Chikungunya virus infection in Aruba: Diagnosis, clinical features and predictors of post-chikungunya chronic polyarthralgia

Sedentary behavior, increasing age, and overweight/obesity increase the presence and intensity of the chronic joint pain in individuals affected by Chikungunya fever

BACKGROUND

Chikungunya fever (CF) is a viral disease, transmitted by alphavirus through Aedes aegypti, and albopictus mosquitoes, affecting several people, mainly in tropical countries, when its transmitter is not under control, and the main symptom of the chronic phase of CF is joint pain.

OBJECTIVES

The primary objective of this study was to observe the prevalence, most affected joints, and intensity of chronic joint pain in individuals affected by CF, and also identify the factors associated with chronic joint pain in these individuals.

METHODS

Cross-sectional study that evaluated one hundred and thirty volunteers, of both sexes, aged between 20-65 years, with a clinical and/or laboratory diagnosis of CF. The presence of joint pain was investigated using the Brazilian version of the Nordic Questionnaire of Musculoskeletal Symptoms and the intensity of pain using the Visual Analogue Scale.

RESULTS

Of the 130 volunteers evaluated, n = 112 (86%) reported currently experiencing chronic joint pain, persistent, for approximately 38.6 ± 1.73 months, with the greatest predominance in the morning (58%). The joints most affected by pain were: the ankles (65.5%), interphalangeal joints of the hands (59.2%), and knees (59.2%). The joints that presented the greatest intensity of pain were: the ankles (5.13 ± 0.34), interphalangeal joints of the hands (4.63 ± 0.34), and knees (4.33 ± 0.33). Sedentary behavior (p = 0.037), increasing age (p = 0.000), and overweight/obesity (p = 0.002) were factors associated with chronic joint pain.

CONCLUSION

A high prevalence of chronic, persistent joint pain was observed, with a greater prevalence in the morning. The joints most affected by chronic pain and with the greatest pain intensity were the ankles, and interphalangeal joints of the hands and knees. Sedentary behavior, increasing age, and overweight/obesity were the factors associated with chronic joint pain in individuals affected by CF in this study. Key Points • Individuals affected by CF had a high prevalence of chronic joint pain, persistent and more prevalent in the mornings • The ankles and interphalangeal joints of the hands and knees were the joints with the highest prevalence of pain • The ankles and interphalangeal joints of the hands and knees were the joints with the greatest pain intensity • Sedentary behavior, increasing age, and overweight/obesity were factors associated with chronic joint pain in individuals affected by CF.

Clinical outcomes of chikungunya: A systematic literature review and meta-analysis

BACKGROUND

Chikungunya is a viral disease caused by a mosquito-borne alphavirus. The acute phase of the disease includes symptoms such as fever and arthralgia and lasts 7-10 days. However, debilitating symptoms can persist for months or years. Despite the substantial impact of this disease, a comprehensive assessment of its clinical picture is currently lacking.

METHODS

We conducted a systematic literature review on the clinical manifestations of chikungunya, their prevalence and duration, and related hospitalization. Embase and MEDLINE were searched with no time restrictions. Subsequently, meta-analyses were conducted to quantify pooled estimates on clinical outcomes, the symptomatic rate, the mortality rate, and the hospitalization rate. The pooling of effects was conducted using the inverse-variance weighting methods and generalized linear mixed effects models, with measures of heterogeneity reported.

RESULTS

The systematic literature review identified 316 articles. Out of the 28 outcomes of interest, we were able to conduct 11 meta-analyses. The most prevalent symptoms during the acute phase included arthralgia in 90% of cases (95% CI: 83-94%), and fever in 88% of cases (95% CI: 85-90%). Upon employing broader inclusion criteria, the overall symptomatic rate was 75% (95% CI: 63-84%), the chronicity rate was 44% (95% CI: 31-57%), and the mortality rate was 0.3% (95% CI: 0.1-0.7%). The heterogeneity between subpopulations was more than 92% for most outcomes. We were not able to estimate all predefined outcomes, highlighting the existing data gap.

CONCLUSION

Chikungunya is an emerging public health concern. Consequently, a thorough understanding of the clinical burden of this disease is necessary. Our study highlighted the substantial clinical burden of chikungunya in the acute phase and a potentially long-lasting chronic phase. Understanding this enables health authorities and healthcare professionals to effectively recognize and address the associated symptoms and raise awareness in society.

Viremia and clinical manifestations in acute febrile patients of Chikungunya infection during the 2016 CHIKV outbreak in Delhi, India

Background

Chikungunya virus (CHIKV) is an infectious agent that caused several outbreaks among different countries and affected approximately 1.3 million Indian populations. It is transmitted by Aedes mosquito-either A. albopictus or A. aegypti. Generally, the clinical manifestations of CHIKV infection involve high-grade fever, joint pain, skin rashes, headache, and myalgia. The present study aims to investigate the relationship between the CHIKV virus load and clinical symptoms of the CHIKV infection so that better patient management can be done in the background of the CHIKV outbreak as there is no licensed anti-viral drug and approved vaccines available against CHIKV.

Methods

CHIKV RTPCR positive samples (n = 18) (Acute febrile patients having D.O.F ≤ 7 days) were taken for the quantification of CHIKV viremia by Real-Time PCR. Clinical features of the febrile patients were recorded during the collection of blood samples.

Results

The log mean virus load of 18 RT-PCR-positive samples was 1.3 × 106 copies/mL (1.21 × 103-2.33 × 108 copies/mL). Among the observed clinical features, the log mean virus load (CHIKV) of the patients without skin rash is higher than in the patients with skin rash (6.61 vs 5.5, P = 0.0435).

Conclusion

The conclusion of the study was that the patients with skin rashes had lower viral load and those without skin rashes had higher viral load.

Joint Involvement Can Predict Chikungunya in a Dengue Syndemic Setting in India

Dengue and chikungunya have been endemic in India but have the tendency to cause periodic epidemics, often together, wherein they are termed 'syndemic'. Such a syndemic was observed in 2016 in India which resulted in a further scarcity of already resource-poor specific diagnostic infrastructure even in many urban conglomerates. A cross-sectional study was thus conducted, on 978 fever patients that consulted the ICMR-NIMR fever clinic, New Delhi, in September 2016, with an objective to identify symptom/s that could predict chikungunya with certainty. The overall aim was to rationally channelize the most clinically suitable patients for the required specific diagnosis of chikungunya. Based on their clinical profile, febrile patients attending NIMR's clinic, appropriate laboratory tests and their association analyses were performed. Bivariate analysis on 34 clinical parameters revealed that joint pain, joint swelling, rashes, red spots, weakness, itching, loss of taste, red eyes, and bleeding gums were found to be statistically significantly associated predictors of chikungunya as compared to dengue. While, in multivariate analysis, only four symptoms (joint pain in elbows, joint swelling, itching and bleeding gums) were found in statistically significant association with chikungunya. Hence, based on the results, a clinician may preferably channelize febrile patients with one or more of these four symptoms for chikungunya-specific diagnosis and divert the rest for dengue lab diagnosis in a dengue-chikungunya syndemic setting.

