Chikungunya fever: Atypical and lethal cases in the Western hemisphere: A Venezuelan experience

Pathogenesis and clinical management of arboviral diseases

Arboviral diseases are viral infections transmitted to humans through the bites of arthropods, such as mosquitoes, often causing a variety of pathologies associated with high levels of morbidity and mortality. Over the past decades, these infections have proven to be a significant challenge to health systems worldwide, particularly following the considerable geographic expansion of the dengue virus (DENV) and its most recent outbreak in Latin America as well as the difficult-to-control outbreaks of yellow fever virus (YFV), chikungunya virus (CHIKV), and Zika virus (ZIKV), leaving behind a substantial portion of the population with complications related to these infections. Currently, the world is experiencing a period of intense globalization, which, combined with global warming, directly contributes to wider dissemination of arbovirus vectors across the globe. Consequently, all continents remain on high alert for potential new outbreaks. Thus, this review aims to provide a comprehensive understanding of the pathogenesis of the four main arboviruses today (DENV, ZIKV, YFV, and CHIKV) discussing their viral characteristics, immune responses, and mechanisms of viral evasion, as well as important clinical aspects for patient management. This includes associated symptoms, laboratory tests, treatments, existing or developing vaccines and the main associated complications, thus integrating a broad historical, scientific and clinical approach.

Chikungunya: From Hypothesis to Evidence of Increased Severe Disease and Fatalities

Chikungunya virus infection often manifests as an acute, self-limiting febrile illness, with arthralgia and musculoskeletal symptoms being the most commonly reported. Arthralgia can persist for months or even years, and approximately 50% of cases progress to chronic conditions. However, recent outbreaks have revealed a rising number of severe cases and fatalities. This review examines evidence from the past decade that suggests a higher incidence of severe chikungunya virus (CHIKV) infections and increased mortality rates, challenging official reports and guidelines from many countries. The literature review includes case reports, series, and studies with comparison groups to assess whether CHIKV-related mortality is underreported. Evaluating excess mortality involves analyzing consistent findings across different regions, biological plausibility, and systemic manifestations that contribute to severe outcomes. These findings aim to expand disease classifications in international guidelines and raise awareness among healthcare professionals to better identify severe CHIKV cases and related deaths. Studies were identified through PubMed using the search terms "chikungunya", "death", "severe", "pathogenesis", and "pathophysiology".

Chikungunya infection in children: clinical profile and outcome

The clinical profile and outcomes of children with chikungunya infection differ from those observed in adults. As there is a paucity of data on chikungunya infection in children, this study aimed to find the clinical course, complications, and mortality rates of chikungunya infection in children. This was a combined retrospective and prospective observational study. Children aged 1 month to 15 years who tested positive for chikungunya infection by IgM enzyme-linked immunosorbent assay and reverse transcription polymerase chain reaction in serum or body fluids were included. The demographic details, clinical presentation, laboratory parameters, treatment given, and outcomes were recorded in a structured proforma. Fifty-eight cases (41 retrospective and 17 prospective) were recruited, out of which 30 (52%) were males. The median age was 8 (3-11) years. The most common clinical feature at admission was fever observed in 55 patients (94.8%), followed by vomiting [25 (43.1%)] and myalgia [23 (39.7%)]. Commonly observed clinical signs were skin rash [32 (55.2%)], hepatomegaly [25 (43.1%)], and anemia [22 (37.9%)]. Frequently observed acute complications were lymphopenia [46 (79.3%)], hyponatremia [32 (55.2%)], capillary leak [27 (46.6%)], and thrombocytopenia [26 (44.8%)]. Of 58 cases, 8 (13.8%) children had co-infection with other microbes. Overall, 55 (94.8%) children had complete recovery, 2 (3.4%) children died of complications (one with acute encephalitis and one child with acute respiratory distress syndrome), and 5 children had prolonged arthralgia. Children with chikungunya had more skin manifestations and neurological manifestations than arthralgia. Also, a significant proportion of children developed serious complications like a capillary leak.

The research progress of Chikungunya fever

Chikungunya fever, an acute infectious disease caused by Chikungunya virus (CHIKV), is transmitted by Aedes aegypti mosquitoes, with fever, rash, and joint pain as the main features. 1952, the first outbreak of Chikungunya fever was in Tanzania, Africa, and the virus was isolated in 1953. The epidemic has expanded from Africa to South Asia, the Indian Ocean islands and the Americas, and is now present in more than 100 countries and territories worldwide, causing approximately 1 million infections worldwide each year. In addition, fatal cases have been reported, making CHIKV a relevant public health disease. The evolution of the virus, globalization, and climate change may have contributed to the spread of CHIKV. 2005-2006 saw the most severe outbreak on Reunion Island, affecting nearly 35% of the population. Since 2005, cases of Chikungunya fever have spread mainly in tropical and subtropical regions, eventually reaching the Americas through the Caribbean island. Today, CHIKV is widely spread worldwide and is a global public health problem. In addition, the lack of a preventive vaccine and approved antiviral treatment makes CHIKV a major global health threat. In this review, we discuss the current knowledge on the pathogenesis of CHIKV, focusing on the atypical disease manifestations. We also provide an updated review of the current development of CHIKV vaccines. Overall, these aspects represent some of the most recent advances in our understanding of CHIKV pathogenesis and also provide important insights into the current development of CHIKV and potential CHIKV vaccines for current development and clinical trials.

The relationship between chikungunya virus and the kidneys: A scoping review

Several atypical forms of chikungunya fever (CHIK) have been described, including neurological, cardiac and renal involvement. These forms may be related to high morbidity and mortality rates. This scoping review based on the PubMed, Scopus, and WOS databases aims to identify and summarise all the available evidence regarding the clinical and histopathological presentations and risk factors associated with kidney injury related to CHIK, as well as the clinical impact. Thus, a total of 54 papers were selected from 1606 initial references after applying the defined inclusion criteria. Data on the association between kidney injury and CHIK are scarce, with studies only conducted in the acute phase of the disease, lacking further characterisation. Kidney injury incidence in hospitalised patients using the Kidney Disease Improving Global Outcomes criteria varies from 21% to 45%, being higher among patients with atypical and severe manifestations. Although acute kidney injury does not seem to be related to viraemia, it may be related to higher mortality. Few studies have described the renal histopathological changes in the acute phase of CHIK, with prevalent findings of acute interstitial nephritis with mononuclear infiltrate, glomerular congestion and nephrosclerosis. Only one study assessed the kidney function of patients in the subacute and chronic phases of CHIK. Additionally, individuals with comorbidities, including chronic kidney disease, may be among those with a greater risk of presenting worse outcomes when affected by CHIK. The results described herein may contribute to better understand the relationship between the kidneys and chikungunya virus.

