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.

• Health officials concerned about spread of chikungunya to US - Travel Weekly
  Thu, 06 Mar 2014 15:17:
• Health Check - Chikungunya Disease - BBC News
  Thu, 06 Mar 2014 12:25:
• This Virus Will Twist Your Limbs - Daily Beast
  Wed, 05 Mar 2014 15:25:
• Health officials prepare for chikungunya virus - The Advocate
  Mon, 03 Mar 2014 13:33:
• More cases of chikungunya virus reported in the Caribbean - Jamaica Observer
  Mon, 03 Mar 2014 00:10:
• Nearly six thousand suspected cases of chikungunya virus reported in the ... - Caribbean360.com
  Sun, 02 Mar 2014 19:18:
• Chikungunya confirmed cases increase by nearly 400, suspected cases almost ... - The Global Dispatch
  Sat, 01 Mar 2014 01:46:
• Over ten thousand chikungunya cases suspected in Caribbean - Examiner.com
  Fri, 28 Feb 2014 17:26:
• Chikungunya Disease - BBC News
  Fri, 28 Feb 2014 20:33:
• Chikungunya reaches South America - Examiner.com
  Wed, 26 Feb 2014 16:25:

• Painful cervical lymphadenopathy: An unusual presentation of chikungunya.
  Keny MS, Pereira IA, Desa SB, et al. Painful cervical lymphadenopathy: An unusual presentation of chikungunya. [Journal Article]Int J Appl Basic Med Res 2014 Jan; 4(1):47-9.Chikungunya is an arboviral disease transmitted by Aedes mosquito that represents a major public health burden worldwide including India. The disease presents as sudden onset of high-grade fever, severe arthralgias, and rash. Here, we describe a case of a patient who presented with cervical lymphadenopathy, fever, and myalgia and later was diagnosed as chikungunya. Lymphadenopathy has been described before as a less common symptom of chikungunya. But this is probably, the first case of chikungunya with cervical lymphadenopathy as a presenting feature.


• Genome-wide analysis of codon usage and influencing factors in chikungunya viruses.
  Butt AM, Nasrullah I, Tong Y Genome-wide analysis of codon usage and influencing factors in chikungunya viruses. [Journal Article]PLoS One 2014; 9(3):e90905.AbstractPMC Free Full TextPublisher Full TextChikungunya virus (CHIKV) is an arthropod-borne virus of the family Togaviridae that is transmitted to humans by Aedes spp. mosquitoes. Its genome comprises a 12 kb single-strand positive-sense RNA. In the present study, we report the patterns of synonymous codon usage in 141 CHIKV genomes by calculating several codon usage indices and applying multivariate statistical methods. Relative synonymous codon usage (RSCU) analysis showed that the preferred synonymous codons were G/C and A-ended. A comparative analysis of RSCU between CHIKV and its hosts showed that codon usage patterns of CHIKV are a mixture of coincidence and antagonism. Similarity index analysis showed that the overall codon usage patterns of CHIKV have been strongly influenced by Pan troglodytes and Aedes albopictus during evolution. The overall codon usage bias was low in CHIKV genomes, as inferred from the analysis of effective number of codons (ENC) and codon adaptation index (CAI). Our data suggested that although mutation pressure dominates codon usage in CHIKV, patterns of codon usage in CHIKV are also under the influence of natural selection from its hosts and geography. To the best of our knowledge, this is first report describing codon usage analysis in CHIKV genomes. The findings from this study are expected to increase our understanding of factors involved in viral evolution, and fitness towards hosts and the environment.


• Generation and characterization of monoclonal antibodies against rift valley Fever virus nucleoprotein.
  Fafetine JM, Domingos A, Antunes S, et al. Generation and characterization of monoclonal antibodies against rift valley Fever virus nucleoprotein. [Journal Article]Transbound Emerg Dis 2013 Nov.:24-30.AbstractPublisher Full TextDue to the unpredictable and explosive nature of Rift Valley fever (RVF) outbreaks, rapid and accurate diagnostic assays for low-resource settings are urgently needed. To improve existing diagnostic assays, monoclonal antibodies (MAbs) specific for the nucleocapsid protein of RVF virus (RVFV) were produced and characterized. Four IgG2a MAbs showed specific binding to denatured nucleocapsid protein, both from a recombinant source and from inactivated RVFV, in Western blot analysis and in an enzyme-linked immunosorbent assay (ELISA). Cross-reactivity with genetically related and non-related arboviruses including Bunyamwera and Calovo viruses (Bunyaviridae family), West Nile and Dengue-2 viruses (Flaviviridae family), and Sindbis and Chikungunya viruses (Togaviridae family) was not detected. These MAbs represent a useful tool for the development of rapid diagnostic assays for early recognition of RVF.


