Diagnosis Of Chikungunya Virus Research Articles

Detection of Chikungunya Virus RNA in Oral Fluid and Urine: An Alternative Approach to Diagnosis?

To evaluate whether oral fluids (OF) and urine can serve as alternative, non-invasive samples to diagnose chikungunya virus (CHIKV) infection via RT-qPCR, we employed the same RNA extraction and RT-qPCR protocols on paired serum, OF and urine samples collected from 51 patients with chikungunya during the acute phase of the illness. Chikungunya patients were confirmed through RT-qPCR in acute-phase sera (N = 19), IgM seroconversion between acute- and convalescent-phase sera (N = 12), or IgM detection in acute-phase sera (N = 20). The controls included paired serum, OF and urine samples from patients with non-arbovirus acute febrile illness (N = 28) and RT-PCR-confirmed dengue (N = 16). Nine (47%) of the patients with positive RT-qPCR for CHIKV in sera and two (17%) of those with CHIKV infection confirmed solely via IgM seroconversion had OF positive for CHIKV in RT-qPCR. One (5%) patient with CHIKV infection confirmed via serum RT-qPCR was positive in the RT-qPCR performed on urine. None of the negative control group samples were positive. Although OF may serve as an alternative sample for diagnosing acute chikungunya in specific settings, a negative result cannot rule out an infection. Further research is needed to investigate whether OF and urine collected later in the disease course when serum becomes RT-qPCR-negative may be helpful in CHIKV diagnosis and surveillance, as well as to determine whether urine and OF pose any risk of CHIKV transmission.

The Chikungunya virus: A reemerging cause of acute febrile illness in the high jungle of northern Peru

Background The Chikungunya virus (CHIKV) is an emerging arthropod-borne virus (arbovirus) that causes undifferentiated acute febrile illness. Cases of CHIKV may be under-reported in Peru, given the various difficulties in diagnosing it, such as lack of diagnostic tests in remote areas, the passive nature of epidemiological surveillance, and co-circulation of other arthropod-borne pathogens. Therefore, a study was conducted in the high jungle of northern Peru to determine the prevalence of CHIKV among febrile patients and describe their clinical characteristics. Methods A cross-sectional study was conducted in the province of Jaen, Cajamarca, located in the high jungle of northern Peru. Patients attending primary healthcare centers within Cajamarca’s Regional Health Directorate were enrolled. The study took place from June 2020 through June 2021. Patients were eligible if they sought outpatient healthcare for a clinical diagnosis of acute febrile illness (AFI). Serum samples were collected from all patients, and the diagnosis of CHIKV was determined using real-time RT-PCR, as well as the detection of IgM antibodies by ELISA. A logistic regression model was employed to identify the risk factors for CHIKV, and the odds ratios (ORs) were calculated, along with their corresponding 95% confidence intervals (95% CI). Results A total of 1 047 patients with AFI were included during the study period. CHIKV was identified in 130 patients of 1 047 (12.4%). Among the CHIKV positive cases, 84 of 130 (64.6%) were diagnosed by RT-PCR, 42 of 130 (32.3%) by IgM ELISA detection, and 4 of 130 (3.1%) by both assays. The majority of patients with CHIKV infection fell within the 18–39 years age group (50.0%), followed by the 40–59 years age group (23.9%) and those with 60 years or older (10.8%). The most common clinical symptoms observed in patients with CHIKV infection were headache (85.4%), myalgias (72.3%), and arthralgias (64.6%). The highest number of positive CHIKV cases occurred in May (23.1%), followed by March (20.0%) and February (13.8%) of 2021. Conclusion The study reports a considerable frequency of CHIKV infections among patients with AFI from the high jungle of northern Peru. These findings highlight the importance of recognizing CHIKV as an ongoing pathogen with continuous transmission in various areas of Peru. It is crucial to enhance epidemiological surveillance by implementing reliable diagnostic techniques, as the clinical symptoms of CHIKV infection can be nonspecific.

Chikungunya Virus Diagnosis: A Review of Current Antigen Detection Methods.

