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.

 

• New Market Research Report: Chikungunya - Pipeline Review, H1 2013 - SBWire (press release)
  Wed, 22 May 2013 19:57:
• Singapore battles chikungunya spread, 6000 dengue infections - Hong Kong Standard
  Mon, 13 May 2013 04:44:
• 18 new chikungunya cases in Kranji, Bukit Timah clusters - Straits Times
  Thu, 09 May 2013 23:08:
• Steep rise in chikungunya cases recorded - The Star Online
  Tue, 07 May 2013 23:19:
• Steep rise in chikungunya cases this year - Straits Times
  Mon, 06 May 2013 23:27:
• More details on the effects of the Chikungunya disease - Radio Australia
  Mon, 29 Apr 2013 06:12:
• New Caledonia reports three people with chikungunya - Radio New Zealand International
  Mon, 29 Apr 2013 01:10:
• Queensland Health battles mosquito borne diseases: first dengue fever, now ... - The Global Dispatch
  Sun, 28 Apr 2013 19:24:
• New cases of mosquito-borne chikungunya disease found in Cairns - The Cairns Post
  Fri, 26 Apr 2013 02:09:
• Chikungunya continues to spread across PNG - Radio Australia
  Thu, 25 Apr 2013 07:55:

• A Real-Time Reverse Transcription Loop-Mediated Isothermal Amplification Assay For The Rapid Detection Of Yellow Fever Virus.
  Kwallah AO, Inoue S, Muigai AW, et al. A Real-Time Reverse Transcription Loop-Mediated Isothermal Amplification Assay For The Rapid Detection Of Yellow Fever Virus. [JOURNAL ARTICLE]J Virol Methods 2013 May 18.AbstractPublisher Full TextYellow fever, a mosquito-borne disease, is an important viral hemorrhagic fever in Africa and South America where it is endemic. Detection of yellow fever virus (YFV) in Africa remains a challenge due to a lack of highly specific tests. The aim of this study was to develop and optimize a rapid detection reverse transcription loop-mediated isothermal amplification (RT-LAMP) for YFV. The RT-LAMP was done isothermally at 62°C using a real-time turbidimeter that allowed detection within 1 hr. Specificity of the RT-LAMP was determined using RNA from flaviviruses and other related viruses where only YFV RNA was detected: West Nile virus, dengue viruses, Japanese encephalitis virus, Rift Valley fever virus, and chikungunya virus. In addition, equal sensitivity was also observed when the RT-LAMP and the real-time RT-PCR were compared using YFV-spiked human serum samples with a detection limit of 0.29 PFU/ml. Two Kenyan YFV wild strains showed an equal detection limit as the vaccine strain 17D in this study. The RT-LAMP reduced the time of reaction from 3hours to 1hour and increased sensitivity tenfold compared to RT-PCR. Therefore, this test offers a simple, rapid and reliable diagnostic tool for yellow fever when there are outbreaks of acute hemorrhagic fever in Kenya and other African countries.
• Development and evaluation of a pyriproxyfen-treated device to control the dengue vector, Aedes aegypti (L.) (Diptera:Culicidae).
  Ponlawat A, Fansiri T, Kurusarttra S, et al. Development and evaluation of a pyriproxyfen-treated device to control the dengue vector, Aedes aegypti (L.) (Diptera:Culicidae). [Journal Article, Research Support, Non-U.S. Gov't]Southeast Asian J Trop Med Public Health 2013 Mar; 44(2):167-78.The resurgence of dengue fever and the chikungunya epidemic make the control of Aedes aegypti mosquitoes, the vectors of these diseases, critically important. We developed and evaluated an Ae. aegypti control device that is visually-attractive to mosquitoes. This pyriproxyfen-treated device was evaluated for its impact on Ae. aegypti egg production and population dynamics in dengue-endemic areas in Thailand. The device consists of a "high rise" shaped ovitrap/ resting station covered with black cotton cloth. The device is easily collapsible and transportable. Ae. aegypti are generally drawn towards darker, shadier areas making this device physically attractive as a resting station to mosquitoes of all physiological stages. The results show this device suppressed Ae. aegypti populations after it was introduced into a village. The observed effect was primarily the result of the Ae. aegypti exposure to pyriproxyfen shortly after adult emergence or after taking a blood meal resulting in decreased egg production. We believe the device may be further improved physically and the formulation should be replaced to provide even better efficacy for controlling Ae. aegypti mosquito, populations.
