scholarly journals Experimental risk assessment for chikungunya virus transmission based on vector competence, distribution and temperature suitability in Europe, 2018

2018 ◽  
Vol 23 (29) ◽  
Author(s):  
Anna Heitmann ◽  
Stephanie Jansen ◽  
Renke Lühken ◽  
Michelle Helms ◽  
Björn Pluskota ◽  
...  

Background Over the last decade, the abundant distribution of the Asian tiger mosquito Aedes albopictus in southern Europe and the import of chikungunya virus (CHIKV) by infected travellers has resulted in at least five local outbreaks of chikungunya fever in France and Italy. Considering the ongoing spread of Ae. albopictus to central Europe, we performed an analysis of the Europe-wide spatial risk of CHIKV transmission under different temperature conditions. Methods: Ae. albopictus specimens from Germany and Italy were orally infected with CHIKV from an outbreak in France and kept for two weeks at 18 °C, 21 °C or 24 °C. A salivation assay was conducted to detect infectious CHIKV. Results: Analyses of mosquito saliva for infectious virus particles demonstrated transmission rates (TRs) of > 35%. Highest TRs of 50% for the mosquito population from Germany were detected at 18 °C, while the Italian population had highest TRs of 63% at 18 °C and 21 °C, respectively. Temperature data indicated a potential risk of CHIKV transmission for extended durations, i.e. sufficiently long time periods allowing extrinsic incubation of the virus. This was shown for areas already colonised by Ae. albopictus, as well as for large parts of central Europe that are not colonised. Conclusion: The current risk of CHIKV transmission in Europe is not primarily restricted by temperature, which allows extrinsic incubation of the virus, but rather by the vector distribution. Accordingly, all European countries with established populations of Ae. albopictus should implement respective entomological surveillance and monitoring systems, as basis for suitable control measures.

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 177 ◽  
Author(s):  
Tereza Magalhaes ◽  
Alexis Robison ◽  
Michael Young ◽  
William Black ◽  
Brian Foy ◽  
...  

In urban settings, chikungunya, Zika, and dengue viruses are transmitted by Aedes aegypti mosquitoes. Since these viruses co-circulate in several regions, coinfection in humans and vectors may occur, and human coinfections have been frequently reported. Yet, little is known about the molecular aspects of virus interactions within hosts and how they contribute to arbovirus transmission dynamics. We have previously shown that Aedes aegypti exposed to chikungunya and Zika viruses in the same blood meal can become coinfected and transmit both viruses simultaneously. However, mosquitoes may also become coinfected by multiple, sequential feeds on single infected hosts. Therefore, we tested whether sequential infection with chikungunya and Zika viruses impacts mosquito vector competence. We exposed Ae. aegypti mosquitoes first to one virus and 7 days later to the other virus and compared infection, dissemination, and transmission rates between sequentially and single infected groups. We found that coinfection rates were high after sequential exposure and that mosquitoes were able to co-transmit both viruses. Surprisingly, chikungunya virus coinfection enhanced Zika virus transmission 7 days after the second blood meal. Our data demonstrate heterologous arbovirus synergism within mosquitoes, by unknown mechanisms, leading to enhancement of transmission under certain conditions.


2014 ◽  
Vol 281 (1792) ◽  
pp. 20141078 ◽  
Author(s):  
Karima Zouache ◽  
Albin Fontaine ◽  
Anubis Vega-Rua ◽  
Laurence Mousson ◽  
Jean-Michel Thiberge ◽  
...  