Chikungunya is a mosquito-borne viral disease caused by the chikungunya virus (CHIKV). CHIKV is expanding at an alarming rate, potentially spreading and establishing endemicity in new areas where competent vectors are present. The dramatic spread of CHIKV in recent years highlights the urgent need to take precautionary measures and investigate options for control. It is crucial in developing nations where diagnostic tools are limited, and symptoms are similar to other prevalent diseases such as malaria and dengue. The most reliable method for diagnosing chikungunya virus is viral gene detection by RT-PCR. Alternative methods like detecting human antibody and viral antigen can also be used, especially in areas where resources are limited. In this review, we summarize the limited data on antigen detection immunoassays. We further explain the essential structural elements of the virus to help comprehend the scientific concepts underlying the testing methods, as well as future methods and diagnostic approaches under investigation.

Clinical Diagnosis of Chikungunya Infection: An Essential Aid in a Primary Care Setting Where Serological Confirmation Is Not Available.

Chikungunya virus (CHIKV) diagnosis has become a challenge for primary care physicians in areas where the Zika virus and/or Dengue virus are present. Case definitions for the three arboviral infections overlap. A cross-sectional analysis was carried out. A bivariate analysis was made using confirmed CHIKV infection as the outcome. Variables with significant statistical association were included in an agreement consensus. Agreed variables were analyzed in a multiple regression model. The area under the receiver operating characteristic (ROC) curve was calculated to determine a cut-off value and performance. 295 patients with confirmed CHIKV infection were included. A screening tool was created using symmetric arthritis (4 points), fatigue (3 points), rash (2 points), and ankle joint pain (1 point). The ROC curve identified a cut-off value, and a score ≥ 5.5 was considered positive for identifying CHIKV patients with a sensibility of 64.4% and a specificity of 87.4%, positive predictive value of 85.5%, negative predictive value of 67.7%, area under the curve of 0.72, and an accuracy of 75%. We developed a screening tool for CHIKV diagnosis using only clinical symptoms as well as proposed an algorithm to aid the primary care physician.

Manifestações cutâneas em seis crianças pelo CHIKV: uma série de casos

Objectives: To describe a case series of children diagnosed with Chikungunya virus (CHIKV) infection with atypical dermatologic manifestations, in order to broaden the picture of possibilities for differential diagnoses in cases of similar clinical presentations. Methods: This is a series of cases in which were included all patients aged between zero and 18 years and who, between January, 2018 and November, 2020, were admitted to the emergency department of a pediatric public hospital, presenting atypical cutaneous manifestations associated with a clinicalepidemiological or laboratory diagnosis of CHIKV. Results: A total of six patients were screened from a cohort of 432 patients. Of these, four were female and five were under one year of age. The most reported manifestations were fever of sudden onset, besides exanthema and bullous skin lesions, mainly affecting the limbs. There was hospitalization of five of patients, without deaths. Conclusion: Cutaneous presentations are of different magnitude according to the age range affected by CHIKV, especially for children under one year of age, affecting mainly extremity areas of the body surface. It is therefore worth noting that pediatric patients deserve greater attention and early care, in order to reduce complications from the infection and thus also the morbidity of the affected population

A Chikungunya Virus Multiepitope Recombinant Protein Expressed from the Binary System Insect Cell/Recombinant Baculovirus Is Useful for Laboratorial Diagnosis of Chikungunya.

Chikungunya virus (CHIKV) is an arbovirus currently distributed worldwide, causing a disease that shares clinical signs and symptoms with other illnesses, such as dengue and Zika and leading to a challenging clinical differential diagnosis. In Brazil, CHIKV emerged in 2014 with the simultaneous introduction of both Asian and East/Central/South African (ECSA) genotypes. Laboratorial diagnosis of CHIKV is mainly performed by molecular and serological assays, with the latter more widely used. Although many commercial kits are available, their costs are still high for many underdeveloped and developing countries where the virus circulates. Here we described the development and evaluation of a multi-epitope recombinant protein-based IgG-ELISA (MULTREC IgG-ELISA) test for the specific detection of anti-CHIKV antibodies in clinical samples, as an alternative approach for laboratorial diagnosis. The MULTREC IgG-ELISA showed 86.36% of sensitivity and 100% of specificity, and no cross-reactivity with other exanthematic diseases was observed. The recombinant protein was expressed from the binary system insect cell/baculovirus using the crystal-forming baculoviral protein polyhedrin as a carrier of the target recombinant protein to facilitate recovery. The crystals were at least 10 times smaller in size and had an amorphous shape when compared to the polyhedrin wild-type crystal. The assay uses a multi-epitope antigen, representing two replicates of 18 amino acid sequences from the E2 region and a sequence of 17 amino acids from the nsP3 region of CHIKV. The recombinant protein was highly expressed, easy to purify and has demonstrated its usefulness in confirming chikungunya exposure, indeed showing a good potential tool for epidemiological surveillance.

