Displaying publications 1 - 20 of 90 in total

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  1. Fulltext Reemergence of endemic Chikungunya, Malaysia
    AbuBakar S, Sam IC, Wong PF, MatRahim N, Hooi PS, Roslan N
    Emerg Infect Dis, 2007 Jan;13(1):147-9.
    PMID: 17370532
    Chikungunya virus infection recently reemerged in Malaysia after 7 years of nondetection. Genomic sequences of recovered isolates were highly similar to those of Malaysian isolates from the 1998 outbreak. The reemergence of the infection is not part of the epidemics in other Indian Ocean countries but raises the possibility that chikungunya virus is endemic in Malaysia.
    Matched MeSH terms: Chikungunya virus/genetics; Chikungunya virus/isolation & purification*
  2. Fulltext Detection of Wolbachia in Aedes albopictus and Their Effects on Chikungunya Virus
    Ahmad NA, Vythilingam I, Lim YAL, Zabari NZAM, Lee HL
    Am J Trop Med Hyg, 2017 Jan 11;96(1):148-156.
    PMID: 27920393 DOI: 10.4269/ajtmh.16-0516
    Wolbachia-based vector control strategies have been proposed as a means to augment the currently existing measures for controlling dengue and chikungunya vectors. Prior to utilizing Wolbachia as a novel vector control strategy, it is crucial to understand the Wolbachia-mosquito interactions. In this study, field surveys were conducted to screen for the infection status of Wolbachia in field-collected Aedes albopictus The effects of Wolbachia in its native host toward the replication and dissemination of chikungunya virus (CHIKV) was also studied. The prevalence of Wolbachia-infected field-collected Ae. albopictus was estimated to be 98.6% (N = 142) for females and 95.1% (N = 102) for males in the population studied. The Ae. albopictus were naturally infected with both wAlbA and wAlbB strains. We also found that the native Wolbachia has no impact on CHIKV infection and minimal effect on CHIKV dissemination to secondary organs.
    Matched MeSH terms: Chikungunya virus/isolation & purification*
  3. Therapeutics and vaccines against chikungunya virus
    Ahola T, Couderc T, Courderc T, Ng LF, Hallengärd D, Powers A, et al.
    Vector Borne Zoonotic Dis, 2015 Apr;15(4):250-7.
    PMID: 25897811 DOI: 10.1089/vbz.2014.1681
    Currently, there are no licensed vaccines or therapies available against chikungunya virus (CHIKV), and these were subjects discussed during a CHIKV meeting recently organized in Langkawi, Malaysia. In this review, we chart the approaches taken in both areas. Because of a sharp increase in new data in these fields, the present paper is complementary to previous reviews by Weaver et al. in 2012 and Kaur and Chu in 2013 . The most promising antivirals so far discovered are reviewed, with a special focus on the virus-encoded replication proteins as potential targets. Within the vaccines in development, our review emphasizes the various strategies in parallel development that are unique in the vaccine field against a single disease.
    Matched MeSH terms: Chikungunya virus/immunology*
  4. Fulltext Clinical Symptoms of Arboviruses in Mexico
    Ananth S, Shrestha N, Treviño C JA, Nguyen US, Haque U, Angulo-Molina A, et al.
    Pathogens, 2020 Nov 19;9(11).
    PMID: 33228120 DOI: 10.3390/pathogens9110964
    Arboviruses such as Chikungunya (CHIKV), Dengue (DENV), and Zika virus (ZIKV) have emerged as a significant public health concern in Mexico. The existing literature lacks evidence regarding the dispersion of arboviruses, thereby limiting public health policy's ability to integrate the diagnosis, management, and prevention. This study seeks to reveal the clinical symptoms of CHIK, DENV, and ZIKV by age group, region, sex, and time across Mexico. The confirmed cases of CHIKV, DENV, and ZIKV were compiled from January 2012 to March 2020. Demographic characteristics analyzed significant clinical symptoms of confirmed cases. Multinomial logistic regression was used to assess the association between clinical symptoms and geographical regions. Females and individuals aged 15 and older had higher rates of reported significant symptoms across all three arboviruses. DENV showed a temporal variation of symptoms by regions 3 and 5, whereas ZIKV presented temporal variables in regions 2 and 4. This study revealed unique and overlapping symptoms between CHIKV, DENV, and ZIKV. However, the differentiation of CHIKV, DENV, and ZIKV is difficult, and diagnostic facilities are not available in rural areas. There is a need for adequately trained healthcare staff alongside well-equipped lab facilities, including hematological tests and imaging facilities.