• Relationship between rainfall and Aedes larval population at two insular sites in Pulau Ketam, Selangor, Malaysia.
  Wee LK, Weng SN, Raduan N, et al. Relationship between rainfall and Aedes larval population at two insular sites in Pulau Ketam, Selangor, Malaysia. [Journal Article]Southeast Asian J Trop Med Public Health 2013 Mar; 44(2):157-66.Two insular settlements (Kampung Pulau Ketam and Kampung Sungai Lima) were selected to study the population dynamics of Aedes aegypti and Aedes albopictus mosquitoes, vectors of dengue and chikungunya infections. Ovitrap surveillance was conducted between October 2007 and October 2008. There was an inverse negative association between ovitrap index and rainfall at the time of collection, probably because rainfall increased the number of available oviposition sites. Rainfall and ovitrap index were positively associates the 25th day after rainfall occurred. A minor, second peak was observed from the 38th to the 42nd day. The first peak was consistent with the minimum 18-day period between the hatching of eggs to the first oviposition. The second minor peak could be due to the second gonotrophic cycle of the female mosquitoes. Rainfall is an important environmental factor associated with Aedes breeding at the study sites.
• A new challenge for hospitals in southeast France: monitoring local populations of Aedes albopictus to prevent nosocomial transmission of dengue or chikungunya.
  Cotteaux-Lautard C, Berenger JM, Fusca F, et al. A new challenge for hospitals in southeast France: monitoring local populations of Aedes albopictus to prevent nosocomial transmission of dengue or chikungunya. [Journal Article, Research Support, Non-U.S. Gov't]J Am Mosq Control Assoc 2013 Mar; 29(1):81-3.AbstractAggregator Full TextAedes albopictus was first identified in southern France in 2004, inducing an emerging risk for autochthonous transmission around imported cases of dengue or chikungunya, and also for mosquito-borne nosocomial transmission in hospitals. Aedes albopictus has been present in Marseille since September 2009 and in Aix-en-Provence since August 2010. Because of the possible admission of viremic patients with dengue or chikungunya in the hospitals of these cities, a mosquito survey was conducted in 2011 in 2 of the hospitals, with the use of mosquito traps. Aedes albopictus was detected with Eisenhans II traps and egg traps in both hospitals during the warm season.
• Genetic characterization of E2 region of chikungunya virus circulating in Odisha, Eastern India from 2010-2011.
  Sahu A, Das B, Das M, et al. Genetic characterization of E2 region of chikungunya virus circulating in Odisha, Eastern India from 2010-2011. [JOURNAL ARTICLE]Infect Genet Evol 2013 May 15.AbstractPublisher Full TextChikungunya virus (CHIKV) infection has caught attention yet again as it rages around the globe affecting millions of people. The virus caused epidemic outbreaks affecting more than 15000 people in Odisha, Eastern India since 2010. In this study, complete genetic characterization of E2 gene of CHIKV circulating in Odisha from 2010-2011 was performed by virus isolation, RT-PCR, molecular phylogenetics and bioinformatics methods. Phylogenetic analyses revealed the circulation of Indian Ocean Lineage (IOL) strains of ECSA genotype of CHIKV in Odisha. Several mutations were detected in the E2 gene, viz. E2-R82G, E2-L210Q, E2-I211T, E2-V229I and E2-S375T which had various adaptive roles during the evolution of CHIKV. The CHIKV E2 peptide (57)KTDDSHD(63) was predicted to be the most probable T-cell epitope and peptide (84)FVRTSAPCT(92) predicted to be the common T and B cell epitope having high antigenicity. The amino acid positions 356-379 and 365-385 were predicted to be transmembrane helical domains and indicated E2 protein anchorage in intracellular membranes for effective interaction with the host receptors. Positive selection pressure was observed in five specific sites, 210, 211, 318, 375 and 377 which were observed to be fixed advantageously in most viral isolates. Structural modeling revealed that E2 gene of CHIKV was composed of 3 domains and the major adaptive mutations were detected in domain B, which can modulate binding of CHIKV to host cells, while the transmembrane domain in domain C and the epitopes were located in domain A, which was found to be most conserved. This is the first report from Eastern India demonstrating a predictive approach to the genetic variations, epitopic regions and the transmembrane helices of the E2 region. The results of this study, combined with other published observations, will expand our knowledge about the E2 region of CHIKV which can be exploited to develop control measures against CHIKV.