Mayaro virus pathogenesis and immunity in rhesus macaques

Mayaro virus (MAYV) is a mosquito-transmitted alphavirus that causes debilitating and persistent arthritogenic disease. While MAYV was previously reported to infect non-human primates (NHP), characterization of MAYV pathogenesis is currently lacking. Therefore, in this study we characterized MAYV infection and immunity in rhesus macaques. To inform the selection of a viral strain for NHP experiments, we evaluated five MAYV strains in C57BL/6 mice and showed that MAYV strain BeAr505411 induced robust tissue dissemination and disease. Three male rhesus macaques were subcutaneously challenged with 105 plaque-forming units of this strain into the arms. Peak plasma viremia occurred at 2 days post-infection (dpi). NHPs were taken to necropsy at 10 dpi to assess viral dissemination, which included the muscles and joints, lymphoid tissues, major organs, male reproductive tissues, as well as peripheral and central nervous system tissues. Histological examination demonstrated that MAYV infection was associated with appendicular joint and muscle inflammation as well as presence of perivascular inflammation in a wide variety of tissues. One animal developed a maculopapular rash and two NHP had viral RNA detected in upper torso skin samples, which was associated with the presence of perivascular and perifollicular lymphocytic aggregation. Analysis of longitudinal peripheral blood samples indicated a robust innate and adaptive immune activation, including the presence of anti-MAYV neutralizing antibodies with activity against related Una virus and chikungunya virus. Inflammatory cytokines and monocyte activation also peaked coincident with viremia, which was well supported by our transcriptomic analysis highlighting enrichment of interferon signaling and other antiviral processes at 2 days post MAYV infection. The rhesus macaque model of MAYV infection recapitulates many of the aspects of human infection and is poised to facilitate the evaluation of novel therapies and vaccines targeting this re-emerging virus.

Inflammation, fibrosis and E1 glycoprotein persistence in joint tissue of patients with post-Chikungunya chronic articular disease

INTRODUCTION

Chikungunya chronic joint disease causes debilitating arthralgia, significantly impacting the quality of life of affected individuals.

METHODS

In this study, patients underwent clinical follow-ups, joint biopsies, and pre-biopsy and 24 months post-biopsy serum dosage of cytokines.

RESULTS

All participants were female and had pain in 12 joints on average, with 41.17% exhibiting moderate disease activity. Histopathological analysis revealed collagen deposition. Indirect immunofluorescence detected the CHIKV glycoprotein E1 antigen, and an increase in cytokines.

CONCLUSIONS

Persistent inflammation and ineffective antiviral immune responses leading to antigen persistence may contribute to chronic CHIKV arthritis.

Burden of Chikungunya Virus Infection during an Outbreak in Myanmar

Chikungunya virus (CHIKV) infection is a re-emerging arboviral disease with no approved vaccine, although numerous options are in development. Before vaccine implementation, disease burden, affected age group, and hospitalization rate information should be documented. In 2019, a sizeable outbreak of the East Central South African genotype of CHIKV occurred in Myanmar, and during this period, a cross-sectional study was conducted in two regions, Mandalay and Yangon, to examine the molecular and seropositivity rate of the CHIKV infection. The participants (1124) included dengue-suspected pediatric patients, blood donors, and healthy volunteers, who were assessed using molecular assays (quantitative real-time RT-PCR), serological tests (anti-CHIKV IgM capture and IgG indirect enzyme-linked immunosorbent assays), and neutralization tests. The tests confirmed the following positivity rates: 11.3% (127/1124) for the molecular assay, 12.4% (139/1124) for the anti-CHIKV IgM Ab, 44.5% (500/1124) for the anti-CHIKV IgG Ab, and 46.3% (520/1124) for the CHIKV neutralizing Ab. The highest rate for the molecular test occurred with the dengue-suspected pediatric patients. The seroprevalence rate through natural infection was higher in the healthy volunteers and blood donors than that in the pediatric patients. The results of this study will help stakeholders determine the criteria for choosing appropriate recipients when a CHIKV vaccine is introduced in Myanmar.

Incidence and factors associated with chronic chikungunya arthritis following chikungunya virus infection

OBJECTIVES

Chikungunya virus infection is a mosquito-borne illness. First-phase symptoms include fever, malaise, rash, and arthritis (self-limiting). Some patients can have chronic-phase symptoms, including chronic tenosynovitis, bursitis, and arthritis. This study aimed to determine the incidence and risk factors of chronic arthritis in patients with chikungunya infection.

METHODS

This retrospective cohort study analysed all adults diagnosed with chikungunya infection between 2015 and 2020 at our centre. Baseline and follow-up symptoms were evaluated in serologically confirmed cases. Chronic chikungunya arthritis was persistent arthritis >3 months after the onset. Patients who had preexisting chronic inflammatory arthritis and were lost to follow-up before 3 months from diagnosis were excluded.

RESULTS

This study enrolled 120 patients. The median age was 51 (IQR 14) years, and 78% were female. The median number of joints with arthritis was 4 (IQR 8). The initial visual analog scale (VAS) score was 50 mm (IQR 40). Small joints of the hands, wrist, and knee (44.2%, 43.3%, and 42.3%, respectively) were the most affected. The incidence of chronic chikungunya arthritis was 40.4%. From the multivariable logistic regression, the initial number of joints with arthritis, initial VAS scores, and female sex were independently associated with chronic chikungunya arthritis with odds ratios of 1.09 (95% confidence interval [CI] 1.01-1.18), 1.03 (95% CI 1.01-1.06), and 4.17 (95% CI, 1.05-16.67), respectively.

CONCLUSIONS

Chronic chikungunya arthritis is common in patients with chikungunya virus infection. Its predictive factors include the initial number of joints with arthritis, initial VAS scores, and female sex.

Epidemiology and Economic Burden of Chikungunya: A Systematic Literature Review

Chikungunya (CHIK) is a re-emerging viral infection endemic in tropical and subtropical areas. While the typical clinical presentation is an acute febrile syndrome, long-term articular complications and even death can occur. This review characterizes the global epidemiological and economic burden of chikungunya. The search included studies published from 2007 to 2022 in MEDLINE, Embase, LILACS, and SciELO for a thorough evaluation of the literature. Rayyan software was used for data analysis, and data were summarized descriptively and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Seventy-six publications were included. Chikungunya is widely distributed in the tropics, including Africa, Asia, South America, and Oceania/the Pacific Islands, and co-circulates with other simultaneous arboviruses such as DENV, ZIKV, and YFV. Chikungunya infection can lead to chronic articular manifestations with a significant impact on the quality of life in the long term. In addition, it generates absenteeism and economic and social losses and can cause fatal infections in vulnerable populations, mainly in high-risk patients with co-morbidities and at the extremes of age. Reported costs associated with CHIKV diseases are substantial and vary by region, age group, and public/private delivery of healthcare services. The chikungunya disease burden includes chronicity, severe infections, increased hospitalization risks, and associated mortality. The disease can impact the economy in several spheres, significantly affecting the health system and national economies. Understanding and measuring the full impact of this re-emerging disease is essential.

Clinical markers of post-Chikungunya chronic inflammatory joint disease: A Brazilian cohort

BACKGROUND

Chikungunya-fever (CHIKF) remains a public health major issue. It is clinically divided into three phases: acute, post-acute and chronic. Chronic cases correspond to 25-40% individuals and, though most of them are characterized by long-lasting arthralgia alone, many of them exhibit persistent or recurrent inflammatory signs that define post-Chikungunya chronic inflammatory joint disease (pCHIKV-CIJD). We aimed to identify early clinical markers of evolution to pCHIKV-CIJD during acute and post-acute phases.

