Alphaviruses in Latin America and the Introduction of Chikungunya Virus

2017 ◽  
pp. 169-192 ◽  
Author(s):  
Juan-Carlos Navarro ◽  
Jean-Paul Carrera ◽  
Jonathan Liria ◽  
Albert J. Auguste ◽  
Scott C. Weaver
Keyword(s):  
Latin America ◽  
Chikungunya Virus

Serological Responses in Patients Infected with Mayaro Virus and Evaluation of Cross-Protective Responses against Chikungunya Virus

2021 ◽  
Author(s):  
Nathen E. Bopp ◽  
Kara J. Jencks ◽  
Crystyan Siles ◽  
Carolina Guevara ◽  
Stalin Vilcarromero ◽  
...  
Keyword(s):  
Latin America ◽  
South America ◽  
Neutralizing Antibodies ◽  
Chikungunya Virus ◽  
Neutralization Test ◽  
Close Relative ◽  
Previous Exposure ◽  
Chikv Infection ◽  
The Caribbean ◽  
Mayaro Virus

Mayaro virus (MAYV) is an alphavirus endemic to both Latin America and the Caribbean. Recent reports have questioned the ability of MAYV and its close relative, Chikungunya virus (CHIKV), to generate cross-reactive, neutralizing antibodies to one another. Since CHIKV was introduced to South America in 2013, discerning whether individuals have cross-reactive antibodies or whether they have had exposures to both viruses previously has been difficult. Using samples obtained from people infected with MAYV prior to the introduction of CHIKV in the Americas, we performed neutralizing assays and observed no discernable neutralization of CHIKV by sera from patients previously infected with MAYV. These data suggest that a positive CHIKV neutralization test cannot be attributed to prior exposure to MAYV and that previous exposure to MAYV may not be protective against a subsequent CHIKV infection.

scholarly journals Robustness of Serologic Investigations for Chikungunya and Mayaro Viruses following Coemergence

mSphere ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Carlo Fischer ◽  
Fernando Bozza ◽  
Xiomara Jeanleny Merino Merino ◽  
Celia Pedroso ◽  
Edmilson F. de Oliveira Filho ◽  
...  
Keyword(s):  
Latin America ◽  
False Positive ◽  
Chikungunya Virus ◽  
Cross Reactivity ◽  
Positive Test ◽  
Antibody Detection ◽  
Test Results ◽  
Specific Patient ◽  
False Positive Test ◽  
Mayaro Virus

ABSTRACT Since 2013, the arthropod-borne Chikungunya virus (CHIKV) has cocirculated with the autochthonous Mayaro virus (MAYV) in Latin America. Both belong to the same alphavirus serocomplex, termed the Semliki Forest serocomplex. The extent of antibody cross-reactivity due to the antigenic relatedness of CHIKV and MAYV in commonly used serologic tests remains unclear. By testing 64 CHIKV- and 37 MAYV-specific sera from cohort studies conducted in Peru and Brazil, we demonstrate about 50% false-positive test results using commercially available enzyme-linked immunosorbent assays (ELISAs) based on structural antigens. In contrast, combining ELISAs for CHIKV and MAYV significantly increased positive predictive values (PPV) among all cohorts from 35.3% to 88.2% for IgM and from 61.3% to 96.8% for IgG (P < 0.0001). Testing of longitudinally collected CHIKV-specific patient sera indicated that ELISA specificity is highest for IgM testing at 5 to 9 days post-onset of symptoms (dpo) and for IgG testing at 10 to 14 dpo. IgG cross-reactivity in ELISA was asymmetric, occurring in 57.9% of MAYV-specific sera compared to 29.5% of CHIKV-specific sera. Parallel plaque reduction neutralization testing (PRNT) for CHIKV and MAYV increased the PPV from 80.0% to 100% (P = 0.0053). However, labor-intense procedures and delayed seroconversion limit PRNT for patient diagnostics. In sum, individual testing for CHIKV or MAYV only is prone to misclassifications that dramatically impact patient diagnostics and sero-epidemiologic investigation. Parallel ELISAs for both CHIKV and MAYV provide an easy and efficient solution to differentiate CHIKV from MAYV infections. This approach may provide a template globally for settings in which alphavirus coemergence imposes similar problems. IMPORTANCE Geographically overlapping transmission of Chikungunya virus (CHIKV) and Mayaro virus (MAYV) in Latin America challenges serologic diagnostics and epidemiologic surveillance, as antibodies against the antigenically related viruses can be cross-reactive, potentially causing false-positive test results. We examined whether widely used ELISAs and plaque reduction neutralization testing allow specific antibody detection in the scenario of CHIKV and MAYV coemergence. For this purpose, we used 37 patient-derived MAYV-specific sera from Peru and 64 patient-derived CHIKV-specific sera from Brazil, including longitudinally collected samples. Extensive testing of those samples revealed strong antibody cross-reactivity in ELISAs, particularly for IgM, which is commonly used for patient diagnostics. Cross-neutralization was also observed, albeit at lower frequencies. Parallel testing for both viruses and comparison of ELISA reactivities and neutralizing antibody titers significantly increased diagnostic specificity. Our data provide a convenient and practicable solution to ensure robust differentiation of CHIKV- and MAYV-specific antibodies.

