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.

• Chikungunya, a highly infectious disease, may soon arrive in the US - Al Jazeera America
  Mon, 21 Apr 2014 07:18:
• Chikungunya Virus Reaches the Dominican Republic - About - News & Issues
  Fri, 18 Apr 2014 21:23:
• Dominican Republic reports 17 confirmed chikungunya cases, 767 suspected - The Global Dispatch
  Fri, 18 Apr 2014 23:30:
• Dominican Republic releases first chikungunya case numbers - Examiner.com
  Fri, 18 Apr 2014 15:13:
• St Vincent: No cases of chikungunya virus - Trinidad & Tobago Express
  Fri, 18 Apr 2014 00:05:
• Outbreak of chikungunya virus affects 10000 people in Tonga - Islands Business
  Wed, 16 Apr 2014 22:25:
• Warnings of 'catastrophic' Chikungunya epidemic; fears it could spread during ... - MercoPress
  Wed, 16 Apr 2014 04:43:
• Chikungunya outbreak on Tonga affects more than 10000: Health ministry - The Global Dispatch
  Wed, 16 Apr 2014 11:32:
• Warnings Of Chikungunya Epidemic; Fears It Could Spread During Brazil World ... - Bernama
  Wed, 16 Apr 2014 08:17:
• Tonga battles first chikungunya outbreak - Radio Australia
  Wed, 16 Apr 2014 01:31:

• PRO/EDR> Chikungunya (28): Caribbean
  Sun, 20 Apr 2014 16:29:09
  Chikungunya -- Caribbean Sea
  Included in the week 16 communicable disease threats report, issued by the European Centre for Disease Prevention and Control (ECDC) on 18 Apr [2014], are the 1st chikungunya [virus infection] case counts from the Dominican Republic [DR]. The DR has reported 17 confirmed and 767 suspected cases of the mosquito borne disease.
  The number of confirmed and suspected cases for the entire Caribbean outbreak increased nearly 20 per cent in the week, to 29 760.
  The French-speaking islands of

• [Current infection status and epidemic risk analysis of Dengue fever and Chikungunya in Guangdong province, from 1990 to 2012].
  Guo R, Peng Z, Song T, et al. [Current infection status and epidemic risk analysis of Dengue fever and Chikungunya in Guangdong province, from 1990 to 2012]. [English Abstract, Journal Article]Zhonghua Liu Xing Bing Xue Za Zhi 2014 Feb; 35(2):167-9.To understand the status of infection and epidemic trend of Dengue fever and Chikungunya in Guangdong.Retrospective survey and literature review were used to obtain data on the incidence, etiology of Dengue and Chikungunya. Serological survey was conducted to detect the specific-antibodies in healthy individuals for both Dengue virus(DENV)and Chikungunya virus (CHIKV).Three epidemics of Dengue fever were observed during 1990-2012, with the annual incidence rates as 9.75/100 000 in 1995, 1.76/100 000 in 2002 and 1.25/100 000 in 2006, respectively. The predominant epidemic strains appeared to be DENV-2 and DENV-4 during 1990-1994. Since 1995,DENV-1 had become the predominant transmission strain which lasted for almost 13 years. Co-existence of multiple serotypes of DENV started in 2009. Of the 7 718 sera from healthy population during 2003-2012, 180 specimens were detected positive for specific DENV-IgG antibody, ended with a sero-prevalence rate of 2.33%. All 2 132 sera in 2012 were detected negative for CHIKV-IgG antibody.The overall exposure level to Dengue was considered to be low in Guangdong province. However, the predominant transmission mode caused by DENV-1 had been gradually changed into the co-existence of multiple serotypes with the endemic signs appeared in some part of the areas. Chikungunya was a newly emerging disease in Guangdong since local people were lack of basic immunity barrier. Surveillance and control programs thus seemed important.


