Dengue and COVID-19: A double burden to Brazil

Severe dengue in the intensive care unit

Dengue fever is considered the most prolific vector-borne disease in the world, with its transmission rate increasing more than eight times in the last two decades. While most cases present mild to moderate symptoms, 5% of patients can develop severe disease. Although the mechanisms are yet not fully comprehended, immune-mediated activation leading to excessive cytokine expression is suggested as a cause of the two main findings in critical patients: increased vascular permeability that may shock and thrombocytopenia, and coagulopathy that can induce hemorrhage. The risk factors of severe disease include previous infection by a different serotype, specific genotypes associated with more efficient replication, certain genetic polymorphisms, and comorbidities such as diabetes, obesity, and cardiovascular disease. The World Health Organization recommends careful monitoring and prompt hospitalization of patients with warning signs or propensity for severe disease to reduce mortality. This review aims to update the diagnosis and management of patients with severe dengue in the intensive care unit.

Facing the escalating burden of dengue: Challenges and perspectives

Dengue is the most rapidly emerging mosquito-borne infection and, due to climate change and unplanned urbanization, it is predicted that the global burden of dengue will rise further as the infection spreads to new geographical locations. Dengue-endemic countries are often unable to cope with such increases, with health care facilities becoming overwhelmed during each dengue season. Furthermore, although dengue has been predominantly a childhood illness in the past, it currently mostly affects adults in many countries, with higher incidence of severe disease and mortality rates in pregnant women and in those with comorbidities. As there is currently no specific treatment for dengue and no early biomarker to identify those who will progress to develop vascular leakage, all individuals with dengue are closely monitored in case they need fluid management. Furthermore, diagnosing patients with acute dengue is challenging due to the similarity of clinical symptoms during early illness and poor sensitivity and specificity of point-of-care diagnostic tests. Novel vector control methods, such as the release of Wolbachia-infected mosquitoes, have shown promising results by reducing vector density and dengue incidence in clinical trial settings. A new dengue vaccine, TAK-003, had an efficacy of 61.2% against virologically confirmed dengue, 84.1% efficacy against hospitalizations and a 70% efficacy against development of dengue haemorrhagic fever (DHF) at 54 months. While vaccines and mosquito control methods are welcome, they alone are unlikely to fully reduce the burden of dengue, and a treatment for dengue is therefore essential. Several novel antiviral drugs are currently being evaluated along with drugs that inhibit host mediators, such as mast cell products. Although viral proteins such as NS1 contribute to the vascular leak observed in severe dengue, the host immune response to the viral infection also plays a significant role in progression to severe disease. There is an urgent need to discover safe and effective treatments for dengue to prevent disease progression.

Challenge and opportunity for vector control strategies on key mosquito-borne diseases during the COVID-19 pandemic

Mosquito-borne diseases are major global health problems that threaten nearly half of the world's population. Conflicting resources and infrastructure required by the coronavirus disease 2019 (COVID-19) global pandemic have resulted in the vector control process being more demanding than ever. Although novel vector control paradigms may have been more applicable and efficacious in these challenging settings, there were virtually no reports of novel strategies being developed or implemented during COVID-19 pandemic. Evidence shows that the COVID-19 pandemic has dramatically impacted the implementation of conventional mosquito vector measures. Varying degrees of disruptions in malaria control and insecticide-treated nets (ITNs) and indoor residual spray (IRS) distributions worldwide from 2020 to 2021 were reported. Control measures such as mosquito net distribution and community education were significantly reduced in sub-Saharan countries. The COVID-19 pandemic has provided an opportunity for innovative vector control technologies currently being developed. Releasing sterile or lethal gene-carrying male mosquitoes and novel biopesticides may have advantages that are not matched by traditional vector measures in the current context. Here, we review the effects of COVID-19 pandemic on current vector control measures from 2020 to 2021 and discuss the future direction of vector control, taking into account probable evolving conditions of the COVID-19 pandemic.

Estimating the impact of the COVID-19 pandemic on dengue in Brazil

Atypical dengue prevalence was observed in 2020 in many dengue-endemic countries, including Brazil. Evidence suggests that the pandemic disrupted not only dengue dynamics due to changes in mobility patterns, but also several aspects of dengue surveillance, such as care seeking behavior, care availability, and monitoring systems. However, we lack a clear understanding of the overall impact on dengue in different parts of the country as well as the role of individual causal drivers. In this study, we estimated the gap between expected and observed dengue cases in 2020 using an interrupted time series design with forecasts from a neural network and a structural Bayesian time series model. We also decomposed the gap into the impacts of climate conditions, pandemic-induced changes in reporting, human susceptibility, and human mobility. We find that there is considerable variation across the country in both overall pandemic impact on dengue and the relative importance of individual drivers. Increased understanding of the causal mechanisms driving the 2020 dengue season helps mitigate some of the data gaps caused by the COVID-19 pandemic and is critical to developing effective public health interventions to control dengue in the future.