Understanding the Biology and Immune Pathogenesis of Chikungunya Virus Infection for Diagnostic and Vaccine Development

Chikungunya virus, the causative agent of chikungunya fever, is generally characterized by the sudden onset of symptoms, including fever, rash, myalgia, and headache. In some patients, acute chikungunya virus infection progresses to severe and chronic arthralgia that persists for years. Chikungunya infection is more commonly identified in tropical and subtropical regions. However, recent expansions and epidemics in the temperate regions have raised concerns about the future public health impact of chikungunya diseases. Several underlying factors have likely contributed to the recent re-emergence of chikungunya infection, including urbanization, human travel, viral adaptation to mosquito vectors, lack of effective control measures, and the spread of mosquito vectors to new regions. However, the true burden of chikungunya disease is most likely to be underestimated, particularly in developing countries, due to the lack of standard diagnostic assays and clinical manifestations overlapping with those of other endemic viral infections in the regions. Additionally, there have been no chikungunya vaccines available to prevent the infection. Thus, it is important to update our understanding of the immunopathogenesis of chikungunya infection, its clinical manifestations, the diagnosis, and the development of chikungunya vaccines.

Ecological niche modeling based on ensemble algorithms to predicting current and future potential distribution of African swine fever virus in China

African swine fever (ASF) is a tick-borne infectious disease initially described in Shenyang province China in 2018 but is now currently present nationwide. ASF has high infectivity and mortality rates, which often results in transportation and trade bans, and high expenses to prevent and control the, hence causing huge economic losses and a huge negative impact on the Chinese pig farming industry. Ecological niche modeling has long been adopted in the epidemiology of infectious diseases, in particular vector-borne diseases. This study aimed to establish an ecological niche model combined with data from ASF incidence rates in China from August 2018 to December 2021 in order to predict areas for African swine fever virus (ASFV) distribution in China. The model was developed in R software using the biomod2 package and ensemble modeling techniques. Environmental and topographic variables included were mean diurnal range (°C), isothermality, mean temperature of wettest quarter (°C), precipitation seasonality (cv), mean precipitation of warmest quarter(mm), mean precipitation of coldest quarter (mm), normalized difference vegetation index, wind speed (m/s), solar radiation (kJ /day), and elevation/altitude (m). Contribution rates of the variables normalized difference vegetation index, mean temperature of wettest quarter, mean precipitation of coldest quarter, and mean precipitation of warmest quarter were, respectively, 47.61%, 28.85%, 10.85%, and 7.27% (according to CA), which accounted for over 80% of contribution rates related to variables. According to model prediction, most of areas revealed as suitable for ASF distribution are located in the southeast coast or central region of China, wherein environmental conditions are suitable for soft ticks’ survival. In contrast, areas unsuitable for ASFV distribution in China are associated with arid climate and poor vegetation, which are less conducive to soft ticks’ survival, hence to ASFV transmission. In addition, prediction spatial suitability for future ASFV distribution suggests narrower areas for ASFV spread. Thus, the ensemble model designed herein could be used to conceive more efficient prevention and control measure against ASF according to different geographical locations in China.

Chikungunya Immunopathology as It Presents in Different Organ Systems

Chikungunya virus (CHIKV) is currently an urgent public health problem as high morbidity from the virus leaves populations with negative physical, social, and economic impacts. CHIKV has the potential to affect every organ of an individual, leaving patients with lifelong impairments which negatively affect their quality of life. In this review, we show the importance of CHIKV in research and public health by demonstrating the immunopathology of CHIKV as it presents in different organ systems. Papers used in this review were found on PubMed, using “chikungunya and [relevant organ system]”. There is a significant inflammatory response during CHIKV infection which affects several organ systems, such as the brain, heart, lungs, kidneys, skin, and joints, and the immune response to CHIKV in each organ system is unique. Whilst there is clinical evidence to suggest that serious complications can occur, there is ultimately a lack of understanding of how CHIKV can affect different organ systems. It is important for clinicians to understand the risks to their patients.

Molecular and biological characterization of an Asian-American isolate of Chikungunya virus

Chikungunya virus is an arthropod-transmitted virus that causes chikungunya fever, a disease characterized by severe muscle and joint pain. In 2013, the virus was introduced to the Americas and caused approximately 2.7 million cases of infection during the subsequent two years. The lack of knowledge regarding the biological behavior of the viral strains circulating during the outbreak motivated the characterization of an isolate from the Colombian outbreak, starting from analysis of the complete genome to the biological behavior in vitro. The full genome was retrieved using next-generation sequencing. The infective and replicative capacities were evaluated in HEK293T, Huh-7, and MRC-5 cell lines. The infection rates were determined by flow cytometry, and the cytopathic effect was assessed by a resazurin fluorescent metabolic assay. The viral yield was quantified using the virus plaque formation assay, while the viral proteins and genomic RNA kinetics were subsequently evaluated by western-blot and RT-qPCR. The COL7624 isolate clustered with other American and Caribbean sequences in the Asian American lineage. The T669A substitution in E2 protein distinguished it from other Colombian sequences reported in 2014. After 48 h post infection (hpi), the three cell lines analyzed reached infection percentages exceeding 65%, generating a high load of infectious viral progeny. The infection kinetics indicated that the replication peak of this CHIKV isolate is around 24 hpi, although gRNA is detectable in the culture supernatant from 4 hpi onwards. The infection caused the overexpression of interferon and pro-inflammatory cytokines, such as IL-1β, TNF-α, and IL-8. The COL7624 CHIKV isolate exhibited a high infective and replicative capacity as well as activation of cellular immune responses, similar to isolates belonging to the other genotypes.

Atypical skin manifestation in severe acute chikungunya infection in a pregnant woman: a case report

INTRODUCTION

Patients with chikungunya virus infection commonly present with fever, skin rash, and severe joint pain. The vesiculobullous rash is rare in adults but common in infants. In addition, septic shock and acute respiratory distress syndrome are rare complications of atypical and severe acute chikungunya infection.

CASE PRESENTATION

We report the presence of an 18-year-old Thai female, at 31 weeks gestation, with fever, maculopapular rash, and polyarthritis. The rash later progressed to a vesiculobullous pattern, and she developed septic shock and acute respiratory distress syndrome. Skin biopsy and blood were positive for chikungunya virus RNA. The patient was intubated with a mechanical ventilator and subsequently fully recovered.

CONCLUSION

Atypical skin manifestation and severe acute disease is likely due to immune response attenuation in pregnancy. The possibility of progression to severe or atypical disease in pregnant women suffering chikungunya should always be considered.

