ChikDenMaZika Syndrome: the challenge of diagnosing arboviral infections in the midst of concurrent epidemics

Zafirlukast, as a viral inactivator, potently inhibits infection of several flaviviruses, including Zika virus, dengue virus, and yellow fever virus

Zika virus (ZIKV) is one of the mosquito-borne flaviviruses that exhibits a unique tropism to nervous systems and is associated with Guillain-Barre syndrome and congenital Zika syndrome (CZS). Dengue virus (DENV) and yellow fever virus (YFV), the other two mosquito-borne flaviviruses, have also been circulating for a long time and cause severe diseases, such as dengue hemorrhagic fever and yellow fever, respectively. However, there are no safe and effective antiviral drugs approved for the treatment of infections or coinfections of these flaviviruses. Here, we found that zafirlukast, a pregnancy-safe leukotriene receptor antagonist, exhibited potent antiviral activity against infections of ZIKV strains from different lineages in different cell lines, as well as against infections of DENV-2 and YFV 17D. Mechanistic studies demonstrated that zafirlukast directly and irreversibly inactivated these flaviviruses by disrupting the integrity of the virions, leading to the loss of viral infectivity, hence inhibiting the entry step of virus infection. Considering its efficacy against flaviviruses, its safety for pregnant women, and its neuroprotective effect, zafirlukast is a promising candidate for prophylaxis and treatment of infections or coinfections of ZIKV, DENV, and YFV, even in pregnant women.

The E2 glycoprotein holds key residues for Mayaro virus adaptation to the urban Aedes aegypti mosquito

Adaptation to mosquito vectors suited for transmission in urban settings is a major driver in the emergence of arboviruses. To better anticipate future emergence events, it is crucial to assess their potential to adapt to new vector hosts. In this work, we used two different experimental evolution approaches to study the adaptation process of an emerging alphavirus, Mayaro virus (MAYV), to Ae. aegypti, an urban mosquito vector of many other arboviruses. We identified E2-T179N as a key mutation increasing MAYV replication in insect cells and enhancing transmission after escaping the midgut of live Ae. aegypti. In contrast, this mutation decreased viral replication and binding in human fibroblasts, a primary cellular target of MAYV in humans. We also showed that MAYV E2-T179N generates reduced viremia and displays less severe tissue pathology in vivo in a mouse model. We found evidence in mouse fibroblasts that MAYV E2-T179N is less dependent on the Mxra8 receptor for replication than WT MAYV. Similarly, exogenous expression of human apolipoprotein receptor 2 and Mxra8 enhanced WT MAYV replication compared to MAYV E2-T179N. When this mutation was introduced in the closely related chikungunya virus, which has caused major outbreaks globally in the past two decades, we observed increased replication in both human and insect cells, suggesting E2 position 179 is an important determinant of alphavirus host-adaptation, although in a virus-specific manner. Collectively, these results indicate that adaptation at the T179 residue in MAYV E2 may result in increased vector competence-but coming at the cost of optimal replication in humans-and may represent a first step towards a future emergence event.

Spatiotemporal overlapping of dengue, chikungunya, and malaria infections in children in Kenya

Malaria, chikungunya virus (CHIKV), and dengue virus (DENV) are endemic causes of fever among children in Kenya. The risks of infection are multifactorial and may be influenced by built and social environments. The high resolution overlapping of these diseases and factors affecting their spatial heterogeneity has not been investigated in Kenya. From 2014-2018, we prospectively followed a cohort of children from four communities in both coastal and western Kenya. Overall, 9.8% were CHIKV seropositive, 5.5% were DENV seropositive, and 39.1% were malaria positive (3521 children tested). The spatial analysis identified hot-spots for all three diseases in each site and in multiple years. The results of the model showed that the risk of exposure was linked to demographics with common factors for the three diseases including the presence of litter, crowded households, and higher wealth in these communities. These insights are of high importance to improve surveillance and targeted control of mosquito-borne diseases in Kenya.

Antibody seropositivity and endemicity of chikungunya and Zika viruses in Nigeria

Mosquito-borne infections are of global health concern because of their rapid spread and upsurge, which creates a risk for coinfections. chikungunya virus (CHIKV), an arbovirus disease transmitted by Aedes aegypti or A. albopictus, and malaria, a parasitic disease transmitted by Anopheles gambiae, are prevalent in Nigeria and neighbouring countries, but their burden and possible coinfections are poorly understood. In this study, we investigated the antibody seropositivity and endemicity of chikungunya and Zika viruses (ZIKV) in three regions of Nigeria. A cross-sectional sero-survey was conducted on 871 participants. Samples were collected from outpatients by simple random sampling. Analyses of the samples were performed using recomLine Tropical Fever for the presence of antibody serological marker IgG immunoblot with CHIKV VLP (virus like particle), ZIKV NS1 and ZIKV Equad according to manufacturers’ instructions and malaria RDT for malaria parasite. There was a significantly higher antibody seropositivity against CHIKV in the central region than in the northern and southern regions (69.5%, 291/419), while ZIKV-seropositivity (22.4%, 34/152) and CHIKV-ZIKV co-circulating antibody seropositivity (17.8%, 27/152) were notably higher in the southern region than in the central and northern regions. This investigation revealed an unexpectedly high antibody seropositivity and concealed endemicity of CHIKV and ZIKV in three Nigerian regions. The seropositivity of detectable antibodies differed among the three geographical locations.

Dengue Prediction in Latin America Using Machine Learning and the One Health Perspective: A Literature Review

Dengue fever is a serious and growing public health problem in Latin America and elsewhere, intensified by climate change and human mobility. This paper reviews the approaches to the epidemiological prediction of dengue fever using the One Health perspective, including an analysis of how Machine Learning techniques have been applied to it and focuses on the risk factors for dengue in Latin America to put the broader environmental considerations into a detailed understanding of the small-scale processes as they affect disease incidence. Determining that many factors can act as predictors for dengue outbreaks, a large-scale comparison of different predictors over larger geographic areas than those currently studied is lacking to determine which predictors are the most effective. In addition, it provides insight into techniques of Machine Learning used for future predictive models, as well as general workflow for Machine Learning projects of dengue fever.

Clinical features, hospitalisation and deaths associated with monkeypox: a systematic review and meta-analysis

Introduction

A multicountry monkeypox disease (MPX) outbreak began in May 2022 in Europe, leading to the assessment as a potential Public Health Emergency of International Concern (PHEIC) on June 23, 2022. Some observational studies have partially characterised clinical features, hospitalisations, and deaths. However, no systematic reviews of this MPX outbreak have been published.

Methods

We performed a systematic review with meta-analysis, using five databases to assess clinical features, hospitalisations, complications and deaths of MPX confirmed or probable cases. Observational studies, case reports and case series, were included. We performed a random-effects model meta-analysis to calculate the pooled prevalence and 95% confidence interval (95% CI). In addition, we carried out a subgroup analysis according to the continents and a sensitivity analysis excluding studies classified as having a high risk of bias.

Results

A total of 19 articles were included, using only 12 articles in the quantitative synthesis (meta-analysis). For 1958 patients, rash (93%, 95% CI 80–100%), fever (72%, 95% CI 30–99%), pruritus (65%, 95% CI 47–81%), and lymphadenopathy (62%, 47–76%), were the most prevalent manifestations. Among the patients, 35% (95% CI 14–59%) were hospitalised. Some 4% (95% CI 1–9%) of hospitalised patients had fatal outcomes (case fatality rate, CFR).