Community-based mosquito surveillance: an automatic mosquito-on-human-skin recognition system with a deep learning algorithm

BACKGROUND

Public community engagement is crucial for mosquito surveillance programs. To support community participation, one of the approaches is assisting the public in recognizing the mosquitoes that carry pathogens. Therefore, this study aims to build an automatic recognition system to identify mosquitos at the public community level. We construct a customized image dataset consisting of three mosquito species in either damaged or un-damaged body conditions. To distinguish the mosquito in harsh conditions, we explore two state-of-the-art deep learning (DL) architectures: (i) a freezing convolutional base, with partial trainable weights, and (ii) training the entire model with most of the trainable weights. We project a weighted feature map on different layers of the model to visualize the morphological region used by the model in classification and compared it with the morphological key used by the expert.

RESULT

It was found that the model with architecture two and the Adam optimizer achieves at least 98% accuracy in mosquito and conditions identification and when implemented on an independent dataset, the Xception model generalizes the best result with an accuracy of 0.7775 and 0.795 precision. Moreover, most of the morphological regions used by the model are able to match those of the human expert.

CONCLUSION

We report a customized DL model for performing pest mosquito taxonomy identification, and through visualization, some regions using computers to discriminate mosquito species could be adopted later in systematic identification. © 2022 Society of Chemical Industry.

How heterogeneous is the dengue transmission profile in Brazil? A study in six Brazilian states

Dengue is a vector-borne disease present in most tropical countries, infecting an average of 50 to 100 million people per year. Socioeconomic, demographic, and environmental factors directly influence the transmission cycle of the dengue virus (DENV). In Brazil, these factors vary between regions producing different profiles of dengue transmission and challenging the epidemiological surveillance of the disease. In this article, we aimed at classifying the profiles of dengue transmission in 1,823 Brazilian municipalities, covering different climates, from 2010 to 2019. Time series data of dengue cases were obtained from six states: Ceará and Maranhão in the semiarid Northeast, Minas Gerais in the countryside, Espírito Santo and Rio de Janeiro in the tropical Atlantic coast, and Paraná in the subtropical region. To describe the time series, we proposed a set of epi-features of the magnitude and duration of the dengue epidemic cycles, totaling 13 indicators. Using these epi-features as inputs, a multivariate cluster algorithm was employed to classify the municipalities according to their dengue transmission profile. Municipalities were classified into four distinct dengue transmission profiles: persistent transmission (7.8%), epidemic (21.3%), episodic/epidemic (43.2%), and episodic transmission (27.6%). Different profiles were associated with the municipality’s population size and climate. Municipalities with higher incidence and larger populations tended to be classified as persistent transmission, suggesting the existence of critical community size. This association, however, varies depending on the state, indicating the importance of other factors. The proposed classification is useful for developing more specific and precise surveillance protocols for regions with different dengue transmission profiles, as well as more precise public policies for dengue prevention.

Dengue is one of the fastest-growing vector-borne diseases in the world. Currently, vaccines are experimental and are not very effective, so prevention depends on the control of the mosquito Aedes aegypti. Health promotion campaigns aimed at encouraging people to reduce mosquito breeding sites have limited effect. In addition, the heterogeneity of the territories that have dengue becomes a major challenge for the epidemiological surveillance of the disease. Brazil has a territory of continental size, and single standardized surveillance is not very effective for monitoring this arbovirus. Classifying types of dengue dynamics based on features of the epidemiological cycle in each location has the potential to increase the precision of surveillance and control strategies. In our study, we were able to classify areas according to different dengue transmission profiles, ranging from episodic to persistent transmission. These results can provide tools to guide actions aimed at achieving the World Health Organization’s goals of eliminating neglected tropical diseases in countries that have the virus.

Dengue NS1 induces phospholipase A2 enzyme activity, prostaglandins, and inflammatory cytokines in monocytes

INTRODUCTION

Dengue virus (DENV) NS1 is a non-structural secretory protein associated with severe disease and known to cause vascular leak leading to dengue haemorrhagic fever (DHF). As phospholipases A₂ (PLA₂) enzymes, platelet activating factor, and leukotrienes are elevated in dengue, we sought to investigate whether NS1 potentially contributes to disease pathogenesis by inducing PLA₂s.

