Chikungunya Virus Net is the web resource for anyone interested in chikungunya. The objectives of Chikungunya Virus Net are to be the public and professional information resource for chikungunya and to serve as a network in the exchange of information and news related to chikungunya.
Chikungunya virus (CHIKV) is an insect-borne virus, of the genus Alphavirus, that is spread by Aedes mosquitoes. Chikungunya infection causes fever and severe joint pain. Other symptoms include muscle pain, headache, nausea, fatigue and rash. The disease shares some clinical signs with dengue, and can be misdiagnosed in areas where dengue is common. There have been recent breakouts of chikungunya in Africa, Asia and the Indian subcontinent. In recent decades mosquito vectors of chikungunya have spread to Europe and the Americas. In 2007, disease transmission was reported for the first time in Europe. There is no cure for the disease. Treatment is focused on relieving the symptoms.
- Viral disease chikungunya has arrived in Texas - The Eagle
Tue, 02 Sep 2014 23:31:
- Cases of malaria and chikungunya fever keep on the rise in Venezuela - El Universal
Tue, 02 Sep 2014 16:33:
- Nicaragua Reports New Case of Chikungunya - Prensa Latina
Mon, 01 Sep 2014 20:31:
- Aklan PHO reports 2 confirmed cases of chikungunya - Philippine Information Agency
Mon, 01 Sep 2014 04:21:
- Jamaica reports 4 additional autochthonous chikungunya cases - Outbreak News Today
Sun, 31 Aug 2014 13:22:
- Puerto Rico chikungunya cases top 5000, officials investigate potential deaths - Outbreak News Today
Sat, 30 Aug 2014 23:03:
- Chikungunya spreads on St. Thomas, St. John - Virgin Islands Daily News
Sat, 30 Aug 2014 22:03:
- Second case of chikungunya reported in St. Lucie County - TCPalm
Sat, 30 Aug 2014 13:25:
- Four additional cases of Chikungunya confirmed - Jamaica Observer
Sat, 30 Aug 2014 00:58:
- City of Dallas reports first case of Chikungunya Virus - Dallasweekly
Fri, 29 Aug 2014 23:48:
- PRO/EDR> Chikungunya (51): Caribbean
Mon, 01 Sep 2014 17:22:00
Chikungunya -- Caribbean
Cases by Country / Week / Local Susp / Local Conf / Imported Conf / Deaths
Canada / week 32 [ending 1 Aug 2014] / 0 / 0 / 8 / 0
USA / week 35 [ending 29 Aug 2014] / 0 / 4 / 690 / 0
El Salvador / week 34 [ending 22 Aug 2014] / 8032 / 8 / 0 / 0
Nicaragua / week 35 [ending 29 Aug 2014] / 0 / 0 / 9 / 0
Cuba / week 33 [ending 22 Aug 2014] / 0 / 0 / 13 / 0
Dominican Republic / week 33 [ending 15 Aug 2014] / 429 421 / 71 / 0 / 6
- Involvement of ATP synthase β subunit in chikungunya virus entry into insect cells.
Fongsaran C, Jirakanwisal K, Kuadkitkan A, et al. Involvement of ATP synthase β subunit in chikungunya virus entry into insect cells. [JOURNAL ARTICLE]Arch Virol 2014 Aug 29.Chikungunya virus (CHIKV), the virus responsible for the disease chikungunya fever in humans, is transmitted by Aedes mosquitoes. While significant progress has been made in understanding the process by which CHIKV enters into mammalian cells, far less progress has been made in understanding the CHIKV entry process in insect cells. This study sought to identify mosquito-cell-expressed CHIKV-binding proteins through a combination of virus overlay protein binding assays (VOPBA) and mass spectroscopy. A 50-kDa CHIKV-binding protein was identified as the ATP synthase β subunit (ATPSβ). Co-immunoprecipitation studies confirmed the interaction, and colocalization analysis showed cell-surface and intracellular co-localization between CHIKV and ATPSβ. Both antibody inhibition and siRNA-mediated downregulation experiments targeted to ATPSβ showed a significant reduction in viral entry and virus production. These results suggest that ATPSβ is a CHIKV-binding protein capable of mediating the entry of CHIKV into insect cells.
