Acute myelitis associated with dengue infection

Central and Peripheral Nervous System Manifestations Associated with Dengue Illness

Dengue illness, caused by the dengue viruses, continues to be a major global health concern, with increasing incidence and the emergence of severe manifestations such as neurological complications. An overview of the current understanding of dengue epidemiology, clinical manifestations, and research priorities is presented here. Dengue transmission has escalated in recent years, exacerbated by factors such as vector expansion, climate change, and socioeconomic challenges. The clinical spectrum of dengue ranges from mild febrile illness to severe manifestations, including hemorrhagic fever and neurological complications. Neurological manifestations of dengue, once considered rare, are now increasingly reported, encompassing encephalitis, myelitis, and Guillain-Barré Syndrome, among others. Diagnosis primarily relies on laboratory methods such as RT/PCR, NS1 antigen detection, and serological assays. Despite advancements in understanding the dengue pathogenesis, there remains a critical need for effective vaccines, antiviral drugs, improved surveillance methods, predictive models for disease severity, and long-term studies on post-Dengue sequelae. Integrated programs and holistic approaches to dengue control are essential for mitigating its impact. Addressing these research priorities will be pivotal in combating dengue and reducing its global burden.

Dengue hemorrhagic fever: a growing global menace

Dengue virus is an arthropod-borne virus, transmitted by Aedes aegypti among humans. In this review, we discussed the epidemiology of dengue hemorrhagic fever (DHF) as well as the disease's natural history, cycles of transmission, clinical diagnosis, aetiology, prevention, therapy, and management. A systematic literature search was done by databases such as PubMed and Google Scholar using search terms, 'dengue fever', 'symptoms and causes of dengue fever', 'dengue virus transmission', and 'strategies to control dengue'. We reviewed relevant literature to identify hazards related to DHF and the most recent recommendations for its management and prevention. Clinical signs and symptoms of dengue infection range from mild dengue fever (DF) to potentially lethal conditions like DHF or dengue shock syndrome (DSS). Acute-onset high fever, muscle and joint pain, myalgia, a rash on the skin, hemorrhagic episodes, and circulatory shock are among the most common symptoms. An early diagnosis is vital to lower mortality. As dengue virus infections are self-limiting, but in tropical and subtropical areas, dengue infection has become a public health concern. Hence, developing and executing long-term control policies that can reduce the global burden of DHF is a major issue for public health specialists everywhere.

Infectious Myelitis

Myelitis is an extensive group of pathologies, including inflammatory, demyelinating, and infectious disorders, sometimes mimicking tumors. This article will discuss infectious myelitis, mainly the patterns of spinal cord involvement caused by each infectious agent and the contribution of magnetic resonance imaging as a major tool to establish the specific diagnosis.

Longitudinally extensive transverse myelitis with positive aquaporin-4 IgG associated with dengue infection: a case report and systematic review of cases

BACKGROUND

Neuromyelitis Optica Spectrum Disorder can be associated with parainfectious and post-infectious triggers. Dengue virus infection is one of the most common arbovirus infections in the world, and may present with neurological manifestations.

OBJECTIVES

We present a case of DENV-associated with LETM and positive aquaporin-4 IgG, and a systematic review of published cases.

METHODS

Medline (Ovid) and PubMed were search through June 2021, for case reports, series and observational studies that described patients with DENV-associated LETM and/or NMOSD.

RESULTS

An adolescent girl who had recently immigrated from a Dengue-endemic region presented with a LETM with high positive AQP4-IgG titer and seropositive DENV IgM/IgG antibodies. She responded well to steroids and subsequently started maintenance rituximab for her NMOSD diagnosis.

LITERATURE REVIEW

22 publications describing 27 patients met inclusion criteria. In addition to this case, three published cases met current criteria for NMOSD with serological evidence of acute DENV infection.

CONCLUSIONS

It is unknown whether there is a pathophysiological association between DENV infection and NMOSD. Regardless, if an immune-mediated event is suspected, particularly NMOSD, appropriate immunotherapy should be considered early. Decision regarding long term immunotherapy may depend on index of suspicion of true NMOSD, and this is where AQP4-IgG status and follow-up is helpful.

Dengue infection in mice inoculated by the intracerebral route: neuropathological effects and identification of target cells for virus replication

Dengue is an important arboviral infection, causing a broad range symptom that varies from life-threatening mild illness to severe clinical manifestations. Recent studies reported the impairment of the central nervous system (CNS) after dengue infection, a characteristic previously considered as atypical and underreported. However, little is known about the neuropathology associated to dengue. Since animal models are important tools for helping to understand the dengue pathogenesis, including neurological damages, the aim of this work was to investigate the effects of intracerebral inoculation of a neuroadapted dengue serotype 2 virus (DENV2) in immunocompetent BALB/c mice, mimicking some aspects of the viral encephalitis. Mice presented neurological morbidity after the 7^th day post infection. At the same time, histopathological analysis revealed that DENV2 led to damages in the CNS, such as hemorrhage, reactive gliosis, hyperplastic and hypertrophied microglia, astrocyte proliferation, Purkinje neurons retraction and cellular infiltration around vessels in the pia mater and in neuropil. Viral tropism and replication were detected in resident cells of the brain and cerebellum, such as neurons, astrocyte, microglia and oligodendrocytes. Results suggest that this classical mice model might be useful for analyzing the neurotropic effect of DENV with similarities to what occurs in human.