• Deliberate attenuation of chikungunya virus by adaptation to heparan sulfate-dependent infectivity: a model for rational arboviral vaccine design.
  Gardner CL, Hritz J, Sun C, et al. Deliberate attenuation of chikungunya virus by adaptation to heparan sulfate-dependent infectivity: a model for rational arboviral vaccine design. [Journal Article]PLoS Negl Trop Dis 2014 Feb; 8(2):e2719.AbstractPMC Free Full TextPublisher Full TextMosquito-borne chikungunya virus (CHIKV) is a positive-sense, single-stranded RNA virus from the genus Alphavirus, family Togaviridae, which causes fever, rash and severe persistent polyarthralgia in humans. Since there are currently no FDA licensed vaccines or antiviral therapies for CHIKV, the development of vaccine candidates is of critical importance. Historically, live-attenuated vaccines (LAVs) for protection against arthropod-borne viruses have been created by blind cell culture passage leading to attenuation of disease, while maintaining immunogenicity. Attenuation may occur via multiple mechanisms. However, all examined arbovirus LAVs have in common the acquisition of positively charged amino acid substitutions in cell-surface attachment proteins that render virus infection partially dependent upon heparan sulfate (HS), a ubiquitously expressed sulfated polysaccharide, and appear to attenuate by retarding dissemination of virus particles in vivo. We previously reported that, like other wild-type Old World alphaviruses, CHIKV strain, La Réunion, (CHIKV-LR), does not depend upon HS for infectivity. To deliberately identify CHIKV attachment protein mutations that could be combined with other attenuating processes in a LAV candidate, we passaged CHIKV-LR on evolutionarily divergent cell-types. A panel of single amino acid substitutions was identified in the E2 glycoprotein of passaged virus populations that were predicted to increase electrostatic potential. Each of these substitutions was made in the CHIKV-LR cDNA clone and comparisons of the mutant viruses revealed surface exposure of the mutated residue on the spike and sensitivity to competition with the HS analog, heparin, to be primary correlates of attenuation in vivo. Furthermore, we have identified a mutation at E2 position 79 as a promising candidate for inclusion in a CHIKV LAV.


• A polarized cell model for chikungunya virus infection: entry and egress of virus occurs at the apical domain of polarized cells.
  Lim PJ, Chu JJ A polarized cell model for chikungunya virus infection: entry and egress of virus occurs at the apical domain of polarized cells. [Journal Article]PLoS Negl Trop Dis 2014 Feb; 8(2):e2661.AbstractPMC Free Full TextPublisher Full TextChikungunya virus (CHIKV) has resulted in several outbreaks in the past six decades. The clinical symptoms of Chikungunya infection include fever, skin rash, arthralgia, and an increasing incidence of encephalitis. The re-emergence of CHIKV with more severe pathogenesis highlights its potential threat on our human health. In this study, polarized HBMEC, polarized Vero C1008 and non-polarized Vero cells grown on cell culture inserts were infected with CHIKV apically or basolaterally. Plaque assays, viral binding assays and immunofluorescence assays demonstrated apical entry and release of CHIKV in polarized HBMEC and Vero C1008. Drug treatment studies were performed to elucidate both host cell and viral factors involved in the sorting and release of CHIKV at the apical domain of polarized cells. Disruption of host cell myosin II, microtubule and microfilament networks did not disrupt the polarized release of CHIKV. However, treatment with tunicamycin resulted in a bi-directional release of CHIKV, suggesting that N-glycans of CHIKV envelope glycoproteins could serve as apical sorting signals.


• DNA Vaccine Initiates Replication of Live Attenuated Chikungunya Virus In Vitro and Elicits Protective Immune Response in Mice.
  Tretyakova I, Hearn J, Wang E, et al. DNA Vaccine Initiates Replication of Live Attenuated Chikungunya Virus In Vitro and Elicits Protective Immune Response in Mice. [JOURNAL ARTICLE]J Infect Dis 2014 Feb 28.AbstractPublisher Full TextBackground. Chikungunya virus (CHIKV) causes outbreaks of chikungunya fever worldwide and represents an emerging pandemic threat. Vaccine development against CHIKV has proved challenging. Currently there is no approved vaccine or specific therapy for the disease.Methods. To develop novel experimental CHIKV vaccine, we used novel iDNA infectious clone technology that combines the advantages of DNA and live attenuated vaccines. Here we describe an iDNA vaccine composed of plasmid DNA that encode the full-length infectious genome of live attenuated CHIKV clone 181/25 downstream from a eukaryotic promoter. The iDNA approach was designed to initiate replication of live vaccine virus from the plasmid in vitro and in vivo.Results. Experimental CHIKV iDNA vaccines were prepared and evaluated in cultured cells and in mice. Transfection with 10 ng of iDNA was sufficient to initiate replication of vaccine virus in vitro. Vaccination of BALB/c mice with a single 10 µg of CHIKV iDNA plasmid resulted in seroconversion, elicitation of neutralizing antibodies, and protection from experimental challenge with a neurovirulent CHIKV.Conclusions. Live attenuated CHIKV 181/25 vaccine can be delivered in vitro and in vivo by using DNA vaccination. The iDNA approach appears to represent a promising vaccination strategy for CHIK and other alphaviral diseases.