- Chikungunya Virus Spreads to the United States via Caribbean Travel.
Carter D Chikungunya Virus Spreads to the United States via Caribbean Travel. [JOURNAL ARTICLE]Am J Nurs 2014 Sep; 114(9):18.Concerns expressed that the disease may become endemic to the mainland.
- Chikungunya virus and arthritic disease.
Burt F, Chen W, Mahalingam S Chikungunya virus and arthritic disease. [Journal Article]Lancet Infect Dis 2014 Sep; 14(9):789-90.
- Residue 82 of the Chikungunya Virus E2 Attachment Protein Modulates Viral Dissemination and Arthritis in Mice.
Ashbrook AW, Burrack KS, Silva LA, et al. Residue 82 of the Chikungunya Virus E2 Attachment Protein Modulates Viral Dissemination and Arthritis in Mice. [JOURNAL ARTICLE]J Virol 2014 Aug 20.AbstractPublisher Full TextChikungunya virus (CHIKV) is a mosquito-borne alphavirus that has reemerged to cause profound epidemics of fever, rash, and arthralgia throughout sub-Saharan Africa, Southeast Asia, and the Caribbean. Like other arthritogenic alphaviruses, mechanisms of CHIKV pathogenesis are not well defined. Using the attenuated CHIKV strain 181/25 and virulent strain AF15561, we identified a residue in the E2 viral attachment protein that is a critical determinant of viral replication in cultured cells and pathogenesis in vivo. Viruses containing an arginine at E2 residue 82 displayed enhanced infectivity in mammalian cells but reduced infectivity in mosquito cells and diminished virulence in a mouse model of CHIKV disease. Mice inoculated with virus containing an arginine at this position exhibited reduced swelling at the site of inoculation with a concomitant decrease in the severity of necrosis in joint-associated tissues. Viruses containing a glycine at E2 residue 82 produced higher titers in the spleen and serum at early times postinfection. Using wildtype and glycosaminoglycan (GAG)-deficient Chinese hamster ovary (CHO) cell lines and soluble GAGs, we found that an arginine at residue 82 conferred greater dependence on GAGs for infection of mammalian cells. These data suggest that CHIKV E2 interactions with GAGs diminish dissemination to lymphoid tissue, establishment of viremia, and activation of inflammatory responses early in infection. Collectively, these results suggest a function for GAG utilization in regulating CHIKV tropism and host responses that contribute to arthritis.CHIKV is a reemerging alphavirus of global significance with high potential to spread into new, immunologically naïve populations. The severity of CHIKV disease, particularly its propensity for chronic musculoskeletal manifestations, emphasizes the need for identification of genetic determinants that dictate CHIKV virulence in the host. To better understand mechanisms of CHIKV pathogenesis, we probed the function of an amino acid polymorphism in the E2 viral attachment protein using a mouse model of CHIKV musculoskeletal disease. In addition to influencing glycosaminoglycan utilization, we identified roles for this polymorphism in differential infection of mammalian and mosquito cells and targeting of CHIKV to specific tissues within infected mice. These studies demonstrate a correlation between CHIKV tissue tropism and virus-induced pathology modulated by a single polymorphism in E2, which in turn illuminates potential targets for vaccine and antiviral drug development.
- A spatial simulation model for dengue virus infection in urban areas.
