Chikungunya Virus Infection: Why Should U.S. Geriatricians Be Aware of It?

Evolution and immunopathology of chikungunya virus informs therapeutic development

Chikungunya virus (CHIKV), a mosquito-borne alphavirus, is an emerging global threat identified in more than 60 countries across continents. The risk of CHIKV transmission is rising due to increased global interactions, year-round presence of mosquito vectors, and the ability of CHIKV to produce high host viral loads and undergo mutation. Although CHIKV disease is rarely fatal, it can progress to a chronic stage, during which patients experience severe debilitating arthritis that can last from several weeks to months or years. At present, there are no licensed vaccines or antiviral drugs for CHIKV disease, and treatment is primarily symptomatic. This Review provides an overview of CHIKV pathogenesis and explores the available therapeutic options and the most recent advances in novel therapeutic strategies against CHIKV infections.

Impact of Chronic Kidney Disease on Chikungunya Virus Infection Clinical Manifestations and Outcome: Highlights during an Outbreak in Northeastern Brazil

The northeastern region of Brazil has faced in the last 2 years the largest outbreak of chikungunya virus (CHIKV) infection in its history. There are still few studies on kidney involvement in CHIKV. The aim of this study is to describe the impact of chronic kidney disease (CKD) on CHIKV clinical manifestations and outcome. This is a cross-sectional study conducted in the State of Ceara, northeastern Brazil, including all registered cases of CHIKV infection in the period from January 2016 to December 2017. Clinical manifestations were collected from the notification reports from official data bank from the State Secretary of Health of Ceara: National System of Diseases Notification and Laboratory Manager. A total of 182,731 cases were notified. Patients' mean age was 32.4 ± 14.6 years, and 62.2% were female. The most common clinical manifestations were fever (88.6%), headache (72.9%), intense arthralgia (69.5%), and myalgia (65.6%). Hospital admission was required for 3,080 cases (3.3%), and death occurred in 383 cases (0.2%). Chronic kidney disease was reported in 691 cases (0.3%). Patients with CKD had a higher frequency of almost all clinical manifestations, including fever, myalgia, exanthema, vomiting, nausea, back pain, conjunctivitis, arthritis, severe arthralgia, petechiae, and retro-orbital pain. They also had a significantly higher frequency of diabetes, hematological disorders, liver diseases, hypertension, peptic ulcer disease, and autoimmune diseases. Mortality was significantly higher among CKD patients than patients without CKD (3.0% versus 0.2%, P < 0.0001).

Long-term survival and clinical forms in the acute phase of Chikungunya virus infection in older Caribbeans

OBJECTIVE

To investigate whether the long-term survival in elderly patients with prior Chikungunya virus infection (CVI) is associated with the clinical form presented in the acute phase, as defined by the WHO classification.

METHODS

Retrospective cohort study performed in Martinique University Hospitals. Patients who attended the emergency department for suspected CVI, and who had a positive biological diagnosis of CVI by reverse transcription-polymerase chain reaction on a plasma sample between 10 January and 31 December 2014 were eligible for inclusion. Time-to-death was the primary outcome. The independent relationship between clinical forms and time-to-death was analysed using a Cox model.

RESULTS

In total, 268 patients were included. Mean age was 80 ± 8 years, 53% were women. Median length of follow-up was 28 months (range: 0-39). During follow-up, 53 (19.8%) patients died. Median survival time was 13.2 months (range: 0-33.6). At the end of follow-up, death rates were 4.6% for acute clinical cases, 19.0% for atypical cases, 19.2% for severe acute cases and 23.5% for unclassifiable cases. By multivariable analysis, the clinical form of CVI at admission was found to be independently associated with long-term survival (atypical form: HR = 2.38; 95% CI = 2.15-2.62; severe acute form: HR = 2.40; 95% CI = 2.17-2.64; unclassifiable form: HR = 2.28; 95% CI = 2.06-2.51).

CONCLUSION

The clinical form at presentation with CVI has a significant impact on long-term survival. Management of CVI patients should be tailored according to their clinical form at admission.

Chikungunya Virus Vaccines: Platforms, Progress, and Challenges

Chikungunya is a clinically and economically important arbovirus that has spread globally in the twenty-first century. While uncommonly fatal, infection with the virus can lead to incapacitating arthralgia that can persist for months to years. The adverse impacts of viral spread are most severe in developing low- and middle-income countries in which medical infrastructure is insufficient and manual labor is an economic driver. Unfortunately, no prophylactic or therapeutic treatments are approved for human use to combat the virus. Historically, vaccination has proven to be the most efficient and successful strategy for protecting populations and eradicating infectious disease. A large and diverse range of promising vaccination approaches for use against Chikungunya has emerged in recent years and been shown to safely elicit protective immune responses in animal models and humans. Importantly, many of these are based on technologies that have been clinically approved for use against other pathogens. Furthermore, clinical trials are currently ongoing for a subset of these. The purpose of this review is to provide a description of the relevant immunobiology of Chikungunya infection, to present immune-stimulating technologies that have been successfully employed to protect against infection, and discuss priorities and challenges regarding the future development of a vaccine for clinical use.

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.

Interventions to restore appropriate immune function in the elderly

Advanced age is one indicator of likely immune dysfunction. As worldwide, the global population contains progressively more and more older individuals there is likelihood of an increased prevalence and incidence of infectious diseases due to common and emergent pathogens. The resultant increase in mortality and morbidity would be matched by the risk of functional decline and disability. Maintaining immune function at a plateau throughout life may therefore be associated with considerable cost savings. The aim of improving immune function in older individuals may be achieved through considering a therapeutic approach to rejuvenate, stimulate or support the indigenous immune system to perform in a more optimal manner. In terms of cost effectiveness a therapeutic approach may prove difficult because of issues associated with; identifying those who would benefit the most from this treatment, identifying the type of treatment which would suit them and identifying whether the treatment was successful. The alternative of supporting or providing a stronger stimulus through vaccination, whilst more cost effective, may be a more valuable option in the short term. Both approaches will be addressed in this review.