• The genetics of chemoreception in the labella and tarsi of Aedes aegypti.
  Sparks JT, Bohbot JD, Dickens JC The genetics of chemoreception in the labella and tarsi of Aedes aegypti. [JOURNAL ARTICLE]Insect Biochem Mol Biol 2014 Feb 26.AbstractPublisher Full TextThe yellow-fever mosquito Aedes aegypti is a major vector of human diseases, such as dengue, yellow fever, chikungunya and West Nile viruses. Chemoreceptor organs on the labella and tarsi are involved in human host evaluation and thus serve as potential foci for the disruption of blood feeding behavior. In addition to host detection, these contact chemoreceptors mediate feeding, oviposition and conspecific recognition; however, the molecular landscape of chemoreception in these tissues remains mostly uncharacterized. Here we report the expression profile of all putative chemoreception genes in the labella and tarsi of both sexes of adult Ae. aegypti and discuss their possible roles in the physiology and behavior of this important disease vector.


• Chikungunya fever in Canada: fever and polyarthritis in a returned traveller.
  Schwartz KL, Giga A, Boggild AK Chikungunya fever in Canada: fever and polyarthritis in a returned traveller. [JOURNAL ARTICLE]CMAJ 2014 Feb 24.Publisher Full Text


• Rapid evolution of reduced receptivity to interspecific mating in the dengue vector Aedes aegypti in response to satyrization by invasive Aedes albopictus.
  Bargielowski I, Lounibos LP Rapid evolution of reduced receptivity to interspecific mating in the dengue vector Aedes aegypti in response to satyrization by invasive Aedes albopictus. [JOURNAL ARTICLE] 2014 Feb 1; 28(1):193-203.AbstractAggregator Full TextIn this paper we examine the effect of reproductive interference on the dynamics of two mosquito vectors of public health concern and add to the growing literature on the strength and speed with which interspecific reproductive interference may drive evolution. Recent evidence supports a role for asymmetric reproductive interference, or satyrization, in competitive displacements of Aedes aegypti by Aedes albopictus. However, populations of A. aegypti sympatric with A. albopictus in nature evolve resistance to satyrization. Here we report that A. aegypti from Tucson, Arizona (USA), where A. albopictus are not known to occur, are satyrization-susceptible. Furthermore, in cage experiments we demonstrate rapid evolution in satyrization-susceptible lines. Exposing allopatric strains of A. aegypti to A. albopictus in cages led to significant reductions, within 1-3 generations, in the frequency of reproductive interference. We also demonstrate that satyrization-resistant A. aegypti females derived from selection experiments are significantly slower to mate with conspecific males, suggesting a cost for the evolution of satyrization-resistance. Results show how interspecific interactions between these vector species are rapidly evolving, with implications for the arboviral diseases, especially dengue and chikungunya, which they transmit.


• Chikungunya - an emerging infection in Bangladesh: a case series.
  Hassan R, Rahman MM, Moniruzzaman M, et al. Chikungunya - an emerging infection in Bangladesh: a case series. [Journal Article]J Med Case Rep 2014; 8(1):67.AbstractPMC Free Full TextPublisher Full TextChikungunya is an arthropod-borne virus endemic to Africa, Southeast Asia and India that causes acute febrile polyarthralgia and arthritis. In this short case series, we discuss six Bangladeshi patients with chikungunya fever. Though Bangladesh is in endemic zone, it is not common here, hence it demands attention for proper diagnosis and management.The six cases of chikungunya we report occurred in native Bangladeshi women with ages ranging from 20 to 50 years and all having a middle class family background. Three women had severe incapacitating arthralgia as well as a maculo-papular rash and a high fever. The other three had a high grade fever and arthralgia only, but no rash. They were tested for chikungunya immunoglobulin M antibody and found to be positive in all cases. They were treated symptomatically with non-steroidal anti-inflammatory drugs and found responsive in most cases.From this case series, it is evident that chikungunya is not that uncommon in Bangladesh. But the concomitant presence of other arthropod-borne infections with similar courses of illness makes most physicians less aware of this infection. An awareness and clinical knowledge are necessary to diagnose chikungunya infection properly.