Conclusion

MPX is spreading rapidly, with a third of hospitalised patients, but less than 5% with fatal outcomes. As this zoonotic virus spreads globally, countries must urgently prepare human resources, infrastructure and facilities to treat patients according to the emerging guidelines and the most reliable clinical information.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12941-022-00527-1.

Detection of SARS-CoV-2 antibodies in febrile patients from an endemic region of dengue and chikungunya in Peru

Introduction

The rapid expansion of the novel SARS-CoV-2 virus has raised serious public health concerns due to the possibility of misdiagnosis in regions where arboviral diseases are endemic. We performed the first study in northern Peru to describe the detection of SARS-CoV-2 IgM antibodies in febrile patients with a suspected diagnosis of dengue and chikungunya fever.

Materials and methods

A consecutive cross-sectional study was performed in febrile patients attending primary healthcare centers from April 2020 through March 2021. Patients enrolled underwent serum sample collection for the molecular and serological detection of DENV and CHIKV. Also, serological detection of IgM antibodies against SARS-CoV-2 was performed.

Results

464 patients were included during the study period, of which (40.51%) were positive for one pathogen, meanwhile (6.90%) presented co-infections between 2 or more pathogens. The majority of patients with monoinfections were positive for SARS-CoV-2 IgM with (73.40%), followed by DENV 18.09% and CHIKV (8.51%). The most frequent co-infection was DENV + SARS-CoV-2 with (65.63%), followed by DENV + CHIKV and DENV + CHIKV + SARS-CoV-2, both with (12.50%). The presence of polyarthralgias in hands (43.75%, p<0.01) and feet (31.25%, p = 0.05) were more frequently reported in patients with CHIKV monoinfection. Also, conjunctivitis was more common in patients positive for SARS-CoV-2 IgM (11.45%, p<0.01). The rest of the symptoms were similar among all the study groups.

Conclusion

SARS-CoV-2 IgM antibodies were frequently detected in acute sera from febrile patients with a clinical suspicion of arboviral disease. The presence of polyarthralgias in hands and feet may be suggestive of CHIKV infection. These results reaffirm the need to consider SARS-CoV-2 infection as a main differential diagnosis of acute febrile illness in arboviruses endemic areas, as well as to consider co-infections between these pathogens.

Machine learning and deep learning techniques to support clinical diagnosis of arboviral diseases: A systematic review

BACKGROUND

Neglected tropical diseases (NTDs) primarily affect the poorest populations, often living in remote, rural areas, urban slums or conflict zones. Arboviruses are a significant NTD category spread by mosquitoes. Dengue, Chikungunya, and Zika are three arboviruses that affect a large proportion of the population in Latin and South America. The clinical diagnosis of these arboviral diseases is a difficult task due to the concurrent circulation of several arboviruses which present similar symptoms, inaccurate serologic tests resulting from cross-reaction and co-infection with other arboviruses.

OBJECTIVE

The goal of this paper is to present evidence on the state of the art of studies investigating the automatic classification of arboviral diseases to support clinical diagnosis based on Machine Learning (ML) and Deep Learning (DL) models.

METHOD

We carried out a Systematic Literature Review (SLR) in which Google Scholar was searched to identify key papers on the topic. From an initial 963 records (956 from string-based search and seven from a single backward snowballing procedure), only 15 relevant papers were identified.

RESULTS

Results show that current research is focused on the binary classification of Dengue, primarily using tree-based ML algorithms. Only one paper was identified using DL. Five papers presented solutions for multi-class problems, covering Dengue (and its variants) and Chikungunya. No papers were identified that investigated models to differentiate between Dengue, Chikungunya, and Zika.

CONCLUSIONS

The use of an efficient clinical decision support system for arboviral diseases can improve the quality of the entire clinical process, thus increasing the accuracy of the diagnosis and the associated treatment. It should help physicians in their decision-making process and, consequently, improve the use of resources and the patient's quality of life.

Leptospirosis

Leptospirosis is a blood infection caused by the bacterium Leptospira. Signs and symptoms can range from none to mild (headaches, muscle pains, and fevers) to severe (bleeding in the lungs or meningitis). Weil's disease, the acute, severe form of leptospirosis, causes the infected individual to become jaundiced (skin and eyes become yellow), develop kidney failure, and bleed. Pulmonary hemorrhage in association with leptospirosis is known as "severe pulmonary haemorrhage syndrome". More than ten genetic types of Leptospira, which are a type of a spirochaete, cause disease in humans. Both wild and domestic animals can spread the disease, most commonly rodents. The bacteria are spread to humans through animal urine, or water and soil contaminated with animal urine, coming into contact with the eyes, mouth, nose or breaks in the skin. In developing countries, the disease occurs most commonly in farmers and low-income people who live in areas with poor sanitation. In developed countries, it occurs during heavy downpours and can affect those involved in outdoor activities in warm and wet areas. Diagnosis is typically by testing for antibodies against the bacteria or finding bacterial DNA in the blood. Efforts to prevent the disease include protective equipment to block contact when working with potentially infected animals, washing after contact, and reducing rodents in areas where people live and work. The antibiotic doxycycline is effective in preventing leptospirosis infection. Human vaccines are of limited usefulness; vaccines for other animals are more widely available. Treatment when infected is with antibiotics such as doxycycline, penicillin, or ceftriaxone. The overall risk of death is 5–10%. However, when the lungs are involved, the risk of death increases to the range of 50–70%. It is estimated that one million people worldwide are infected by leptospirosis every year, causing approximately 58,900 deaths. The disease is most common in tropical areas of the world but may occur anywhere. Outbreaks may arise after heavy rainfall. The disease was first described by physician Adolf Weil in 1886 in Germany. Infected animals may have no, mild or severe symptoms. These may vary by the type of animal. In some animals Leptospira live in the reproductive tract, leading to transmission during mating.

Hepatoprotective, antioxidant, anti-inflammatory, and antiviral activities of silymarin against mayaro virus infection

Infection caused by Mayaro virus (MAYV) is responsible for causing acute nonspecific fever, in which the majority of patients develop incapacitating and persistent arthritis/arthralgia. Mayaro fever is a neglected and underreported disease without treatment or vaccine, which has gained attention in recent years after the competence of Aedes aegypti to transmit MAYV was observed in the laboratory, coupled with the fact that cases are being increasingly reported outside of endemic forest areas, calling attention to the potential of an urban cycle arising in the near future. Thus, to mitigate the lack of information about the pathological aspects of MAYV, we previously described the involvement of oxidative stress in MAYV infection in cultured cells and in a non-lethal mouse model. Additionally, we showed that silymarin, a natural compound, attenuated MAYV-induced oxidative stress and inhibited MAYV replication in cells. The antioxidant and anti-MAYV effects prompted us to determine whether silymarin could also reduce oxidative stress and MAYV replication after infection in an immunocompetent animal model. We show that infected mice exhibited reduced weight gain, hepatomegaly, splenomegaly, anaemia, thrombocytopenia, leukopenia, increased liver transaminases, increased pro-inflammatory cytokines and liver inflammation, increased oxidative damage biomarkers, and reduced antioxidant enzyme activity. However, in animals infected and treated with silymarin, all these parameters were reversed or significantly improved, and the detection of viral load in the liver, spleen, brain, thigh muscle, and footpad was significantly reduced. This work reinforces the potent hepatoprotective, antioxidant, anti-inflammatory, and antiviral effects of silymarin against MAYV infection, demonstrating its potential against Mayaro fever disease.