Clinical Features of Acute Chikungunya Virus Infection in Children and Adults during an Outbreak in the Maldives

The chikungunya virus is an arthritogenic arbovirus that has re-emerged in many tropical and subtropical regions, causing explosive outbreaks. This re-emergence is due to a genomic polymorphism that has increased the vector susceptibility of the virus. The majority of those infected with chikungunya virus exhibit symptoms of fever, rash, and debilitating polyarthralgia or arthritis. Symptoms can persist for weeks, and patients can relapse months later. Fatalities are rare, but individuals of extreme age can develop severe infection. Here, we describe the 2019 outbreak, the second-largest since the virus re-emerged in the Maldives after the 2004 Indian Ocean epidemic, in which a total of 1,470 cases were reported to the Health Ministry. Sixty-seven patients presenting at the main referral tertiary care hospital in the Maldives capital with acute undifferentiated illness were recruited following a negative dengue serology. A novel point-of-care antigen kit was used to screen suspected cases, 50 of which were subsequently confirmed using real-time reverse transcription-polymerase chain reaction. We describe the genotype and polymorphism of Maldives chikungunya virus using phylogenetic analysis. All isolates were consistent with the East Central South African genotype of the Indian Ocean lineage, with a specific E1-K211E mutation. In addition, we explored the clinical and laboratory manifestations of acute chikungunya in children and adults, of which severe infection was found in some children, whereas arthritis primarily occurred in adults. Arthritides in adults occurred irrespective of underlying comorbidities and were associated with the degree of viremia.

Rediscovering the chikungunya virus

El virus de chikunguña (CHIKV) es un Alfavirus perteneciente al grupo denominado del Viejo Mundo; estos son virus artritogénicos que causan una enfermedad febril caracterizada por artralgias y mialgias. Aunque la muerte por CHIKV es poco frecuente, la enfermedad puede llegar a ser incapacitante y generar un amplio espectro de manifestaciones atípicas, como complicaciones cardiovasculares, respiratorias, oculares, renales y dérmicas, entre otras. Cuando el dolor articular persiste por tres o más meses, da lugar a la forma crónica de la enfermedad denominada reumatismo inflamatorio crónico poschikunguña, el cual es la principal secuela de la enfermedad. Se considera que este virus no es neurotrópico, sin embargo, puede afectar el sistema nervioso central y generar secuelas graves y permanentes, principalmente, en niños y ancianos.

En África, Asia y Europa se habían reportado anteriormente brotes epidémicos por CHIKV, pero solo hasta finales del 2013 se documentó la introducción del virus a las Américas; desde entonces, el virus se ha propagado a 45 países o territorios del continente y el número de casos acumulados ascendió a cerca de dos millones en dos años.

Esta revisión describe de manera general la biología molecular del virus, sus manifestaciones clínicas, su patogénesis y las principales complicaciones posteriores a la infección. Además, reúne la información de la epidemia en Colombia y el continente americano publicada entre el 2014 y el 2020.

Cardiomyopathy and Death Following Chikungunya Infection: An Increasingly Common Outcome

Chikungunya virus (CHIKV) is vectored by Aedes aegypti and Aedes albopictus mosquitoes and is found throughout tropical and sub-tropical regions. While most infections cause mild symptoms such as fever and arthralgia, there have been cases in which cardiac involvement has been reported. In adults, case reports include symptoms ranging from tachycardia and arrythmia, to myocarditis and cardiac arrest. In children, case reports describe symptoms such as arrythmia, myocarditis, and heart failure. Case reports of perinatal and neonatal CHIKV infections have also described cardiovascular compromise, including myocardial hypertrophy, ventricular dysfunction, myocarditis, and death. Myocarditis refers to inflammation of the heart tissue, which can be caused by viral infection, thus becoming viral myocarditis. Since viral myocarditis is linked as a causative factor of other cardiomyopathies, including dilated cardiomyopathy, in which the heart muscle weakens and fails to pump blood properly, the connection between CHIKV and the heart is concerning. We searched Pubmed, Embase, LILACS, and Google Scholar to identify case reports of CHIKV infections where cardiac symptoms were reported. We utilized NCBI Virus and NCBI Nucleotide to explore the lineage/evolution of strains associated with these outbreaks. Statistical analysis was performed to identify which clinical features were associated with death. Phylogenetic analysis determined that CHIKV infections with cardiac symptoms are associated with the Asian, the East Central South African, and the Indian Ocean lineages. Of patients admitted to hospital, death rates ranged from 26-48%. Myocarditis, hypertension, pre-existing conditions, and the development of heart failure were significantly correlated with death. As such, clinicians should be aware in their treatment and follow-up of patients.

Proposal for classifying the different types of descriptive epidemiological studies

Descriptive epidemiological studies are of relevance, given that there are inconsistencies in the literature with regard to their nomenclature and classification. We reviewed 19 international and six national academic textbooks on epidemiology, where the main criterion was to have them available in order to undertake an in-depth review of chapters on descriptive epidemiology and study types. In 11 books, the authors prioritize analytical studies. Twelve foreign texts and two from Brazil include descriptive studies, although the majority did not specifically refer to a category with this name. We propose a classification based on the answers to research questions, including the following types of study: case report, case series, clinical cohort, prevalence study, incidence study (cohort) and descriptive ecological study. We discuss potential uses, implementation of novel data analysis methods and their relevance in health surveillance.

Risk factors for death among patients with Chikungunya virus infection during the outbreak in northeast Brazil, 2016-2017

BACKGROUND

Chikungunya virus (CHIKV) infection is a current public health problem. The aim of this study was to investigate risk factors for death among patients with CHIKV infection during a large epidemic in northeast Brazil.

METHODS

This is a cross-sectional study with all registered cases of CHIKV in Ceara, Brazil, during 2016-2017. Data from notification reports were collected, and we have compared non-survivors and survivors.

RESULTS

A total of 182 731 cases were reported, with a mean age of 38±19 years, and the majority was female (62%). There were 383 deaths. Non-survivors were elderly, with a predominance of males, and with a lower educational level. Conditions that were significantly more frequent in the non-survivor group were systemic arterial hypertension, diabetes mellitus and chronic kidney disease (p<0.0001). Independent risk factors for death were advanced age (OR 7.35, p<0.0001), male gender (OR 2.05, p<0.0001), leukopenia (OR 3.18, p<0.0001) and vomiting (OR 2.19, p<0.0001), and comorbidities like hypertension (OR 3.74, p<0.0001), diabetes (OR 3.29, p<0.0001) and chronic kidney disease (OR 3.14, p<0.0001).

CONCLUSION

Advanced age and low educational level were associated with higher risk of mortality in CHIKV. Leukopenia and vomiting were signs of severity, as well as the presence of comorbidities, especially hypertension, diabetes and kidney disease.