METHODOLOGY/PRINCIPAL FINDINGS

We studied a prospective cohort of CHIKF-confirmed volunteers with longitudinal clinical data collection from symptoms onset up to 90 days, including a 21-day visit (D21). Of 169 patients with CHIKF, 86 (50.9%) completed the follow-up, from whom 39 met clinical criteria for pCHIKV-CIJD (45.3%). The relative risk of chronification was higher in women compared to men (RR = 1.52; 95% CI = 1.15-1.99; FDR = 0.03). None of the symptoms or signs presented at D0 behaved as an early predictor of pCHIKV-CIJD, while being symptomatic at D21 was a risk factor for chronification (RR = 1.31; 95% CI = 1.09-1.55; FDR = 0.03). Significance was also observed for joint pain (RR = 1.35; 95% CI = 1.12-1.61; FDR = 0.02), reported edema (RR = 3.61; 95% CI = 1.44-9.06; FDR = 0.03), reported hand and/or feet small joints edema (RR = 4.22; 95% CI = 1.51-11.78; FDR = 0.02), and peri-articular edema observed during physical examination (RR = 2.89; 95% CI = 1.58-5.28; FDR = 0.002). Furthermore, patients with no findings in physical examination at D21 were at lower risk of chronic evolution (RR = 0.41, 95% CI = 0.24-0.70, FDR = 0.01). Twenty-nine pCHIKV-CIJD patients had abnormal articular ultrasonography (90.6% of the examined). The most common findings were synovitis (65.5%) and joint effusion (58.6%).

CONCLUSION

This cohort has provided important insights into the prognostic evaluation of CHIKF. Symptomatic sub-acute disease is a relevant predictor of evolution to chronic arthritis with synovitis, drawing attention to joint pain, edema, multiple articular involvement including small hand and feet joints as risk factors for chronification beyond three months, especially in women. Future studies are needed to accomplish the identification of accurate and early biomarkers of poor clinical prognosis, which would allow better understanding of the disease's evolution and improve patients' management, modifying CHIKF burden on global public health.

Development and validation of a clinical rule for the diagnosis of chikungunya fever in a dengue-endemic area

Rio de Janeiro is a dengue-endemic city that experienced Zika and chikungunya epidemics between 2015 and 2019. Differential diagnosis is crucial for indicating adequate treatment and assessing prognosis and risk of death. This study aims to derive and validate a clinical rule for diagnosing chikungunya based on 3,214 suspected cases consecutively treated at primary and secondary health units of the sentinel surveillance system (up to 7 days from onset of symptoms) in Rio de Janeiro, Brazil. Of the total sample, 624 were chikungunya, 88 Zika, 51 dengue, and 2,451 were negative for all these arboviruses according to real-time polymerase chain reaction (RT-qPCR). The derived rule included fever (1 point), exanthema (1 point), myalgia (2 points), arthralgia or arthritis (2 points), and joint edema (2 points), providing an AUC (area under the receiver operator curve) = 0.695 (95% CI: 0.662-0.725). Scores of 4 points or more (validation sample) showed 74.3% sensitivity (69.0% - 79.2%) and 51.5% specificity (48.8% - 54.3%). Adding more symptoms improved the specificity at the expense of a lower sensitivity compared to definitions proposed by government agencies based on fever alone (European Center for Disease Control) or in combination with arthralgia (World Health Organization) or arthritis (Pan American Health Organization, Brazilian Ministry of Health). The proposed clinical rule offers a rapid, low-cost, easy-to-apply strategy to differentiate chikungunya fever from other arbovirus infections during epidemics.

The clinical manifestation and the influence of age and comorbidities on long-term chikungunya disease and health-related quality of life: a 60-month prospective cohort study in Curaçao

BACKGROUND

Persistent rheumatic symptoms and its impact on health-related quality of life (QoL), induced by the Indian Ocean Lineage (IOL) chikungunya virus (CHIKV) genotype have been widely studied. In 2014, a major CHIKV outbreak of the Asian genotype occurred in Curaçao, after which we established a longitudinal cohort in 2015, to follow the long-term CHIKV sequalae. Currently, the long-term clinical manifestations and its impact on QoL induced by the Asian CHIKV genotype, followed prospectively through time, and the association of age and comorbidities with rheumatic symptoms persistence, 60 months (M60) after disease onset is unknown.

METHODS

The cohort of 304 laboratory confirmed patients were followed prospectively in time at 3-16 months (M3-16), 30 months (M30), and M60 after disease onset. Demographic and clinical characteristics, and the 36-item short-form survey (SF-36) QoL status were collected through questionnaires. At M60, QoL scores were compared to general population (CHIK-) norms.

RESULTS

A total of 169 (56%) patients participated (74.6% female, mean age 56.1 years) at all time points, 107 (63%) were classified as recovered and 62 (37%) as affected. The affected patients reported an increase in the prevalence of arthralgia (P .001) and arthralgia in the lower extremities (P < .001), at M30 compared to M3-16. At M60, in comparison to recovered patients, affected patients reported a higher prevalence of recurrent rheumatic symptoms of moderate to severe pain, irrespective of age and comorbidities, and a higher prevalence of non-rheumatic symptoms (P < .001). Arthralgia in the upper (odds ratio (OR): 4.79; confidence interval (CI): 2.01-11.44; P < .001) and lower (OR: 8.68; CI: 3.47-21.69; P < .001) extremities, and headache (OR: 3.85; CI: 1.40-10.54; P = .009) were associated with being affected. The SF-36 QoL scores of the recovered patients were less impaired over time compared to the QoL scores of the affected patients. At M60, the QoL scores of the recovered patients were comparable to the CHIK- QoL scores.

CONCLUSIONS

Rheumatic and non-rheumatic symptoms, and QoL impairment may persist, 60 months following infection with the Asian CHIKV genotype, similar to the IOL genotype disease sequelae. Further research is needed to follow the clinical manifestations and QoL impact of each CHIKV genotype.

Virological, Serological and Clinical Analysis of Chikungunya Virus Infection in Thai Patients

From 2018 to 2020, the Chikungunya virus (CHIKV) outbreak re-emerged in Thailand with a record of more than 10,000 cases up until the end of 2020. Here, we studied acute CHIKV-infected patients who had presented to the Bangkok Hospital for Tropical Diseases from 2019 to 2020 by assessing the relationship between viral load, clinical features, and serological profile. The results from our study showed that viral load was significantly high in patients with fever, headache, and arthritis. We also determined the neutralizing antibody titer in response to the viral load in patients, and our data support the evidence that an effective neutralizing antibody response against the virus is important for control of the viral load. Moreover, the phylogenetic analysis revealed that the CHIKV strains we studied belonged to the East, Central, and Southern African (ECSA) genotype, of the Indian ocean lineage (IOL), and possessed E1-K211E and E1-I317V mutations. Thus, this study provides insight for a better understanding of CHIKV pathogenesis in acute infection, along with the genomic diversity of the current CHIKV strains circulating in Thailand.

Post-chikungunya arthritis: a longitudinal study in a tertiary care hospital in Bangladesh

Background and objective

To identify the clinical patterns and consequences of post-chikungunya arthritis was the study's objective.

Methods

This longitudinal study was carried out among 143 Chikungunya virus (CHIKV) infected adult patients at the rheumatology department, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh, during the outbreak of CHIKV infection in 2017. The disease was categorized into three phases: acute or febrile (lasting up to 10 days), subacute (11–90 days), and chronic (> 90 days). Patients who progressed towards the chronic phase were followed up to 1-year. Post-CHIKV de novo chronic inflammatory rheumatisms (CIRs) were characterized by persistent mono or oligoarthritis, undifferentiated polyarthritis, or meet the criteria rheumatoid arthritis (RA) or Spondyloarthritis (SpA). In addition, functional status was assessed by the validated Bangla version of the Health Assessment Questionnaire (HAQ).

