Dengue Chikungunya co-infection: A live-in relationship??

Seroprevalence of Alphaviruses (Togaviridae) among Urban Population in Nouakchott, Mauritania, West Africa

The presence of alphaviruses, such as chikungunya virus (CHIKV), has never been reported in Mauritania. We assessed the seroprevalence of CHIKV among Nouakchott residents. A cross-sectional study involving 1300 non-febrile patients consulting at the Nouakchott hospital center was conducted between January and June 2021. The presence of anti-CHIKV IgG and neutralizing antibodies against CHIKV, O'nyong-nyong virus (ONNV), and Semliki Forest virus (SFV) was determined by an enzyme-linked immunosorbent assay (ELISA) and a serum neutralization test, respectively, and the associated risk factors were investigated. Of the 1300 study participants, serological evidence of previous exposure to CHIKV was observed in 37 individuals (2.8%). Sex, age, reported use of repellants, and bed net ownership and usage were not associated with CHIKV seropositivity. Our results showed the co-circulation of two other alphaviruses, ONNV and SFV, in Nouakchott in 30 (2.3%) individuals. This is the first study that documents the co-circulation of CHIKV, ONNV, and SFV in Mauritania, albeit at low prevalence. Surveillance and routine testing for alphaviruses and other arboviruses in symptomatic patients should be implemented in health facilities to assess the health burden associated with these viruses. Efforts should also be made to strengthen the vector control measures.

Short communication: Virological and B cell profiles of chikungunya and Dengue virus co-infections in Delhi during 2017-2019

With explosive epidemics of chikungunya in India since 2004, chikungunya virus (CHIKV) now co-circulates in geographical areas where Dengue virus (DENV) is already endemic and thus provides opportunity for the same mosquito to be infected with both viruses. Although there are excellent studies that have addressed the clinical of mono and co-infection, we have little to no knowledge on the current viral sequences that pre-dominate co-infections, and the B cell response elicited. In this study, we analyzed febrile patients that were confirmed to have DENV-CHIKV co-infections and asked the following questions: 1) what is the frequency of co-infections found in a single cycle of transmission; 2) what are the viral sequences associated with them; 3) what does the antibody secreting cell / plasmablast response look like in patients that are co-infected with both viruses. We report those co-infections occur at a frequency of 6.7% in the transmission cycle, and while DENV-3 is now frequently detected, we do not see a serotype bias in the patients that are co-infected with ESCA strain of CHIKV. Moreover, the effector B cell response (plasmablasts) observed are specific to both infecting viruses indicating no overt bias. Further studies to associate whether any of these properties have a bearing on clinical disease manifestation will be both timely and important.

Identification, Validation and Standardization of Bioactive Molecules Using UPLC/MS-QToF, UHPLC and HPTLC in Divya-Denguenil-Vati: A Penta-Herbal Formulation for Dengue Fever

For the last fifty years, Dengue has been one of the most common mosquito-borne arboviral infections which has spread over the tropical and subtropical world. Divya-Denguenil-Vati (DNV) has been formulated by blending five specific herbs for effective resolution of Dengue fever. In the present study, we aimed to identify, develop, validate, and standardize methods for Divya-Denguenil-Vati (DNV), on UHPLC and HPTLC analytical platforms, with rapid, sensitive, accurate and rugged attributes. At first, 97 phyto-constituents were identified by UPLC/MS-QToF in Divya-Denguenil-Vati. UHPLC method was then developed and validated for simultaneous determination of gallic acid, 5-HMF, protocatechuic acid, magnoflorine, methyl gallate, berberine, rutin, ellagic acid, β-ecdysone and rosmarinic acid in DNV. Four selected markers, gallic acid, rosmarinic acid, magnoflorine and rutin were further developed and validated on HPTLC. Analytical processes were validated as per ICH Q2 (R1) guidelines; and were found linear (r² > 0.99), sensitive, precise (%RSD < 5%), and accurate, as indicated by high recovery values (88–105%). The limit of detection and quantification were also established for these phyto-metabolites, with their respective RSDs within 5% limits. Finally, these validated methods were employed to test twenty six different commercial batches of DNV. The quality, reproducibility and consistency of DNV have been well established using these developed and reliable analytical tools. These analytical strategies successfully set a path forward for robust quality evaluation and standardization of Divya-Denguenil-Vati, and other related herbal formulations.