    Matched MeSH terms: Chikungunya virus
  5. Fulltext Identification of Chikungunya virus strains circulating in Kelantan, Malaysia in 2009
    Apandi Y, Lau SK, Izmawati N, Amal NM, Faudzi Y, Mansor W, et al.
    Southeast Asian J. Trop. Med. Public Health, 2010 Nov;41(6):1374-80.
    PMID: 21329313
    Malaysia experienced its first outbreak of chikungunya virus (CHIKV) infection in late 1998 in Klang District in Selangor; six years later the virus re-emerged in the state of Perak. All the CHIKV isolates in 1988 and 2006 shared high sequence similarities and belonged to the Asian genotype. In 2007 and 2008 CHIKV infection again reemerged but the genotype was the Central/East African genotype. This strain was found to be similar to the strains causing outbreaks in the India Ocean. In 2009, the strains circulating in Malaysia, including the state of Kelantan, based on the partial E1 gene, also belong to the Central/East African genotype.
    Matched MeSH terms: Chikungunya virus/classification*; Chikungunya virus/isolation & purification*
  6. Fulltext Seroprevalence survey of Chikungunya virus in Bagan Panchor, Malaysia
    Ayu SM, Lai LR, Chan YF, Hatim A, Hairi NN, Ayob A, et al.
    Am J Trop Med Hyg, 2010 Dec;83(6):1245-8.
    PMID: 21118929 DOI: 10.4269/ajtmh.2010.10-0279
    In 2006, an outbreak of Chikungunya virus (CHIKV) of the Asian genotype affected over 200 people in Bagan Panchor village in Malaysia. One year later, a post-outbreak survey was performed to determine attack rate, asymptomatic rate, and post-infection sequelae. Findings were compared with recent CHIKV outbreaks of the Central/East African genotype. A total of 180 residents were interviewed for acute symptoms and post-infection physical quality of life and depressive symptoms. Sera from 72 residents were tested for CHIKV neutralizing antibodies. The estimated attack rate was 55.6%, and 17.5% of infected residents were asymptomatic. Arthralgia was reported up to 3 months after infection, but there were no reports of long-term functional dependence or depression. Symptomatic and seropositive residents were significantly more likely to live in the area with the most dense housing and commercial activities. CHIKV had a high attack rate and considerable clinical impact during the Bagan Panchor outbreak.
    Matched MeSH terms: Chikungunya virus/genetics; Chikungunya virus/isolation & purification*
  7. Fulltext Emergence of chikungunya seropositivity in healthy Malaysian adults residing in outbreak-free locations: chikungunya seroprevalence results from the Malaysian Cohort
    Azami NA, Salleh SA, Shah SA, Neoh HM, Othman Z, Zakaria SZ, et al.
    BMC Infect Dis, 2013;13:67.
    PMID: 23379541 DOI: 10.1186/1471-2334-13-67
    In 1998, Malaysia experienced its first chikungunya virus (CHIKV) outbreak in the suburban areas followed by another two in 2006 (rural areas) and 2008 (urban areas), respectively. Nevertheless, there is still a lack of documented data regarding the magnitude of CHIKV exposure in the Malaysian population. The aim of this study was to determine the extent of chikungunya virus infection in healthy Malaysian adults residing in outbreak-free locations.
    Matched MeSH terms: Chikungunya virus/immunology*
  8. Fulltext Genome-wide identification of Aedes albopictus long noncoding RNAs and their association with dengue and Zika virus infection
    Azlan A, Obeidat SM, Theva Das K, Yunus MA, Azzam G
    PLoS Negl Trop Dis, 2021 01;15(1):e0008351.