Karl S, Halder N, Kelso JK, et al. A spatial simulation model for dengue virus infection in urban areas. [JOURNAL ARTICLE]BMC Infect Dis 2014 Aug 20; 14(1):447.AbstractPublisher Full TextThe World Health Organization estimates that the global number of dengue infections range between 80-100 million per year, with some studies estimating approximately three times higher numbers. Furthermore, the geographic range of dengue virus transmission is extending with the disease now occurring more frequently in areas such as southern Europe. Ae. aegypti, one of the most prominent dengue vectors, is endemic to the far north-east of Australia and the city of Cairns frequently experiences dengue outbreaks which sometimes lead to large epidemics.A spatially-explicit, individual-based mathematical model that accounts for the spread of dengue infection as a result of human movement and mosquito dispersion is presented. The model closely couples the four key sub-models necessary for representing the overall dynamics of the physical system, namely those describing mosquito population dynamics, human movement, virus transmission and vector control. Important features are the use of high quality outbreak data and mosquito trapping data for calibration and validation and a strategy to derive local mosquito abundance based on vegetation coverage and census data.The model has been calibrated using detailed 2003 dengue outbreak data from Cairns, together with census and mosquito trapping data, and is shown to realistically reproduce a further dengue outbreak. The simulation results replicating the 2008/2009 Cairns epidemic support several hypotheses (formulated previously) aimed at explaining the large-scale epidemic which occurred in 2008/2009; specifically, while warmer weather and increased human movement had only a small effect on the spread of the virus, a shorter virus strain-specific extrinsic incubation time can explain the observed explosive outbreak of 2008/2009.The proof-of-concept simulation model described in this study has potential as a tool for understanding factors contributing to dengue spread as well as planning and optimizing dengue control, including reducing the Ae. aegypti vector population and for estimating the effectiveness and cost-effectiveness of future vaccination programmes. This model could also be applied to other vector borne viral diseases such as chikungunya, also spread by Ae. aegypti and, by re-parameterisation of the vector sub-model, to dengue and chikungunya viruses spread by Aedes albopictus.
- An in vitro assay to study chikungunya virus RNA synthesis and the mode of action of inhibitors.
Albulescu IC, Tas A, Scholte FE, et al. An in vitro assay to study chikungunya virus RNA synthesis and the mode of action of inhibitors. [JOURNAL ARTICLE]J Gen Virol 2014 Aug 18.AbstractPublisher Full TextChikungunya virus (CHIKV) is a re-emerging mosquito-borne alphavirus that causes severe persistent arthralgia. To better understand the molecular details of CHIKV RNA synthesis and the mode of action of inhibitors, we have developed an in vitro assay to study CHIKV replication/transcription complexes isolated from infected cells. In this assay (32)P-CTP was incorporated into CHIKV genome and subgenomic (sg) RNA, as well as into a ~7.5 kb positive-stranded RNA, termed RNA II. We mapped RNA II, which was also found in CHIKV-infected cells, to the 5'-end of the genome up to the start of the sgRNA promoter region. Most of the RNA-synthesizing activity, negative-stranded RNA and a relatively large proportion of nsP1 and nsP4 were recovered from a crude membrane fraction obtained by pelleting at 15,000 x g. Positive-stranded RNA was mainly found in the cytosolic S15 fraction, suggesting it was released from the membrane-associated RTCs. The newly synthesized RNA was relatively stable and remained protected from cellular nucleases, possibly by encapsidation. A set of compounds that inhibit CHIKV replication in cell culture was tested in the in vitro RTC assay. In contrast to 3'dNTPs, chain terminators that acted as potent inhibitors of RTC activity, ribavirin triphosphate and 6-aza-UTP did not affect the RNA-synthesizing activity in vitro. In conclusion, this in vitro assay for CHIKV RNA synthesis is a useful tool for mechanistic studies on the CHIKV RTC and mode of action studies on compounds with anti-CHIKV activity.
- Coexistence of Philodina roseola (Rotifera: Bdelloidea) with larvae of Aedes aegypti in India.