Infection-provoked psoriasis: Induced or aggravated (Review)

Psoriasis is a common chronic, immune-mediated, inflammatory skin disorder, with a reported prevalence of 0.0-2.1% among children and 0.91-8.50% among adults, worldwide. Psoriasis is induced by several environmental factors, including infection, alcohol consumption, drugs, trauma, acute withdrawal of systemic or potent topical corticosteroids, body mass index and endocrine disorders. Increasing evidence suggest that a variety of microorganisms play key roles in the induction and exacerbation of psoriasis. Pathogens, such as streptococci and staphylococci are considered causal factors, presumably via superantigen activation of skin-seeking T cells. In addition, fungal pathogens, such as Candida and Malassezia, and viral agents, such as human immunodeficiency virus, hepatitis C virus infection and human papillomavirus, are also closely associated with psoriasis. Recently, several types of pathogens, such as Helicobacter pylori infection, Zika virus and scabies, have been reported to potentially trigger psoriasis. The present review discusses the underlying molecular mechanisms by which these infections influence psoriasis to provide a better understanding of the pathogenesis of psoriasis.

A silent public health threat: emergence of Mayaro virus and co-infection with Dengue in Peru

OBJECTIVE

To describe frequency and clinical characteristics of MAYV infection in Piura, as well as the association of this pathogen with DENV.

RESULTS

A total of 86/496 (17.3%) cases of MAYV were detected, of which 54 were MAYV mono-infection and 32 were co-infection with DENV, accounting for 10.9% and 6.4%, respectively. When evaluating monoinfection by MAYV the main groups were 18-39 and 40-59 years old, with 25.9% and 20.4% respectively. Co-infections were more common in the age group 18-39 and those > 60 years old, with 34.4% and 21.9%, respectively. The most frequent clinical presentation were headaches (94.4%, 51/54) followed by arthralgias (77.8%, 42/54). During the 8-month study period the most cases were identified in the months of May (29.1%) and June (50.0%).

Antiviral Drug Discovery and Development for Mayaro Fever - What do we have so far?

Tropical infectious diseases cause millions of deaths every year in developing countries, with about half of the world population living at risk. Mayaro virus (MAYV) is an emerging arbovirus that causes Mayaro fever, which is characterized by fever, headache, diarrhea, arthralgia, and rash. These symptoms can be clinically indistinguishable from other arboviruses, such as Dengue, Zika, and Chikungunya, which makes the diagnosis and treatment of the disease more difficult. Though, the Mayaro virus is a potential candidate to cause large-scale epidemics on the scale of ZIKV and CHIKV. Despite this, there is no licensed vaccine or antiviral for the treatment of Mayaro fever and most arboviruses, so the design and development of candidates for antiviral drugs are urgently needed. In this context, this mini-review aims to provide an overview of studies of anti-MAYV derivatives and highlight the importance of the discovery and development of promising drug candidates for Mayaro fever.

Kawasaki disease seasonality in Venezuela supports an arbovirus infection trigger

Kawasaki disease (KD) is an inflammatory disease primarily affecting infants and young children, whose etiology remains uncertain. Observational studies of the overlap between KD outbreaks and seasonal peaks of arboviral infections, suggest the possible role of these pathogens as triggers of KD. In Venezuela, regions with the highest reported arboviral infections simultaneously have the highest incidence of KD. One proposed explanation for this association involves the role of proinflammatory mediators, interleukin-1 (IL-1), IL-6, tumor necrosis factor, and vascular endothelial growth factor as mediators of coronary endothelial damage. The promotion of inflammation and tissue destruction by these cytokines is thought to contribute to the coronary endothelial damage experienced in KD. The utilization of overlapping KD and arboviral infection trends contribute to the comprehension of KD etiology, with improvements in diagnosis, prognosis and treatment.

Co-infection of Dengue, Zika and Chikungunya in a group of pregnant women from Tuxtla Gutiérrez, Chiapas: Preliminary data. 2019

INTRODUCTION

Dengue, Zika and Chikungunya are RNA Arboviruses present in some areas of Mexico, mainly in the endemic state of Chiapas that is characterized by presence of the vector that transmit them and an ecology that favors high transmission. According to the national epidemiological surveillance system, Dengue has intensified since 2018 and outbreaks continue in various states while for Zika and Chikungunya a decrease in cases has been reported in recent years. The main objective of this study was to determine the incidence of Dengue, Zika and Chikungunya infections during pregnancy in the state of Chiapas.

PRINCIPAL FINDINGS

The presence of previous and current infections and coinfections diagnosed by molecular (RT-PCR) and immunological (ELISA for IgG determination) techniques indicates a wide circulation of viruses in asymptomatic people, specifically in pregnant women showing that silent infections in dry season contributes to the preservation of viruses.

CONCLUSIONS

From 136 studied samples, 27.7% tested positive for DENV, 8% for ZIKV and 24.1% for CHIKV by RTPCR and the values of IgG in sera show that 83.9% were positive for IgG antibodies against DENV, 65% against ZIKV and 59.1% against CHIKV. Results demonstrated presence of ZIKV and CHIKV, not detected by the epidemiological surveillance system, so the importance of establishing proactive epidemiological systems more strict, especially because these infections in pregnant women can cause severe health problems for newborn children.

Adenoviral-Vectored Mayaro and Chikungunya Virus Vaccine Candidates Afford Partial Cross-Protection From Lethal Challenge in A129 Mouse Model

Mayaro (MAYV) and chikungunya viruses (CHIKV) are vector-borne arthritogenic alphaviruses that cause acute febrile illnesses. CHIKV is widespread and has recently caused large urban outbreaks, whereas the distribution of MAYV is restricted to tropical areas in South America with small and sporadic outbreaks. Because MAYV and CHIKV are closely related and have high amino acid similarity, we investigated whether vaccination against one could provide cross-protection against the other. We vaccinated A129 mice (IFNAR -/-) with vaccines based on chimpanzee adenoviral vectors encoding the structural proteins of either MAYV or CHIKV. ChAdOx1 May is a novel vaccine against MAYV, whereas ChAdOx1 Chik is a vaccine against CHIKV already undergoing early phase I clinical trials. We demonstrate that ChAdOx1 May was able to afford full protection against MAYV challenge in mice, with most samples yielding neutralizing PRNT80 antibody titers of 1:258. ChAdOx1 May also provided partial cross-protection against CHIKV, with protection being assessed using the following parameters: survival, weight loss, foot swelling and viremia. Reciprocally, ChAdOx1 Chik vaccination reduced MAYV viral load, as well as morbidity and lethality caused by this virus, but did not protect against foot swelling. The cross-protection observed is likely to be, at least in part, secondary to cross-neutralizing antibodies induced by both vaccines. In summary, our findings suggest that ChAdOx1 Chik and ChAdOx1 May vaccines are not only efficacious against CHIKV and MAYV, respectively, but also afford partial heterologous cross-protection.