    PMID: 33481791 DOI: 10.1371/journal.pntd.0008351
    The Asian tiger mosquito, Aedes albopictus (Ae. albopictus), is an important vector that transmits arboviruses such as dengue (DENV), Zika (ZIKV) and Chikungunya virus (CHIKV). Long noncoding RNAs (lncRNAs) are known to regulate various biological processes. Knowledge on Ae. albopictus lncRNAs and their functional role in virus-host interactions are still limited. Here, we identified and characterized the lncRNAs in the genome of an arbovirus vector, Ae. albopictus, and evaluated their potential involvement in DENV and ZIKV infection. We used 148 public datasets, and identified a total of 10, 867 novel lncRNA transcripts, of which 5,809, 4,139, and 919 were intergenic, intronic and antisense respectively. The Ae. albopictus lncRNAs shared many characteristics with other species such as short length, low GC content, and low sequence conservation. RNA-sequencing of Ae. albopictus cells infected with DENV and ZIKV showed that the expression of lncRNAs was altered upon virus infection. Target prediction analysis revealed that Ae. albopictus lncRNAs may regulate the expression of genes involved in immunity and other metabolic and cellular processes. To verify the role of lncRNAs in virus infection, we generated mutations in lncRNA loci using CRISPR-Cas9, and discovered that two lncRNA loci mutations, namely XLOC_029733 (novel lncRNA transcript id: lncRNA_27639.2) and LOC115270134 (known lncRNA transcript id: XR_003899061.1) resulted in enhancement of DENV and ZIKV replication. The results presented here provide an important foundation for future studies of lncRNAs and their relationship with virus infection in Ae. albopictus.
    Matched MeSH terms: Chikungunya virus
  9. Fulltext Investigation of twenty selected medicinal plants from Malaysia for anti-Chikungunya virus activity
    Chan YS, Khoo KS, Sit NWW
    Int Microbiol, 2016 Sep;19(3):175-182.
    PMID: 28494087 DOI: 10.2436/20.1501.01.275
    Chikungunya virus is a reemerging arbovirus transmitted mainly by Aedes mosquitoes. As there are no specific treatments available, Chikungunya virus infection is a significant public health problem. This study investigated 120 extracts from selected medicinal plants for anti-Chikungunya virus activity. The plant materials were subjected to sequential solvent extraction to obtain six different extracts for each plant. The cytotoxicity and antiviral activity of each extract were examined using African monkey kidney epithelial (Vero) cells. The ethanol, methanol and chloroform extracts of Tradescantia spathacea (Commelinaceae) leaves showed the strongest cytopathic effect inhibition on Vero cells, resulting in cell viabilities of 92.6% ± 1.0% (512 μg/ml), 91.5% ± 1.7% (512 μg/ml) and 88.8% ± 2.4% (80 μg/ml) respectively. However, quantitative RT-PCR analysis revealed that the chloroform extract of Rhapis excelsa (Arecaceae) leaves resulted in the highest percentage of reduction of viral load (98.1%), followed by the ethyl acetate extract of Vernonia amygdalina (Compositae) leaves (95.5%). The corresponding 50% effective concentrations (EC50) and selectivity indices for these two extracts were 29.9 ± 0.9 and 32.4 ± 1.3 μg/ml, and 5.4 and 5.1 respectively. Rhapis excelsa and Vernonia amygdalina could be sources of anti-Chikungunya virus agents. [Int Microbiol 19(3):175-182 (2016)].
    Matched MeSH terms: Chikungunya virus/drug effects*
  10. Fulltext Diagnosis and management of imported Chikungunya fever in Taiwan: a case report
    Chang K, Hsieh HC, Tsai JJ, Lin WR, Lu PL, Chen YH
    Kaohsiung J. Med. Sci., 2010 May;26(5):256-60.