Computational analysis of human host binding partners of chikungunya and dengue viruses during coinfection

Mosquito-borne viral diseases like chikungunya and dengue infections can cause severe illness and have become major public health concerns. Chikungunya virus (CHIKV) and dengue virus (DENV) infections share similar primary clinical manifestations and are transmitted by the same vector. Thus, the probability of their coinfection gets increased with more severe clinical complications in the patients. The present study was undertaken to elucidate the common human interacting partners of CHIKV and DENV proteins during coinfection. The viral-host protein-protein interactome was constructed using Cytoscape. Subsequently, significant host interactors were identified during coinfection. The network analysis elucidated 57 human proteins interacting with both CHIKV and DENV, represented as hub-bottlenecks. The functional and biological analyses of the 40 hub-bottlenecks revealed that they are associated with phosphoinositide 3-kinases (PI3K)/AKT, p53 signaling pathways, regulation of cell cycle and apoptosis during coinfection. Moreover, the molecular docking analysis uncovered the tight and robust binding of selected hub-bottlenecks with CHIKV/DENV proteins. Additionally, 23 hub-bottlenecks were predicted as druggable candidates that could be targeted to eradicate the host-viral interactions. The elucidated common host binding partners during DENV and CHIKV coinfection as well as indicated approved drugs can support the therapeutics development.

Translational Research Consortia (TRC) for Chikungunya Virus in India. Current Status of Chikungunya in India

Chikungunya fever (CHIKF) is an arbovirus disease caused by chikungunya virus (CHIKV), an alphavirus of Togaviridae family. Transmission follows a human-mosquito-human cycle starting with a mosquito bite. Subsequently, symptoms develop after 2-6 days of incubation, including high fever and severe arthralgia. The disease is self-limiting and usually resolve within 2 weeks. However, chronic disease can last up to several years with persistent polyarthralgia. Overlapping symptoms and common vector with dengue and malaria present many challenges for diagnosis and treatment of this disease. CHIKF was reported in India in 1963 for the first time. After a period of quiescence lasting up to 32 years, CHIKV re-emerged in India in 2005. Currently, every part of the country has become endemic for the disease with outbreaks resulting in huge economic and productivity losses. Several mutations have been identified in circulating strains of the virus resulting in better adaptations or increased fitness in the vector(s), effective transmission, and disease severity. CHIKV evolution has been a significant driver of epidemics in India, hence, the need to focus on proper surveillance, and implementation of prevention and control measure in the country. Presently, there are no licensed vaccines or antivirals available; however, India has initiated several efforts in this direction including traditional medicines. In this review, we present the current status of CHIKF in India.

Pharyngeal-cervical-brachial variant of Guillain-Barré syndrome: a case report of a rare complication following Dengue-Chikungunya co-infection

Pharyngeal-cervical-brachial (PCB) variant of Guillain-Barré Syndrome (GBS) is characterized by weakness in cervicobrachial and oropharyngeal region, together with areflexia of upper limbs. Being an uncommon variant, it is often misdiagnosed as other neurological conditions resembling GBS. Although most of the cases occur as a post-infectious complication, no reports describing its development following dengue-chikungunya co-infection have been documented. A young female presented with a progressive history of swallowing difficulty, bilateral arm weakness and neck weakness. Three weeks earlier, she was presented with clinical features corresponding to dengue and was symptomatically treated. Currently, hypotonia and decreased muscle strength were observed in both upper limbs and neck. Detailed investigation revealed the presence of Immunoglobulin M (IgM) antibodies against dengue antigen (NS 1) and Chikungunya virus (CHIKV), confirming the possibility of previous dengue-chikungunya co-infection. Nerve conduction studies and electromyography of upper limbs pointed towards findings consistent with the early stages of acute motor demyelinating and possible axonal neuropathy. The detection of antiganglioside antibodies (anti-GT1a antibodies), confirmed the diagnosis of the pharyngeal-cervical-brachial variant of GBS. A five days treatment of intravenous immunoglobulin (IVIG) along with physical rehabilitation was started which led to significant improvement and the patient was discharged after 15 days. PCB is an unfamiliar variant of GBS for many clinicians. Diagnosis can be made by a thorough history, clinical examination and investigations that can rule out other potential causes of cervicobrachial and oropharyngeal weakness. It also necessitates careful monitoring and followups after mono- and co-arboviral infections to prevent any debilitating neurological complications.

Computer-Aided Design, Synthesis, and Antiviral Evaluation of Novel Acrylamides as Potential Inhibitors of E3-E2-E1 Glycoproteins Complex from Chikungunya Virus