• Arthritogenic alphaviral infection perturbs osteoblast function and triggers pathologic bone loss.
  Chen W, Foo SS, Rulli NE, et al. Arthritogenic alphaviral infection perturbs osteoblast function and triggers pathologic bone loss. [JOURNAL ARTICLE]Proc Natl Acad Sci U S A 2014 Apr 14.AbstractPublisher Full TextArthritogenic alphaviruses including Ross River virus (RRV), Sindbis virus, and chikungunya virus cause worldwide outbreaks of musculoskeletal disease. The ability of alphaviruses to induce bone pathologies remains poorly defined. Here we show that primary human osteoblasts (hOBs) can be productively infected by RRV. RRV-infected hOBs produced high levels of inflammatory cytokine including IL-6. The RANKL/OPG ratio was disrupted in the synovial fluid of RRV patients, and this was accompanied by an increase in serum Tartrate-resistant acid phosphatase 5b (TRAP5b) levels. Infection of bone cells with RRV was validated using an established RRV murine model. In wild-type mice, infectious virus was detected in the femur, tibia, patella, and foot, together with reduced bone volume in the tibial epiphysis and vertebrae detected by microcomputed tomographic (µCT) analysis. The RANKL/OPG ratio was also disrupted in mice infected with RRV; both this effect and the bone loss were blocked by treatment with an IL-6 neutralizing antibody. Collectively, these findings provide previously unidentified evidence that alphavirus infection induces bone loss and that OBs are capable of producing proinflammatory mediators during alphavirus-induced arthralgia. The perturbed RANKL/OPG ratio in RRV-infected OBs may therefore contribute to bone loss in alphavirus infection.


• Comprehensive proteomic analysis of white blood cells from chikungunya fever patients of different severities.
  Wikan N, Khongwichit S, Phuklia W, et al. Comprehensive proteomic analysis of white blood cells from chikungunya fever patients of different severities. [Journal Article]J Transl Med 2014; 12(1):96.AbstractPublisher Full TextChikungunya fever (CHIKF) is a recently re-emerged mosquito transmitted viral disease caused by the chikungunya virus (CHIKV), an Alphavirus belonging to the family Togaviridae. Infection of humans with CHIKV can result in CHIKF of variable severity, although the factors mediating disease severity remain poorly defined.White blood cells were isolated from blood samples collected during the 2009-2010 CHIKF outbreak in Thailand. Clinical presentation and viral load data were used to classify samples into three groups, namely non chikungunya fever (non-CHIKF), mild CHIKF, and severe CHIKF. Five samples from each group were analyzed for protein expression by GeLC-MS/MS.CHIKV proteins (structural and non-structural) were found only in CHIKF samples. A total of 3505 human proteins were identified, with 68 proteins only present in non-CHIKF samples. A total of 240 proteins were found only in CHIKF samples, of which 65 and 46 were found only in mild and severe CHIKF samples respectively. Proteins with altered expression mapped predominantly to cellular signaling pathways (including toll-like receptor and PI3K-Akt signaling) although many other processes showed altered expression as a result of CHIKV infection. Expression of proteins consistent with the activation of the inflammasome was detected, and quantitation of (pro)-caspase 1 at the protein and RNA levels showed an association with disease severity.This study confirms the infection of at least a component of white blood cells by CHIKV, and shows that CHIKV infection results in activation of the inflammasome in a manner that is associated with disease severity.


• Chikungunya outbreak in the Caribbean region, December 2013 to March 2014, and the significance for Europe.
  Van Bortel W, Dorleans F, Rosine J, et al. Chikungunya outbreak in the Caribbean region, December 2013 to March 2014, and the significance for Europe. [Journal Article]Euro Surveill 2014; 19(13)Publisher Full Text


• Importance of case definition to monitor ongoing outbreak of chikungunya virus on a background of actively circulating dengue virus, St Martin, December 2013 to January 2014.
  Omarjee R, Prat C, Flusin O, et al. Importance of case definition to monitor ongoing outbreak of chikungunya virus on a background of actively circulating dengue virus, St Martin, December 2013 to January 2014. [Journal Article]Euro Surveill 2014; 19(13)Publisher Full Text


