Monitoring and Intervention Strategies for Bluetongue Virus Epidemics in Rural India

印度农村地区蓝舌病毒流行的监测和干预策略

• 批准号: BB/H009493/1
• 负责人: John Pickett
• 金额: $ 27.19万
• 依托单位: Rothamsted Research
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FH009493%2F1
• 关键词: Monitoring; Intervention; Strategies; Bluetongue; Virus

Bluetongue virus (BTV) is an arboviral pathogen of ruminants spread by Culicoides biting midges, which causes the disease bluetongue (BT) in sheep (particularly certain fine wool and mutton breeds). During the 1980's clinical BT began to appear in flocks of native Indian breeds of sheep, particularly in the southern states, possibly as a result of exotic strains of the virus introduced via sheep-breeding programmes. This change in epidemiology led to outbreaks among family-based subsistence farming communities in these areas, and BTV has since been become a significant constraint in both the rearing and productivity of indigenous flocks. In addition, in rain-fed agricultural areas, massive periodic outbreaks of disease occur that are thought to be related to the influence of timing and intensity of monsoon conditions on populations of vectors responsible for spreading BTV. Due to the circulation of 21 serotypes of BTV in southern India and the prohibitive costs of vaccination to the vast majority of the population, vector control remains the only feasible way of combating BTV transmission in the field. Despite this, virtually no quantitative data concerning the efficiency of available techniques in this role is available to inform control strategies. We will adopt a multidisciplinary approach involving mathematical modelling, entomology and chemical ecology to examine the epidemiology of BTV in the southern Indian states and to produce prediction, monitoring and mitigation techniques that can reduce the impact of BT in this region. Initially we will characterise southern India using mapping techniques that delineate land areas according to climate and land use patterns. We will then establish field sites across the region that are representative of both these factors and also the types of husbandry employed (with an emphasis on small holdings and landless husbandry workers). Having characterised these sites, we will then use light trapping to define adult seasonality and distribution and ground truth this survey with direct collection of Culicoides from livestock. These studies will be combined with detection of BTV within collected individual midges to define regional variation in which species are involved in transmission in southern India for the first time. The larval development sites of major vector species identified will then also be characterised via field investigations. Using data generated on adult seasonality, larval habitat preference and historic surveys of BT cases across southern India, we will then model the relationship between monsoon conditions and adult Culicoides/BT activity to assess the potential to produce an early warning system for major BTV epidemics based on meteorological variables. The provision of fundamental epidemiological knowledge will also enable an assessment of husbandry-based control techniques for Culicoides that could be employed to reduce BTV transmission by subsistence farmers in a cost-neutral fashion. We will examine traditional and novel means of control, both in the laboratory and in the field. The former will include the use of larval site modification, or targeted treatment with traditional, low environmental impact, insecticidal products available to villagers and additionally the use of stabling. In addition, information regarding host location by identified vector Culicoides will allow novel intervention strategies based upon the application of masking semiochemicals that could also reduce the use of synthetic insecticides by these communities in the medium term. The effect of combinations of these techniques will be examined via monitoring viral infection in livestock, as a gold standard for evidence of impact in the field. These data will then be assessed for integration into the everyday lives of user groups as part of wider dissemination frameworks for improvement of ruminant productivity and control of vectors of human and veterinary pathogens.