Results

Mean age was 43.3 ± 11.5 years, and 51.0% were male. Within 1-year follow-up, 60 (41.9%) patients were suffering from arthralgia/ arthritis. Of them 52 patients did not have any pre-existing arthralgia/arthritis. 35 (65.3%) had undifferentiated arthritis, 10 (19.2%) had SpA, and 7 (13.5%) had RA. Patients with pre-existing rheumatological disorders, 6(4.2%) had SpA, 1(0.7%) had RA and 1(0.7%) had osteoarthritis. Polyarthralgia (n = 33, 55.0%) and polyarthritis (n = 20, 33.3%) were the main presentations. Female gender (OR: 0.45; CI: 0.21–0.96), positive IgG (OR: 0.30; CI: 0.12–0.76), and moderate to severe functional disability (OR: 3.46; CI: 1.62–7.40) were independent predictors of developing chronic post-CHIKV rheumatism.

Conclusions

At 1-year follow-up, more than one-third of the patients remained symptomatic. Female gender, positive IgG, and moderate to severe functional disability contributed to the development of chronicity.

Long-term Chikungunya sequelae and quality of life 2.5 years post-acute disease in a prospective cohort in Curaçao

Background

Little is known about the persistence and impact of non-rheumatic symptoms after acute chikungunya disease. We have studied the clinical presentation and long-term impact of rheumatic and non-rheumatic symptoms on health related quality of life (QoL) 2.5 years after disease onset. Additionally, the validity of the Curaçao Long-Term Chikungunya Sequelae (CLTCS) score in classifying disease severity over time was evaluated.

Methodology/Principal findings

This prospective cohort study followed 248 chikungunya patients. Symptoms and SF-36 QoL were evaluated during baseline and follow-up at 2.5 years using questionnaires. Chikungunya disease status was classified using the CLTCS-score. At 2.5 years after disease onset patients were classified as being recovered (43%), mildly (35%) or highly (22%) affected. In comparison to mildly affected, highly affected patients reported the highest prevalence of ongoing rheumatic and non-rheumatic/psychological symptoms, with increased prevalence of arthralgia in the lower extremities (p = .01) and fatigue (p = .049) over time, and higher pain intensity (p < .001). Compared to mildly affected, being highly affected was associated with weakness in the lower extremities (OR: 1.90; CI: 1.29–2.80, p = .001) and worsened physical and mental QoL impairment.

Conclusions

Patients are both physically and psychologically affected by rheumatic and non-rheumatic symptoms of long-term chikungunya disease.

The CLTCS-score is an easy to use instrument for classifying long-term chikungunya disease severity and impact and can facilitate health care providers in identifying highly affected patients who are prone to develop severe QoL impairment. Highly affected patients are recommended to be treated in a multidisciplinary setting to improve physical and psychological functioning, and QoL.

Chikungunya disease manifestation is characterized by a sudden onset of non-rheumatic flu-like symptoms and debilitating rheumatic symptoms in the acute phase. Little is known about the persistence of non-rheumatic symptoms after acute disease. In this prospective cohort study we investigated the clinical manifestations and persistence of baseline rheumatic and non-rheumatic/psychological symptoms and their impact on health related quality of life (QoL) 2.5 years after disease onset. Moreover, we investigated the performance of the classification instrument the Curaçao Long-Term Chikungunya Sequelae (CLTCS) score in classifying chikungunya disease severity over time. We found that 57% of the patients were still affected 2.5 years after disease onset. An increase of mainly recurrent rheumatic and non-rheumatic/psychological symptoms including fatigue, insomnia, sombreness, and loss of vitality were reported, with a significantly higher symptom recurrence and pain intensity reported by highly affected patients. In addition, QoL assessment indicates that the disease burden impaired the physiological well-being of these patients. We also showed that the CLTCS-score can be used to easily identify highly affected patients. This study demonstrates that disease severity increases non-rheumatic symptoms and subsequent physiological impairments and suggests a multidisciplinary treatment approach to treat the psychological effects of long-term chikungunya disease.

Detection of Chikungunya virus in bodily fluids: The INOVACHIK cohort study

Background

Chikungunya is a widely distributed, re-emerging tropical disease caused by the chikungunya virus (CHIKV). Little is known about the duration for which CHIK RNA are detectable in bodily fluids, especially genital secretions, and current evidence is based on small series or case reports. An understanding of viral dynamics across different body compartments can inform diagnostic testing algorithms and public health prevention interventions.

Methodology

A prospective cohort study was conducted to assess the presence and duration of detectable levels of CHIKV RNA in blood, urine, saliva, semen, and vaginal secretions. Men and women (≥ 18 years) with a positive reverse transcriptase-polymerase chain reaction (RT-PCR) test for CHIKV in the acute phase (1–14 days) of the disease were included. After enrollment, clinical data and samples were collected every 15 days over the first 2 months, and a final collection was performed 3 months after recruitment. The Kaplan–Meier interval-censoring method and the parametric Weibull model were fitted to estimate the median time of viral persistence until the lack of CHIKV RNA detection among all body fluids. Punctual estimates of the median time of CHIKV RNA persistence for each fluid were estimated using a 95% confidence interval (CI).

Results

From April to December 2019, 170 participants were screened. Of these, 152 (100 women) were enrolled in the study. The median and interquartile range (IQR) ages for men and women were 39.3 (IQR: 26.9, 50.7) and 43.5 (IQR: 33.8, 53.6) years, respectively. CHIKV RNA was detected in 80.3% (122/152) of serum samples, 23.0% (35/152) of urine samples, 30.3% (46/152) of saliva samples, 14.3% (6/42) of semen samples, and 20.2% (20/99) of vaginal secretion samples. The median time until the loss of CHIKV RNA detection was 19.6 days (95% CI, 17.5–21.7) in serum, 25.3 days (95% CI, 17.8–32.8) in urine, 23.1 days (95% CI, 17.9–28.4) in saliva, and 25.8 days (95% CI, 20.6–31.1) in vaginal secretion. The number of semen samples available was too small to make statistical estimates, but a last positive sample was obtained from a participant 56 days after the onset of symptoms.

Conclusions

CHIKV RNA could be detected in all bodily fluids studied, including genital secretions during the acute and convalescent phases and additional studies on viral infectivity in semen and vaginal secretions are warranted.

This prospective cohort study of adult patients aimed to estimate the presence and duration of detectable levels of chikungunya virus RNA in bodily fluids, including genital secretions, among participants in the acute and convalescent phases of the disease. In addition to the fluids usually used for diagnosis in humans (serum and plasma), we reported the detection of chikungunya virus RNA in all body fluids. Reports have shown that chikungunya virus RNA in serum declines to undetectable levels within 1–2 weeks after symptom onset. The viral persistence in the serum in our study was longer than expected. In addition, we showed that saliva and urine contained detectable viral RNA in both the acute and convalescent phases of the disease. To the best of our knowledge, this is the first cohort study assessing the presence and persistence of CHIKV in genital fluids (vaginal secretions and semen). Knowledge of viral persistence can help inform recommendations for the control, treatment, and prevention of the disease. Additional studies on viral infectivity are warranted.

