Arboviral central nervous system infections

Purpose of review Emerging and re-emerging central nervous system (CNS) infections are a major public health concern in the tropics. The reasons for this are myriad; climate change, rainfall, deforestation, increased vector density combined with poverty, poor sanitation and hygiene. This review focuses on pathogens, which have emerged and re-emerged, with the potential for significant morbidity and mortality. Recent findings In recent years, multiple acute encephalitis outbreaks have been caused Nipah, which carries a high case fatality. Arboviral infections, predominantly dengue, chikungunya and Zika are re-emerging increasingly especially in urban areas due to changing human habitats, vector behaviour and viral evolution. Scrub typhus, another vector borne disease caused by the bacterium Orientia tsutsugamushi, is being established as a leading cause of CNS infections in the tropics. Summary A syndromic and epidemiological approach to CNS infections in the tropics is essential to plan appropriate diagnostic tests and management. Rapid diagnostic tests facilitate early diagnosis and thus help prompt initiation and focusing of therapy to prevent adverse outcomes. Vector control, cautious urbanization and deforestation, and reducing disturbance of ecosystems can help prevent spread of vector-borne diseases. Regional diagnostic and treatment approaches and specific vaccines are required to avert morbidity and mortality.

Section: Key Pointsmentioning

confidence: 99%

Central nervous system infections in the tropics

Singh,

Rupali

2024

“…The initial symptoms are nonspecific and might be dismissed, whereas the more severe second phase, particularly encephalitis, indicates that the virus is already present in the brain. Even then confirmation of a diagnosis relies on detection of IgM, tentatively in serum but conclusively in cerebrospinal fluid [33]. However, if virus is replicating within the CNS any therapeutic, in order to be effective, must cross the blood-brain barrier and then enter cells in an active form to inhibit virus replication.…”

Section: Development Of Effective Therapeuticsmentioning

confidence: 99%

Tick-borne encephalitis

Johnson

Migné

Gonzalez

2023

Purpose of reviewTick-borne encephalitis continues to be one of the most significant causes of viral encephalitis in Europe and Asia. This review will focus on recent developments in the epidemiology, pathogenesis and therapeutic approaches related to infection with tick-borne encephalitis virus. Recent findingsThere is a growing consensus that tick-borne encephalitis viruses are increasing in geographical range, with countries previously free of disease reporting detection of both human cases and presence of virus within indigenous tick populations. The drivers for this are multifactorial but underpinned by humanmediated climate change. Recent developments in pathogenesis have focussed on the intracellular response to infection, particularly in different cell types within the central nervous system (CNS) that are revealing the array of cellular networks triggered by infection. This in turn highlights the need for small molecule therapeutics, such as nucleoside analogues, that can enter the CNS, and the intracellular environment, to inhibit virus replication following neuroinvasion.

“…Arboviruses or arthropod viruses are primarily transmitted by mosquitos, ticks, and sand flies [24]. West Nile Virus (WNV) which is transmitted through mosquito bite is the most common arbovirus in the United Stated however most patients are asymptomatic.…”

Section: West Nile Virusmentioning

confidence: 99%

Viral meningitis and encephalitis: an update

Gundamraj

Hasbun

2023

Purpose of reviewThe most common infectious etiologies of meningitis and encephalitis are viruses. In this review, we will discuss current epidemiology, prevention, diagnosis, and treatment of the most common causes of viral meningitis and encephalitis worldwide. Recent findingsViral meningitis and encephalitis are increasingly diagnosed as molecular diagnostic techniques and serologies have become more readily available worldwide but recent progress in novel antiviral therapies remains limited. Emerging and re-emerging viruses that have caused endemic or worldwide outbreaks or epidemics are arboviruses (e.g., West Nile virus, Japanese encephalitis, Tick borne encephalitis, Dengue, Zika, Toscana), enteroviruses (e.g., Enterovirus 71, Enterovirus D68), Parechoviruses, respiratory viruses [e.g., severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza, metapneumoviruses, measles, mumps], and herpes viruses [e.g., herpes simplex virus (HSV) type 1 (HSV-1), HSV-2, human herpes (HV) 6, varicella zoster virus (VZV)]. Future efforts should concentrate in increasing availability for those viruses with effective vaccination [e.g., Japanese encephalitis, Tick borne encephalitis, varicella zoster viruses, SARS-CoV-2, influenza], prompt initiation of those with encephalitis with treatable viruses (e.g., HSV-1, VZV), increasing the diagnostic yield by using novel techniques such as metagenomic sequencing and avoiding unnecessary antibiotics in those with viral meningitis or encephalitis.