Chikungunya virus (CHIKV) causes an infectious disease characterized by inflammation and pain of the musculoskeletal tissues accompanied by swelling in the joints and cartilage damage. Currently, there are no licensed vaccines or chemotherapeutic agents to prevent or treat CHIKV infections. In this context, our research aimed to explore the potential in vitro anti-CHIKV activity of acrylamide derivatives. In silico methods were applied to 132 Michael’s acceptors toward the six most important biological targets from CHIKV. Subsequently, the ten most promising acrylamides were selected and synthesized. From the cytotoxicity MTT assay, we verified that LQM330, 334, and 336 demonstrate high cell viability at 40 µM. Moreover, these derivatives exhibited anti-CHIKV activities, highlighting the compound LQM334 which exhibited an inhibition value of 81%. Thus, docking simulations were performed to suggest a potential CHIKV-target for LQM334. It was observed that the LQM334 has a high affinity towards the E3-E2-E1 glycoproteins complex. Moreover, LQM334 reduced the percentage of CHIKV-positive cells from 74.07 to 0.88%, 48h post-treatment on intracellular flow cytometry staining. In conclusion, all virtual simulations corroborated with experimental results, and LQM334 could be used as a promising anti-CHIKV scaffold for designing new drugs in the future.

RNA recombination at Chikungunya virus 3'UTR as an evolutionary mechanism that provides adaptability

The potential of RNA viruses to adapt to new environments relies on their ability to introduce changes in their genomes, which has resulted in the recent expansion of re-emergent viruses. Chikungunya virus is an important human pathogen transmitted by mosquitoes that, after 60 years of exclusive circulation in Asia and Africa, has rapidly spread in Europe and the Americas. Here, we examined the evolution of CHIKV in different hosts and uncovered host-specific requirements of the CHIKV 3'UTR. Sequence repeats are conserved at the CHIKV 3'UTR but vary in copy number among viral lineages. We found that these blocks of repeated sequences favor RNA recombination processes through copy-choice mechanism that acts concertedly with viral selection, determining the emergence of new viral variants. Functional analyses using a panel of mutant viruses indicated that opposite selective pressures in mosquito and mammalian cells impose a fitness cost during transmission that is alleviated by recombination guided by sequence repeats. Indeed, drastic changes in the frequency of viral variants with different numbers of repeats were detected during host switch. We propose that RNA recombination accelerates CHIKV adaptability, allowing the virus to overcome genetic bottlenecks within the mosquito host. These studies highlight the role of 3'UTR plasticity on CHIKV evolution, providing a new paradigm to explain the significance of sequence repetitions.

Antiviral activity of ethanolic extract of Nilavembu Kudineer against dengue and chikungunya virus through in vitro evaluation

Background

Currently, no vaccines or modern drugs are available for dengue and chikungunya and only symptomatic relief is provided to the patients. Siddha medicine, a traditional form of indigenous medical system uses specific polyherbal formulations for the treatment of such infections with considerable success. One such polyherbal formulation for the treatment of chikungunya and dengue is Nilavembu kudineer (NVK). The mechanistic details of this drug as an antiviral for chikungunya virus (CHIKV) and dengue virus (DENV) is poorly understood.

Objectives

The current study was undertaken to study the efficacy of NVK as an antiviral formulation against CHIKV and DENV.

Materials and methods

Cytotoxicity assays (MTT) were performed to determine the role of NVK as an antiviral during chikungunya and dengue infections in the following conditions-i). post infection, ii). during active infections and iii) protective, not allowing virus infection.

Results

It was observed that NVK provides protection against CHIKV and DENV-2 during active infection as well can help to prevent virus infection in the cells and it mainly depends on the cellular availability of drugs for maximum protection against both the infections.

Conclusion

Our study establishes that extraction protocols are important to ensure maximum efficacy of NVK along with the time of addition of the drug during CHIKV and DENV infections in the cells. This study provides insights to the possible mode of action of NVK in in vitro condition during CHIKV and DENV infection.

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Andrographis is a major component of Nilavembu kudineer.

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Andrographis is more cytotoxic when used singularly and hence is used as a polyherbal formulation.

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Ethanol Extract of Nilavembu Kudineer (NVK) exhibit antiviral properties.

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NVK has a prophylactic effect during chikungunya and dengue virus (CHIKV and DENV respectively) infection.

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NVK exhibits antiviral activity during active CHIKV and DENV infections.

Evaluation of an immunochromatography rapid diagnosis kit for detection of chikungunya virus antigen in India, a dengue-endemic country

Background

Chikungunya virus (CHIKV) and dengue virus (DENV) are arboviruses that share the same Aedes mosquito vector, and there is much overlap in endemic areas. In India, co-infection with both viruses is often reported. Clinical manifestations of Chikungunya fever is often confused with dengue fever because clinical symptoms of both infections are similar. It is, therefore, difficult to differentiate from those of other febrile illnesses, especially dengue fever. We previously developed a CHIKV antigen detection immunochromatography (IC) rapid diagnosis kit [1]. The current study examined the efficacy of previously mentioned IC kit in India, a dengue-endemic country.