    PMID: 20466336 DOI: 10.1016/S1607-551X(10)70037-1
    Chikungunya virus, a mosquito-borne alphavirus, is endemic in Africa and Southeast Asia but is rarely reported in Taiwan. We report the case of a Taiwanese woman who developed Chikungunya fever, which was first diagnosed by a clinician rather than by fever screening at an airport. The woman presented with fever, maculopapular rash, and arthralgia, the triad for the disease, on the day she returned home after a trip to Malaysia. These symptoms are very similar to those of dengue fever, which is endemic in Southern Taiwan. Chikungunya infection was confirmed by reverse transcriptase-polymerase chain reaction and seroconversion on paired serum specimens. For approximately 40 years until 2006, no cases of Chikungunya fever had been found in Taiwan. Clinicians in Taiwan should consider Chikungunya fever as a possible diagnosis for a febrile patient with arthralgia, rash, and a history of travel to an endemic area, such as Africa or Southeast Asia.
    Matched MeSH terms: Chikungunya virus/genetics; Chikungunya virus/isolation & purification*
  11. Fulltext Molecular epidemiology of chikungunya virus in Malaysia since its first emergence in 1998
    Chem YK, Zainah S, Berendam SJ, Rogayah TA, Khairul AH, Chua KB
    Med J Malaysia, 2010 Mar;65(1):31-5.
    PMID: 21265245 MyJurnal
    Malaysia experienced the first outbreak of chikungunya (CHIK) in Klang in late 1998 due to CHIK virus of Asian genotype. The CHIK virus of Asian genotype reemerged causing outbreak in Bangan Panchor, Perak in March 2006. CHIK virus of Central/East African genotype was first detected from a patient who returned from India in August 2006. In December 2006, CHIK virus of Central/East African genotype was re-introduced into Malaysia from India and caused an outbreak in Kinta district, Perak but was successfully controlled following an early detection and institution of intensive vector control measures. In late April 2008, CHIK virus of Central/East African genotype was laboratory confirmed as the cause of CHIK outbreak in Johore which spread to other parts of Malaysia by August 2008. Phylogenetic analysis based on the 254-bp fragment of the virus envelope protein gene as the genetic marker showed that three different strains of CHIK virus of Central/East African genotype were introduced into Malaysia on three separate occasions from 2006 to 2008. The strain that was introduced into Johor state was responsible for its subsequent spread to other parts of Malaysia, inclusive of Sarawak.
    Matched MeSH terms: Chikungunya virus/genetics*
  12. Fulltext Outbreak of chikungunya in Johor Bahru, Malaysia: clinical and laboratory features of hospitalized patients
    Chew LP, Chua HH
    Med J Malaysia, 2009 Sep;64(3):220-2.
    PMID: 20527272
    In 2008, an outbreak of chikungunya infection occurred in Johor. We performed a retrospective review of all laboratory confirmed adult chikungunya cases admitted to Hospital Sultanah Aminah, Johor Bahru from April to August 2008, looking into clinical and laboratory features. A total of 18 laboratory confirmed cases of chikungunya were identified with patients presenting with fever, joint pain, rash and vomiting. Haemorrhagic signs were not seen. Lymphopenia, neutropenia, thrombocytopenia, raised liver enzymes and deranged coagulation profile were the prominent laboratory findings. We hope this study can help guide physician making a diagnosis of chikungunya against other arborviruses infection.
    Matched MeSH terms: Chikungunya virus/isolation & purification*
  13. Real-time polymerase chain reaction for diagnosis and quantitation of negative strand of chikungunya virus
    Chiam CW, Chan YF, Loong SK, Yong SS, Hooi PS, Sam IC
    Diagn Microbiol Infect Dis, 2013 Oct;77(2):133-7.