Molecular aspects of Chikungunya virus infections in cancer patients.

BACKGROUND Chikungunya virus (CHIKV) is an arbovirus that can cause chronic and debilitating manifestations. The first autochthonous case in Rio de Janeiro state was diagnosed in 2015, and an outbreak was declared in 2016.OBJECTIVE The aim of this work was to evaluate CHIKV viral load in serum, plasma and urine in cancer patients to determine the best sample for diagnosis, as well as perform molecular characterisation and phylogenetic analysis of circulating strains.METHODS Paired serum, plasma and urine collected from 31 cancer patients were tested by real-time quantitative polymerase chain reaction (qPCR) and a segment of the CHIKV E1 gene was sequenced.FINDINGS We detected 11 CHIKV+ oncological patients. Paired samples analyses of nine patients showed a different pattern of detection. Also, a higher viral load in plasma (6.84 log10) and serum (6.07 log10) vs urine (3.76 log10) was found. Phylogenetic analysis and molecular characterisation revealed East/Central/Southern Africa (ECSA) genotype circulation and three amino acids substitutions (E1-K211T, E1-M269V, E1-T288I) in positive patients.MAIN CONCLUSION The results indicate the bioequivalence of serum and plasma for CHIKV diagnosis, with urine being an important complement. ECSA genotype was circulating among patients in the period of the 2016 outbreak with K211T, M269V and T288I substitution.

Chikungunya virus titration, detection and diagnosis using N-Acetylglucosamine (GlcNAc) specific lectin based virus capture assay

Re-emergence and global expansion of Chikungunya virus (CHIKV) from Africa to Indian Subcontinent in 2013, has significantly resulted in chronic morbidities in infected individuals. The burden of CHIKV on human population is still uncertain, owing to lack of vaccine and underdiagnosis. Due to the absence of vaccine or antiviral therapeutics, timely diagnosis and detection of CHIKV is vital for minimizing virus transmission. Commercially available diagnostic and titration kits relies on the traditional methods such as real-time PCR (RT-PCR), serodiagnostic assays, and plaque assay, which are expensive, time-consuming and technically challenging. To overcome these limitations and to increase the diagnostic coverage of CHIKV infections, a rapid and economical antigen capture assay has been developed in this study for serological diagnosis of CHIKV, using tamarind chitinase (chi)-like lectin (TCLL). TCLL extracted and purified from tamarind seeds (Tamarindus indica), has been reported recently to bind to N-acetylglucosamine (GlcNAc) containing glycan on the envelope protein of virus. Evaluation of antigen capture assay for serological diagnosis of CHIKV signified that the developed assay is able to detect CHIKV in both laboratory and clinical samples efficiently. Furthermore, a standard graph using different concentrations of CHIKV has been established using samples with known virus titer, to assist in quantification of viral load in a given sample. The feasibility of antigen capture assay for broad-spectrum diagnosis of alphaviral infections was evaluated using Sindbis virus (SINV) belonging to the same alphavirus genus, and the results obtained were in agreement with those of CHIKV. In summary, the developed glycan-based virus capture assay can be potentially applied as point-of-care routine diagnostic and titration assay for CHIKV as well for other re-emerging alphaviral infections.

Chikungunya in Indonesia: Epidemiology and diagnostic challenges.