METHODS

THP-1 cells and primary human monocytes of healthy adults (n = 6) were co-cultured with DENV1 NS1, LPS and media alone. The latter two were used as positive and negative controls. The cell culture supernatants and lysates were harvested at 12 and 24 h and the activity of secretory and cytoplasmic PLA₂, prostaglandins (PGE₂ and PGD₂) were measured by ELISA and cytokines levels were measured using a magnetic Luminex assay. Expression of PLA2G4A, PLA2G2A, PLA2G5, PLA2G10, PLA2G7, GAPDH, NLRP3 and DDX58 genes were assessed using quantitative RT-PCR.

RESULTS

cPLA₂ (p = 0.005), sPLA₂ (p = 0.04), PGE₂ metabolite (p = 0.02) and PGD₂ metabolite (p = 0.04) levels were significantly higher at 12 h in monocytes co-cultured with NS1. Levels of IP-10 (p = 0.005) and IL-10 (p = 0.009) was significantly higher at 24 h, whereas IFNα level was significantly higher (p = 0.013) only at 12 h. IL-1β (p = 0.028 and p = 0.031) and TNFα (p = 0.007 and p = 0.011) showed significantly higher levels at both time points. At 12 h significant upregulation of PLA2G4A (p < 0.0001) was seen, whereas PLA2G7 (p = <0.0001), NLRP3 (p = 0.0009) and DDX58 (p = 0.0056) were significantly downregulated. This pattern changed at 24 h with PLA2G4A (p = 0.0069) showing a marked downregulation and PLA2G7, DDX58 and NLRP3 showing an upregulation, although not significant.

CONCLUSION

Dengue NS1 induces the production of PLA₂ enzymes, prostaglandins and inflammatory cytokines from primary human monocytes, which could play a role in vascular leak in dengue.

Dengue Virus Cases Surge Amidst COVID-19 in Pakistan: Challenges, Efforts and Recommendations

Pakistan is currently facing two outbreaks, dengue and COVID-19; both have strained its healthcare system resulting in multiple concerns including the co-diagnosis of two. Due to poor healthcare capacity, low vaccination rate, increasing COVID-19 variants, socioeconomic disparities, and misinformation, it is inevitable that implications will prove to be damaging to both healthcare workers and civilians. Among these challenges, it is important to note the need for stronger epidemiological surveillance for both COVID-19 and dengue and the implementation of public health measures without endangering sources of livelihood. To sustain this, cooperation between WHO and Pakistan’s government must continue through smart lockdowns, dengue awareness campaigns, and double laboratory procedures.

The deuce-ace of Lassa Fever, Ebola virus disease and COVID-19 simultaneous infections and epidemics in West Africa: clinical and public health implications

Globally, the prevailing COVID-19 pandemic has caused unprecedented clinical and public health concerns with increasing morbidity and mortality. Unfortunately, the burden of COVID-19 in Africa has been further exacerbated by the simultaneous epidemics of Ebola virus disease (EVD) and Lassa Fever (LF) which has created a huge burden on African healthcare systems. As Africa struggles to contain the spread of the second (and third) waves of the COVID-19 pandemic, the number of reported cases of LF is also increasing, and recently, new outbreaks of EVD. Before the pandemic, many of Africa's frail healthcare systems were already overburdened due to resource limitations in staffing and infrastructure, and also, multiple endemic tropical diseases. However, the shared epidemiological and pathophysiological features of COVID-19, EVD and LF as well their simultaneous occurrence in Africa may result in misdiagnosis at the onset of infection, an increased possibility of co-infection, and rapid and silent community spread of the virus(es). Other challenges include high population mobility across porous borders, risk of human-to-animal transmission and reverse zoonotic spread, and other public health concerns. This review highlights some major clinical and public health challenges toward responses to the COVID-19 pandemic amidst the deuce-ace of recurrent LF and EVD epidemics in Africa. Applying the One Health approach in infectious disease surveillance and preparedness is essential in mitigating emerging and re-emerging (co-)epidemics in Africa and beyond.

Dengue Versus Multisystem Inflammatory Syndrome – When the Grey Zone Gets Thinner

Despite the decline in COVID-19 cases, the potential threat of multisystem inflammatory syndrome (MIS) - a hyperinflammatory response following acute SARS-CoV-2 infection - looms large. Although initially described in children, it is being increasingly reported in adults. In dengue endemic regions, MIS is likely to cause diagnostic dilemma with dengue due to overlapping clinical and laboratory features. We describe a young male with fever, gastrointestinal symptoms, a transient rash, thrombocytopenia, and positive dengue NS1 antigen test. Early onset of thrombocytopenia, significant gastrointestinal symptoms and protracted fever were atypical, raising suspicion of MIS-A in view of a recovery from a recent SARS-CoV-2 infection. However, absence of neurologic and cardiac manifestations, stable hemodynamics, absence of mucosal involvement and negative inflammatory markers helped in managing the patient conservatively as dengue. This case highlights diagnostic challenges faced by clinicians treating suspected dengue in the face of increasing recognition of MIS and need for systematic research to establish diagnostic criteria for MIS-A.