    PMID: 23886793 DOI: 10.1016/j.diagmicrobio.2013.06.018
    Quantitative real-time polymerase chain reaction (qRT-PCR) is useful for diagnosis and studying virus replication. We developed positive- and negative-strand qRT-PCR assays to detect nsP3 of chikungunya virus (CHIKV), a positive-strand RNA alphavirus that causes epidemic fever, rash, and arthritis. The positive- and negative-strand qRT-PCR assays had limits of quantification of 1 and 3 log10 RNA copies/reaction, respectively. Compared to a published E1 diagnostic assay using 30 laboratory-confirmed clinical samples, the positive-strand nsP3 qRT-PCR assay had higher R(2) and efficiency and detected more positive samples. Peak viral load of 12.9 log(10) RNA copies/mL was reached on day 2 of illness, and RNA was detectable up to day 9, even in the presence of anti-CHIKV IgM. There was no correlation between viral load and persistent arthralgia. The positive-strand nsP3 assay is suitable for diagnosis, while the negative-strand nsP3 assay, which uses tagged primers to increase specificity, is useful for study of active viral replication kinetics.
    Matched MeSH terms: Chikungunya virus/genetics; Chikungunya virus/isolation & purification*
  14. Immunohistochemical Detection of Chikungunya Virus Antigens in Formalin-Fixed and Paraffin-Embedded Tissues
    Chiam CW, Sam IC, Chan YF, Wong KT, Ong KC
    Methods Mol Biol, 2016;1426:235-40.
    PMID: 27233276 DOI: 10.1007/978-1-4939-3618-2_21
    Immunohistochemistry is a histological technique that allows detection of one or more proteins of interest within a cell using specific antibody binding, followed by microscopic visualization of a chromogenic substrate catalyzed by peroxidase and/or alkaline phosphatase. Here, we describe a method to localize Chikungunya virus (CHIKV) antigens in formalin-fixed and paraffin-embedded infected mouse brain.
    Matched MeSH terms: Chikungunya virus/immunology; Chikungunya virus/metabolism*
  15. Expression and Purification of E2 Glycoprotein from Insect Cells (Sf9) for Use in Serology
    Chua CL, Sam IC, Chan YF
    Methods Mol Biol, 2016;1426:51-61.
    PMID: 27233260 DOI: 10.1007/978-1-4939-3618-2_5
    Chikungunya virus (CHIKV) is a mosquito-borne arbovirus which poses a major threat to global public health. Definitive CHIKV diagnosis is crucial, especially in distinguishing the disease from dengue virus, which co-circulates in endemic areas and shares the same mosquito vectors. Laboratory diagnosis is mainly based on serological or molecular approaches. The E2 glycoprotein is a good candidate for serological diagnosis since it is the immunodominant antigen during the course of infection, and reacts with seropositive CHIKV sera. In this chapter, we describe the generation of stable clone Sf9 (Spodoptera frugiperda) cells expressing secreted, soluble, and native recombinant CHIKV E2 glycoprotein. We use direct plasmid expression in insect cells, rather than the traditional technique of generating recombinant baculovirus. This recombinant protein is useful for serological diagnosis of CHIKV infection.
    Matched MeSH terms: Chikungunya virus/immunology; Chikungunya virus/metabolism*
  16. Fulltext Antigenic Variation of East/Central/South African and Asian Chikungunya Virus Genotypes in Neutralization by Immune Sera
    Chua CL, Sam IC, Merits A, Chan YF
    PLoS Negl Trop Dis, 2016 08;10(8):e0004960.
    PMID: 27571254 DOI: 10.1371/journal.pntd.0004960
    BACKGROUND: Chikungunya virus (CHIKV) is a re-emerging mosquito-borne virus which causes epidemics of fever, severe joint pain and rash. Between 2005 and 2010, the East/Central/South African (ECSA) genotype was responsible for global explosive outbreaks across India, the Indian Ocean and Southeast Asia. From late 2013, Asian genotype CHIKV has caused outbreaks in the Americas. The characteristics of cross-antibody efficacy and epitopes are poorly understood.