Chikungunya virus (CHIKV) is often overlooked as an etiology of fever in tropical and sub-tropical regions. Lack of diagnostic testing capacity in these areas combined with co-circulation of clinically similar pathogens such as dengue virus (DENV), hinders CHIKV diagnosis. To better address CHIKV in Indonesia, an improved understanding of epidemiology, clinical presentation, and diagnostic approaches is needed. Acutely hospitalized febrile patients ≥1-year-old were enrolled in a multi-site observational cohort study conducted in Indonesia from 2013 to 2016. Demographic and clinical data were collected at enrollment; blood specimens were collected at enrollment, once during days 14 to 28, and three months after enrollment. Plasma samples negative for DENV by serology and/or molecular assays were screened for evidence of acute CHIKV infection (ACI) by serology and molecular assays. To address the co-infection of DENV and CHIKV, DENV cases were selected randomly to be screened for evidence of ACI. ACI was confirmed in 40/1,089 (3.7%) screened subjects, all of whom were DENV negative. All 40 cases initially received other diagnoses, most commonly dengue fever, typhoid fever, and leptospirosis. ACI was found at five of the seven study cities, though evidence of prior CHIKV exposure was observed in 25.2% to 45.9% of subjects across sites. All subjects were assessed during hospitalization as mildly or moderately ill, consistent with the Asian genotype of CHIKV. Subjects with ACI had clinical presentations that overlapped with other common syndromes, atypical manifestations of disease, or persistent or false-positive IgM against Salmonella Typhi. Two of the 40 cases were possibly secondary ACI. CHIKV remains an underdiagnosed acute febrile illness in Indonesia. Public health measures should support development of CHIKV diagnostic capacity. Improved access to point-of-care diagnostic tests and clinical training on presentations of ACI will facilitate appropriate case management such as avoiding unneccessary treatments or antibiotics, early response to control mosquito population and eventually reducing disease transmission.

Development of an E2 ELISA Methodology to Assess Chikungunya Seroprevalence in Patients from an Endemic Region of Mexico.

Chikungunya fever is a debilitating disease caused by Chikungunya virus (CHIKV) that can result in long-lasting arthralgias. The early diagnosis of CHIKV relies on PCR during the acute infection phase to allow differential diagnosis with other co-circulating arboviruses such as dengue and Zika. Alternatively, serology can support diagnosis and provide epidemiological information on current and past outbreaks. Many commercial serological ELISA assays are based on the inactivated whole CHIKV, but their sensitivity and specificity show great variability. We produced recombinant CHIKV E2 that is suitable for ELISA assays, which was used for the serodiagnosis of CHIKV infections occurring in an arbovirus endemic Mexican region within Michoacán state. A cross-sectional study was conducted in 2016–2017; sera was obtained from 15 healthy donors and 68 patients presenting undifferentiated febrile illness. Serum samples were screened by RT-PCR and by our in-house ELISA assay. Our results indicate that IgM and IgG anti-CHIKV E2 antibodies were detected with our ELISA assay with higher sensitivity than a commercially available CHIKV ELISA kit. Our simple and sensitive ELISA assay for the serodiagnosis of CHIKV infections can be applied to population-based seroprevalence surveys and has potential for monitoring vaccine immunogenicity in CHIKV vaccine clinical trials.

Laboratory Diagnostic Options and Challenges for Chikungunya Viruses

Background: Chikungunya infection is a Aedes mosquito transmitted viral disease caused by Chikungunya virus (CHIKV), a member of the Alphavirus genus. It is an important human pathogen that causes a syndrome characterized by fever, chills, headache and severe joint pain usually of the smaller joints, with or without swelling. Though the disease is almost self-limiting, during the recent outbreak CHIKV was also found to cause long-term arthralgia, neurological disease and even few fatalities. Despite the fact that CHIKV is associated with epidemics of unprecedented magnitude, only a few specific serological and molecular diagnostic tools are available.Objective: CHIKV diagnosis is essentially based on virus isolation, reverse transcription (RT)-PCR and ELISA assays. The gold standard of CHIKV diagnosis is culture, however, required facilities and skills are not available in any routine laboratory in the country. Highly sensitive and specific PCR assays for CHIKV have been developed and commercially available.Conclusion: Although the reagents and equipment are costly for widespread use RT-PCR is the method of choice for the early detection and confirmation of virus in clinical samples as most acutely infected patients seek medical attention within the first few days of illness when role of serology based diagnosis is minimum.Pulse Vol.10 January-December 2017 p.18-24