HIV/AIDS among children in Ratodero, Pakistan amidst the COVID-19 pandemic: Challenges, efforts, and recommendations

In Pakistan, HIV has increased at an alarming rate in recent decades, and the death toll has risen. It is a public health challenge amidst the COVID-19 pandemic that is not being given due importance. The present article looks at the challenges and efforts being made to deal with HIV among children in Ratodero, Pakistan, and addresses measures that can be taken to control the disease in the child population epidemiologically.

Diagnosis of Dengue in a returning traveler from Pakistan suspected of COVID-19, California, USA

Dengue and COVID-19 cocirculation presents a diagnostic conundrum for physicians evaluating patients with acute febrile illnesses, both in endemic regions and among returning travelers. We present a case of a returning traveler from Pakistan who, following repeated negative SARS-CoV-2 tests, was found to have a Dengue virus serotype 2 infection.

Malaria amidst COVID-19 in India: Challenges, Efforts, and Recommendations

Since the outbreak of COVID-19 in India, the country has faced a slew of new challenges, spawning a slew of other deadly viruses and diseases while also serving as a breeding ground for them. Not only did Malaria (a vector-borne disease) emerge as a coincidental outbreak during the pandemic, but many others did as well, causing severe diseases in humans due to flaws in health-care systems that were already overburdened with identifying, preventing, and treating the recently introduced coronavirus disease. Inadequate water cleanliness, as well as the delayed and misdiagnosis of Malaria with COVID-19 due to overlapping symptoms, are major impediments in the incidence of these unique outbreaks. Appropriate steps, such as providing clean water and diagnostic facilities to control Malaria cases, should be adopted to prevent such epidemics in the country.

Double Trouble: Dengue Followed by COVID-19 Infection Acquired in Two Different Regions: A Doctor's Case Report and Spatial Distribution of Cases in Presidente Prudente, São Paulo, Brazil

Co-epidemics of COVID-19 and dengue in dengue-endemic countries represent a serious public health concern. In Brazil, São Paulo state ranks first for cases and deaths from COVID-19, and dengue is endemic in most regions of the country. In 2020, an outbreak of dengue occurred in western São Paulo. We determined the spatiotemporal distribution of dengue in the context of COVID-19 cases in Presidente Prudente, a mid-sized city in western São Paulo. To illustrate the burden of both infections, a case report of a doctor and his family, infected with dengue and COVID-19, is presented. There were three clusters of dengue and COVID-19 in the periphery. A dengue cluster was found in a region where there were no corresponding COVID-19 cases. Meanwhile, there were COVID-19 clusters where dengue activity was lower. In 2020, the COVID-19 epidemic emerged when dengue reached its seasonal peak, resulting in a simultaneous outbreak of both diseases. Lower rates of dengue were found in the city compared with 2019, and the fear of patients with mild dengue symptoms about remaining in hospital and acquiring COVID-19 infection may be the main cause. Simultaneous spatial clusters of dengue and COVID-19 in environmentally and socioeconomically vulnerable areas can guide public health authorities in intensive interventions to improve clinical diagnosis, epidemiological surveillance, and management of both diseases. The patient and his family were first infected with dengue and he then carried COVID-19 to his family, reinforcing the risk of health care workers spreading the virus to the community. We highlight the epidemiological significance of presenting a case report and spatial analysis of COVID-19 in the same study in the context of a dengue outbreak.

Viral infections amidst COVID-19 in Africa: Implications and recommendations

Viral infections have been on the rise for the past decades. The impact of the viruses worsened amidst the pandemic burdening the already overwhelmed health care system in African countries. This article sheds light on how the coronavirus together with the already existing viral infections, some of which re‐emerged, impacted the continent. The strategies in place such as immunization, education, will have to be strengthened in all African countries to reduce the burden. Furthermore, governments can further collaborate with other countries in creating guidelines to reduce co‐infection of the diseases.

Epidemic of plague amidst COVID-19 in Madagascar: efforts, challenges, and recommendations

The plague has been wreaking havoc on people in Madagascar with the COVID-19 pandemic. Madagascar’s healthcare sector is striving to respond to COVID-19 in the face of a plague outbreak that has created a new strain on the country’s public health system. The goal and activities of the gradual epidemic of plague in Madagascar during COVID-19 are described in this research. In order to contain the plague and the COVID-19 pandemic in this country, we have suggested long-term recommendations that can help to contain the outbreak so that it may spread to non-endemic areas.