Muniaraj M, Sathish Babu R Coexistence of Philodina roseola (Rotifera: Bdelloidea) with larvae of Aedes aegypti in India. [Journal Article]Trop Biomed 2014 Jun; 31(2):207-14.AbstractAggregator Full TextThe vector mosquitoes, Aedes aegypti and Aedes albopictus of dengue and Chikungunya fever are closely associated with human habitations and adapted to feed on human blood. They undergo larval and pupal development in natural and artificial freshwater collections in the urban and peri-urban environment. Although reports are available about the feeding behaviour of the thriving mosquito larvae, much information is still required to understand the successful survival of Aedes mosquitoes in small and temporary water collections. This study was undertaken to determine the co-existence and prevalence of Philodina roseola and other Bdelloid rotifers in the container habitats of Ae. aegypti mosquitoes. The investigation was conducted in 43 villages which belong to four districts in South India, affected by the epidemic of either dengue or Chikungunya fever. A total of 2093 houses and 12980 containers were examined for Aedes breeding and those containers with Aedes larvae were chosen for further investigation. The investigation showed that, the P. roseola was found associated in 502 (98.2%) containers, P. roseola along with other Philodina sp. in 126 containers (25%) and P. roseola along with other Philodina sp. and other Bdelloid rotifers found in 93 containers (19%). Since the members of the genus Philodina can survive desiccation, reproduce by parthenogenesis, can be transported by wind easily and more importantly, it can incorporate the genome of other organisms including viruses, understanding the co-existence and relationship of Philodina sp. with Aedes larvae would be helpful in the control of Aedes breeding and the control measures can be designed keeping the association of Bdelloids with Aedes in mind.
- Safety and tolerability of chikungunya virus-like particle vaccine in healthy adults: a phase 1 dose-escalation trial.
Chang LJ, Dowd KA, Mendoza FH, et al. Safety and tolerability of chikungunya virus-like particle vaccine in healthy adults: a phase 1 dose-escalation trial. [JOURNAL ARTICLE]Lancet 2014 Aug 14.Chikungunya virus-a mosquito-borne alphavirus-is endemic in Africa and south and southeast Asia and has recently emerged in the Caribbean. No drugs or vaccines are available for treatment or prevention. We aimed to assess the safety, tolerability, and immunogenicity of a new candidate vaccine.VRC 311 was a phase 1, dose-escalation, open-label clinical trial of a virus-like particle (VLP) chikungunya virus vaccine, VRC-CHKVLP059-00-VP, in healthy adults aged 18-50 years who were enrolled at the National Institutes of Health Clinical Center (Bethesda, MD, USA). Participants were assigned to sequential dose level groups to receive vaccinations at 10 μg, 20 μg, or 40 μg on weeks 0, 4, and 20, with follow-up for 44 weeks after enrolment. The primary endpoints were safety and tolerability of the vaccine. Secondary endpoints were chikungunya virus-specific immune responses assessed by ELISA and neutralising antibody assays. This trial is registered with ClinicalTrials.gov, NCT01489358.25 participants were enrolled from Dec 12, 2011, to March 22, 2012, into the three dosage groups: 10 μg (n=5), 20 μg (n=10), and 40 μg (n=10). The protocol was completed by all five participants at the 10 μg dose, all ten participants at the 20 μg dose, and eight of ten participants at the 40 μg dose; non-completions were for personal circumstances unrelated to adverse events. 73 vaccinations were administered. All injections were well tolerated, with no serious adverse events reported. Neutralising antibodies were detected in all dose groups after the second vaccination (geometric mean titres of the half maximum inhibitory concentration: 2688 in the 10 μg group, 1775 in the 20 μg group, and 7246 in the 40 μg group), and a significant boost occurred after the third vaccination in all dose groups (10 μg group p=0·0197, 20 μg group p<0·0001, and 40 μg group p<0·0001). 4 weeks after the third vaccination, the geometric mean titres of the half maximum inhibitory concentration were 8745 for the 10 μg group, 4525 for the 20 μg group, and 5390 for the 40 μg group.The chikungunya VLP vaccine was immunogenic, safe, and well tolerated. This study represents an important step in vaccine development to combat this rapidly emerging pathogen. Further studies should be done in a larger number of participants and in more diverse populations.Intramural Research Program of the Vaccine Research Center, National Institute of Allergy and Infectious Diseases, and National Institutes of Health.
- Chikungunya virus control: is a vaccine on the horizon?
Powers AM Chikungunya virus control: is a vaccine on the horizon? [JOURNAL ARTICLE]Lancet 2014 Aug 14.
- Chikungunya virus: new risk to transfusion safety in the Americas.
Petersen LR, Epstein JS Chikungunya virus: new risk to transfusion safety in the Americas. [Editorial]Transfusion 2014 Aug; 54(8):1911-5.Publisher Full Text