High Seroprevalence of Antibodies against Arboviruses among Pregnant Women in Rural Caribbean Colombia in the Context of the Zika Virus Epidemic

Mosquito-borne viruses such as dengue (DENV), chikungunya (CHIKV), and Zika (ZIKV) have spread in recent decades. We aimed to assess seroprevalence of arboviral infections in pregnant women living in Cereté, Caribbean Colombia. In 2016 a cross-sectional facility-based sero-survey study was performed among pregnant women (N = 90). Most of them (66%) reported at least one symptom or sign compatible with arboviral infection over the previous 15 days. All screened women had a positive IgG for DENV, 89% for ZIKV, and 82% for CHIKV. One woman tested positive for ZIKV IgM. This study shows the high exposure among pregnant women to arboviruses in endemic areas, shown by the high seroprevalence of past arboviral infections. Given the evidence on the potential risks of these arboviral infections on pregnancy and infant outcomes, these results highlight the need for continuous epidemiological surveillance of arboviral diseases, particularly among those most of risk of their harmful consequences.

DENV and ZIKV detection in patients with acute febrile syndrome in Córdoba, Colombia

OBJECTIVE

To determine simultaneous circulation of DENV serotypes and ZIKV in Córdoba, Colombia, during 2015 and 2016.

MATERIAL AND METHODS

A total of 294 samples from patients with clinical diagnosis of febrile syndrome compatible with dengue were collected between June 2015 and December 2016. All samples were tested for DENV and ZIKV by RT-PCR using C6/36 cells culture supernatant.

RESULTS

Thirty-three percent of the samples were positive (97/294); from these, 61.8% were positive for DENV and 31% were positive for Zika. The predominant serotype was DENV-2 (70.1%), followed by DENV-3 (8.9%), DENV-4 (6%), and DENV-1 (3%). DENV/ZIKV coinfection was identified in 7.2% of the cases associated with DENV-1 and DENV-3 serotypes. The confirmed cases of dengue, Zika, and DENV/ZIKV coinfections were clinically mild and self-limited.

CONCLUSIONS

We reported the co-circulation of all four DENV serotypes, with a higher frequency of DENV-2, and ZIKV introduction in Córdoba department-Colombia in August 2015. This scenario favored the appearance of DENV/ZIKV coinfections.

Reconstructing Mayaro virus circulation in French Guiana shows frequent spillovers

Characterizing the circulation of Mayaro virus (MAYV), an emerging arbovirus threat, is essential for risk assessment but challenging due to cross-reactivity with other alphaviruses such as chikungunya virus (CHIKV). Here, we develop an analytical framework to jointly assess MAYV epidemiology and the extent of cross-reactivity with CHIKV from serological data collected throughout French Guiana (N = 2697). We find strong evidence of an important sylvatic cycle for MAYV with most infections occurring near the natural reservoir in rural areas and in individuals more likely to go to the forest (i.e., adult males) and with seroprevalences of up to 18% in some areas. These findings highlight the need to strengthen MAYV surveillance in the region and showcase how modeling can improve interpretation of cross-reacting assays.

Chikungunya outbreak (2015) in the Colombian Caribbean: Latent classes and gender differences in virus infection

Chikungunya virus (CHIKV), a mosquito-borne alphavirus of the Togaviridae family, is part of a group of emergent diseases, including arbovirus, constituting an increasing public health problem in tropical areas worldwide. CHIKV causes a severe and debilitating disease with high morbidity. The first Colombian autochthonous case was reported in the Colombian Caribbean region in September 2014. Within the next two to three months, the CHIKV outbreak reached its peak. Although the CHIKV pattern of clinical symptomatology has been documented in different epidemiological studies, understanding of the relationship between clinical symptomatology and variation in phenotypic response to CHIKV infection in humans remains limited. We performed a cross sectional study following 1160 individuals clinically diagnosed with CHIKV at the peak of the Chikungunya outbreak in the Colombian Caribbean region. We examined the relationship between symptomatology and diverse phenotypic responses. Latent Class Cluster Analysis (LCCA) models were used to characterize patients’ symptomatology and further identify subgroups of individuals with differential phenotypic response. We found that most individuals presented fever (94.4%), headache (73.28%) and general discomfort (59.4%), which are distinct clinical symptoms of a viral infection. Furthermore, 11/26 (43.2%) of the categorized symptoms were more frequent in women than in men. LCCA disclosed seven distinctive phenotypic response profiles in this population of CHIKV infected individuals. Interestingly, 282 (24.3%) individuals exhibited a lower symptomatic “extreme” phenotype and 74 (6.4%) patients were within the severe complex “extreme” phenotype. Although clinical symptomatology may be diverse, there are distinct symptoms or group of symptoms that can be correlated with differential phenotypic response and perhaps susceptibility to CHIKV infection, especially in the female population. This suggests that, comparatively to men, women are a CHIKV at-risk population. Further study is needed to validate these results and determine whether the distinct LCCA profiles are a result of the immune response or a mixture of genetic, lifestyle and environmental factors. Our findings could contribute to the development of machine learning approaches to characterizing CHIKV infection in other populations. Preliminary results have shown prediction models achieving up to 92% accuracy overall, with substantial sensitivity, specificity and accuracy values per LCCA-derived cluster.

The Chikungunya virus (CHIKV) infection is a mosquito-borne virus of the Togaviridae family, part of the arbovirus group of mosquito-transmitted pathogens. CHIKV causes a severe and debilitating disease with high morbidity. In this study, we comprehensively analysed clinical data from 1160 individuals from the Colombian Caribbean, who were diagnosed with CHIKV infection during the 2014 epidemic peak and before the Zika epidemic (registered back in 2015). Further, the presence of latent classes and predictors of CHIKV susceptibility and severity of the CHIKV infection were analysed. Although it is well known that people respond differently to infection, our results showed that these differences are not arbitrary and may come from the specific orchestration of our immune response and specific genetic makeup. For example, we identified that females infected with CHIKV exhibited significant and heterogeneous phenotypic response patterns compared to men. Overall, these results inform about potential predictors and outlining strategies to study the natural history of CHIKV infection. Future studies assessing the contribution of demographic, immunological and genetic factors to symptom co-occurrence could shed some light on the severity of the clinical symptomatology and, ultimately, lead to more accurate, more efficient and differential diagnosis. These results could contribute to the development of machine learning approaches to characterizing CHIKV infection in other populations and provide more accurate and differential diagnosis.

Isolation of Mayaro Virus from a Venezuelan Patient with Febrile Illness, Arthralgias, and Rash: Further Evidence of Regional Strain Circulation and Possible Long-Term Endemicity

Fifty-two febrile patients living in Barquisimeto, Venezuela, were screened for arbovirus infection by virus culture during an outbreak of what was thought to be Zika virus infection. We report identification of Mayaro virus (MAYV) on culture of plasma from one patient, an 18-year-old woman with acute febrile illness, arthralgias, and psoriasiform rash. The strain was sequenced and was found to be most closely related to a 1999 strain from French Guiana, which, in turn, was related to two 2014 strains from Haiti. By contrast, previously reported outbreak-related MAYV strains from a sylvatic area approximately 80 miles from where the case patient lived were most closely related to Peruvian isolates. The two strain groups show evidence of having diverged genetically approximately 100 years ago.