蓝舌病病毒（BTV）是一种由库蠓传播的反刍动物虫媒病毒，可引起绵羊（特别是某些细毛羊和羊肉品种）的蓝舌病（BT）。20世纪80年代，临床BT开始出现在印度本土品种的羊群中，特别是在南部各州，这可能是通过绵羊繁殖计划引入的外来病毒株的结果。流行病学的这种变化导致这些地区以家庭为基础的自给农业社区爆发，BTV已成为当地鸡群饲养和生产力的重要制约因素。此外，在雨水灌溉的农业地区，发生大规模的周期性疾病暴发，据认为这与季风条件的时间和强度对传播BTV的媒介种群的影响有关。由于在印度南部有21种血清型的BTV在传播，而且绝大多数人口的疫苗接种费用过高，因此病媒控制仍然是在实地防治BTV传播的唯一可行方法。尽管如此，实际上没有关于现有技术在这一作用中的效率的定量数据可用于指导控制战略。我们将采用涉及数学建模，昆虫学和化学生态学的多学科方法，研究印度南部各州BTV的流行病学，并制定预测，监测和缓解技术，以减少BT在该地区的影响。最初，我们将使用根据气候和土地利用模式划分土地区域的绘图技术来测量印度南部。然后，我们将在整个地区建立实地考察点，这些实地考察点既能代表这些因素，也能代表所采用的畜牧业类型（重点是小农场和无地畜牧业工人）。在描述了这些地点的特征后，我们将使用灯光诱捕来确定成虫的季节性和分布，并在本次调查中直接从牲畜中收集库蠓。这些研究将结合检测BTV内收集的个别蠓，以确定区域的变化，其中物种参与在印度南部的第一次传输。然后还将通过实地调查确定主要病媒物种的幼虫发育部位。使用成年季节性，幼虫栖息地偏好和历史调查的BT情况下，整个印度南部的数据，然后，我们将模拟季风条件和成年库蠓/BT活动之间的关系，以评估潜在的主要BTV流行病的预警系统的基础上气象变量。提供基本的流行病学知识也将使基于养殖的库蠓控制技术的评估，可以用来减少BTV传播的自给农民在一个成本中性的方式。我们将在实验室和实地考察传统和新颖的控制手段。前者将包括使用幼虫场地改造，或有针对性地使用传统的、对环境影响小的杀虫剂产品进行处理，并向村民提供，此外还使用马厩。此外，关于确定的媒介库蠓宿主位置的信息将允许基于掩蔽化学信息素的应用的新的干预策略，这也可以减少这些社区在中期内使用合成杀虫剂。将通过监测牲畜中的病毒感染来检查这些技术组合的效果，作为实地影响证据的金标准。然后将对这些数据进行评估，以便将其纳入用户群体的日常生活，作为提高反刍动物生产力和控制人类和兽医病原体载体的更广泛传播框架的一部分。

项目成果

Additional file 1: Table S1. of DNA barcoding and surveillance sampling strategies for Culicoides biting midges (Diptera: Ceratopogonidae) in southern India

附加文件 1：表 S1。

• DOI: 10.6084/m9.figshare.c.3616160_d2
• 发表时间: 2016
• 作者: Harrup L

DNA barcoding and surveillance sampling strategies for Culicoides biting midges (Diptera: Ceratopogonidae) in southern India.

• DOI: 10.1186/s13071-016-1722-z
• 发表时间: 2016-08-22
• 期刊: Parasites & vectors
• 影响因子: 3.2
• 作者: Harrup LE;Laban S;Purse BV;Reddy YK;Reddy YN;Byregowda SM;Kumar N;Purushotham KM;Kowalli S;Prasad M;Prasad G;Bettis AA;De Keyser R;Logan J;Garros C;Gopurenko D;Bellis G;Labuschagne K;Mathieu B;Carpenter S
• 通讯作者: Carpenter S

Vertebrate pheromones and other semiochemicals: the potential for accommodating complexity in signalling by volatile compounds for vertebrate management.

脊椎动物信息素和其他半化学物质：通过挥发性化合物来容纳脊椎动物管理的信号传导复杂性的潜力。

• DOI: 10.1042/bst20140134
• 发表时间: 2014-08
• 期刊: Biochemical Society transactions
• 影响因子: 3.9
• 作者: Pickett JA;Barasa S;Birkett MA
• 通讯作者: Birkett MA

Insecticidal effects of deltamethrin in laboratory and field populations of Culicoides species: how effective are host-contact reduction methods in India?

• DOI: 10.1186/s13071-017-1992-0
• 发表时间: 2017-01-31
• 期刊: Parasites & vectors
• 影响因子: 3.2
• 作者: De Keyser R;Cassidy C;Laban S;Gopal P;Pickett JA;Reddy YK;Prasad M;Prasad G;Chirukandoth S;Senthilven K;Carpenter S;Logan JG
• 通讯作者: Logan JG