Diagnostic accuracy of serological tests for the diagnosis of Chikungunya virus infection: A systematic review and meta-analysis

BACKGROUND

Chikungunya virus (CHIKV) causes febrile illnesses and has always been misdiagnosed as other viral infections, such as dengue and Zika; thus, a laboratory test is needed. Serological tests are commonly used to diagnose CHIKV infection, but their accuracy is questionable due to varying degrees of reported sensitivities and specificities. Herein, we conducted a systematic review and meta-analysis to evaluate the diagnostic accuracy of serological tests currently available for CHIKV.

METHODOLOGY AND PRINCIPAL FINDINGS

A literature search was performed in PubMed, CINAHL Complete, and Scopus databases from the 1st December 2020 until 22nd April 2021. Studies reporting sensitivity and specificity of serological tests against CHIKV that used whole blood, serum, or plasma were included. QUADAS-2 tool was used to assess the risk of bias and applicability, while R software was used for statistical analyses. Thirty-five studies were included in this meta-analysis; 72 index test data were extracted and analysed. Rapid and ELISA-based antigen tests had a pooled sensitivity of 85.8% and 82.2%, respectively, and a pooled specificity of 96.1% and 96.0%, respectively. According to our meta-analysis, antigen detection tests serve as a good diagnostic test for acute-phase samples. The IgM detection tests had more than 90% diagnostic accuracy for ELISA-based tests, immunofluorescence assays, in-house developed tests, and samples collected after seven days of symptom onset. Conversely, low sensitivity was found for the IgM rapid test (42.3%), commercial test (78.6%), and for samples collected less than seven of symptom onset (26.2%). Although IgM antibodies start to develop on day 2 of CHIKV infection, our meta-analysis revealed that the IgM detection test is not recommended for acute-phase samples. The diagnostic performance of the IgG detection tests was more than 93% regardless of the test formats and whether the test was commercially available or developed in-house. The use of samples collected after seven days of symptom onset for the IgG detection test suggests that IgG antibodies can be detected in the convalescent-phase samples. Additionally, we evaluated commercial IgM and IgG tests for CHIKV and found that ELISA-based and IFA commercial tests manufactured by Euroimmun (Lübeck, Germany), Abcam (Cambridge, UK), and Inbios (Seattle, WA) had diagnostic accuracy of above 90%, which was similar to the manufacturers' claim.

CONCLUSION

Based on our meta-analysis, antigen or antibody-based serological tests can be used to diagnose CHIKV reliably, depending on the time of sample collection. The antigen detection tests serve as a good diagnostic test for samples collected during the acute phase (≤7 days post symptom onset) of CHIKV infection. Likewise, IgM and IgG detection tests can be used for samples collected in the convalescent phase (>7 days post symptom onset). In correlation to the clinical presentation of the patients, the combination of the IgM and IgG tests can differentiate recent and past infections.

A Multidisciplinary Investigation of the First Chikungunya Virus Outbreak in Matadi in the Democratic Republic of the Congo

Early March 2019, health authorities of Matadi in the Democratic Republic of the Congo alerted a sudden increase in acute fever/arthralgia cases, prompting an outbreak investigation. We collected surveillance data, clinical data, and laboratory specimens from clinical suspects (for CHIKV-PCR/ELISA, malaria RDT), semi-structured interviews with patients/caregivers about perceptions and health seeking behavior, and mosquito sampling (adult/larvae) for CHIKV-PCR and estimation of infestation levels. The investigations confirmed a large CHIKV outbreak that lasted February–June 2019. The total caseload remained unknown due to a lack of systematic surveillance, but one of the two health zones of Matadi notified 2686 suspects. Of the clinical suspects we investigated (n = 220), 83.2% were CHIKV-PCR or IgM positive (acute infection). One patient had an isolated IgG-positive result (while PCR/IgM negative), suggestive of past infection. In total, 15% had acute CHIKV and malaria. Most adult mosquitoes and larvae (>95%) were Aedes albopictus. High infestation levels were noted. CHIKV was detected in 6/11 adult mosquito pools, and in 2/15 of the larvae pools. This latter and the fact that 2/6 of the CHIKV-positive adult pools contained only males suggests transovarial transmission. Interviews revealed that healthcare seeking shifted quickly toward the informal sector and self-medication. Caregivers reported difficulties to differentiate CHIKV, malaria, and other infectious diseases resulting in polypharmacy and high out-of-pocket expenditure. We confirmed a first major CHIKV outbreak in Matadi, with main vector Aedes albopictus. The health sector was ill-prepared for the information, surveillance, and treatment needs for such an explosive outbreak in a CHIKV-naïve population. Better surveillance systems (national level/sentinel sites) and point-of-care diagnostics for arboviruses are needed.

Arthralgia resolution rate following chikungunya virus infection

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This study investigated the duration of persistence of chikungunya-related arthralgia.

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Statisticalanalysis of multiple cohorts of chikungunya patients was performed.

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First estimates of the average rate of chronic chikungunya virus arthralgia resolution were calculated.

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Varying rates of arthralgia resolution are associated with age and other factors.

Background

Arthralgia, persistent pain or stiffness of the joints, is the hallmark symptom of chronic chikungunya virus (CHIKV) disease. Associated with significant disability and reduced quality of life, arthralgia can persist for many months following CHIKV infection. Understanding the expected duration of arthralgia persistence is important for managing clinical expectations at the individual-level as well as for estimating long-term burdens on population health following a CHIKV epidemic.

Methods

A review of cohort studies reporting the prevalence of arthralgia post-CHIKV infection over multiple time points was conducted. Generalized linear models were used to estimate the average rate of arthralgia resolution following CHIKV infection.

Results

Sixteen cohort studies matching the inclusion criteria were identified and included in the analysis. An average rate of arthralgia resolution of 10.85% (95% confidence interval (CI) 9.05–12.66%) per month was estimated across studies, corresponding to an expected median time to arthralgia resolution of 6.39 months (95% CI 5.48–7.66 months) and an expected arthralgia prevalence of 72.21% (95% CI 68.40–76.23%) at 3 months post-CHIKV infection.

Conclusions

Estimates of the average rate of arthralgia resolution and the expected prevalence of arthralgia over time post-CHIKV infection were derived. These can help inform expectations regarding the long-term public health burdens associated with CHIKV epidemics.

Clinical Manifestations and Outcomes in Disease-Modifying Antirheumatic Drug-Naive Adult Patients with Chronic Chikungunya Arthritis

Most studies on chronic chikungunya virus (CHIKV) arthritis include patients treated with disease-modifying antirheumatic drugs (DMARDs), likely altering the expression of clinical manifestations and outcome. Therefore, we sought to evaluate the clinical features and correlates in DMARD-naive patients with chronic CHIKV arthritis. We conducted a case-control study in adult patients with serologically confirmed CHIKV infection in Puerto Rico. Demographic features, clinical manifestations, comorbidities, disease activity (per Clinical Disease Activity Index [CDAI]), functional status (per Health Assessment Questionnaire Disability Index [HAQ-DI]), and pharmacologic treatment were ascertained. Patients with and without chronic CHIKV arthritis were compared. Furthermore, a sub-analysis was performed among patients with chronic CHIKV who presented with mild disease activity versus moderate-to-high disease activity at study visit. In total, 61 patients were studied; 33 patients had chronic arthritis and 28 had resolved arthritis. Patients with chronic arthritis had significantly more diabetes mellitus, chronic back pain, and fever, tiredness, and myalgias on the acute phase. The mean (SD) HAQ score was 0.95 (0.56), and 57.6% had moderate-to-high disease activity. Patients with moderate-to-high disease activity had higher scores in overall HAQ-DI and HAQ-DI categories (dressing and grooming, arising, hygiene, reaching, and activities) than in those with mild activity. In conclusion, in this group of DMARD-naive patients with chronic CHIKV arthritis, nearly 58% had moderate-to-high disease activity and had substantial functional disability. Diabetes mellitus, chronic back pain, and some manifestations on acute infection were associated with chronic CHIKV arthritis.