• Emergence of chikungunya fever on the French side of Saint Martin island, October to December 2013.
  Cassadou S, Boucau S, Petit-Sinturel M, et al. Emergence of chikungunya fever on the French side of Saint Martin island, October to December 2013. [Journal Article]Euro Surveill 2014; 19(13)Publisher Full Text


• Genetic Structure and Wolbachia Genotyping in Naturally Occurring Populations of Aedes albopictus across Contiguous Landscapes of Orissa, India.
  Das B, Satapathy T, Kar SK, et al. Genetic Structure and Wolbachia Genotyping in Naturally Occurring Populations of Aedes albopictus across Contiguous Landscapes of Orissa, India. [Journal Article]PLoS One 2014; 9(4):e94094.AbstractPMC Free Full TextPublisher Full TextAedes albopictus has recently been implicated as a major vector in the emergence of dengue and chikungunya in several parts of India, like Orissa, which is gradually gaining endemicity for arboviral diseases. Ae. albopictus is further known to be naturally infected with Wolbachia (maternally inherited bacterium), which causes cytoplasmic incompatibility (CI) in mosquitoes leading to sperm-egg incompatibility inducing the death of embryo. Knowledge of genetic diversity of Ae. albopictus, along with revealing the type of Wolbachia infection in Ae. albopictus is important to explore the genetic and biological characteristics of Ae. albopictus, prior to exploring the uses of CI-based vector control strategies. In this study, we assessed the population genetic structure and the pattern of Wolbachia infection in Ae. albopictus mosquitoes of Orissa.Ae. albopictus mosquitoes were collected from 15 districts representing the four physiographical regions of Orissa from 2010-2012, analyzed for genetic variability at seven microsatellite loci and genotyped for Wolbachia strain detection using wsp gene primers. Most microsatellite markers were successfully amplified and were polymorphic, showing moderate genetic structure among all geographic populations (FST = 0.088). Genetic diversity was high (FST = 0.168) in Coastal Plains populations when compared with other populations, which was also evident from cluster analyses that showed most Coastal Plains populations consisted of a separate genetic cluster. Genotyping analyses revealed that Wolbachia-infected Ae. albopictus field populations of Orissa were mostly superinfected with wAlbA and wAlbB strains. Wolbachia superinfection was more pronounced in the Coastal Plain populations.High genetic structure and Wolbachia superinfection, observed in the Coastal Plain populations of Orissa suggested it to be genetically and biologically more unique than other populations, and hence could influence their vectorial attributes. Such high genetic diversity observed among Coastal Plains populations could be attributed to multiple introductions of Ae. albopictus in this region.


• Enhanced Production of Chikungunya Virus-Like Particles Using a High-pH Adapted Spodoptera frugiperda Insect Cell Line.
  Wagner JM, Pajerowski JD, Daniels CL, et al. Enhanced Production of Chikungunya Virus-Like Particles Using a High-pH Adapted Spodoptera frugiperda Insect Cell Line. [Journal Article]PLoS One 2014; 9(4):e94401.AbstractPMC Free Full TextPublisher Full TextChikungunya virus-like particles (VLPs) have potential to be used as a prophylactic vaccine based on testing in multiple animal models and are currently being evaluated for human use in a Phase I clinical trial. The current method for producing these enveloped alphavirus VLPs by transient gene expression in mammalian cells presents challenges for scalable and robust industrial manufacturing, so the insect cell baculovirus expression vector system was evaluated as an alternative expression technology. Subsequent to recombinant baculovirus infection of Sf21 cells in standard culture media (pH 6.2-6.4), properly processed Chikungunya structural proteins were detected and assembled capsids were observed. However, an increase in culture pH to 6.6-6.8 was necessary to produce detectable concentrations of assembled VLPs. Since this elevated production pH exceeds the optimum for growth medium stability and Sf21 culture, medium modifications were made and a novel insect cell variant (SfBasic) was derived by exposure of Sf21 to elevated culture pH for a prolonged period of time. The high-pH adapted SfBasic insect cell line described herein is capable of maintaining normal cell growth into the typical mammalian cell culture pH range of 7.0-7.2 and produces 11-fold higher Chikungunya VLP yields relative to the parental Sf21 cell line. After scale-up into stirred tank bioreactors, SfBasic derived VLPs were chromatographically purified and shown to be similar in size and structure to a VLP standard derived from transient gene expression in HEK293 cells. Total serum anti-Chikungunya IgG and neutralizing titers from guinea pigs vaccinated with SfBasic derived VLPs or HEK293 derived VLPs were not significantly different with respect to production method, suggesting that this adapted insect cell line and production process could be useful for manufacturing Chikungunya VLPs for use as a vaccine. The adaptation of Sf21 to produce high levels of recombinant protein and VLPs in an elevated pH range may also have applications for other pH-sensitive protein or VLP targets.