Optic Neuritis and Acute Transverse Myelitis after Chikungunya virus infection

Background: Since 2015, an outbreak of the Chikungunya virus (CHIKV), was identified in north and northeastern Brazil and Caribbean. The infection has demonstrated itself to be benign and self-limited in the vast majority of cases; however, complications, including injuries to the central and peripheral nervous systems, have been reported. Complete Acute Transverse Myelitis (ATM) associated with Optic Neuritis (ON) after this virus infection has never been reported in the literature. Methods & Materials: Medical record and clinical interview. Results: Case report: 63-year-old white woman, presented after acute fever, headache, and arthralgia, urinary retention associated with progressive paraparesis, evolving with paraplegia in a few days. Simultaneously presented reduction of visual acuity, sudden installation, associated with bilateral diplopia. The beginning of neurological symptoms surfaced about of 30 days after the beginning of fever. Confirmed the serological diagnosis of CHIKV (IgM/ELISA). Spinal cord MRI showed multiple lesions in cervical and thoracic areas, with gadolinium uptake. Assessment of visual acuity was reduced in both eyes, with bilateral scotomas. Cerebrospinal fluid analysis revealed normal patterns of protein and glucose, but lymphocytic pleocytosis. Bacterial (Gram and Ziehl Neelsen methods), fungal (Cryptococcus) and viral (herpes simplex, cytomegalovirus, varicella-zoster, HTLV, dengue, zika and chikungunya) analyses were negative; intrathecal synthesis of IgG, IgM and oligoclonal bands presented with normal values. Blood test results were normal throughout the clinical course. She began treatment with methylprednisolone (1 g/daily) for 3 days. There was visual deficit improvement and total disappearance of spinal cord lesions, but with persistence of motor neurological deficits. Conclusion: This is an unprecedented case report of association between the CHIKV infection and neurologic manifestations: optic neuritis and acute transverse myelitis. Although the association between the arbovirus and demyelinating syndromes is rare it is possible the involvement of the nervous system secondary to the infectious process. If a patient who lives in or who has traveled to an area with endemic CHIKV presents with signs of ATM or ON, the existence of this agent must be investigated. If its presence is confirmed in the blood and/or CSF, in the absence of other causes, its relationship with nervous injury is confirmed.

Neurological evaluation in patients infected with Chikungunya virus: analysis of a cohort of Rio de Janeiro/Brazil

Background: In addition to fever and typical joint pain caused by Chikungunya virus (CHIKV), demonstrations as meningoencephalitis, mielorradiculopathy, mieloneuropathy and myelitis, Guillain-Barre syndrome have been described. However, most of the neurological changes have been reported in the acute phase, there are few records in the chronic phase of the disease. Given this, the objectives is to describe in this study the main changes to the neurological examination in patients infected by CHIKV in the chronic phase of the disease. Methods & Materials: Neurological assessment of patients with diagnosis of CHIKV served in a reference center in Rio de Janeiro/Brazil between February and July 2017. Results: Twelve patients were evaluated, 10 women, 2 men. All patients evaluated were chronic phase of the disease, with no signs of acute infection. Changes found in the clinical examination: hipopalestesia by at least two members in 5 (41.6%) patients, and hypoesthesia (tactile, thermal and painful) in 5 (41.6%). 3 patients (25%) presented concomitance of the two amendments. 2 (16.6%) did not show any changes to the neurological examination. Only 1 patient developed neurological symptoms during the acute phase of the disease (paresthesia in the lower limbs). No patient presented any neurological symptoms during the evaluation. 3 (25%) were in use of metrotexate (10 mg/day) due to the severity of the joint pain, but did not provide different neurological changes. Rheumatologic tests (FAN, rheumatoid factor) were negative in all. One patient has diabetes and other Sjogren's syndrome-neurological deficits remained with the same sensitivity pattern in these two cases. All patients had diagnostic confirmation for CHIKV (serological evaluation); no other infectious disease was identified. The pain described by all patients was of origin nociceptive, not neuropathic (according to the application questionnaire for neuropathic pain DN4). Conclusion: Patients in acute and chronic phase of infection by CHIKV may have neurological changes, even without a specific manifestation. The commitment of superficial sensitivity was the dominant one in this sample evaluation; no central symptom was observed. The severity of the joint pain, the most important thing in these cases, has not been directly linked to neurological changes.