Rheumatic manifestations of Chikungunya virus infection: Prevalence, patterns, and enthesitis

Chikungunya virus (CHIKV) is an arthropod-borne virus transmitted by mosquitoes of the genus Aedes. CHIKV infection causes various rheumatic symptoms, including enthesitis; however, these effects are rarely investigated. The aim of this study was to describe the rheumatic manifestations in CHIKV infection, estimate the prevalence of enthesitis in CHIKV-infected patients, and determine the factors associated with CHIKV-induced enthesitis. We conducted a prospective, observational study in patients with CHIKV infection confirmed by positive RT-PCR or IgM assay from October 2019 to March 2020. Patients with pre-existing inflammatory rheumatic diseases were excluded. A rheumatologist evaluated the demographic and clinical characteristics of the patients, including the number of inflamed joints, enthesitis sites, tendinitis, and tenosynovitis. The Leeds enthesitis index (LEI) and the Maastricht ankylosing spondylitis enthesis score (MASES) were used to evaluate enthesitis sites. Factors associated with enthesitis were determined using logistic regression analysis. One hundred and sixty-four participants diagnosed with CHIKV infection were enrolled. The mean (SD) age of the patients was 48.2 (14) years. The most common pattern of rheumatic manifestations was polyarthritis with or without enthesitis. Enthesitis was observed in 63 patients (38.4%). The most common site of enthesitis was the left lateral epicondyle as assessed by LEI and the posterior superior iliac spine as assessed by MASES. Multivariate analysis indicated that the number of actively inflamed joints and Thai-HAQ score at the initial evaluation were significantly associated with the presence of enthesitis. The main rheumatic manifestations of CHIKV infection were arthritis/arthralgia, with enthesitis as a prominent extraarticular feature. CHIKV infection can cause enthesitis at peripheral and axial sites. We found that enthesitis was associated with a high number of inflamed joints and reduced physical function. These results indicate that the assessment of enthesitis should be considered when monitoring disease activity and as a treatment response parameter in CHIKV-infected patients.

Risk of chronic arthralgia and impact of pain on daily activities in a cohort of patients with chikungunya virus infection from Brazil

OBJECTIVES

To investigate risk factors for persistent arthralgia in patients with chikungunya, and describe its impact on daily activities.

METHODS

From September 2014 to July 2016, a surveillance study enrolled patients with acute febrile illness in Salvador, Brazil, and detected those with chikungunya virus infection using IgM enzyme-linked immunosorbent assay or reverse transcriptase polymerase chain reaction. Telephone follow-ups were performed to ascertain the progression of disease.

RESULTS

Of 153 followed cases, 65 (42.5%) reported chronic arthralgia that lasted >3 months, and 47 (30.7%) were still symptomatic at the time of the interview (approximately 1.5 years after symptom onset). Limitations in daily activities and mental distress were reported by 93.8% and 61.5% of those with chronic arthralgia, respectively. Female sex [risk ratio (RR) 1.79, 95% confidence interval (CI) 1.95-2.69] and age (RR 1.02 for each 1-year increase, 95% CI 1.01-1.03) were independent risk factors for chronic arthralgia. Chronic arthralgia was not associated with co-infection with dengue virus (RR 0.97, 95% CI 0.48-1.94) or chikungunya viral load at diagnosis (median chikungunya virus RNA of 5.60 and 5.52 log₁₀ copies/μL for those with and without chronic arthralgia, respectively; P = 0.75).

CONCLUSIONS

These findings reinforce the high frequency of chronic chikungunya arthralgia, and highlight the substantial disability associated with the persistence of pain. Development of novel strategies to mitigate the transmission of chikungunya virus and to provide long-term medical assistance for patients with chikungunya are needed urgently.

Measuring the global burden of chikungunya and Zika viruses: A systematic review

Throughout the last decade, chikungunya virus (CHIKV) and Zika virus (ZIKV) infections have spread globally, causing a spectrum of disease that ranges from self-limited febrile illness to permanent severe disability, congenital anomalies, and early death. Nevertheless, estimates of their aggregate health impact are absent from the literature and are currently omitted from the Global Burden of Disease (GBD) reports. We systematically reviewed published literature and surveillance records to evaluate the global burden caused by CHIKV and ZIKV between 2010 and 2019, to calculate estimates of their disability-adjusted life year (DALY) impact. Extracted data on acute, chronic, and perinatal outcomes were used to create annualized DALY estimates, following techniques outlined in the GBD framework. This study is registered with PROSPERO (CRD42020192502). Of 7,877 studies identified, 916 were screened in detail, and 21 were selected for inclusion. Available data indicate that CHIKV and ZIKV caused the average yearly loss of over 106,000 and 44,000 DALYs, respectively, between 2010 and 2019. Both viruses caused substantially more burden in the Americas than in any other World Health Organization (WHO) region. This unequal distribution is likely due to a combination of limited active surveillance reporting in other regions and the lack of immunity that left the previously unexposed populations of the Americas susceptible to severe outbreaks during the last decade. Long-term rheumatic sequelae provided the largest DALY component for CHIKV, whereas congenital Zika syndrome (CZS) contributed most significantly for ZIKV. Acute symptoms and early mortality accounted for relatively less of the overall burden. Suboptimal reporting and inconsistent diagnostics limit precision when determining arbovirus incidence and frequency of complications. Despite these limitations, it is clear from our assessment that CHIKV and ZIKV represent a significant cause of morbidity that is not included in current disease burden reports. These results suggest that transmission-blocking strategies, including vector control and vaccine development, remain crucial priorities in reducing global disease burden through prevention of potentially devastating arboviral outbreaks.

Chikungunya and Zika are 2 mosquito-borne viral diseases that can cause both acute symptoms and long-term, debilitating complications in infected individuals. Chikungunya is best known as a cause of persistent arthritis in otherwise recovered patients and Zika as a cause of cognitive, motor, and sensory anomalies in newborn children. Both diseases emerged in the Americas within the last decade and have since spread rapidly throughout the region. Despite their widespread transmission there and throughout much of the world, chikungunya and Zika remain neglected diseases. One of the most significant obstacles to address their spread is a lack of data involving their burden. We searched the published literature and surveillance reports to collect information about the incidence, mortality, and morbidity associated with each of these diseases to estimate their regional and global burden during the last decade. Our estimates confirm that chikungunya and Zika caused substantial burden throughout this time frame and place them among the most problematic mosquito-borne viral diseases worldwide. We found that the largest proportion of global burden linked to each disease between 2010 and 2019 occurred in the Americas, although this observation is likely due to limited reporting in other regions.

