Dengue hemorrhagic fever and severe thrombocytopenia in a patient on mandatory anticoagulation: balancing two life threatening conditions: a case report

Co-Infection of Dengue in a Pregnant Woman With COVID-19 Disease

The pandemic due to severe respiratory syndrome coronavirus 2 (SARS-Cov-2) was one of the most damaging healthcare emergencies the world has ever seen. Co-infection with dengue virus in COVID-19-positive patients is an additional challenge especially in dengue-endemic areas. Both dengue and COVID-19 infection cause increased morbidity and adverse outcomes in pregnant women, and simultaneous infection of these two illnesses can be further detrimental and sometimes fatal in pregnant women. Here, we present a case of a pregnant woman in her early second trimester with co-infection of dengue and moderate COVID-19 disease who was managed successfully and had a favorable outcome.

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.

Dengue virus induces interferon-β by activating RNA sensing pathways in megakaryocytes

Activation of innate receptors in megakaryocytes (MKs) may affect the ability to produce functional platelets. Low platelet count is one of the clinical manifestations of dengue virus (DENV) infection. In MKs, the effect of innate receptors during DENV-infection is not well studied. Here we used MEG-01 cells to investigate DENV serotype 2 induced innate receptors in these cells. DENV RNA was estimated by qRT-PCR in the culture supernatant. The expression of innate receptors was determined by western blot and qPCR. DENV infection led to increased expression of RIG-I at 24 hrs post-infection (hpi) and MDA-5 at 48 and 72 hpi (p<0.05). However, no change in the expression of TLR3 at protein level was observed. Activation of MDA-5 resulted in increased expression of IFN-β and ISG-15 in DENV infected MEG-01 cells, which was further confirmed by MDA-5 siRNA treatment. Apart from inducing innate receptors, DENV significantly decreases the expression of CD61, an activation marker of megakaryocyteson MEG-01 cells as observed by flow cytometry analysis (p<0.01). Results from this study confirm that DENV infection activates the type-I interferon in megakaryocytes and may play a significant role in maturation and development.

Clinical Indicators of Fatal Dengue in Two Endemic Areas of Colombia: A Hospital-Based Case-Control Study

According to the World Health Organization, 98% of fatal dengue cases can be prevented; however, endemic countries such as Colombia have recorded higher case fatality rates during recent epidemics. We aimed to identify the predictors of mortality that allow risk stratification and timely intervention in patients with dengue. We conducted a hospital-based, case-control (1:2) study in two endemic areas of Colombia (2009-2015). Fatal cases were defined as having either 1) positive serological test (IgM or NS1), 2) positive virological test (RT-PCR or viral isolation), or 3) autopsy findings compatible with death from dengue. Controls (matched by state and year) were hospitalized nonfatal patients and had a positive serological or virological dengue test. Exposure data were extracted from medical records by trained staff. We used conditional logistic regression (adjusting for age, gender, disease's duration, and health-care provider) in the context of multiple imputation to estimate exposure to case-control associations. We evaluated 110 cases and 217 controls (mean age: 35.0 versus 18.9; disease's duration pre-admission: 4.9 versus 5.0 days). In multivariable analysis, retro-ocular pain (odds ratios [OR] = 0.23), nausea (OR = 0.29), and diarrhea (OR = 0.19) were less prevalent among fatal than nonfatal cases, whereas increased age (OR = 2.46 per 10 years), respiratory distress (OR = 16.3), impaired consciousness (OR = 15.9), jaundice (OR = 32.2), and increased heart rate (OR = 2.01 per 10 beats per minute) increased the likelihood of death (AUC: 0.97, 95% confidence interval: 0.96, 0.99). These results provide evidence that features of severe dengue are associated with higher mortality, which strengthens the recommendations related to triaging patients in dengue-endemic areas.

Bilateral rectus sheath haematoma complicating dengue virus infection in a patient on warfarin for mechanical aortic valve replacement: a case report

Background

The management of Dengue virus infection can be challenging. Varied presentations and numerous complications intrinsic to dengue by itself increase the complexity of treatment and potential mortality. When burdened with the presence of additional comorbidities and the need to continue compulsory medications, clear stepwise definitive guidance is lacking and patients tend to have more complex complications and outcomes calling to question the clinical decisions that may have been taken. The use and continuation of warfarin in dengue virus infection is one such example.

Case presentation

We report a 65 year old South Asian female who presented with dengue fever. She had a history bronchial asthma, a prior abdominal surgery, and was on warfarin and maintained a therapeutically appropriate internationalized normalized ratio for a mechanical aortic valve replacement. Though preemptive decision to stop warfarin was taken with decreasing platelet counts, her clinical course was complicated with the development of bilateral rectus sheath haematoma’s requiring resuscitation with blood transfusions.

Conclusion

Though management of dengue viral fever has seen drastic evolution with recent updated guidance, clinical scenarios seen in the course of the illness still pose challenges to the managing physician. The need to continue obligatory anticoagulation which may seem counterintuitive during a complex disease such as dengue virus infection must be considered after understanding the potential risks versus that of its benefits. Though case by case decisions maybe warranted, a clear protocol would be very helpful in making clinical decisions, as the correct preemptive decision may potentially avert catastrophic and unpredictable bleeding events.

Describing complex clinical scenarios at the bed-side: Is a systems science approach useful? Exploring a novel diagrammatic approach to facilitate clinical reasoning

Clinicians often encounter patients having complex clinical scenarios (CCS) where diverse and dynamic diagnostic and therapeutic issues interact. A limited range of bedside methods are available to describe such patients and most often it is a diagnostic summary, a problem list, or a list of differential diagnoses. These methods fail to portray the interconnected nature of CCCs. They prevent visualization of a system of networks or a web of causation operative in CCSs.A more holistic conceptualization is required and the author argues for an approach based on systems science. The latter views the human body to consist of several closely linked organ systems, constantly interacting with each other and embedded in, and 'open' to the external environment. In order to capture the systems nature at bedside, a tool based on network diagrams, termed a Clinical Reasoning Map (CRM) is proposed which depicts diseases or conditions as nodes linked to each other by lines or arrows. The latter linkages follow simple rules: possible causes or associations as mere lines; probable cause using a single dotted arrow with directionality (from 'cause' to 'effect'); definite causal pathways by directional arrows; and bi-directional arrows to indicate organs-systems influencing each other.CRM's utility was investigated in several groups of undergraduate medical students. The results varied: 289, 5th year and 4th year medical students showed that 245 (85.5 %) perceived CRM improve their understanding of the case. However, there was no clear advantage in the CRM over a list of diagnoses in recall of key information. A majority (83.9 %) were keen to learn the technique of drawing a CRM. Postgraduates too found the tool to be useful to understand the interconnected nature of real-life complex case scenarios and pathogenesis of their multifaceted condition to generate differential diagnosis and to select appropriate investigations. Effectiveness of CRM is supported by adult learning theories such as meaningful learning and experiential learning.The author proposes that systems science and tools based in this approach such as CRM has utility in understanding and managing complex case scenarios. They differ significantly from other diagrammatic methods available in the medical literature.