Chikungunya virus exposure partially cross-protects against Mayaro virus infection in mice

2021 ◽  
Author(s):  
Marcilio Jorge Fumagalli ◽  
William Marciel de Souza ◽  
Luiza Antunes de Castro-Jorge ◽  
Renan Villanova Homem de Carvalho ◽  
Ítalo de Araújo Castro ◽  
...  
Keyword(s):  
Latin America ◽  
Virus Infection ◽  
Immune Cells ◽  
Chikungunya Virus ◽  
Secondary Infection ◽  
Viral Transmission ◽  
Cross Protection ◽  
Adaptive Immune ◽  
Adaptive Immune Cells ◽  
Mayaro Virus

Chikungunya virus (CHIKV) and Mayaro virus (MAYV) are closely related members of the Semliki Forest virus antigenic complex classified as belonging to the genus Alphavirus of the Togaviridae family. These viruses cause human disease, with sudden fever and joint inflammation that can persist for long periods. CHIKV is the causative agent of large outbreaks worldwide, and MAYV infection represents a growing public health concern in Latin America, causing sporadic cases and geographically limited outbreaks. Considering the relationship between CHIKV and MAYV, the present study aimed to evaluate if pre-existing CHIKV immunity protects against MAYV infection. Immunocompetent C57BL/6 mice were intraperitoneally infected with CHIKV and, four weeks later, they were infected with MAYV in their hind paw. We observed that the pre-existence of CHIKV immunity confers partial cross-protection against secondary MAYV infection, reducing disease severity, tissue viral load, and histopathological scores. Interestingly, CHIKV antibodies from humans or mice showed low cross-neutralization to MAYV, but neutralizing activity significantly increased after secondary infection. Furthermore, depletion of adaptive immune cells (CD4 + , CD8 + T, and CD19 + B cells) did not alter the cross-protection phenotype, suggesting that distinct cell subsets or a combination of adaptive immune cells stimulated by CHIKV are responsible for the partial cross-protection against MAYV. The reduction of pro-inflammatory cytokines, such as IFN-γ, in animals secondarily infected by MAYV, suggests a role of innate immunity in cross-protection. Our findings shed light on how pre-existing immunity to arthritogenic alphaviruses may affect secondary infection, which may further develop relevant influence in disease outcome and viral transmission. Importance Mosquito-borne viruses have a worldwide impact, especially in tropical climates. Chikungunya virus has been present mostly in developing countries, causing millions of infections, while Mayaro virus, a close relative, has been limited to the Caribbean and tropical regions of Latin America. The potential emergence and spread of Mayaro virus to other high-risk areas have increased the scientific community’s attention to an imminent worldwide epidemic. Here, we designed an experimental protocol of chikungunya and Mayaro virus mice infection, which develops a measurable and quantifiable disease that allows us to make inferences about potential immunological effects during secondary virus infection. Our results demonstrate that previous chikungunya virus infection is able to reduce clinical outcomes during secondary Mayaro infection. We provide scientific understanding of immunological features during secondary infection with the closely related virus, thus assisting in better comprehending viral transmission and the pathological outcome of these diseases.

The Genesis and Internal Dynamics of El Salvador's People's Revolutionary Army, 1970–1976

2014 ◽  
Vol 38 (01) ◽  
pp. 102-129
Author(s):  
ALBERTO MARTÍN ÁLVAREZ ◽  
EUDALD CORTINA ORERO
Keyword(s):  
Latin America ◽  
El Salvador ◽  
Early Years ◽  
Left Wing ◽  
Internal Dynamics ◽  
Internal Coherence ◽  
The 1960S

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.

Latin America

1998 ◽  
Author(s):  
Leslie Bethell
Keyword(s):  
Latin America
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