A natural polymorphism in Zika virus NS2A protein responsible of virulence in mice

Zika virus (ZIKV) infection is currently one of the major concerns in human public health due to its association with neurological disorders. Intensive effort has been implemented for the treatment of ZIKV, however there are not currently approved vaccines or antivirals available to combat ZIKV infection. In this sense, the identification of virulence factors associated with changes in ZIKV virulence could help to develop safe and effective countermeasures to treat ZIKV or to prevent future outbreaks. Here, we have compared the virulence of two related ZIKV strains from the recent outbreak in Brazil (2015), Rio Grande do Norte Natal (RGN) and Paraiba. In spite of both viruses being identified in the same period of time and region, significant differences in virulence and replication were observed using a validated mouse model of ZIKV infection. While ZIKV-RGN has a 50% mouse lethal dose (MLD50) of ~105 focus forming units (FFUs), ZIKV-Paraiba infection resulted in 100% of lethality with less than 10 FFUs. Combining deep-sequencing analysis and our previously described infectious ZIKV-RGN cDNA clone, we identified a natural polymorphism in the non-structural protein 2 A (NS2A) that increase the virulence of ZIKV. Moreover, results demonstrate that the single amino acid alanine to valine substitution at position 117 (A117V) in the NS2A was sufficient to convert the attenuated rZIKV-RGN in a virulent Paraiba-like virus (MLD50 < 10 FFU). The mechanism of action was also evaluated and data indicate that substitution A117V in ZIKV NS2A protein reduces host innate immune responses and viral-induced apoptosis in vitro. Therefore, amino acid substitution A117V in ZIKV NS2A could be used as a genetic risk-assessment marker for future ZIKV outbreaks.

Arboviruses (chikungunya, dengue, and Zika) associated with ophthalmic changes: a focus on aqueous fluid and vitreous humor

The aim of this study was to conduct a bibliographic survey and correlates the presence of arboviroses in the eyeball with the main eye changes presented by the population under study. This study is a systematic review of journals and indexed articles, carried out between January 2019 and June 2019, in which there was a query in the Pubmed/Medline and Scielo databases without temporal restriction. In addition to the aforementioned databases, the Brazilian Association of Organ Transplantation Association database, which provides epidemiological data on organ and tissue transplants in Brazil, was used as a research source. The Midwest region contributed to the increase in the number of organ transplants in Brazil. The number of corneal transplants in Brazil surpassed the number of organ transplants by four times. Several ophthalmic changes associated with Chikungunya, Dengue, and Zika virus infections have been diagnosed; however, few studies have identified the presence of the virus in the eyeball. Arboviruses are of great relevance to public health due to a number of factors, ranging from the diversity of infectious agents involved and the plurality of clinical manifestations because the absence of efficient laboratory support, leading to delayed disease confirmation due to lack of differential diagnostics available. Added to these difficulties is the lack of specific therapy, leaving only the symptomatic control of clinical manifestations as the only treatment option. However, the manifestations are directly associated with the decreased quality of vision and consequently the quality of life of patients.

The fertility-inhibiting effect of mosquitoes: Socio-economic differences in response to the Zika crisis in Colombia

We estimated the impact of the Zika virus outbreak on birth rates and demand for health care services in Colombia. Our analysis exploits the variation in the level of natural protection against mosquito-transmitted diseases across the country. This characteristic induced exogenous variation in Zika incidence, which allows us to construct a control group of municipalities with similar historical fertility trends but with differential exposure to the Zika crisis. We implemented a difference-in-differences model after matching, as well as synthetic control. We found a decrease in birth rates of approx. 10% in the last two quarters of 2019. The impact of the virus was similar irrespective of the women's education level, and we found no discernible impact on teenage pregnancy.

Spatial distribution of dengue in Honduras during 2016-2019 using a geographic information systems (GIS)-Dengue epidemic implications for public health and travel medicine

BACKGROUND

After serious epidemics of chikungunya (CHIKV) and Zika (ZIKV) in the Americas, dengue (DENV) have reemerged in most countries. We analyzed the incidence, incidence rates, and evolution of DENV cases in Honduras from 2015 to 2018 and the ongoing 2019 epidemic.

METHODS

Using epidemiological weeks (EW) surveillance data on the DENV in Honduras, we estimated incidence rates (cases/100,000 population), and developed maps at national, departmental, and municipal levels.

RESULTS

From January 1, 2016 to July 21, 2019, a total of 109,557 cases of DENV were reported, 28,603 in 2019, with an incidence rate of 312.32 cases/100,000 population this year; 0.13% laboratory-confirmed. The highest peak was reached on the EW 28°, 2019 (5299 cases; 57.89 cases/100,000 population). The department with the highest number of cases and incidence rate was Cortes (8404 cases, 479.68 cases/100,000 population in 2019).

DISCUSSION

The pattern and evolution of DENV epidemic in 2019 in Honduras has been similar to that which occurred for in 2015. As previously reported, this epidemic involved the north and central areas of the country predominantly, reaching municipality incidences there >1000 cases/100,000 population (or 1%). Studies using geographical information systems linked with clinical disease characteristics are necessary to obtain accurate epidemiological data for public health systems. Such information is also useful for assessment of risk for travelers who visit specific areas in a destination country.

Changing patterns in the distribution of the Mayaro virus vector Haemagogus species in Trinidad, West Indies

The Mayaro virus disease (MAYVD) is an emerging mosquito borne zoonosis that was first reported on the island of Trinidad in 1954. The viral agent for this disease is known to presently be endemic to Central and South America. The enzootic cycle of the Mayaro virus (MAYV) is not fully characterized, though primates are thought to be the main reservoir with Haemagogus species of mosquitoes as the primary vector. This virus has been responsible for several sporadic cases of infections and limited outbreaks, but it is postulated that the MAYVD will become a major epidemic in the future, following in the steps of the recent pandemics caused by Chikungunya and Zika viruses. Mitigating possible major outbreaks of MAYVD in the future would require effective strategies for vector control, for which knowledge on the ecology and distribution of the Haemagogus mosquitoes would be vitally important. In Trinidad, Haemagogus species have only been reported in the northwestern peninsula of the island based on studies up to 1995. However, no recent investigations have been completed to determine the status of this important vector on the island. The aim of this study was to investigate the current spatial distribution of Haemagogus species in the island of Trinidad, West Indies. Adult Haemagogus (Hag.) mosquitoes and larvae were surveyed during a twenty-month period using human bait trapping and ovitraps in major forested areas on the island. Mosquito species were identified using classical taxonomic keys. Haemagogus species were widespread and found in all forest types surveyed. Hag. janthinomys (85.7%) was the most widely distributed and dominant species on the island. Lower levels of Hag. leucocelaneus (7.3%), Hag. equinus (6.4%) and Hag. celeste (0.6%) were also collected. Overall, the proportion of mosquitoes collected in the wet season (June-December) was 3.5 times more than in the dry season (January-May). Mangroves, young secondary forests, semi-evergreen and evergreen forest types had relatively high mean abundance levels of Haemagogus species as compared to deciduous and montane forests. Proximity analysis suggests that population settlements within a 1 km buffer of the forest peripherals may be at risk for any emerging arboviral disease associated with these mosquito vectors. Haemagogus species showed a much wider distribution in Trinidad as compared to previous reports from up to 20 years ago and were prevalent in areas with no known presence of non-human primates. Since the MAYV has been previously implicated in causing infections in vertebrate hosts like rodents, birds and small mammals, the findings of this study suggest that there may be alternative hosts and reservoirs of this virus in the sylvatic cycle in Trinidad, other than primates. This has significant epidemiological implications for mosquito-borne viral infections in the region.