Detection of chikungunya virus DNA using two-dimensional MoS2 nanosheets based disposable biosensor

Development of platforms for a reliable, rapid, sensitive and selective detection of chikungunya virus (CHIGV) is the need of the hour in developing countries. To the best of our knowledge, there are no reports available for the electrochemical detection of CHIGVDNA. Therefore, we aim at developing a biosensor based on molybdenum disulphide nanosheets (MoS2 NSs) for the point-of-care diagnosis of CHIGV. Briefly, MoS2 NSs were synthesized by chemical route and characterized using scanning electron microscopy, transmission electron microscopy, UV-Vis spectroscopy, Raman spectroscopy and X-Ray Diffraction. MoS2 NSs were then subjected to physical adsorption onto the screen printed gold electrodes (SPGEs) and then employed for the detection of CHIGV DNA using electrochemical voltammetric techniques. Herein, the role of MoS2 NSs is to provide biocompatibility to the biological recognition element on the surface of the screen printed electrodes. The detection strategy employed herein is the ability of methylene blue to interact differentially with the guanine bases of the single and double-stranded DNA which leads to change in the magnitude of the voltammetric signal. The proposed genosensor exhibited a wide linear range of 0.1 nM to 100 µM towards the chikungunya virus DNA.

The 2016-2017 Chikungunya Outbreak in Karachi.

Introduction: Chikungunya is an incipient disease, caused by Chikungunya virus (CHKV) that belongs to genus alphavirus of the family Togaviridae.Materials and Methods: In this study, during an outbreak of CHKV in Dec 2016 in Karachi, Pakistan, samples were collected from patients presenting with fever, tiredness and pain in muscles and joints. Total 126 sera were tested for the presence of Chikungunya infection through ELISA and Real-time Reverse Transcriptase PCR assay.Results and Discussion: This study showed that approx 79.4% samples were positive for CHKV. To our knowledge, this is the first reported outbreak from last decades in which the presence of CHKV is confirmed in Karachi while affecting such large no. of individuals.. Conclusion: CHKV diagnosis should be considered by the scientists and clinicians as a differential diagnosis in febrile patients, and appropriate control strategies must be adopted for its surveillance.

Chikungunya virus in Canada

This article presents a previously reported case involving the first Canadian patient to acquire Chikungunya virus (CHIKV) infection after travelling to a newly endemic region in the Americas. The specific history and clinical presentation of this patient is examined, including the treatment and complete resolution of the patient’s symptoms. A brief overview of the general disease course and diagnosis of CHIKV is provided. This case emphasizes the importance of global health education in Canadian medical curricula. The current standards of global health education in Canadian medical schools are briefly reviewed and recommendations based on expert opinions are provided. Although such programs exist, their implementation was found to be variable between schools and increased attention and standardization is currently required.

Clinical characterization of acute and convalescent illness of confirmed chikungunya cases from Chiapas, S. Mexico: A cross sectional study.

BackgroundThe emerging chikungunya virus (CHIKV), is an arbovirus causing intense outbreaks in North America. The situation in Mexico is alarming, and CHIKV threatens to spread further throughout North America. Clinical and biological features of CHIKF outbreaks in Mexico have not been well described; thus, we conducted a cross sectional study of a CHIKV outbreak in Chiapas, Southern Mexico to further characterize these features.Methodology/Principal findingsWe collected blood samples from patients suspected of having chikungunya fever (CHIKF) who presented to Clinical Hospital ISSSTE Dr. Roberto Nettel in Tapachula, Chiapas, Mexico. In addition to the clinical examination, real-time polymerase chain reaction (PCR) standardized for the Asian Chikungunya lineage and/or enzyme-linked immunosorbent assay for immunoglobulin M (IgM) were used to confirm CHIKV diagnosis. Of a total of 850 patients who presented with probably CHIKV at Hospital “Dr. Roberto Nettel”, 112 probable CHIKF cases were enrolled in this study from November 2014- June 2015, of which 95 patients (84.8%) were CHIKV positive and 17 were negative (15.2%). Of these 95 CHIKV positive patients, 62 were positive by real-time reverse transcriptase PCR (+qRT-PCR); and 33 were seropositive to +IgM with a negative qRT-PCR. The most frequent symptoms reported were fever (100%), headache (82.3%), polyarthralgia (72.1%), and exanthem (82.3%). Biological abnormalities observed during CHIKV infection were lymphopenia (41.1%), leukopenia (51.6%), elevated transaminases (30.5%-46.3%) and high LDH (46.3%) and CRP (60.0%).ConclusionClinical and biological data obtained from this study is providing more useful information for benchmarking purposes with outbreaks from different parts of the world and would be helpful for better patient care and treatment.