    METHODOLOGY/PRINCIPAL FINDINGS: We characterized human immune sera collected during two independent outbreaks in Malaysia of the Asian genotype in 2006 and the ECSA genotype in 2008-2010. Neutralizing capacity was analyzed against representative clinical isolates as well as viruses rescued from infectious clones of ECSA and Asian CHIKV. Using whole virus antigen and recombinant E1 and E2 envelope glycoproteins, we further investigated antibody binding sites, epitopes, and antibody titers. Both ECSA and Asian sera demonstrated stronger neutralizing capacity against the ECSA genotype, which corresponded to strong epitope-antibody interaction. ECSA serum targeted conformational epitope sites in the E1-E2 glycoprotein, and E1-E211K, E2-I2T, E2-H5N, E2-G118S and E2-S194G are key amino acids that enhance cross-neutralizing efficacy. As for Asian serum, the antibodies targeting E2 glycoprotein correlated with neutralizing efficacy, and I2T, H5N, G118S and S194G altered and improved the neutralization profile. Rabbit polyclonal antibody against the N-terminal linear neutralizing epitope from the ECSA sequence has reduced binding capacity and neutralization efficacy against Asian CHIKV. These findings imply that the choice of vaccine strain may impact cross-protection against different genotypes.

    CONCLUSION/SIGNIFICANCE: Immune serum from humans infected with CHIKV of either ECSA or Asian genotypes showed differences in binding and neutralization characteristics. These findings have implications for the continued outbreaks of co-circulating CHIKV genotypes and effective design of vaccines and diagnostic serological assays.

    Matched MeSH terms: Chikungunya virus/genetics*; Chikungunya virus/immunology*; Chikungunya virus/isolation & purification
  17. Fulltext The neutralizing role of IgM during early Chikungunya virus infection
    Chua CL, Sam IC, Chiam CW, Chan YF
    PLoS One, 2017;12(2):e0171989.
    PMID: 28182795 DOI: 10.1371/journal.pone.0171989
    The antibody isotype IgM appears earlier than IgG, within days of onset of symptoms, and is important during the early stages of the adaptive immune response. Little is known about the functional role of IgM during infection with chikungunya virus (CHIKV), a recently reemerging arbovirus that has caused large global outbreaks. In this study, we studied antibody responses in 102 serum samples collected during CHIKV outbreaks in Malaysia. We described the neutralizing role of IgM at different times post-infection and examined the independent contributions of IgM and IgG towards the neutralizing capacity of human immune sera during the early phase of infection, including the differences in targets of neutralizing epitopes. Neutralizing IgM starts to appear as early as day 4 of symptoms, and their appearance from day 6 is associated with a reduction in viremia. IgM acts in a complementary manner with the early IgG, but plays the main neutralizing role up to a point between days 4 and 10 which varies between individuals. After this point, total neutralizing capacity is attributable almost entirely to the robust neutralizing IgG response. IgM preferentially binds and targets epitopes on the CHIKV surface E1-E2 glycoproteins, rather than individual E1 or E2. These findings provide insight into the early antibody responses to CHIKV, and have implications for design of diagnostic serological assays.
    Matched MeSH terms: Chikungunya virus/immunology*
  18. Characterisation of mouse monoclonal antibodies targeting linear epitopes on Chikungunya virus E2 glycoprotein
    Chua CL, Chan YF, Sam IC
    J Virol Methods, 2014 Jan;195:126-33.
    PMID: 24134938 DOI: 10.1016/j.jviromet.2013.10.015
    Chikungunya virus (CHIKV) is a mosquito-borne arbovirus which has recently re-emerged globally and poses a major threat to public health. Infection leads to severe arthralgia, and disease management remains supportive in the absence of vaccines and anti-viral interventions. The high specificities of monoclonal antibodies (mAbs) have been exploited in immunodiagnostics and immunotherapy in recent decades. In this study, eight different clones of mAbs were generated and characterised. These mAbs targeted the linear epitopes on the CHIKV E2 envelope glycoprotein, which is the major target antigen during infection. All the mAbs showed binding activity against the purified CHIKV virion or recombinant E2 when analysed by immunofluorescence, ELISA and Western blot. The epitopes of each mAb were mapped by overlapping synthetic peptide-based ELISA. The epitopes are distributed at different functional domains of E2 glycoprotein, namely at domain A, junctions of β-ribbons with domains A and B, and domain C. Alignment of mAb epitope sequences revealed that some are well-conserved within different genotypes of CHIKV, while some are identical to and likely to cross-react with the closely-related alphavirus O'nyong-nyong virus. These mAbs with their mapped epitopes are useful for the development of diagnostic or research tools, including immunofluorescence, ELISA and Western blot.
