A change in circulating chikungunya virus variant impacts Aedes aegypti vector competence and spatiotemporal distribution of disease in Malaysia.

Background: In 2008-2010, Malaysia experienced a nationwide chikungunya virus (CHIKV) outbreak caused by the Indian Ocean lineage E1-226V (valine) variant, adapted to Aedes albopictus. In 2017-2022, transition to an E1-226A (alanine) variant occurred. Ae.

Susceptibility of Aedes albopictus, Ae. aegypti and human populations to Ross River virus in Kuala Lumpur, Malaysia.

Background: Emerging arboviruses such as chikungunya and Zika viruses have unexpectedly caused widespread outbreaks in tropical and subtropical regions recently. Ross River virus (RRV) is endemic in Australia and has epidemic potential. In Malaysia, Aedes mosquitoes are abundant and drive dengue and chikungunya outbreaks.

Replication and innate immune responses of two chikungunya virus genotypes in human monocyte-derived macrophages.

Chikungunya virus (CHIKV) is a re-emerging mosquito-borne virus, which causes epidemics of fever, joint pain and rash. There are three genotypes: West African, East/Central/South/Africa (ECSA) and Asian, with the latter two predominant globally. Genotype-specific differences in clinical presentations, virulence and immunopathology have been described.

Vector competence of Malaysian Aedes aegypti to Zika virus and impact of sequential arbovirus infections.

Zika virus (ZIKV) is a mosquito-borne flavivirus with global impact since 2015. Although ZIKV was first isolated from Aedes aegypti in Malaysia in 1965, not much is known about the competency of Malaysian Ae. aegypti to ZIKV.

An amino acid change in nsP4 of chikungunya virus confers fitness advantage in human cell lines rather than in .

Chikungunya virus (CHIKV) has caused large-scale epidemics of fever, rash and arthritis since 2004. This unprecedented re-emergence has been associated with mutations in genes encoding structural envelope proteins, providing increased fitness in the secondary vector . In the 2008-2013 CHIKV outbreaks across Southeast Asia, an R82S mutation in non-structural protein 4 (nsP4) emerged early in Malaysia or Singapore and quickly became predominant.

Low seroprevalence rates of Zika virus in Kuala Lumpur, Malaysia.

Background: Zika virus (ZIKV) is believed to be endemic in Southeast Asia. However, there have been few Zika cases reported to date in Malaysia, which could be due to high pre-existing levels of population immunity.

Methods: To determine Zika virus (ZIKV) seroprevalence in Kuala Lumpur, Malaysia, 1085 serum samples from 2012, 2014-2015 and 2017 were screened for anti-ZIKV antibodies using a ZIKV NS1 blockade-of-binding assay.

Little Evidence of Zika Virus Infection in Wild Long-Tailed Macaques, Peninsular Malaysia.

We tested a sample of 234 wild long-tailed macaques (Macaca fascicularis) trapped in Peninsular Malaysia in 2009, 2010, and 2016 for Zika virus RNA and antibodies. None were positive for RNA, and only 1.3% were seropositive for neutralizing antibodies.

The neutralizing role of IgM during early Chikungunya virus infection.

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.

Antigenic Variation of East/Central/South African and Asian Chikungunya Virus Genotypes in Neutralization by Immune Sera.

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.

Expression and Purification of E2 Glycoprotein from Insect Cells (Sf9) for Use in Serology.

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.

Characterisation of mouse monoclonal antibodies targeting linear epitopes on Chikungunya virus E2 glycoprotein.

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.

Genotypic and phenotypic characterization of Chikungunya virus of different genotypes from Malaysia.

Background: Mosquito-borne Chikungunya virus (CHIKV) has recently re-emerged globally. The epidemic East/Central/South African (ECSA) strains have spread for the first time to Asia, which previously only had endemic Asian strains. In Malaysia, the ECSA strain caused an extensive nationwide outbreak in 2008, while the Asian strains only caused limited outbreaks prior to this.

Early neutralizing IgG response to Chikungunya virus in infected patients targets a dominant linear epitope on the E2 glycoprotein.

Chikungunya virus (CHIKV) and related arboviruses have been responsible for large epidemic outbreaks with serious economic and social impact. The immune mechanisms, which control viral multiplication and dissemination, are not yet known. Here, we studied the antibody response against the CHIKV surface antigens in infected patients.