Chikungunya: important lessons from the Jamaican experience

ABSTRACTObjectives.To describe the clinical presentation of chikungunya virus (CHIKV) illness in adults during the 2014 outbreak in Jamaica and to determine the predictive value of the case definition.Methods.A cross-sectional study was conducted using clinical data from suspected cases of CHIKV that were reported to the Ministry of Health in April – December 2014. In addition, charts were reviewed of all individuals over 15 years of age with suspected CHIKV based on a diagnosis of CHIKV or “acute viral illness” that presented to four major health centers in Jamaica during the week prior to and the peak week of the epidemic. Data abstracted from these charts using a modified CHIKV Case Investigation Form included demographics, clinical findings, and laboratory tests.Results.In 2014, the Ministry of Health of Jamaica received 4 447 notifications of CHIKV infection. PCR testing was conducted on 137 suspected CHIKV cases (56 men and 81 women; median age 28 years) and was positive for 89 (65%) persons. In all, 205 health charts were identified that met the selection criteria (51 men and 154 women, median age 43 years). The most commonly reported symptoms were arthralgia (86%) and fever (76%). Of those who met the epidemiologic case definition for CHIKV as defined by the Pan American Health Organization, only 34% had this diagnosis recorded. Acute viral illness was the most frequently recorded diagnosis (n = 79; 58%).Conclusions.Broader case definitions for acute CHIKV illness may be needed to identify suspected cases during an outbreak. Standardized data collection forms and validation of case definitions may be useful for future outbreaks.

Molecular and Phylogenetic Evidence of Chikungunya Virus Circulating in Assam, India

Purpose: Northeast Region of India possesses an abundant number of Aedes mosquitoes, the common vector for Dengue and Chikungunya (CHIK). Dengue is reported every year from Assam, but active surveillance for CHIK virus (CHIKV) infection is lacking in this part of India. Therefore, this present study has been undertaken to detect any CHIKV infection during a dengue outbreak in Assam. Materials and Methods: A total of 42 dengue negative samples collected from Guwahati were screened for the presence of CHIK IgM antibodies. Further, all the samples were processed for CHIKV RNA detection by reverse transcriptase-polymerase chain reaction (RT-PCR). Phylogenetic analysis was done by Maximum Likelihood method using Kimura-2 parameter model. Results: No IgM positivity was found in the processed samples; however, 7 samples were positive for CHIKV by RT-PCR. Phylogenetic analysis revealed that the circulating CHIKV belonged to Eastern, Central and Southern African genotype. Sequence analysis showed two uniform nucleotide substitutions and very less amino acid substitution.Conclusion: Silent existence of CHIKV beside dengue is reported from this study. Therefore, CHIKV diagnosis should be included as a regular practice for active surveillance of the disease and its accomplishment before commencing an outbreak.

Development of in-house serological methods for diagnosis and surveillance of chikungunya

ABSTRACTObjective.To develop and evaluate serological methods for chikungunya diagnosis and research in Nicaragua.Methods.Two IgM ELISA capture systems (MAC-ELISA) for diagnosis of acute chikungunya virus (CHIKV) infections, and two Inhibition ELISA Methods (IEM) to measure total antibodies against CHIKV were developed using monoclonal antibodies (mAbs) and hyperimmune serum at the National Virology Laboratory of Nicaragua in 2014–2015. The sensitivity, specificity, predictive values, and agreement of the MAC-ELISAs were obtained by comparing the results of 198 samples (116 positive; 82 negative) with the Centers for Disease Control and Prevention’s IgM ELISA (Atlanta, Georgia, United States; CDC-MAC-ELISA). For clinical evaluation of the four serological techniques, 260 paired acute and convalescent phase serum samples of suspected chikungunya cases were used.Results.All four assays were standardized by determining the optimal concentrations of the different reagents. Processing times were substantially reduced compared to the CDC-MAC-ELISA. For the MAC-ELISA systems, a sensitivity of 96.6% and 97.4%, and a specificity of 98.8% and 91.5% were obtained using mAb and hyperimmune serum, respectively, compared with the CDC method. Clinical evaluation of the four serological techniques versus the CDC real-time RT-PCR assay resulted in a sensitivity of 95.7% and a specificity of 88.8%–95.9%.Conclusion.Two MAC-ELISA and two IEM systems were standardized, demonstrating very good quality for chikungunya diagnosis and research demands. This will achieve more efficient epidemiological surveillance in Nicaragua, the first country in Central America to produce its own reagents for serological diagnosis of CHIKV. The methods evaluated here can be applied in other countries and will contribute to sustainable diagnostic systems to combat the disease.