Geographical trends of chikungunya and Zika in the Colombian Amazonian gateway department, Caqueta, 2015-2018 - Implications for public health and travel medicine

BACKGROUND

Chikungunya (CHIKV) and Zika (ZIKV) significantly affected Latin America in the period 2015-2017. Most studies were reported from urban areas of Brazil and Colombia. In this paper we estimate Incidence rates for CHIKV and ZIKV in Caqueta, the Amazonian gateway area of Colombia, from 2015 to 2018.

METHODS

Using surveillance data of CHIKV and ZIKV in Caqueta, Colombia, incidence rates were estimated (cases/100,000 population). Sixteen geographical information systems (GIS)-based municipal maps were developed. GIS software used was Kosmo 3.0®.

RESULTS

From 1st of January 2015 to the 24th of November 2018, 825 cases of CHIK and 1079 of ZIKV were reported, yielding cumulated incidence rates of 169.42 and 221.59 cases/100,000 population respectively. In 2016, 48.7% of the CHIKV cases (402) and 96.6% of the ZIKV cases (1042) were reported. The highest number of both arboviral diseases occurred at Florencia (capital department city), 225 cases for CHIKV (127.17 cases/100,000 pop.) and 611 for ZIKV (345.34 cases/100,000 pop.).

DISCUSSION

The temporo-spatial distribution of CHIKV and ZIKV infections in Caquetá reflected the pattern of concurrent epidemics, especially in 2016. Studies using GIS-linked maps are necessary to attain accurate epidemiological analyses for public health decisions. That is also useful for an epidemiologically based assessment of traveler risks when visiting specific areas in destination countries.

Fatal Zika virus infection in the Americas: A systematic review

INTRODUCTION

While death due to Zika virus (ZIKV) infection has been described, reports of fatal cases have been infrequent and no systematic reviews on the subject have been published.

METHODS

A systematic review of the literature in four databases was performed to assess fatal outcomes of postnatal ZIKV infection and the available evidence that links ZIKV infection to death.

RESULTS

Three hundred and eleven articles were retrieved; 20 of them were epidemiological reports from surveillance agencies and ministries of health. After screening by abstract and title, 59 articles were selected for full-text assessment. Of these, 35 were excluded (with reasons) and 24 were finally included for qualitative analysis. A total of 51 reported deaths associated with ZIKV infection in nine countries were identified. The majority of cases (56.9%) were not related to Guillain-Barré syndrome. Cases from three countries accounted for 67.6% of the deaths. ZIKV infection was laboratory-confirmed in the majority of cases (64.7%).

DISCUSSION

ZIKV was not considered to be a dangerous, and much less a lethal pathogen, until very recently. However, an increasing number of fatalities have been published in the literature since the first death was reported in 2016. Additional research is needed to elucidate factors that may mediate the pathogenesis of severe, atypical, and fatal disease.

Combining anti-IgM and IgG immunoassays for comprehensive chikungunya virus diagnostic testing

Chikungunya virus (CHIKV) is a mosquito-borne pathogen that causes CHIKV fever. Definitive diagnosis is crucial for patients experiencing symptoms similar to other arboviral diseases because they can vary in clinical consequences. An increasing number of patients experience long-term rheumatic effects of CHIKV infection, but these cases may not be optimally detected by molecular assays and anti-CHIKV IgM ELISAs (M-ELISAs) used for confirmation and screening, respectively. The subsequent confirmatory serological test, the plaque reduction neutralization test (PRNT), is laborious and time-consuming. In this study, we evaluated a new diagnostic algorithm in which the M-ELISA is conducted in parallel with an anti-CHIKV IgG ELISA (G-ELISA) and observed that the Euroimmun M-ELISA combined with the Euroimmun G-ELISA or the Abcam G-ELISA exhibited excellent sensitivity and specificity for CHIKV. The combinations demonstrated perfect and near perfect inter-rater agreement with the PRNT, respectively, suggesting their potential to be used as alternatives to the confirmatory serological PRNT assay for CHIKV.

Vertically transmitted chikungunya, Zika and dengue virus infections: The pathogenesis from mother to fetus and the implications of co-infections and vaccine development

Chikungunya (CHIKV), Zika (ZIKV), and Dengue viruses (DENV) exhibit similar epidemiological and clinical patterns but have different pathophysiological mechanisms of disease manifestations. Differences occur in the severity of clinical presentations with the highest mortality in the general population attributed to DENV and neurological morbidity due to ZIKV. ZIKV and DENV infections can cause fetal loss with ZIKV exhibiting teratogenesis. CHIKV is associated with severe complications in the newborn. Co-circulation of the three viruses and the cross-reactive immune response between ZIKV and DENV viruses has implications for an attenuated clinical response and future vaccine development. Co-infections could increase due to the epidemiologic synergy, but there is limited evidence about the clinical effects, especially for the vulnerable newborn. The purpose of this paper is to review the pathophysiological basis for vertically transmission manifestations due to CHIKV, DENV, and ZIKV, to determine the potential effects of co-circulation on newborn outcomes and the potential for vaccine protection. Inflammatory cytokines are responsible for placental breaches in DENV and ZIKV; Hofbauer cells facilitate the transfer of ZIKV from the placenta to the fetal brain, and high viral loads and mechanical placental disruption facilitate the transmission of CHIKV. Co-infection of these viruses can present with severe manifestations, but the clinical and serologic evidence suggests that one virus predominates which may influence fetal transmission. All three viruses are in different stages of vaccine development with DENV vaccine being fully licensed. Antibody-enhanced infections in seronegative vaccinated candidates who develop natural infection to dengue limit its use and have implications for ZIKV vaccine development. Targeting transmission capacity in the vector could prevent transmission to all three viruses, and breast milk immunity could provide further clues for vaccine development.

Spatiotemporal Heterogeneity in the Distribution of Chikungunya and Zika Virus Case Incidences during their 2014 to 2016 Epidemics in Barranquilla, Colombia

Chikungunya virus (CHIKV) and Zika virus (ZIKV) have recently emerged as globally important infections. This study aimed to explore the spatiotemporal heterogeneity in the occurrence of CHIKV and ZIKV outbreaks throughout the major international seaport city of Barranquilla, Colombia in 2014 and 2016 and the potential for clustering. Incidence data were fitted using multiple Bayesian Poisson models based on multiple explanatory variables as potential risk factors identified from other studies and options for random effects. A best fit model was used to analyse their case incidence risks and identify any risk factors during their epidemics. Neighbourhoods in the northern region were hotspots for both CHIKV and ZIKV outbreaks. Additional hotspots occurred in the southwestern and some eastern/southeastern areas during their outbreaks containing part of, or immediately adjacent to, the major circular city road with its import/export cargo warehouses and harbour area. Multivariate conditional autoregressive models strongly identified higher socioeconomic strata and living in a neighbourhood near a major road as risk factors for ZIKV case incidences. These findings will help to appropriately focus vector control efforts but also challenge the belief that these infections are driven by social vulnerability and merit further study both in Barranquilla and throughout the world's tropical and subtropical regions.

Clinical and Epidemiologic Patterns of Chikungunya Virus Infection and Coincident Arboviral Disease in a School Cohort in Haiti, 2014-2015

BACKGROUND

Beginning in December 2013, an epidemic of chikungunya virus (CHIKV) infection spread across the Caribbean and into virtually all countries in the Western hemisphere, with >2.4 million cases reported through the end of 2017.

METHODS

We monitored a cohort of school children in rural Haiti from May 2014, through February 2015, for occurrence of acute undifferentiated febrile illness, with clinical and laboratory data available for 252 illness episodes.