• Chikungunya virus: An update on antiviral development and challenges.
  Kaur P, Chu JJ Chikungunya virus: An update on antiviral development and challenges. [JOURNAL ARTICLE]Drug Discov Today 2013 May 15.AbstractPublisher Full TextChikungunya virus (CHIKV) has re-emerged as a significant public health threat since the 2005 chikungunya fever epidemic in La Réunion. Driven by the medical importance of this virus, as well as the lack of approved antivirals, research into the field of CHIKV antivirals has recently intensified. Potential therapeutics that have been reported to show anti-CHIKV activity in vitro range from known broad-spectrum antivirals like chloroquine to novel strategies involving RNA silencing technology. Although most of the earlier efforts focused on compounds that target host components, some recent studies have reported viral targets such as nonstructural proteins. This article examines the reported in vitro and in vivo efficacies, as well as the therapeutic potential of these antiviral compounds.
• Economic impact of chikungunya epidemic: out-of-pocket health expenditures during the 2007 outbreak in Kerala, India.
  Vijayakumar K, George B, Anish TS, et al. Economic impact of chikungunya epidemic: out-of-pocket health expenditures during the 2007 outbreak in Kerala, India. [Journal Article]Southeast Asian J Trop Med Public Health 2013 Jan; 44(1):54-61.The southern state of Kerala, India was seriously affected by a chikungunya epidemic in 2007. As this outbreak was the first of its kind, the morbidity incurred by the epidemic was a challenge to the state's public health system. A cross sectional survey was conducted in five districts of Kerala that were seriously affected by the epidemic, using a two-stage cluster sampling technique to select households, and the patients were identified using a syndromic case definition. We calculated the direct health expenditure of families and checked whether it exceed the margins of catastrophic health expenditure (CHE). The median (IQR) total out-of-pocket (OOP) health expenditure in the study population was USD7.4 (16.7). The OOP health expenditure did not show any significant association with increasing per-capita monthly income.The major share (47.4%) of the costs was utilized for buying medicines, but costs for transportation (17.2%), consultations (16.6%), and diagnoses (9.9%) also contributed significantly to the total OOP health expenditure. The OOP health expenditure was high in private sector facilities, especially in tertiary care hospitals. For more than 15% of the respondents, the OOP was more than double their average monthly family income. The chikungunya outbreak of 2007 had significantly contributed to the OOP expenditure of the affected community in Kerala.The OOP health expenditure incurred was high, irrespective of the level of income. Governments should attempt to ensure comprehensive financial protection by covering the costs of care, along with loss of productivity.
• [Updated inventory of mosquitoes (Diptera: Culicidae) of the island of La Réunion, Indian Ocean.]