Events preceding death among chikungunya virus infected patients: a systematic review

Since its re-emergence in the late 1990s, there have been reports of Chikungunya fever (CHIK-F) presenting with severe or atypical findings. There is little knowledge regarding the clinical events leading to the death of patients with CHIK-F. This study aimed to systematically review the literature regarding CHIK-F and identify clinical features preceding death. We searched PubMed, Scopus, Embase, Lilacs, and IsiWeb for case-reports, case-series, or cohorts of CHIK-F reporting at least one death, up to December 2019. Fifty-seven reports were analyzed, including 2140 deaths. Data about specific clinical events that precede death are scarce. The central tendency of time between disease onset and death ranged from 2 days to 150 days. The most common clinical findings among decedents were fever (22.0%), arthralgia (15.7%), myalgia (10.7%), and headache (8.2%). Excluding pediatric populations, the reported central tendency of age among the decedents was 53 or older, with a non-weighted median of 67, ranging up to 80 years old. Authors mentioned organic dysfunction in 91.2% reports. Among all the 2140 decedents, the most common dysfunctions were cardiovascular (7.2%), respiratory (6.4%), neurological (5.4%), renal (4.2%), liver (3.0%), and hematological (1.3%) dysfunction. Exacerbation of previous diabetes (5.6%) or hypertension (6.9%) was mentioned as conditions preceding death. Currently, older age, primary neurological, cardiovascular, or respiratory dysfunction and a previous diagnosis of diabetes or hypertension are the main clinical events preceding death.

Manifestations of Atypical Symptoms of Chikungunya during the Dhaka Outbreak (2017) in Bangladesh

Chikungunya (CHIK) has emerged as a major public health concern worldwide. Recently, atypical manifestations are drawing special attention because these might be associated with various complications. Information on atypical manifestations of CHIK is still limited. Here, we analyzed a dataset of 1,326 cases from our recent Dhaka outbreak study to explore the demographics and distributions of atypical manifestations. About 80% of cases reported at least one atypical symptom. Among all atypical symptoms, the most common and unique atypical symptom was joint pain before fever (90.2%), occurred predominantly in female respondents. Other common symptoms included red eye (68.2%), oral ulcer (37.7%), and dermatological manifestations (27.1%). More than two-thirds of patients reported multiple atypical symptoms. Atypical manifestations were not significantly different across age groups, except ocular complications. This study would be an important resource for clinicians and epidemiologists to understand the diversity of Chikungunya infection and, thus, help in better patient management.

Secondary lower limbs lymphedema in patients with Chikungunya fever

Chikungunya fever (CHIKF) is an arbovirus characterized by acute fever, myalgia and polyarthralgia. Lymphedema in the lower limbs (LL) was observed in several patients during an outbreak of CHIKF in the state of Pernambuco (Brazil) in 2016. No reports on lymphatic vessels disease due to CHIKF have been described. The aim of the study was to follow lymphatic abnormalities in the LL of 16 patients with CHIKF, using lymphoscintigraphy.An observational, prospective study with patients in the acute phase of CHIKF (confirmed serological diagnosis) with LL edema submitted to clinical evaluation and lymphoscintigraphy at baseline and after 90 days.Sixteen patients (81% females) participated in this study. All patients presented with lower limb lymphedema, being 15 (94%) bilateral. Of the 31 limbs affected by lymphedema, 24 (77%) presented abnormalities in lymphatic drainage by lymphoscintigraphy. The delay to visualize pelvic lymph nodes was the most frequent lymphoscintigraphic abnormality, observed in 16 (51,6%) LL. Nine (56%) patients were clinically reevaluated after 90 days, and all 18 LL remained with lymphedema. A second lymphoscintigraphy showed persistent abnormalities in 13 (72%) of the 18 LL.CHIKF can lead to lymphedema, and lymphedema may persist or progress after 3 months of the acute phases of the disease.

Evaluation of functional disability after Chikungunya infection

INTRODUCTION

Chikungunya (CHIK) is caused by the Chikungunya virus, which is an Alphavirus of the Family Togaviridae transmitted to humans through female mosquitoes of the genus Aedes.

METHODS

A cross-sectional study was conducted involving the administration of a questionnaire addressing sociodemographic and health variables and the Roland-Morris Disability Questionnaire on general pain to patients with CHIK in the City of Imperatriz, Brazil, between January and December 2017.

RESULTS

Data of a total of 130 patients were evaluated. The mean age was 52 years (standard deviation=13.3); majority of the patients were female (n=120) with a prevalence of 38.0% for functional disability. Statistical differences were noted for marital status (p=0.037), presence/absence of comorbidities (p=0.050), and the use of medications prior to the diagnosis of CHIK (p=0.050), use of methotrexate (p=0.030), use of nonsteroidal anti-inflammatory drugs (p≤0.035), and use of nonhormonal anti-inflammatory drugs (p=0.001).

CONCLUSIONS

Patients in the chronic phase of CHIK present functional disability, thus alerting healthcare professionals to the importance of implementing actions aimed at an adequate treatment in all phases of the disease, mainly related to pain treatment and motor rehabilitation.

Autocidal gravid ovitraps protect humans from chikungunya virus infection by reducing Aedes aegypti mosquito populations

Background

Public health responses to outbreaks of dengue, chikungunya, and Zika virus have been stymied by the inability to control the primary vector, Aedes aegypti mosquitos. Consequently, the need for novel approaches to Aedes vector control is urgent. Placement of three autocidal gravid ovitraps (AGO traps) in ~85% of homes in a community was previously shown to sustainably reduce the density of female Ae. aegypti by >80%. Following the introduction of chikungunya virus (CHIKV) to Puerto Rico, we conducted a seroprevalence survey to estimate the prevalence of CHIKV infection in communities with and without AGO traps and evaluate their effect on reducing CHIKV transmission.

Methods and findings

Multivariate models that calculated adjusted prevalence ratios (aPR) showed that among 175 and 152 residents of communities with and without AGO traps, respectively, an estimated 26.1% and 43.8% had been infected with CHIKV (aPR = 0.50, 95% CI: 0.37–0.91). After stratification by time spent in their community, protection from CHIKV infection was strongest among residents who reported spending many or all weekly daytime hours in their community:10.3% seropositive in communities with AGO traps vs. 48.7% in communities without (PR = 0.21, 95% CI: 0.11–0.41). The age-adjusted rate of fever with arthralgia attributable to CHIKV infection was 58% (95% CI: 46–66%). The monthly number of CHIKV-infected mosquitos and symptomatic residents were diminished in communities with AGO traps compared to those without.

Conclusions

These findings indicate that AGO traps are an effective tool that protects humans from infection with a virus transmitted by Ae. aegypti mosquitos. Future studies should evaluate their protective effectiveness in large, urban communities.

