Emerging viral diseases

This study aims to provide an overview of systemic and ocular manifestations of preselected emerging viral diseases. A comprehensive review of the literature was conducted in the PubMed database. We describe current insights into epidemiology, systemic manifestations, ocular features, diagnosis, treatment, and prognosis of preselected emerging arboviral and nonarboviral diseases. Arboviruses refer to a group of ribonucleic acid viruses transmitted to humans by the bite of hematophagous arthropods, mainly mosquitoes. They mostly circulate in tropical and subtropical zones and pose important public health challenges worldwide because of rising incidence, expanding geographic range, and occurrence of prominent outbreaks as a result of climate change, travel, and globalization. The clinical signs associated with infection from these arboviruses are often inapparent, mild, or nonspecific, but they may include serious, potentially disabling, or life-threatening complications. A wide spectrum of ophthalmic manifestations has been described in association with specific arboviruses, including West Nile fever, dengue fever, chikungunya, Zika, Rift Valley fever, yellow fever, and other specific arboviruses. Other emerging nonarboviral agents can cause ocular involvement, including Ebola, severe acute respiratory syndrome coronavirus 2, human T-cell lymphotropic virus 1, and mumps. Diagnosis of emerging viral diseases relies on a combination of clinical evaluation, epidemiological history (travel/exposure), and specialized laboratory tests such as serology, real-time polymerase chain reaction, next-generation sequencing, and other specific tests. Management involves supportive care as there are currently no specific antiviral drug options. Corticosteroids are often used for the treatment of associated ocular inflammation. Most patients have a good visual prognosis, but there may be permanent visual impairment due to ocular structural complications in some. Community-based integrated mosquito management programs and personal protection measures against mosquito bites and other sources of contamination are the best ways to prevent human infection and disease. Emerging viral diseases should be considered in the differential diagnosis of ocular inflammatory conditions in patients living in or returning from endemic regions. Early clinical consideration followed by confirmatory testing can limit or prevent unnecessary treatments for emerging viral causes of ocular inflammation. Prevention of these infections is crucial.