RESULTS

Our findings document passage of the major CHIKV epidemic between May and July 2014, with 82 laboratory-confirmed cases. Subsequent peaks of febrile illness were found to incorporate smaller outbreaks of dengue virus serotypes 1 and 4 and Zika virus, with identification of additional infections with Mayaro virus, enterovirus D68, and coronavirus NL63. CHIKV and dengue virus serotype 1 infections were more common in older children, with a complaint of arthralgia serving as a significant predictor for infection with CHIKV (odds ratio, 16.2; 95% confidence interval, 8.0-34.4; positive predictive value, 66%; negative predictive value, 80%).

CONCLUSIONS

Viral/arboviral infections were characterized by a pattern of recurrent outbreaks and case clusters, with the CHIKV epidemic representing just one of several arboviral agents moving through the population. Although clinical presentations of these agents are similar, arthralgias are highly suggestive of CHIKV infection.

Spatial distribution of Zika in Honduras during 2016-2017 using geographic information systems (GIS) - Implications for public health and travel medicine

BACKGROUND

Zika virus (ZIKV) infection has significantly affected Latin America in 2015-2017. Most studies have been reported from Brazil and Colombia, and only a few from Central America. For these reasons, we analyzed the incidence, incidence rates and evolution of cases in Honduras from 2016 to 2017.

METHODS

Using epidemiological weeks (EW) surveillance data on the ZIKV epidemics in Honduras, we estimated incidence rates (cases/100,000 population), and developed maps at national, departmental and municipal levels.

RESULTS

From 1 January 2016 to 31 December 2017, a total of 32,607 cases of ZIKV were reported (98.5% in 2016 for an incidence rate of 36.85 cases/100,000 pop; 1% confirmed by RT-PCR). The highest peak was reached on the EW 6°, 2016 (2559 cases; 29.34 cases/100,000 pop). The department with the highest number of cases and incidence rate was Cortés (13,128 cases, 791.08 cases/100,000 pop in 2016).

DISCUSSION

The pattern and evolution of ZIKV infection in Honduras have been similar to that which occurred for chikungunya in 2015. As previously reported, infection with chikungunya involved predominantly the central and capital area of the country, reaching incidences there >750 cases/100,000 pop. Studies using geographical information systems linked with clinical disease characteristics are necessary to attain accurate epidemiological data for public health systems. Such information is also useful for assessment of risk for travelers who visit specific areas in a destination country.

Fatal Dengue, Chikungunya and Leptospirosis: The Importance of Assessing Co-infections in Febrile Patients in Tropical Areas

The febrile patient from tropical areas, in which emerging arboviruses are endemic, represents a diagnostic challenge, and potential co-infections with other pathogens (i.e., bacteria or parasites) are usually overlooked. We present a case of an elderly woman diagnosed with dengue, chikungunya and Leptospira interrogans co-infection. Study Design: Case report. An 87-year old woman from Colombia complained of upper abdominal pain, arthralgia, myalgia, hyporexia, malaise and intermittent fever accompanied with progressive jaundice. She had a medical history of chronic heart failure (Stage C, New York Heart Association, NYHA III), without documented cardiac murmurs, right bundle branch block, non-valvular atrial fibrillation, hypertension, and chronic venous disease. Her cardiac and pulmonary status quickly deteriorated after 24 h of her admission without electrocardiographic changes and she required ventilatory and vasopressor support. In the next hours the patient evolved to pulseless electrical activity and then she died. Dengue immunoglobulin M (IgM), non-structural protein 1 (NS1) enzyme-linked immunosorbent assay (ELISA), microagglutination test (MAT) for Leptospira interrogans and reverse transcription polymerase chain reaction (RT-PCR) for chikungunya, were positive. This case illustrates a multiple co-infection in a febrile patient from a tropical area of Latin America that evolved to death.

Cutaneous features of Zika virus infection: a clinicopathological overview

Zika virus (ZIKV) is an emerging mosquito-borne flavivirus transmitted mainly by Aedes species of mosquitos. Although the infection is usually mild and self-limiting, it is emerging as a public health challenge in tropical and subtropical countries owing to its unprecedented pathogenicity and increased risk for fetal malformations and neurological symptoms. Cutaneous manifestations as for other mosquito-borne viruses remain a hallmark of the disease. This article provides a detailed overview on ZIKV infection, including its varied cutaneous clinical manifestations and diagnostic aspects, and also provides detailed insights into its pathogenesis in human skin.

Mayaro: an emerging viral threat?

Mayaro virus (MAYV), an enveloped RNA virus, belongs to the Togaviridae family and Alphavirus genus. This arthropod-borne virus (Arbovirus) is similar to Chikungunya (CHIKV), Dengue (DENV), and Zika virus (ZIKV). The term “ChikDenMaZika syndrome” has been coined for clinically suspected arboviruses, which have arisen as a consequence of the high viral burden, viral co-infection, and co-circulation in South America. In most cases, MAYV disease is nonspecific, mild, and self-limited. Fever, arthralgia, and maculopapular rash are among the most common symptoms described, being largely indistinguishable from those caused by other arboviruses. However, severe manifestations of the infection have been reported, such as chronic polyarthritis, neurological complications, hemorrhage, myocarditis, and even death. Currently, there are no specific commercial tools for the diagnosis of MAYV, and the use of serological methods can be affected by cross-reactivity and the window period. A diagnosis based on clinical and epidemiological data alone is still premature. Therefore, new entomological research is warranted, and new highly specific molecular diagnostic methods should be developed. This comprehensive review is intended to encourage public health authorities and scientific communities to actively work on diagnosing, preventing, and treating MAYV infection.

Spotting Zika spots: descriptive features of the rash used in 66 published cases

Zika virus (ZV) is an important emerging infection. Rash is a key feature, but the summative literature lacks description of the rash beyond 'maculopapular'. Our aim was to identify the cutaneous features described in the published literature. A literature search using defined terms for ZV cases reports and series was performed on the OVID, Clinical Key and University of Dundee's e-library journals databases in December 2016; a later case report was included while the paper was under review. Diagnosis in all cases was via PCR. Exclusion criteria were Zika cases without rash or omitting any description of the rash. Ocular features (conjunctivitis) were not included. In total, 42 publications with 66 cases met the criteria. The most frequent descriptive features included maculopapular (59%), lower limb petechial purpura (11%) and erythematous/red (9%). Pruritus was described in 44% and tenderness in 3%. Lesions were located on the trunk (29%), limbs (5% arms, 11% both arms and legs), face (17%) and extremities (14%) or were diffuse/generalized (12%). There was facial sparing in 3%. Other features were centrifugal spread (6%), palmar and/or plantar involvement (6%), palmoplantar desquamation (2%) and malar erythema with oedema (2%). Mucosal features included gingival bleeding (11%), oral haemorrhagic blisters (8%) and painful blisters/vesicles (4%). Oedema/swelling was described in the upper limbs (5%), lower limbs (5%) and both (3%). Mean rash duration was 6 days (range 3-11 days). The ZV exanthema is most frequently maculopapular, pruritic, sometimes with centrifugal spread from the trunk to extremities. This may include lower limb petechial purpura, palmoplantar lesions, oedema of limb extremities, and gingival bleeding or painful oral bullae. As ZV becomes more prevalent, recognition of the clinical features will enable earlier diagnosis and appropriate testing.