Aedes species mosquitos transmit pathogens of public health importance, including dengue, Zika, and chikungunya viruses. No tools exist to control these mosquitos that sustainably and effectively prevent human infections. Autocidal gravid ovitraps (AGO traps) have been shown to sustainably reduce Aedes populations by >80%. After chikungunya virus was introduced into Puerto Rico, we conducted serosurveys in communities with and without AGO traps. We observed a two-fold lower prevalence of chikungunya virus infection among residents of communities with AGO traps compared to communities without. Among infected residents of communities with traps, a significant proportion likely had been infected while outside their community. These findings indicate that AGO traps are an effective tool that protects humans from infection with pathogens transmitted by Aedes mosquitos.

Venezuela's humanitarian crisis, resurgence of vector-borne diseases, and implications for spillover in the region

In the past 5-10 years, Venezuela has faced a severe economic crisis, precipitated by political instability and declining oil revenue. Public health provision has been affected particularly. In this Review, we assess the impact of Venezuela's health-care crisis on vector-borne diseases, and the spillover into neighbouring countries. Between 2000 and 2015, Venezuela witnessed a 359% increase in malaria cases, followed by a 71% increase in 2017 (411 586 cases) compared with 2016 (240 613). Neighbouring countries, such as Brazil, have reported an escalating trend of imported malaria cases from Venezuela, from 1538 in 2014 to 3129 in 2017. In Venezuela, active Chagas disease transmission has been reported, with seroprevalence in children (<10 years), estimated to be as high as 12·5% in one community tested (n=64). Dengue incidence increased by more than four times between 1990 and 2016. The estimated incidence of chikungunya during its epidemic peak is 6975 cases per 100 000 people and that of Zika virus is 2057 cases per 100 000 people. The re-emergence of many vector-borne diseases represents a public health crisis in Venezuela and has the possibility of severely undermining regional disease elimination efforts. National, regional, and global authorities must take action to address these worsening epidemics and prevent their expansion beyond Venezuelan borders.

Severe Manifestations of Chikungunya Fever in Children, India, 2016

Chikungunya is a relatively benign disease, and a paucity of literature on severe manifestations in children exits. We describe a cohort of pediatric chikungunya fever patients in New Delhi, India, who had severe sepsis and septic shock, which can develop during the acute phase of illness.

Spectrum of candidate molecules against Chikungunya virus - an insight into the antiviral screening platforms

INTRODUCTION

Chikungunya disease has undergone a phenomenal transition in its status from being recognized as a sporadic infection to acquiring a global prominence over the last couple of decades. The causative agent behind the explosive epidemics worldwide is the re-emerging pathogen, Chikungunya virus (CHIKV). Areas covered: The current review discusses all the possible avenues of antiviral research towards combating CHIKV infection. Aspects of antiviral drug discovery such as antiviral targets, candidate molecules screened, and the various criteria to be a potential inhibitor are all discussed at length. Existing antiviral drug screening tools for CHIKV and their applications are thoroughly described. Clinical trial status of agents with therapeutic potential has been updated with special mention of candidate molecules under patent approval. Databases such as PubMed, Google Scholar, ScienceDirect, Google Patent, and Clinical Trial Registry platforms were referred. Expert opinion: The massive outbreaks of Chikungunya viral disease in the recent past and the serious health concerns imposed thereby, have driven the search for effective therapeutics. The greatest challenge being the non-availability of robust, reproducible, cost-effective and biologically accurate assay models. Nevertheless, there is a need to identify good models mimicking the appropriate microenvironment of an infectious setting.

Intensive Care Admissions for Severe Chikungunya Virus Infection, French Polynesia

During the 2014–2015 chikungunya outbreak in French Polynesia, 64 patients with confirmed chikungunya virus infection were admitted into intensive care. Sixty-three were nonpregnant adults; 11 had an atypical form, 21 had severe sepsis or septic shock, and 18 died. These findings indicate that critical illness frequently complicates the course of chikungunya virus infection.

Atypical and severe manifestations of chikungunya virus infection in French Guiana: A hospital-based study

BACKGROUND

French Guiana (FG) was the first country in South America to declare chikungunya virus infection (CHIKV). The outbreak affected about 16,000 persons between February 2014 and October 2015, with several atypical cases, but only two fatal cases. We aimed to describe the clinical presentation of patients hospitalized for CHIKV infection, to estimate and identify risk factors of unusual and severe forms in adult patients.

MATERIALS AND METHODS

A monocentric retrospective study was conducted in Cayenne hospital, the main city and the main hospital in FG, from March 1st 2014 to August 31st 2015. All patients admitted for at least one night with a biological diagnosis of CHIKV infection during the 2014/2015 outbreak were included, except pregnant women and children under 15 years.

RESULTS

During the study period, 285 patients with a diagnosis of CHIKV infection were hospitalized in Cayenne hospital, among whom 96 nonpregnant adults were studied. Five were classified as severe forms (5.2%) and 23 as unusual forms (23.9%). The most frequent atypical and/or severe form was neurological (n = 20), followed by cardio-respiratory failure (acute respiratory failure n = 4, acute heart failure n = 2), digestive and hepatic disorders (acute hepatitis n = 3, acute pancreatitis n = 2), renal disorders (acute renal failure n = 5) and muscular impairment (rhabdomyolysis n = 3).

CONCLUSION

During the outbreak, hospitalizations were frequent, particularly for common forms, driven by algic clinical presentations and concerns due to the novelty of this infection. Despite atypical neurological and liver forms of CHIKV infection, case-fatality was low in French Guiana. No specific risk factor of atypical and/or severe forms was found in our study.

A scoping review of published literature on chikungunya virus

Chikungunya virus (CHIKV) has caused several major epidemics globally over the last two decades and is quickly expanding into new areas. Although this mosquito-borne disease is self-limiting and is not associated with high mortality, it can lead to severe, chronic and disabling arthritis, thereby posing a heavy burden to healthcare systems. The two main vectors for CHIKV are Aedes aegypti and Aedes albopictus (Asian tiger mosquito); however, many other mosquito species have been described as competent CHIKV vectors in scientific literature. With climate change, globalization and unfettered urban planning affecting many areas, CHIKV poses a significant public health risk to many countries. A scoping review was conducted to collate and categorize all pertinent information gleaned from published scientific literature on a priori defined aspects of CHIKV and its competent vectors. After developing a sensitive and specific search algorithm for the research question, seven databases were searched and data was extracted from 1920 relevant articles. Results show that CHIKV research is reported predominantly in areas after major epidemics have occurred. There has been an upsurge in CHIKV publications since 2011, especially after first reports of CHIKV emergence in the Americas. A list of hosts and vectors that could potentially be involved in the sylvatic and urban transmission cycles of CHIKV has been compiled in this scoping review. In addition, a repository of CHIKV mutations associated with evolutionary fitness and adaptation has been created by compiling and characterizing these genetic variants as reported in scientific literature.

