裂谷热病毒媒介多样性以及气象和环境因素对博茨瓦纳奥卡万戈三角洲库蚊动态的影响。

Rift Valley fever vector diversity and impact of meteorological and environmental factors on Culex pipiens dynamics in the Okavango Delta, Botswana.

机构信息

UPR AGIRs, F-34398, CIRAD, Montpellier, France.

Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa.

出版信息

Parasit Vectors. 2016 Aug 8;9(1):434. doi: 10.1186/s13071-016-1712-1.

DOI:10.1186/s13071-016-1712-1

PMID:27502246

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4977755/

Abstract

BACKGROUND

In Northern Botswana, rural communities, livestock, wildlife and large numbers of mosquitoes cohabitate around permanent waters of the Okavango Delta. As in other regions of sub-Saharan Africa, Rift Valley Fever (RVF) virus is known to circulate in that area among wild and domestic animals. However, the diversity and composition of potential RVF mosquito vectors in that area are unknown as well as the climatic and ecological drivers susceptible to affect their population dynamics.

METHODS

Using net traps baited with carbon dioxide, monthly mosquito catches were implemented over four sites surrounding cattle corrals at the northwestern border of the Okavango Delta between 2011 and 2012. The collected mosquito species were identified and analysed for the presence of RVF virus by molecular methods. In addition, a mechanistic model was developed to assess the qualitative influence of meteorological and environmental factors such as temperature, rainfall and flooding levels, on the population dynamics of the most abundant species detected (Culex pipiens).

RESULTS

More than 25,000 mosquitoes from 32 different species were captured with an overabundance of Cx. pipiens (69,39 %), followed by Mansonia uniformis (20,67 %) and a very low detection of Aedes spp. (0.51 %). No RVF virus was detected in our mosquito pooled samples. The model fitted well the Cx. pipiens catching results (ρ = 0.94, P = 0.017). The spatial distribution of its abundance was well represented when using local rainfall and flooding measures (ρ = 1, P = 0.083). The global population dynamics were mainly influenced by temperature, but both rainfall and flooding presented a significant influence. The best and worst suitable periods for mosquito abundance were around March to May and June to October, respectively.

CONCLUSIONS

Our study provides the first available data on the presence of potential RVF vectors that could contribute to the maintenance and dissemination of RVF virus in the Okavango Delta. Our model allowed us to understand the dynamics of Cx. pipiens, the most abundant vector identified in this area. Potential predictions of peaks in abundance of this vector could allow the identification of the most suitable periods for disease occurrence and provide recommendations for vectorial and disease surveillance and control strategies.

摘要

背景

在博茨瓦纳北部，农村社区、牲畜、野生动物和大量蚊子共同生活在奥卡万戈三角洲的永久性水域周围。与撒哈拉以南非洲的其他地区一样，裂谷热（RVF）病毒已知在该地区的野生动物和家畜中传播。然而，该地区潜在 RVF 蚊子媒介的多样性和组成以及易受影响其种群动态的气候和生态驱动因素尚不清楚。

方法

使用二氧化碳诱饵的网捕每月在奥卡万戈三角洲西北部的牛栏周围的四个地点进行蚊子捕获，时间为 2011 年至 2012 年。收集的蚊子种类通过分子方法鉴定并分析 RVF 病毒的存在。此外，还开发了一种机制模型，以评估温度、降雨量和洪水水平等气象和环境因素对最丰富物种（库蚊属）种群动态的定性影响。

结果

从 32 种不同的物种中捕获了超过 25000 只蚊子，其中库蚊属（69.39%）过度繁殖，其次是曼蚊属（20.67%）和非常低的伊蚊属（0.51%）检测到。在我们的蚊子混合样本中未检测到 RVF 病毒。该模型很好地拟合了库蚊属的捕获结果（ρ=0.94，P=0.017）。当使用当地的降雨和洪水测量值时，其丰度的空间分布得到了很好的表示（ρ=1，P=0.083）。全球种群动态主要受温度影响，但降雨和洪水均有显著影响。蚊子丰度的最佳和最差适宜期分别约为 3 月至 5 月和 6 月至 10 月。