• National capacity for surveillance, prevention, and control of west nile virus and other arbovirus infections - United States, 2004 and 2012.
  Hadler JL, Patel D, Bradley K, et al. National capacity for surveillance, prevention, and control of west nile virus and other arbovirus infections - United States, 2004 and 2012. [Journal Article]MMWR Morb Mortal Wkly Rep 2014 Apr 4; 63(13):281-4.AbstractPublisher Full TextIn the first 5 years after its introduction in the United States in 1999, West Nile virus (WNV) spread to the 48 contiguous states, resulting in 667 reported deaths. To establish detection and response capacity, WNV surveillance and prevention was supported through CDC Epidemiology and Laboratory Capacity (ELC) cooperative agreements with all 50 states and six large cities/counties. In 2005, the Council of State and Territorial Epidemiologists (CSTE) conducted an assessment of ELC recipients and determined that, since 1999, all had developed WNV surveillance and control programs, resulting in a national arboviral surveillance infrastructure. From 2004 to 2012, ELC funding for WNV surveillance decreased by 61%. In 2012, the United States had its most severe WNV season since 2003, prompting a follow-up assessment of the capacity of ELC-supported WNV programs. Since the first assessment, 22% of jurisdictions had stopped conducting active human surveillance, 13% had stopped mosquito surveillance, 70% had reduced mosquito trapping and testing, and 64% had eliminated avian mortality surveillance. Reduction in early detection capacity compromises local and national ability to rapidly detect changes in WNV and other arboviral activity and to initiate prevention measures. Each jurisdiction is encouraged to review its current surveillance systems in light of the local threat of WNV and emerging arboviruses (e.g., dengue and chikungunya) and ensure it is able to rapidly detect and respond to critical changes in arbovirus activity.


• Association of human leukocyte antigen class II allele and haplotypes in chikungunya viral infection in a western Indian population.
  Thanapati S, Hande A, Das R, et al. Association of human leukocyte antigen class II allele and haplotypes in chikungunya viral infection in a western Indian population. [Journal Article]Trans R Soc Trop Med Hyg 2014 May; 108(5):277-82.AbstractPublisher Full TextPublisher Full TextGenes coding for human leukocyte antigen (HLA) class II molecules are polymorphic and have been shown to influence susceptibility to viral diseases.One hundred patients with acute chikungunya with and without viral load and 250 chikungunya negative controls from western India were studied for the distribution of HLA class II alleles by PCR with sequence-specific primer (SSP) method.Frequency of DRB1*11 allele group (patients vs controls: p=0.002, Pc=0.036, OR=0.21) and haplotype DRB1*11/DQB1*03 (patients vs controls: p=0.007, OR=0.15) were significantly low, while haplotype DRB1*04/DQB1*03 (patients vs controls: p=0.042, OR=1.94) was significantly high in the patient population. HLA DQB1*04 allele was found only in the patient group with viral load (n=17), suggesting possible involvement of the same with chikungunya virus (CHIKV) replication.Association of HLA-DRB1*11 and the emergence of DRB1*11/DQB1*03 & DRB1*04/DQB1*03 as resistant and susceptible haplotypes towards CHIKV infection is being reported for the first time. Our results suggest that genetic susceptibility and/or resistance to chikungunya infection may be modulated by HLA class II alleles.