Integrated control of ticks and tick-borne diseases

Integrated control of ticks and tick-borne diseases (ICTTD) is currently promoted by an international project, supported by the European Union, with the aim to increase livestock productivity through the development of improved strategies for tick control, vaccine delivery and integrated diagnostics for tickborne diseases. This paper gives a brief overview of the ICTTD project activities against the background of recent initiatives to assess the impact of ticks and tick-borne diseases in the Mediterranean region.     

菊花病虫害综合防治研究

系统调查了菊花病毒病、霜霉病、叶斑病、叶面害虫,蚜虫天敌种类及其流行规律,研究了组培脱毒苗,地膜覆盖移栽,与高秆作物套作、摘顶稍、利用昆虫天敌及化学防治等综合治理效果,测定了农药残留量,结果表明,菊花组培苗脱毒率在60％左右,脱毒苗增产50％以上,叶枯病,霜霉病病叶率下降28％－30％,虫口密度下降40％,在收菊花前1个月使用拟菊酯杀虫剂,农药残留量低于允许值,不会对菊花和和环境造成污染。     

遗传不育技术在蚊媒疾病防控中的应用

疟疾、登革热等重大传染性蚊媒疾病严重危害人类健康,且目前缺乏有效的药物和疫苗,防治埃及伊蚊、冈比亚按蚊等媒介昆虫是控制和消除这些疾病的有效手段。化学杀虫剂的大规模使用在一定程度上控制了疾病的传播,但其抗药性和环境污染等问题也随之而来。分子生物学的飞速发展为昆虫不育技术(SIT)的更新及害虫防治提供了新的策略,由此发展起来的以释放携带显性致死基因昆虫(RIDL)为代表的一系列遗传不育技术为蚊虫种群防控提供了更加有效的选择。本文概述了遗传技术在蚊虫防控中的应用进展,包括蚊虫遗传防治的历史和策略,阐述了RIDL技术体系的原理,同时介绍了相关遗传控制品系和已经开展的田间释放研究,展示了遗传修饰不育技术在蚊媒疾病防治中的巨大潜力。     

Plant species from Brazilian Caatinga: a control alternative for Aedes aegypti

The mosquito Aedes aegypti is the main vector for the virus dengue, chikungunya and Zika. For its control, it is essential to search for natural products with insecticidal effects. The climatic singularity of Caatinga, an exclusive Brazilian biome, aids the survival of plants that produce secondary metabolites, which could be toxic to insects. Therefore, this review discusses the insecticidal potential of Caatinga plants on Aedes aegypti mosquitoes. The meta-analysis was performed using Review Manager Software 5.4.1®. Several studies have demonstrated the insecticidal efficacy of Caatinga plants on the egg, larvae, pupae and adult phases of Ae. aegypti, with a predominance of the plant activity in the larval stage. The leaves were the most utilized part of the plant. The essential oils from Caatinga plants were significantly active against Ae. aegypti (RR = 0.21, 95 % CI = 0.07 – 0.68, p = 0.009). The most promising botanical genera as an insecticide are: Abarema, Myracrodruon, Croton, Lippia and Syagrus. Among chemical compounds from these insecticidal plants has been identified and isolated flavonoids and fatty acids. Therefore, the Caatinga plant is a promising plant that contain bioactive compounds that are useful in the control of vector insects. This could contribute to the characterisation and valorisation of flora of this biome, as well as the production of environmentally friendly insecticides with specific action on target insects.     

菊花病虫害综合防治研究

系统调查鉴定了菊花病毒病、霜霉病、叶斑病、叶面害虫、蚜虫天敌种类及其流行规律,研究了组培脱毒苗、地膜覆盖移栽、与高秆作物套作、摘顶稍、利用昆虫天敌及化学防治等综合治理效果.测定了农药残留量.结果表明,菊花组培苗脱毒率在60%左右,脱毒苗增产50%以上,叶枯病、霜霉病病叶率下降28%～30%,虫口密度下降40%,在收菊花前1个月使用拟菊酯杀虫剂,农药残留量低于允许值,不会对菊花和环境造成污染.     

Strategies for the control of geminivirus diseases

Geminiviruses are unique plant DNA viruses that frequently cause significant yield reductions in a wide range of cereal, vegetable and fibre crops. Encouraging progress has recently been made towards the control of geminiviruses that infect dicotyledonous plants. Under laboratory conditions, defective interfering (DI) DNA and antisense strategies, both directed against viral DNA replication, have been used to protect Nicotiana spp. against the bipartite geminivirus African cassava mosaic virus and tomato golden mosaic virus. The use of dominant negative mutants of virus systemic movement might also be adapted as a novel strategy for the control of these important pathogens.     