Methods

Sera from 104 CHIKV-positive (by qRT-PCR) and/or IgM-positive (ELISA) subjects collected in 2016, were examined. Fifteen samples from individuals with CHIKV-negative/DENV-positive and 4 samples from healthy individuals were also examined. Of the 104 CHIKV-positive sera, 20 were co-infected with DENV.

Results

The sensitivity, specificity and overall agreement of the IC assay were 93.7, 95.5 and 94.3%, respectively, using qRT-PCR as a gold standard. Also, there was a strong, statistically significant positive correlation between the IC kit device score and the CHIKV RNA copy number. The IC kit detected CHIKV antigen even in DENV-co-infected patient sera and did not cross-react with DENV NS1-positive/CHIKV-negative samples.

Conclusions

The results suggest that the IC kit is useful for rapid diagnosis of CHIKV in endemic areas in which both CHIKV and DENV are circulating.

Electronic supplementary material

The online version of this article (10.1186/s12985-018-1000-0) contains supplementary material, which is available to authorized users.

Consequences of a recent past dengue infection for acute and long-term chikungunya outcome: A retrospective cohort study in Curaçao

BACKGROUND

Dengue and chikungunya co-infections are an emerging threat to public health in tropical and sub-tropical areas. This study investigates acute and long-term clinical presentation patterns of chikungunya against a backdrop of preceding dengue infection and determines predicting factors for long-term chikungunya sequelae.

METHODS

A retrospective cohort study was performed in 2015, including 299 previously confirmed chikungunya cases, of which 162 subjects were assessed for dengue serology at disease onset.

RESULTS

Those with previous dengue infection (35.2% of the examined population) had a similar acute disease presentation, and suffered (not statistically significantly) more frequently from long-term musculoskeletal and neuropsychological symptoms compared to chikungunya-only patients. Patients with a preceding dengue infection (vs. those without) (OR = 4.17; p = 0.004), female sex (OR = 3.17; p = 0.034) and pre-existing joint disease (OR = 2.95; p = 0.031) had a higher risk of developing aggravated long-term chikungunya. Chronic disease (sequelae lasting >90 days) was predicted by an age between 41 and 60 (OR = 3.07; p = 0.009) and concomitant cardiovascular disease (OR = 4.08; p = 0.010), but not by a preceding dengue infection.

CONCLUSIONS

This study suggests several predicting factors of, and a possible link between preceding dengue and chikungunya infection and aggravated long-term sequelae, which should be interpreted in the light of the limitations of this study.

Standardization of in vitro assays to evaluate the activity of polyherbal siddha formulations against Chikungunya virus infection

Chikungunya, a viral fever caused by Aedes mosquito results in extreme morbidity in affected individuals and is a major public health concern in India. Currently, modern vaccines or formulations prescribed by physicians can only provide symptomatic relief for the pyretic and post pyretic phase of the disease. Siddha practitioners follows strict medical regimen based on traditional Indian knowledge/concepts to treat Chikungunya with considerable results. The current study was undertaken to standardize assays for the study of these siddha formulations and to check their efficacy and potential mode of action as antivirals for Chikungunya virus infection in in vitro system. Although, siddha practitioners follow a regime containing 4-6 formulations, of these Brahmanandha bairavam mathirai, a part of the regime for Chikungunya followed at National Institute of Siddha and Vishnu chakram along with Brahmanandha bairavam mathirai, a part of Thiruchergodu Regime were found of have antiviral activities. It was observed that both Vishnu chakram and Brahmanandha bairavam mathirai were equally effective in blocking Chikungunya virus from entering susceptible cells in the concentrations range of 0.0625 and 0.5 mg/ml. Additionally, it was also observed that Brahmanandha bairavam mathirai was more effective than Vishnu chakram against entry of Chikungunya in the cells. The assays used in this study provides insights to the possible mode of action of various formulations used by siddha practitioners for the treatment of Chikungunya infection.

Interaction of Flavivirus with their mosquito vectors and their impact on the human health in the Americas

Some of the major arboviruses with public health importance, such as dengue, yellow fever, Zika and West Nile virus are mosquito-borne or mosquito-transmitted Flavivirus. Their principal vectors are from the family Culicidae, Aedes aegypti and Aedes albopictus being responsible of the urban cycles of dengue, Zika and yellow fever virus. These vectors are highly competent for transmission of many arboviruses. The genetic variability of the vectors, the environment and the viral diversity modulate the vector competence, in this context, it is important to determine which vector species is responsible of an outbreak in areas where many vectors coexist. As some vectors can transmit several flaviviruses and some flaviviruses can be transmitted by different species of vectors, through this review we expose importance of yellow fever, dengue and Zika virus in the world and the Americas, as well as the updated knowledge about these flaviviruses in their interaction with their mosquito vectors, guiding us on what is probably the beginning of a new stage in which the simultaneity of outbreaks will occur more frequently.