Immunopathogenesis of alphaviruses

Alphaviruses, members of the enveloped, positive-sense, single-stranded RNA Togaviridae family, represent a reemerging public health threat as mosquito vectors expand into new geographic territories. The Old World alphaviruses, which include chikungunya virus, Ross River virus, and Sindbis virus, tend to cause a clinical syndrome characterized by fever, rash, and arthritis, whereas the New World alphaviruses, which consist of Venezuelan equine encephalitis virus, eastern equine encephalitis virus, and western equine encephalitis virus, induce encephalomyelitis. Following recovery from the acute phase of infection, many patients are left with debilitating persistent joint and neurological complications that can last for years. Clues from human cases and studies using animal models strongly suggest that much of the disease and pathology induced by alphavirus infection, particularly atypical and chronic manifestations, is mediated by the immune system rather than directly by the virus. This review discusses the current understanding of the immunopathogenesis of the arthritogenic and neurotropic alphaviruses accumulated through both natural infection of humans and experimental infection of animals, particularly mice. As treatment following alphavirus infection is currently limited to supportive care, understanding the contribution of the immune system to the disease process is critical to developing safe and effective therapies.

Promising application of monoclonal antibody against chikungunya virus E1-antigen across genotypes in immunochromatographic rapid diagnostic tests

BACKGROUND

Three different genotypes of chikungunya virus (CHIKV) have been classified: East/Central/South African (ECSA), West African (WA), and Asian. Previously, a rapid immunochromatographic (IC) test detecting CHIKV E1-antigen showed high sensitivity for certain ECSA-genotype viruses, but this test showed poor performance against the Asian-genotype virus that is spreading in the American continents. We found that the reactivity of one monoclonal antibody (MAb) used in the IC rapid diagnostic test (RDT) is affected by a single amino acid substitution in E1. Therefore, we developed new MAbs that exhibited specific recognition of all three genotypes of CHIKV.

METHODS

Using a combination of the newly generated MAbs, we developed a novel version of the IC RDT with improved sensitivity to Asian-genotype CHIKV. To evaluate the sensitivity, specificity, and cross-reactivity of the new version of the IC RDT, we first used CHIKV isolates and E1-pseudotyped lentiviral vectors. We then used clinical specimens obtained in Aruba in 2015 and in Bangladesh in 2017 for further evaluation of RDT sensitivity and specificity. Another alphavirus, sindbis virus (SINV), was used to test RDT cross-reactivity.

RESULTS

The new version of the RDT detected Asian-genotype CHIKV at titers as low as 10^4 plaque-forming units per mL, a concentration that was below the limit of detection of the old version. The new RDT had sensitivity to the ECSA genotype that was comparable with that of the old version, yielding 92% (92 out of 100) sensitivity (95% confidence interval 85.0-95.9) and 100% (100 out of 100) specificity against a panel of 100 CHIKV-positive and 100 CHIKV-negative patient sera obtained in the 2017 outbreak in Bangladesh.

CONCLUSIONS

Our newly developed CHIKV antigen-detecting RDT demonstrated high levels of sensitivity and lacked cross-reactivity against SINV. These results suggested that our new version of the CHIKV E1-antigen RDT is promising for use in areas in which the Asian and ECSA genotypes of CHIKV circulate. Further validation with large numbers of CHIKV-positive and -negative clinical samples is warranted. (323 words).

Prevalence of and risk factors for long-term disabilities following chikungunya virus disease: A meta-analysis

BACKGROUND

The main aim of this study was to investigate the percentage of individuals who developed long-term disabilities after chikungunya virus (CHIKV) disease on the basis of follow up time interval and its associated risk factors.

METHOD

In this meta-analysis, electronic databases PubMed, Science Direct and Google Scholar were searched to identify cohort studies of CHIKV disease from January 2000 to June 2018. Total 28 eligible studies were selected for analysis. The pooled prevalence rate (PR), risk ratio (RR) and 95% confidence interval (CI) for both effect measures were calculated using a random effects model.

RESULT

Among 28 studies, 24 studies were used for PR calculation and the PR for the long-term disabilities of CHIKV disease patients were found 39.70%, [95% CI: (31.77-47.64), p < 0.01] for follow up time between 6 and 12 months, 35.85%, [95% CI: (24.09-47.61), p < 0.01] for follow up time between 12 and 18 months and 28.20%, [95% CI: (19.74-36.66), p < 0.01] for greater than 18 months respectively. Eighteen studies were used for RR calculation and significant association were found between long-term disabilities after CHIKV disease and gender [RR: 1.46, p < 0.01], age [RR: 1.61, p < 0.01], diabetes [RR: 1.40, p < 0.01], hypertension [RR: 1.37, p < 0.01], severity of pain at acute stage [RR: 2.02, p < 0.01].

CONCLUSION

Approximately 40% patients developed long-term disabilities after 6 months of CHIKV disease and 28% patients still suffer from this disease after 18 months of acute infection.

Persistence of chikungunya ECSA genotype and local outbreak in an upper medium class neighborhood in Northeast Brazil

The chikungunya East/Central/South/Africa virus lineage (CHIKV-ECSA) was first detected in Brazil in the municipality of Feira de Santana (FS) by mid 2014. Following that, a large number of CHIKV cases have been notified in FS, which is the second-most populous city in Bahia state, northeastern Brazil, and plays an important role on the spread to other Brazilian states due to climate conditions and the abundance of competent vectors. To better understand CHIKV dynamics in Bahia state, we generated 5 complete genome sequences from a local outbreak raised in Serraria Brasil, a neighbourhood in FS, by next-generation sequencing using Illumina approach. Phylogenetic reconstructions revealed that the new FS genomes belongs to the ECSA genotype and falls within a single strongly supported monophyletic clade that includes other older CHIKV sequences from the same location, suggesting the persistence of the virus during distinct epidemic seasons. We also performed minor variants analysis and found a small number of SNPs per sample (b_29L and e_45SR = 16 SNPs, c_29SR = 29 and d_45PL and f_45FL = 21 SNPs). Out of the 93 SNPs found, 71 are synonymous, 21 are non-synonymous and one generated a stop codon. Although those mutations are not related to the increase of virus replication and/or infectivity, some SNPs were found in non-structural proteins which may have an effect on viral evasion from the mammal immunological system. These findings reinforce the needing of further studies on those variants and of continued genomic surveillance strategies to track viral adaptations and to monitor CHIKV epidemics for improved public health control.

Two distinct lineages of chikungunya virus cocirculated in Aruba during the 2014-2015 epidemic

Chikungunya virus (CHIKV), a positive-sense, single-stranded RNA virus in the family Togaviridae, is transmitted by Aedes mosquitoes. Of three known CHIKV genotypes, the Asian genotype was introduced into the Caribbean islands and rapidly spread throughout Central and South Americas. We previously found patients with symptoms compatible with chikungunya fever in 2014-2015 in Aruba, a Caribbean island of 180 km². We here describe the full genome sequences of eight CHIKV strains isolated from patient sera of the Aruban outbreak. Phylogenetic analysis revealed that two closely related but distinct lineages of Asian-genotype CHIKV circulated simultaneously during the epidemic in 2014-2015. These results suggested that CHIKV was introduced into Aruba more than once in a short period, reflecting the importance of Aruba as a travel hub within the region.

Exacerbation of Chikungunya Virus Rheumatic Immunopathology by a High Fiber Diet and Butyrate

Chikungunya virus (CHIKV) is a mosquito transmitted alphavirus associated with a robust systemic infection and an acute inflammatory rheumatic disease. A high fiber diet has been widely promoted for its ability to ameliorate inflammatory diseases. Fiber is fermented in the gut into short chain fatty acids such as acetate, propionate, and butyrate, which enter the circulation providing systemic anti-inflammatory activities. Herein we show that mice fed a high fiber diet show a clear exacerbation of CHIKV arthropathy, with increased edema and neutrophil infiltrates. RNA-Seq analyses illustrated that a high fiber diet, in this setting, promoted a range of pro-neutrophil responses including Th17/IL-17. Gene Set Enrichment Analyses demonstrated significant similarities with mouse models of inflammatory psoriasis and significant depression of macrophage resolution phase signatures in the CHIKV arthritic lesions from mice fed a high fiber diet. Supplementation of the drinking water with butyrate also increased edema after CHIKV infection. However, the mechanisms involved were different, with modulation of AP-1 and NF-κB responses identified, potentially implicating deoptimization of endothelial barrier repair. Thus, neither fiber nor short chain fatty acids provided benefits in this acute infectious disease setting, which is characterized by widespread viral cytopathic effects and a need for tissue repair.