Effective surveillance systems for vector-borne diseases in urban settings and translation of the data into action: a scoping review

Background

Vector-borne diseases (VBDs) continue to represent a global threat, with “old” diseases like malaria, and “emergent” or “re-emergent” ones like Zika, because of an increase in international trade, demographic growth, and rapid urbanization. In this era of globalization, surveillance is a key element in controlling VBDs in urban settings, but surveillance alone cannot solve the problem. A review of experiences is of interest to examine other solution elements. The objectives were to assess the different means of VBD surveillance in urban environments, to evaluate their potential for supporting public health actions, and to describe the tools used for public health actions, the constraints they face, and the research and health action gaps to be filled.

Main body

For this scoping review we searched peer-reviewed articles and grey literature published between 2000 and 2016. Various tools were used for data coding and extraction. A quality assessment was done for each study reviewed, and descriptive characteristics and data on implementation process and transferability were analyzed in all studies.

After screening 414 full-text articles, we retained a total of 79 articles for review. The main targets of the articles were arboviral diseases (65.8%) and malaria (16.5%). The positive aspects of many studies fit within the framework of integrated vector management. Public awareness is considered a key to successful vector control programs. Advocacy and legislation can reinforce both empowerment and capacity building. These can be achieved by collaboration within the health sector and with other sectors. Research is needed to develop well designed studies and new tools for surveillance and control.

Conclusions

The need for surveillance systems in urban settings in both developing and developed countries was highlighted. Countries face the same challenges relating to human, financial, and structural resources. These findings also constitute a wake-up call for governments, academia, funders, and World Health Organization to strengthen control programs and enhance VBD research in urban environments.

Electronic supplementary material

The online version of this article (10.1186/s40249-018-0473-9) contains supplementary material, which is available to authorized users.

Prediction of Zika-confirmed cases in Brazil and Colombia using Google Trends

Zika virus infection in humans has been linked to severe neurological sequels and foetal malformations. The rapidly evolving epidemics and serious complications made the frequent updates of Zika virus mandatory. Web search query has emerged as a low-cost real-time surveillance system to anticipate infectious diseases' outbreaks. Hence, we developed a prediction model that could predict Zika-confirmed cases based on Zika search volume in Google Trends. We extracted weekly confirmed Zika cases of two epidemic countries, Brazil and Colombia. We got the weekly Zika search volume in the two countries from Google Trends. We used standard time-series regression (TSR) to predict the weekly confirmed Zika cases based on the Zika search volume (Zika query). The basis TSR model - using 1-week lag of Zika query and using 1-week lag of Zika cases as a control for autocorrelation - was the best for predicting Zika cases in Brazil and Colombia because it balanced the performance of the model and the advance time in the prediction. Our results showed that we could use Google search queries to predict Zika cases 1 week earlier before the outbreak. These findings are important to help healthcare authorities evaluate the outbreak and take necessary precautions.

Generalized pustular psoriasis triggered by Zika virus infection

Zika virus is an emerging arbovirus, which is expanding in epidemic proportions through tropical and subtropical areas of the world. Although Zika is linked to a number of congenital and neurological complications, there is scarce knowledge on the impact of ZIKV infection in human skin. We report the case of a 68-year old woman who presented with generalized pustular psoriasis after a preceding and otherwise uneventful episode of ZIKV infection. Based on recent experimental data on the biology of ZIKV infection in the cutaneous environment, we speculate that ZIKV may have directly triggered the development of generalized pustular psoriasis by stimulation of keratinocyte-derived mediators of inflammation and a polyfunctional T-cell driven immune reaction in the cutaneous milieu.

Serum Metabolic Alterations upon Zika Infection

Zika virus (ZIKV) infection has recently emerged as a major concern worldwide due to its strong association with nervous system malformation (microcephaly) of fetuses in pregnant women infected by the virus. Signs and symptoms of ZIKV infection are often mistaken with other common viral infections. Since transmission may occur through biological fluids exchange and coitus, in addition to mosquito bite, this condition is an important infectious disease. Thus, understanding the mechanism of viral infection has become an important research focus, as well as providing potential targets for assertive clinical diagnosis and quality screening for hemoderivatives. Within this context, the present work analyzed blood plasma from 79 subjects, divided as a control group and a ZIKV-infected group. Samples underwent direct-infusion mass spectrometry and statistical analysis, where eight markers related to the pathophysiological process of ZIKV infection were elected and characterized. Among these, Angiotensin (1-7) and Angiotensin I were upregulated under infection, showing an attempt to induce autophagy of the infected cells. However, this finding is concerning about hypertensive individuals under treatment with inhibitors of the Renin-Angiotensin System (RAS), which could reduce this response against the virus and exacerbate the symptoms of the infection. Moreover, one of the most abundant glycosphingolipids in the nervous tissue, Ganglioside GM2, was also elected in the present study as an infection biomarker. Considered an important pathogen receptor at membrane's outer layer, this finding represents the importance of gangliosides for ZIKV infection and its association with brain tropism. Furthermore, a series of phosphatidylinositols were also identified as biomarkers, implying a significant role of the PI3K-AKT-mTOR Pathway in this mechanism. Finally, these pathways may also be understood as potential targets to be considered in pharmacological intervention studies on ZIKV infection management.

The African Zika virus MR-766 is more virulent and causes more severe brain damage than current Asian lineage and dengue virus

The Zika virus (ZIKV) has two lineages, Asian and African, and their impact on developing brains has not been compared. Dengue virus (DENV) is a close family member of ZIKV and co-circulates with ZIKV. Here, we performed intracerebral inoculation of embryonic mouse brains with dengue virus 2 (DENV2), and found that DENV2 is sufficient to cause smaller brain size due to increased cell death in neural progenitor cells (NPCs) and neurons. Compared with the currently circulating Asian lineage of ZIKV (MEX1-44), DENV2 grows slower, causes less neuronal death and fails to cause postnatal animal death. Surprisingly, our side-by-side comparison uncovered that the African ZIKV isolate (MR-766) is more potent at causing brain damage and postnatal lethality than MEX1-44. In comparison with MEX1-44, MR-766 grows faster in NPCs and in the developing brain, and causes more pronounced cell death in NPCs and neurons, resulting in more severe neuronal loss. Together, these results reveal that DENV2 is sufficient to cause smaller brain sizes, and suggest that the ZIKV African lineage is more toxic and causes more potent brain damage than the Asian lineage.

Community context and sub-neighborhood scale detail to explain dengue, chikungunya and Zika patterns in Cali, Colombia

Background

Cali, Colombia has experienced chikungunya and Zika outbreaks and hypoendemic dengue. Studies have explained Cali’s dengue patterns but lack the sub-neighborhood-scale detail investigated here.

Methods

Spatial-video geonarratives (SVG) with Ministry of Health officials and Community Health Workers were collected in hotspots, providing perspective on perceptions of why dengue, chikungunya and Zika hotspots exist, impediments to control, and social outcomes. Using spatial video and Google Street View, sub-neighborhood features possibly contributing to incidence were mapped to create risk surfaces, later compared with dengue, chikungunya and Zika case data.

Results

SVG captured insights in 24 neighborhoods. Trash and water risks in Calipso were mapped using SVG results. Perceived risk factors included proximity to standing water, canals, poverty, invasions, localized violence and military migration. These risks overlapped case density maps and identified areas that are suitable for transmission but are possibly underreporting to the surveillance system.

Conclusion

Resulting risk maps with local context could be leveraged to increase vector-control efficiency- targeting key areas of environmental risk.