Overproduction of IL-6 and Type-I IFN in a Lethal Case of Chikungunya Virus Infection in an Elderly Man During the 2017 Italian Outbreak

Chikungunya fever is caused by Chikungunya virus (CHIKV) and is generally considered a self-limiting disease. However, severe clinical presentations with a high mortality rate have been reported in association with underlying medical conditions. This study reports the molecular characterization of the virus and an abnormal pattern of circulating cytokines in a unique lethal CHIKV case during the 2017 outbreak in Italy, which involved an elderly patient with underlying cardiac disease. Analysis of inflammatory cytokines revealed a strong increase of interferon (IFN)-α and IFN-β, as well as interleukin-6, suggesting a possible role of type-I IFN in the cytokine storm, which may be correlated with unfavorable prognosis of CHIKV infection.

Chikungunya fever: a threat to global public health

Chikungunya fever is an emerging arbovirus infection, representing a serious public health problem. Its etiological agent is the Chikungunya virus (CHIKV). Transmission of this virus is mainly vector by mosquitoes of the genus Aedes, although transmission by blood transfusions and vertical transmission has also been reported. The disease presents high morbidity caused mainly by the arthralgia and arthritis generated. Cardiovascular and neurological manifestations have also been reported. The severity of the infection seems to be directly associated with the action of the virus, but also with the decompensation of preexisting comorbidities. Currently, there are no therapeutic products neither vaccines licensed to the infection CHIKV control, although several vaccine candidates are being evaluated and human polyvalent immunoglobulins anti-CHIKV had been tested. Antibodies can protect against the infection, but in sub-neutralizing concentrations can augment virus infection and exacerbate disease severity. So, the prevention still depends on the use of personal protection measures and vector control, which are only minimally effective.

Outbreak of Chikungunya in the French Caribbean Islands of Martinique and Guadeloupe: Findings from a Hospital-Based Surveillance System (2013-2015)

Chikungunya virus (CHIKV) emerged in the Caribbean island of Saint-Martin in December 2013. We implemented a hospital-based surveillance system to detect and describe CHIKV cases including severe forms of the infection and deaths in the islands of Martinique and Guadeloupe. A case was defined as a patient with a CHIKV laboratory confirmation cared for in a public hospital for chikungunya for at least 24 hours, and a severe CHIKV case was defined as a CHIKV case presenting one or more organ failures. Sociodemographic, clinical, and laboratory data were collected and cases classified into severe or nonsevere based on medical records. From December 2013 to January 2015, a total of 1,836 hospitalized cases were identified. Rate of hospital admissions for CHIKV infection was 60 per 10,000 suspected clinical CHIKV cases and severity accounted for 12 per 10,000. A total of 74 deaths related to CHIKV infection occurred. Infants and elderly people were more frequently hospitalized compared with others and severity was more frequently reported in elderly subjects and subjects with underlying health condition. Fifteen neonatal infections consecutive to mother-to-child transmission were diagnosed, seven of which were severe. The most vulnerable groups of the population, such as the elderly, infants, individuals with comorbidities, and pregnant women, should remain the main targets of public health priorities.

Clinical Profile, Intensive Care Unit Course, and Outcome of Patients Admitted in Intensive Care Unit with Chikungunya

OBJECTIVE

Chikungunya is generally a mild disease, rarely requiring Intensive Care Unit (ICU) admission. However, certain populations may develop organ dysfunction necessitating ICU admission. The purpose of the study was to assess the clinical profile and course of chikungunya patients admitted to the ICU, and to ascertain factors linked with poor outcome.

METHODS

All patients with chikungunya admitted to ICU were included in the study. Admission Acute Physiology and Chronic Health Evaluation (APACHE) II score and sequential organ failure assessment (SOFA) score were calculated. Primary outcome measured was 28-day mortality and secondary outcomes measured were length of hospital and ICU stay and the need for vasopressor support, renal replacement therapy (RRT), and mechanical ventilation (MV). Logistic regression analysis was performed to identify factors predicting mortality.

RESULTS

The most common complaints were fever (96.67%) and altered sensorium (56.67%). Mean admission APACHE II and SOFA scores were 17.28 ± 7.9 and 7.15 ± 4.2, respectively. Fifty-one patients had underlying comorbidities. Vasopressors were required by 46.76%; RRT by 26.67%, and MV by 58.33%, respectively. The 28-day mortality was 36.67%. High APACHE II score (odds ratio: 1.535; 95% confidence interval: 1.053-2.237; P = 0.026) and need for dialysis (odds ratio: 833.221; 95% confidence interval: 1.853-374,664.825; P = 0.031) could independently predict mortality.

CONCLUSIONS

Patients with chikungunya fever may require ICU admission for organ failure. They are generally elderly patients with underlying comorbidities. Despite aggressive resuscitation and organ support, these patients are at high risk of death. Admission APACHE II score and need for dialysis may predict patients at higher risk of death.

Long-term Chikungunya Sequelae in Curaçao: Burden, Determinants, and a Novel Classification Tool

Background

Beyond the acute illness phase, chikungunya constitutes a public health problem given its chronic disease phase, which may include long-term arthralgia, arthritis, fatigue, and depression. Currently, there is no consensus on how to define chikungunya chronicity.

Methods

A comprehensive cross-sectional survey was performed in Curaçao in June and July 2015 to evaluate 304 adult laboratory-confirmed chikungunya patients 3-16 months after diagnosis. We developed a novel tool, the Curaçao Long-Term Chikungunya Sequelae (CLTCS) score, to classify chronic chikungunya disease and estimate its burden regarding disease duration, clinical presentation, and impact on quality of life.

Results

Disease persistence was estimated to be 79% one month after symptom onset and 64% after 400 days. Chikungunya persistence was characterized by higher proportions of arthralgia, weakness, myalgia, and age 41-60 years. Individuals were classified as "highly affected," "mildly affected," and "recovered." "Highly affected" disease status was associated with clinical complaints (arthralgia, weakness, loss of vitality, and being diabetic) and major decreases in quality-of-life scores.

Conclusions

In the Caribbean, a high proportion of chikungunya patients remains chronically affected. We propose the CLTCS as a suitable score to easily and rapidly classify the severity of chikungunya chronic disease and to assess the need for symptom-alleviating treatment.

Fatal case of chikungunya and concomitant thrombotic thrombocytopenic purpura in French Guiana during air flight medical evacuation

Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy associated to severe ADAMTS13 deficiency. It has been linked to various viral infections. Among arboviruses, only Crimean-Congo haemorrhagic fever and dengue fever have been linked to this severe disease. We report the first documented case of TTP concomitant to Chikungunya virus infection.