Larval development of Aedes aegypti and Aedes albopictus in peri-urban brackish water and its implications for transmission of arboviral diseases

Aedes aegypti (Linnaeus) and Aedes albopictus Skuse mosquitoes transmit serious human arboviral diseases including yellow fever, dengue and chikungunya in many tropical and sub-tropical countries. Females of the two species have adapted to undergo preimaginal development in natural or artificial collections of freshwater near human habitations and feed on human blood. While there is an effective vaccine against yellow fever, the control of dengue and chikungunya is mainly dependent on reducing freshwater preimaginal development habitats of the two vectors. We show here that Ae. aegypti and Ae. albopictus lay eggs and their larvae survive to emerge as adults in brackish water (water with <0.5 ppt or parts per thousand, 0.5-30 ppt and >30 ppt salt are termed fresh, brackish and saline respectively). Brackish water with salinity of 2 to 15 ppt in discarded plastic and glass containers, abandoned fishing boats and unused wells in coastal peri-urban environment were found to contain Ae. aegypti and Ae. albopictus larvae. Relatively high incidence of dengue in Jaffna city, Sri Lanka was observed in the vicinity of brackish water habitats containing Ae. aegypti larvae. These observations raise the possibility that brackish water-adapted Ae. aegypti and Ae. albopictus may play a hitherto unrecognized role in transmitting dengue, chikungunya and yellow fever in coastal urban areas. National and international health authorities therefore need to take the findings into consideration and extend their vector control efforts, which are presently focused on urban freshwater habitats, to include brackish water larval development habitats.     

Lessons of Aedes aegypti control in Thailand

Abstract. The incidence of dengue haemorrhagic fever (DHF) in Thailand has increased cyclically since the first recognized outbreak in 1958. Without an effective vaccine against dengue, and considering the clinical difficulty of treating DHF cases, vector control is needed to prevent dengue transmission. Since the establishment of the WHO Aedes Research Unit in 1964, continued since 1973 as the WHO Collaborating Centre at the Department of Medical Research in Bangkok, much operational research has been carried out in Thailand on the bionomics and control of dengue vectors: Aedes aegypti and Ae.albopictus. This review shows that, as in most other countries, dengue vector control programmes in Thailand make little use of the procedures arising from research, nor have they reduced the upward trend of dengue or prevented DHF outbreaks. Implications of the reluctance to use results of operational research on vector control are considered and remedial suggestions made.     

Appropriate models for the management of infectious diseases

BackgroundMathematical models have become invaluable management tools for epidemiologists, both shedding light on the mechanisms underlying observed dynamics as well as making quantitative predictions on the effectiveness of different control measures. Here, we explain how substantial biases are introduced by two important, yet largely ignored, assumptions at the core of the vast majority of such models.ConclusionThis work aims to highlight that, when developing models for public health use, we need to pay careful attention to the intrinsic assumptions embedded within classical frameworks.     

Continuous health monitoring: integrating biomarkers for the management of chronic diseases

With the recent progresses of the information and communication technologies, biosensors and nanotechnologies, the access to continuing health monitoring is becoming real. The development of efficient, accurate and interactive solutions integrating biomarkers for continuing health monitoring might contribute to an improved care of some chronic diseases like hypertension, diabetes or heart failure. Continuing health monitoring might also enhance the efficiency and safety of patient’s treatments.     

Engineered exosomes: A new promise for the management of musculoskeletal diseases

Background

Exosomes are nanovesicles actively secreted by potentially all cell types, including tumour cells, with the primary role of extracellular systemic communication mediators, both at autocrine and paracrine levels, at short and long distances. Recently, different studies have used exosomes as a delivery system for a plethora of different molecules, such as drugs, microRNAs and proteins. This has been made possible thanks to the simplicity in exosomes engineering, their great stability and versatility for applications in oncology as well as in regenerative medicine.

Female-specific flightless (fsRIDL) phenotype for control of Aedes albopictus

Background

Aedes albopictus, the Asian tiger mosquito, is a vector of several arboviruses including dengue and chikungunya, and is also a significant nuisance mosquito. It is one of the most invasive of mosquitoes with a relentlessly increasing geographic distribution. Conventional control methods have so far failed to control Ae. albopictus adequately. Novel genetics-based strategies offer a promising alternative or aid towards efficient control of this mosquito.

Methodology/Principal Findings

We describe here the isolation, characterisation and use of the Ae. albopictus Actin-4 gene to drive a dominant lethal gene in the indirect flight muscles of Ae. albopictus, thus inducing a conditional female-specific late-acting flightless phenotype. We also show that in this context, the Actin-4 regulatory regions from both Ae. albopictus and Ae. aegypti can be used to provide conditional female-specific flightlessness in either species.

Conclusion/Significance

With the disease-transmitting females incapacitated, the female flightless phenotype encompasses a genetic sexing mechanism and would be suitable for controlling Ae. albopictus using a male-only release approach as part of an integrated pest management strategy.