    Matched MeSH terms: Chikungunya virus/immunology*
  19. Chikungunya fever: CNS infection and pathologies of a re-emerging arbovirus
    Das T, Jaffar-Bandjee MC, Hoarau JJ, Krejbich Trotot P, Denizot M, Lee-Pat-Yuen G, et al.
    Prog. Neurobiol., 2010 Jun;91(2):121-9.
    PMID: 20026374 DOI: 10.1016/j.pneurobio.2009.12.006
    Chikungunya virus (CHIKV) is transmitted by Aedes mosquitoes and causes an acute symptomatic illness with fever, skin rash, and incapacitating arthralgia, which can evolve into chronic rheumatoid arthritis in elderly patients. This is a tropical disease originally described in central/east Africa in the 1960s, but its 2004 re-emergence in Africa and rapid spread in lands in and around the Indian Ocean (Reunion island, India, Malaysia) as well as Europe (Italy) led to almost 6 million cases worldwide. The risk of importation and spreading diseases with long-term sequelae is even greater today given the global distribution of the vectors (including in the Americas), increased tourism and the apparent capacity of CHIKV to produce high levels of viremia (10(9)-10(12) virus/ml of blood) and new mutants. CHIKV-associated neuropathology was described early in the 1960s, but it is the unprecedented incidence rate in Indian Ocean areas with efficient clinical facilities that allowed a better description of cases with severe encephalitis, meningoencephalitis, peripheral neuropathies and deaths among newborns (mother-to-child infection), infants and elderly patients. Death rates following CHIKV infection were estimated at 1:1000 cases in la Reunion's outbreak. These clinical observations have been corroborated by experimental infection in several mouse models, leading to CNS pathologies. We further describe in this review the capacity of CHIKV to infect neurons and glial cells, delineate the fundamental innate (intrinsic) immune defence mechanisms to protect from infection and argue about the possible mechanisms involved in the encephalopathy.
    Matched MeSH terms: Chikungunya virus/pathogenicity*
  20. Spatiotemporal spread of chikungunya virus in Sarawak, Malaysia
    Dass S, Ngui R, Gill BS, Chan YF, Wan Sulaiman WY, Lim YAL, et al.
    Trans R Soc Trop Med Hyg, 2021 08 02;115(8):922-931.
    PMID: 33783526 DOI: 10.1093/trstmh/trab053
    BACKGROUND: We studied the spatiotemporal spread of a chikungunya virus (CHIKV) outbreak in Sarawak state, Malaysia, during 2009-2010.

    METHODS: The residential addresses of 3054 notified CHIKV cases in 2009-2010 were georeferenced onto a base map of Sarawak with spatial data of rivers and roads using R software. The spatiotemporal spread was determined and clusters were detected using the space-time scan statistic with SaTScan.

    RESULTS: Overall CHIKV incidence was 127 per 100 000 population (range, 0-1125 within districts). The average speed of spread was 70.1 km/wk, with a peak of 228 cases/wk and the basic reproduction number (R0) was 3.1. The highest age-specific incidence rate was 228 per 100 000 in adults aged 50-54 y. Significantly more cases (79.4%) lived in rural areas compared with the general population (46.2%, p<0.0001). Five CHIKV clusters were detected. Likely spread was mostly by road, but a fifth of rural cases were spread by river travel.

    CONCLUSIONS: CHIKV initially spread quickly in rural areas mainly via roads, with lesser involvement of urban areas. Delayed spread occurred via river networks to more isolated areas in the rural interior. Understanding the patterns and timings of arboviral outbreak spread may allow targeted vector control measures at key transport hubs or in large transport vehicles.

    Matched MeSH terms: Chikungunya virus*
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