Cardiovascular involvement and manifestations of systemic Chikungunya virus infection: A systematic review

BACKGROUND

In the last three years, chikungunya virus disease has been spreading, affecting particularly the Americas, producing more than two million cases. In this setting, not only new disease-related epidemiological patterns have been found, but also new clinical findings have been reported by different research groups. These include findings on the cardiovascular system, including clinical, electrocardiographic and echocardiographic alterations. No previous systemic reviews have been found in major databases about it.

METHODS

We performed a systematic review looking for reports about cardiovascular compromise during chikungunya disease. Cardiac compromise is not so common in isolated episodes; but countries where chikungunya virus is an epidemic should be well informed about this condition. We used 6 bibliographical databases as resources: Medline/Pubmed, Embase, ScienceDirect, ClinicalKey, Ovid and SciELO. Dengue reports on cardiovascular compromise were included as well, to compare both arbovirus' organic compromises. Articles that delved mainly into the rheumatic articular and cutaneous complications were not considered, as they were not in line with the purpose of this study. The type of articles included were reviews, meta-analyses, case-controls, cohort studies, case reports and case series. This systematic review does not reach or performed a meta-analysis.

RESULTS

Originally based on 737 articles, our reviewed selected 40 articles with 54.2% at least mentioning CHIKV cardiovascular compromise within the systemic compromise. Cardiovascular manifestations can be considered common and have been reported in France, India, Sri Lanka, Malaysia, Colombia, Venezuela and USA, including mainly, but no limited to: hypotension, shock and circulatory collapse, Raynaud phenomenon, arrhythmias, murmurs, myocarditis, dilated cardiomyopathy, congestive insufficiency, heart failure and altered function profile (Troponins, CPK).

CONCLUSIONS

Physicians should be encouraged to keep divulgating reports on the cardiovascular involvement of chikungunya virus disease, to raise awareness and ultimately encourage suitable diagnosis and intervention worldwide. More research about cardiovascular involvement and manifestations of systemic Chikungunya virus infection is urgently needed.

Cardiovascular involvement and manifestations of systemic Chikungunya virus infection: A systematic review

BACKGROUND

In the last three years, chikungunya virus disease has been spreading, affecting particularly the Americas, producing more than two million cases. In this setting, not only new disease-related epidemiological patterns have been found, but also new clinical findings have been reported by different research groups. These include findings on the cardiovascular system, including clinical, electrocardiographic and echocardiographic alterations. No previous systemic reviews have been found in major databases about it.

METHODS

We performed a systematic review looking for reports about cardiovascular compromise during chikungunya disease. Cardiac compromise is not so common in isolated episodes; but countries where chikungunya virus is an epidemic should be well informed about this condition. We used 6 bibliographical databases as resources: Medline/Pubmed, Embase, ScienceDirect, ClinicalKey, Ovid and SciELO. Dengue reports on cardiovascular compromise were included as well, to compare both arbovirus' organic compromises. Articles that delved mainly into the rheumatic articular and cutaneous complications were not considered, as they were not in line with the purpose of this study. The type of articles included were reviews, meta-analyses, case-controls, cohort studies, case reports and case series. This systematic review does not reach or performed a meta-analysis.

RESULTS

Originally based on 737 articles, our reviewed selected 40 articles with 54.2% at least mentioning CHIKV cardiovascular compromise within the systemic compromise. Cardiovascular manifestations can be considered common and have been reported in France, India, Sri Lanka, Malaysia, Colombia, Venezuela and USA, including mainly, but no limited to: hypotension, shock and circulatory collapse, Raynaud phenomenon, arrhythmias, murmurs, myocarditis, dilated cardiomyopathy, congestive insufficiency, heart failure and altered function profile (Troponins, CPK).

CONCLUSIONS

Physicians should be encouraged to keep divulgating reports on the cardiovascular involvement of chikungunya virus disease, to raise awareness and ultimately encourage suitable diagnosis and intervention worldwide. More research about cardiovascular involvement and manifestations of systemic Chikungunya virus infection is urgently needed.

Clinical and histopathological features of fatal cases with dengue and chikungunya virus co-infection in Colombia, 2014 to 2015

We report clinical features and histopathological findings in fatal cases with dengue (DENV) and chikungunya (CHIKV) co-infection identified at the Colombian National Institute of Health between September 2014 and October 2015. Seven such cases were documented. Dengue serotype 2 virus was identified in six cases. All patients were adults and comorbidities were present in four. Fever, arthralgia or myalgia was present in all cases. The frequency of rash, haemorrhage, oedema, and gastrointestinal symptoms was variable. Laboratory findings such as thrombocytopenia, renal failure, and leukocyte count were also inconsistent between cases. Post-mortem tissue examination documented focal hepatocellular coagulative necrosis in three cases, incipient acute pericarditis in one and tubulointerstitial nephritis in one. This study provides evidence of mortality in patients with DENV and CHIKV co-infection. Fatal cases were characterised by variable clinical and laboratory features. Evaluation of histopathology of autopsy tissues provided evidence of the pathological consequences of the disease.

Severe Chikungunya infection in Northern Mozambique: a case report

Background

Although Chikungunya virus has rapidly expanded to several countries in sub-Saharan Africa, little attention has been paid to its control and management. Until recently, Chikungunya has been regarded as a benign and self-limiting disease. In this report we describe the first case of severe Chikungunya disease in an adult patient in Pemba, Mozambique.

Case presentation

A previously healthy 40 year old male of Makonde ethnicity with no known past medical history and resident in Pemba for the past 11 years presented with a severe febrile illness. Despite administration of broad spectrum intravenous antibiotics the patient rapidly deteriorated and became comatose while developing anaemia, thrombocytopenia and later, melaena. Laboratory testing revealed IgM antibodies against Chikungunya virus. Malaria tests were consistently negative.

Conclusions

This report suggests that Chikungunya might cause unsuspected severe disease in febrile patients in Mozambique and provides insights for the improvement of national protocols for management of febrile patients in Mozambique. We recommend that clinicians should consider Chikungunya in the differential diagnosis of febrile illness in locations where Aedes aegypti mosquitos are abundant.

Unusual pattern of chikungunya virus epidemic in the Americas, the Panamanian experience

BACKGROUND

Chikungunya virus (CHIKV) typically causes explosive epidemics of fever, rash and polyarthralgia after its introduction into naïve populations. Since its introduction in Panama in May of 2014, few autochthonous cases have been reported; most of them were found within limited outbreaks in Panama City in 2014 and Puerto Obaldia town, near the Caribbean border with Colombia in 2015. In order to confirm that Panama had few CHIKV cases compared with neighboring countries, we perform an epidemiological analysis of chikungunya cases reported from May 2014 to July 2015. Moreover, to understand this paucity of confirmed CHIKV cases, a vectorial analysis in the counties where these cases were reported was performed.