Interactions between pathogens and their insect vectors in nature are under the control of both genetic and non-genetic factors, yet most studies on mosquito vector competence for human pathogens are conducted in laboratory systems that do not consider genetic and/or environmental variability. Evaluating the risk of emergence of arthropod-borne viruses (arboviruses) of public health importance such as chikungunya virus (CHIKV) requires a more realistic appraisal of genetic and environmental contributions to vector competence. In particular, sources of variation do not necessarily act independently and may combine in the form of interactions. Here, we measured CHIKV transmission potential by the mosquito Aedes albopictus in all combinations of six worldwide vector populations, two virus strains and two ambient temperatures (20°C and 28°C). Overall, CHIKV transmission potential by Ae. albopictus strongly depended on the three-way combination of mosquito population, virus strain and temperature. Such genotype-by-genotype-by-environment (G × G × E) interactions question the relevance of vector competence studies conducted with a simpler set of conditions. Our results highlight the need to account for the complex interplay between vectors, pathogens and environmental factors to accurately assess the potential of vector-borne diseases to emerge.


2018 ◽  
Vol 23 (22) ◽  
Author(s):  
Claudia Fortuna ◽  
Luciano Toma ◽  
Maria Elena Remoli ◽  
Antonello Amendola ◽  
Francesco Severini ◽  
...  

We compared the vector competence of an Italian population of Aedes albopictus for two strains of chikungunya virus (CHIKV), with and without E1:A226V mutation, responsible for outbreaks in 2007 in the Emilia Romagna region and 2017 in the Lazio and Calabria regions, respectively. Ae. albopictus showed similar vector competence for both viral strains indicating that E1:A226V mutation is not exclusively responsible for ability of CHIKV to replicate well in this mosquito species.


2018 ◽  
Author(s):  
Irina Maljkovic Berry ◽  
Fredrick Eyase ◽  
Simon Pollett ◽  
Samson Limbaso Konongoi ◽  
Katherine Figueroa ◽  
...  

AbstractBackgroundIn 2016, a chikungunya virus (CHIKV) outbreak was reported in Mandera, Kenya. This was the first major CHIKV outbreak in the country since the global re-emergence of this virus, which arose as an initial outbreak in Kenya in 2004. Therefore, we collected samples and sequenced viral genomes from the 2016 Mandera outbreak.Methodology/Principal FindingsAll Kenyan genomes contained two mutations, E1:K211E and E2:V264A, recently reported to have an association with increased infectivity, dissemination and transmission in the Aedes aegypti (Ae. aegypti) vector. Phylogeographic inference of temporal and spatial virus relationships using Bayesian approaches showed that this Ae. aegypti adapted strain emerged within the East, Central, and South African (ECSA) lineage of CHIKV between 2005 and 2008, most probably in India. It was also in India where the first large outbreak caused by this strain appeared, in New Delhi, 2010. More importantly, our results also showed that this strain is no longer contained to India, and that it has more recently caused several major outbreaks of CHIKV, including the 2016 outbreaks in India, Pakistan and Kenya, and the 2017 outbreak in Bangladesh. In addition to its capability to cause large outbreaks in different regions of the world, this CHIKV strain has the capacity to replace less adapted wild type strains in Ae. aegypti-rich regions. Indeed, all the latest full CHIKV genomes of the ECSA Indian Ocean Lineage (IOL), from the regions of high Ae. aegypti prevalence, carry these two mutations, including samples collected in Japan, Australia, and China.Conclusions/SignificanceOur results point to the importance of continued genomic-based surveillance of this strain’s global spread, and they prompt urgent vector competence studies in Asian and African countries, in order to assess the level of vector receptiveness, virus transmission, and the impact this might have on this strain’s ability to cause major outbreaks.Author summaryChikungunya virus (CHIKV) causes a debilitating infection with high fever, intense muscle and bone pain, rash, nausea, vomiting and headaches, and persistent and/or recurrent joint pains for months or years after contracting the virus. CHIKV is spread by two mosquito vectors, Aedes albopictus and Aedes aegypti, with increased presence around the globe. In this study, we report global spread of a CHIKV strain that carries two mutations that have been suggested to increase this virus’ ability to infect the Aedes aegypti mosquito, as well as to increase CHIKV’s ability to be transmitted by this vector. We show that this strain appeared sometime between 2005 and 2008, most probably in India, and has now spread to Africa, Asia, and Australia. We show that this strain is capable of driving large outbreaks of CHIKV in the human population, causing recent major outbreaks in Kenya, Pakistan, India and Bangladesh. Thus, our results stress the importance of monitoring this strain’s global spread, as well as the need of improved vector control strategies in the areas of Aedes aegypti prevalence.


Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 659 ◽  
Author(s):  
Sandra R. Abbo ◽  
Chantal B. F. Vogels ◽  
Tessa M. Visser ◽  
Corinne Geertsema ◽  
Monique M. van Oers ◽  
...  

Zika virus (ZIKV) is a mosquito-borne pathogen that caused a large outbreak in the Americas in 2015 and 2016. The virus is currently present in tropical areas around the globe and can cause severe disease in humans, including Guillain-Barré syndrome and congenital microcephaly. The tropical yellow fever mosquito, Aedes aegypti, is the main vector in the urban transmission cycles of ZIKV. The discovery of ZIKV in wild-caught Culex mosquitoes and the ability of Culex quinquefasciatus mosquitoes to transmit ZIKV in the laboratory raised the question of whether the common house mosquito Culex pipiens, which is abundantly present in temperate regions in North America, Asia and Europe, could also be involved in ZIKV transmission. In this study, we investigated the vector competence of Cx. pipiens (biotypes molestus and pipiens) from the Netherlands for ZIKV, using Usutu virus as a control. After an infectious blood meal containing ZIKV, none of the tested mosquitoes accumulated ZIKV in the saliva, although 2% of the Cx. pipiens pipiens mosquitoes showed ZIKV–positive bodies. To test the barrier function of the mosquito midgut on virus transmission, ZIKV was forced into Cx. pipiens mosquitoes by intrathoracic injection, resulting in 74% (molestus) and 78% (pipiens) ZIKV–positive bodies. Strikingly, 14% (molestus) and 7% (pipiens) of the tested mosquitoes accumulated ZIKV in the saliva after injection. This is the first demonstration of ZIKV accumulation in the saliva of Cx. pipiens upon forced infection. Nevertheless, a strong midgut barrier restricted virus dissemination in the mosquito after oral exposure and we, therefore, consider Cx. pipiens as a highly inefficient vector for ZIKV.


2018 ◽  
Vol 12 (10) ◽  
pp. e0006746 ◽  
Author(s):  
Francis Mulwa ◽  
Joel Lutomiah ◽  
Edith Chepkorir ◽  
Samwel Okello ◽  
Fredrick Eyase ◽  
...  

Pathogens ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 780
Author(s):  
Cristian Răileanu ◽  
Oliver Tauchmann ◽  
Ana Vasić ◽  
Ulrike Neumann ◽  
Birke Andrea Tews ◽  
...  

West Nile virus (WNV) is a mosquito-borne agent that has also been isolated from several tick species. Vector competence of Ixodes ricinus, one of the most common tick species in Europe, has been poorly investigated for WNV to date. As such, to evaluate the vector competence, laboratory reared Ixodes ricinus nymphs were in vitro fed with WNV lineage 1 infectious blood, allowed to molt, and the resulting females artificially fed to study the virus transmission. Furthermore, we studied the kinetics of WNV replication in ticks after infecting nymphs using an automatic injector. Active replication of WNV was detected in injected nymphs from day 7 post-infection until 28 dpi. In the nymphs infected by artificial feeding, the transstadial transmission of WNV was confirmed molecularly in 46.7% of males, while virus transmission during in vitro feeding of I. ricinus females originating from infected nymphs was not registered. The long persistence of WNV in I. ricinus ticks did not correlate with the transmission of the virus and it is unlikely that I. ricinus represents a competent vector. However, there is a potential reservoir role that this tick species can play, with hosts potentially acquiring the viral agent after ingesting the infected ticks.


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