  Boussès P, Dehecq JS, Brengues C, et al. [Updated inventory of mosquitoes (Diptera: Culicidae) of the island of La Réunion, Indian Ocean.] [JOURNAL ARTICLE]Bull Soc Pathol Exot 2013 May 17.AbstractPublisher Full TextA literature analysis coupled with new entomological surveys conducted between 2009 and 2012 led to changes in the list of mosquito species present on the island of La Réunion. Using morphological criteria, Orthopodomyia arboricollis is replaced by Or. reunionensis. On the basis of morphometrical and genetic criteria, Culex univittatus is replaced by Cx. neavei. Cx. poicilipes, which was already reported missing 40 years ago, has not been found again. Anopheles arabiensis is confirmed as the only species of the Gambiae complex present on the island. Thus, twelve species are currently known. For each of them, elements of taxonomic, biological and medical interest are listed. An. arabiensis is a major vector of human Plasmodium (last case of indigenous malaria in 1967). In the Indian Ocean, Aedes albopictus and Ae. aegypti both are competent for transmitting dengue and chikungunya viruses. In Africa, Cx. quinquefasciatus transmits Wuchereria bancrofti and Cx. neavei transmits the Sindbis virus; both species also transmit the West Nile virus. Cx. tritaeniorhynchus is the major vector of Japanese Encephalitis virus in Asia. Two species are endemic (Ae. dufouri and Or. reunionensis), the ten other ones are also found in Madagascar and on the African continent (An. coustani, An. arabiensis, Ae. fowleri, Cx. tritaeniorhynchus, Cx. neavei, Cx. insignis, Lutzia tigripes), with three of them having also a cosmopolitan distribution (Ae. aegypti, Ae. albopictus and Cx. quinquefasciatus). Among the twelve recorded taxa, eight species are anthropophilic, three are supposedly zoophilic and one is a predatory species. No new invasive anthropophilic species did settle on the island. Updated identification keys of larval and adult stages are proposed.
• An Essential Role of Antibodies in the Control of Chikungunya Virus Infection.
  Lum FM, Teo TH, Lee WW, et al. An Essential Role of Antibodies in the Control of Chikungunya Virus Infection. [JOURNAL ARTICLE]J Immunol 2013 May 13.AbstractPublisher Full TextIn recent years, Chikungunya virus (CHIKV) was responsible for epidemic outbreaks in intertropical regions. Although acquired immunity has been shown to be crucial during CHIKV infection in both humans and mice, their exact role in the control of CHIKV infection remains unclear. In this study, wild-type (WT), CD4(-/-), and B cell (μMT) knockout mice were infected with CHIKV. Sera were taken at different days postinfection and measured for anti-CHIKV Ab levels. Isotype and neutralizing capacity of these Abs were assessed in vitro, and specific linear epitopes were mapped. Viremia in CHIKV-infected μMT mice persisted for more than a year, indicating a direct role for B cells in mediating CHIKV clearance. These animals exhibited a more severe disease than WT mice during the acute phase. Characterization of CHIKV-specific Abs revealed that anti-CHIKV Abs were elicited early and targeted epitopes mainly at the C terminus of the virus E2 glycoprotein. Furthermore, CD4(-/-) mice could still control CHIKV infection despite having lower anti-CHIKV Ab levels with reduced neutralizing capacity. Lastly, pre-existing natural Abs in the sera of normal WT mice recognized CHIKV and were able to partially inhibit CHIKV. Taken together, natural and CHIKV infection-induced specific Abs are essential for controlling CHIKV infections.
• Isolation of infectious chikungunya virus and dengue virus using anionic polymer-coated magnetic beads.
  Patramool S, Bernard E, Hamel R, et al. Isolation of infectious chikungunya virus and dengue virus using anionic polymer-coated magnetic beads. [JOURNAL ARTICLE]J Virol Methods 2013 May 10.AbstractPublisher Full TextMosquitoes-borne viruses are a major threat for human populations. Among them, chikungunya virus (CHIKV) and dengue virus (DENV) cause thousands of cases worldwide. The recent propagation of mosquito vectors competent to transmit these viruses to temperate areas increases their potential impact on susceptible human populations. The development of sensitive methods allowing the detection and isolation of infectious viruses is of crucial interest for determination of virus contamination in humans and in competent mosquito vectors. However, simple and rapid method allowing the capture of infectious CHIKV and DENV from samples with low viral titers useful for further genetic and functional characterization of circulating strains is lacking. The present study reports a fast and sensitive isolation technique based on viral particles adsorption on magnetic beads coated with anionic polymer, poly(methyl vinyl ether-maleic anhydrate) and suitable for isolation of infectious CHIKV and DENV from the four serotypes. Starting from quite reduced biological material, this method was accurate to combine with conventional detection techniques, including qRT-PCR and immunoblotting and allowed isolation of infectious particles without resorting to a step of cultivation. The use of polymer-coated magnetic beads is therefore of high interest for rapid detection and isolation of CHIKV and DENV from samples with reduced viral loads and represents an accurate approach for the surveillance of mosquito vector in area at risk for arbovirus outbreaks.