METHODS

Chikungunya cases were identified at medical centers and notified to health authorities. Sera samples were analyzed at Gorgas Memorial Institute for viral RNA and CHIKV-specific antibody detection.

RESULTS

A total of 413 suspected cases of CHIKV infections were reported, with incidence rates of 0.5 and 0.7 per 100,000 inhabitants in 2014 and 2015, respectively. During this period, 38.6% of CHIKV cases were autochthonous with rash and polyarthralgia as predominant symptoms. CHIKV and DENV incidence ratios were 1:306 and 1:34, respectively. A phylogenetic analysis of E1/E2 genomic segment indicates that the outbreak strains belong to the Asian genotype and cluster together with CHIKV isolates from other American countries during the same period. Statistical analysis of the National Vector Control program at the district level shows low and medium vector infestation level for most of the counties with CHIKV cases. This index was lower than for neighboring countries.

CONCLUSIONS

Previous training of clinical, laboratory and vector workers allowed a good caption and detection of the chikungunya cases and fast intervention. It is possible that low/medium vector infestation level could explain in part the paucity of chikungunya infections in Panama.

Severe Sepsis and Septic Shock Associated with Chikungunya Virus Infection, Guadeloupe, 2014

During a 2014 outbreak, 450 patients with confirmed chikungunya virus infection were admitted to the University Hospital of Pointe-à-Pitre, Guadeloupe. Of these, 110 were nonpregnant adults; 42 had severe disease, and of those, 25 had severe sepsis or septic shock and 12 died. Severe sepsis may be a rare complication of chikungunya virus infection.

Surveillance for Chikungunya and Dengue During the First Year of Chikungunya Virus Circulation in Puerto Rico

After chikungunya virus (CHIKV) transmission was detected in Puerto Rico in May 2014, multiple surveillance systems were used to describe epidemiologic trends and CHIKV-associated disease. Of 28 327 cases reported via passive surveillance, 6472 were tested for evidence of CHIKV infection, and results for 4399 (68%) were positive. Of 250 participants in household cluster investigations, 70 (28%) had evidence of recent CHIKV infection. Enhanced surveillance for chikungunya at 2 hospitals identified 1566 patients who tested positive for CHIKV, of whom 10.9% were hospitalized. Enhanced surveillance for fatal cases enabled identification of 31 cases in which CHIKV was detected in blood or tissue specimens. All surveillance systems detected a peak incidence of chikungunya in September 2014 and continued circulation in 2015. Concomitant surveillance for dengue demonstrated low incidence, which had decreased before CHIKV was introduced. Multifaceted chikungunya surveillance in Puerto Rico resolved gaps in traditional passive surveillance and enabled a holistic description of the spectrum of disease associated with CHIKV infection.

Estimating the burden of disease and the economic cost attributable to chikungunya, Colombia, 2014

BACKGROUND

Chikungunya (CHIK) virus disease is expected to be a considerable cause of disability and economic burden in Latin America given its chronic sequelae, particularly its chronic inflammatory rheumatism. There have been no previous studies assessing CHIK costs and disability in Latin America.

METHODS

We calculated incidence rates for CHIK during the 2014 outbreak in Colombia using epidemiological data provided by the Colombian National Institute of Health, using demographic data from the National Administrative Department of Statistics. The burden of disease was estimated through disability adjusted life years (DALYs) lost and the costs were estimated based on the national recommendations for CHIK acute and chronic phase attention.

RESULTS

There were a total of 106 592 cases, with incidence rates ranging from 0 to 1837.3 cases/100 000 population in different departments. An estimate was made of total DALYs lost of 40.44 to 45.14 lost/100 000 population. The 2014 outbreak estimated costs were at least US$73.6 million.

CONCLUSIONS

Our estimates raise concerns about the effects of continued CHIK spread in Colombia and other Latin-American countries. The lack of transmission control for this disease and potential for spread means that there will be significant acute and chronic disability and related costs in the short and long term for Latin American health care systems.

The viral capping enzyme nsP1: a novel target for the inhibition of chikungunya virus infection

The chikungunya virus (CHIKV) has become a substantial global health threat due to its massive re-emergence, the considerable disease burden and the lack of vaccines or therapeutics. We discovered a novel class of small molecules ([1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-ones) with potent in vitro activity against CHIKV isolates from different geographical regions. Drug-resistant variants were selected and these carried a P34S substitution in non-structural protein 1 (nsP1), the main enzyme involved in alphavirus RNA capping. Biochemical assays using nsP1 of the related Venezuelan equine encephalitis virus revealed that the compounds specifically inhibit the guanylylation of nsP1. This is, to the best of our knowledge, the first report demonstrating that the alphavirus capping machinery is an excellent antiviral drug target. Considering the lack of options to treat CHIKV infections, this series of compounds with their unique (alphavirus-specific) target offers promise for the development of therapy for CHIKV infections.

Three atypical lethal cases associated with acute Zika virus infection in Suriname

Acute Zika virus infection usually presents with a self-limiting triad of fever, rash and arthritis. There is limited information on severe or lethal cases. We report three cases of lethal acute Zika infection, confirmed with polymerase chain reaction, in adult patients with some co-morbidities. The patients showed rapid clinical deterioration with hemorrhagic and septic shock, and exaggerated acute and innate inflammatory responses with pronounced coagulopathy, and died soon after admission to the hospital. It remains unclear whether the fatal outcomes were due to acute Zika virus infection alone or to the combination with exacerbated underlying prior disease or co-infection. Nonetheless, the severity of these cases implies that increased awareness for atypical presentations of Zika virus infection, and careful clinical assessment of patients with symptoms of Zika, is warranted during current and future outbreaks.

Ophthalmologic aspects of chikungunya infection

Chikungunya fever, a viral disease epidemic in some parts of the world is newly introduced in the Americas. This is of considerable international concern, with a growing incidence owing to developing urbanization, tourism, and trade. Ocular manifestations of chikungunya fever are not frequent, but of great relevance. Common manifestations include conjunctivitis, optic neuritis, iridocyclitis, episcleritis, retinitis and uveitis. Diagnostic and monitoring investigations would include optical coherence tomography, fundus fluorescein and indocyanine green angiography, visual field analysis, and electrophysiologic tests. There have been no prospective, randomized therapeutic trials, and it is unclear if the disease is self-limiting or if treatment is actually beneficial. Prognosis varies, ranging from full resolution to permanent vision loss despite intervention.