would prevent the entry of Anopheles gambiae , the principal African malaria vector, in rural Gambia. Nightly collections of mosquitoes were made using light traps from four inhabited experimental huts, each of which could be moved up or down. Mosquito house entry declined with increasing height, with a hut at 3 m reducing An. gambiae house entry by 84% when compared with huts on the ground. A propensity for malaria vectors to fly close to the ground and reduced levels of carbon dioxide, a major mosquito attractant, in elevated huts, may explain our findings. Raised buildings may help reduce malaria transmission in Africa.