Clinical profile and factors associated with hospitalization during a Chikungunya epidemic in Ceará, Brazil

INTRODUCTION

The aim of this study was to characterize the clinical-epidemiological profile of Chikungunya virus infection and the factors associated with hospitalization during the peak of the most recent epidemic period in Brazil (2016-2017).

METHODS

Two official databases of the State Health Secretariat of Ceará were used, and a total of 182,731 notifications were analyzed.

RESULTS

Independent factors associated with hospital admission were chronic kidney disease (OR 4.56, 95% CI 3.36-6.17), hypertension (OR 1.90, 95% CI 1.69-2.14), leukopenia (OR 1.89, 95% CI 1.56-2.30) and diabetes mellitus (OR 1.70, 95% CI 1.44-1.99).

CONCLUSIONS

The pre-existing comorbidities have shown the potential to destabilize the patients' clinical status.

Dermal and muscle fibroblasts and skeletal myofibers survive chikungunya virus infection and harbor persistent RNA

Chikungunya virus (CHIKV) is an arthritogenic alphavirus that acutely causes fever as well as severe joint and muscle pain. Chronic musculoskeletal pain persists in a substantial fraction of patients for months to years after the initial infection, yet we still have a poor understanding of what promotes chronic disease. While replicating virus has not been detected in joint-associated tissues of patients with persistent arthritis nor in various animal models at convalescent time points, viral RNA is detected months after acute infection. To identify the cells that might contribute to pathogenesis during this chronic phase, we developed a recombinant CHIKV that expresses Cre recombinase (CHIKV-3'-Cre). CHIKV-3'-Cre replicated in myoblasts and fibroblasts, and it induced arthritis during the acute phase in mice. Importantly, it also induced chronic disease, including persistent viral RNA and chronic myositis and synovitis similar to wild-type virus. CHIKV-3'-Cre infection of tdTomato reporter mice resulted in a population of tdTomato+ cells that persisted for at least 112 days. Immunofluorescence and flow cytometric profiling revealed that these tdTomato+ cells predominantly were myofibers and dermal and muscle fibroblasts. Treatment with an antibody against Mxra8, a recently defined host receptor for CHIKV, reduced the number of tdTomato+ cells in the chronic phase and diminished the levels of chronic viral RNA, implicating these tdTomato+ cells as the reservoir of chronic viral RNA. Finally, isolation and flow cytometry-based sorting of the tdTomato+ fibroblasts from the skin and ankle and analysis for viral RNA revealed that the tdTomato+ cells harbor most of the persistent CHIKV RNA at chronic time points. Therefore, this CHIKV-3'-Cre and tdTomato reporter mouse system identifies the cells that survive CHIKV infection in vivo and are enriched for persistent CHIKV RNA. This model represents a useful tool for studying CHIKV pathogenesis in the acute and chronic stages of disease.

Beyond Fever and Pain: Diagnostic Methods for Chikungunya Virus

Chikungunya virus (CHIKV) is an alphavirus that is primarily transmitted by Aedes species mosquitoes. Though reports of an illness consistent with chikungunya date back over 200 years, CHIKV only gained worldwide attention during a massive pandemic that began in East Africa in 2004. Chikungunya, the clinical illness caused by CHIKV, is characterized by a rapid onset of high fever and debilitating joint pain, though in practice, etiologic confirmation of CHIKV requires the availability and use of specific laboratory diagnostics. Similar to infections caused by other arboviruses, CHIKV infections are most commonly detected with a combination of molecular and serological methods, though cell culture and antigen detection are reported. This review provides an overview of available CHIKV diagnostics and highlights aspects of basic virology and epidemiology that pertain to viral detection. Although the number of chikungunya cases has decreased since 2014, CHIKV has become endemic in countries across the tropics and will continue to cause sporadic outbreaks in naive individuals. Consistent access to accurate diagnostics is needed to detect individual cases and initiate timely responses to new outbreaks.

Arthritogenic Alphaviruses: A Worldwide Emerging Threat?

Arthritogenic alphaviruses are responsible for a dengue-like syndrome associated with severe debilitating polyarthralgia that can persist for months or years and impact life quality. Chikungunya virus is the most well-known member of this family since it was responsible for two worldwide epidemics with millions of cases in the last 15 years. However, other arthritogenic alphaviruses that are as of yet restrained to specific territories are the cause of neglected tropical diseases: O'nyong'nyong virus in Sub-Saharan Africa, Mayaro virus in Latin America, and Ross River virus in Australia and the Pacific island countries and territories. This review evaluates their emerging potential in light of the current knowledge for each of them and in comparison to chikungunya virus.

Cellular and Molecular Immune Response to Chikungunya Virus Infection

Chikungunya virus (CHIKV) is a re-emergent arthropod-borne virus (arbovirus) that causes a disease characterized primarily by fever, rash and severe persistent polyarthralgia. In the last decade, CHIKV has become a serious public health problem causing several outbreaks around the world. Despite the fact that CHIKV has been around since 1952, our knowledge about immunopathology, innate and adaptive immune response involved in this infectious disease is incomplete. In this review, we provide an updated summary of the current knowledge about immune response to CHIKV and about soluble immunological markers associated with the morbidity, prognosis and chronicity of this arbovirus disease. In addition, we discuss the progress in the research of new vaccines for preventing CHIKV infection and the use of monoclonal antibodies as a promising therapeutic strategy.

Prevalence and risk factors of post chikungunya rheumatic musculoskeletal disorders: a prospective follow-up study in French Guiana

The estimated seroprevalence in the general population after chikungunya virus (CHIKV) epidemics ranged from 38 to 63%. Despite a low case fatality, subacute and chronic rheumatic forms of CHIKV infection generate significant morbidity and have a socioeconomic impact. The objective of the study was to estimate the prevalence of chronic post-CHIKV rheumatic or musculoskeletal pain (pCHIK-RMSP) at 3 and 6 months after the initial symptoms. An observational study was conducted at Cayenne General Hospital in French Guiana between April 1 and June 30, 2014. All patients seen for CHIKV infection confirmed by RT-PCR were prospectively included. Pregnant women and children under 15 were excluded from the study. All patients were called by phone at 3 and 6 months to enquire about the presence of pCHIK-RMSP. Out of a total of 254 eligible patients, 168 were selected. The mean age was 45.3 years (SD ± 1.4 yo) and the sex ratio (M/F) was 0.75. No death was reported. At 3 months, 40.2% (95% CI 31.1-49.3) of patients (n = 45/112) had pCHIK-RMSP and 31.3% (95% CI 22.2-40.4) of patients (n = 31/99) at 6 months. The median time of end to pain was 2 weeks after the date of onset of signs. The present study provides succinct but informative data about pCHIK-RMSP, which represents the real burden of the disease. There are few studies on that subject in the Amazonian region, but our study shows a lower impact than in the Indian Ocean islands where the population is older.