Early diagnosis is essential for appropriate management to minimise the risk of systemic and ocular morbidity associated with a broad spectrum of emerging infectious diseases, according to Moncef Khairallah MD.
At a special symposium on uveitis infections held during the 17th EURETINA Congress in Barcelona, Dr Khairallah of the University of Monastir, Tunisia, discussed the challenge of emerging infectious diseases such as Rickettsial infections, West Nile virus, dengue fever, chikungunya, Zika virus and Ebola virus.
“Early diagnosis of these diseases can be achieved based on the association of typical ocular findings with a history of high fever and other systemic symptoms allied to specific epidemiological data,” he said. There are certain criteria to look for when potential emerging infectious posterior uveitis is suspected.
“Any patient with specific ocular findings, with a history of recent systemic febrile syndrome, living in or travelling from a specific endemic area should be examined very carefully,” he said.
Rickettsial diseases such as Mediterranean spotted fever or Rocky Mountain spotted fever or other variants are usually spread by ticks and should be suspected in patients with typical retinitis, retinal vasculitis or optic neuropathy with the classic triad of high fever, headache and skin rash, said Dr Khairallah.
Treatment for Rickettsial disease includes antibiotics, mainly doxycycline, for seven-to-15 days, in combination with systemic corticosteroids, in selected severe cases. Prognosis of systemic and ocular disease is good in most patients, said Dr Khairallah.
West Nile virus infections spread by mosquitoes are usually subclinical in about 80% of cases or manifest as febrile illness in 20%, said Dr Khairallah. Severe neurologic disease occurs in less of 1% of patients. Ocular manifestations include typical bilateral multifocal chorioretinitis with linear clustering of lesions, and no or mild vitritis.
“Active lesions appear as yellow, deep, round chorioretinal spots, with early hypofluorescence and late staining on angiography. Other findings may include macular oedema, RPE changes, anterior uveitis, subconjunctival haemorrhage, papilloedema, oculomotor nerve palsy and nystagmus,” he said.
Ocular manifestations of Dengue fever, which infects about 50 million annually in tropical and subtropical regions, include dengue maculopathy with round foveal lesion, retinal pigment epithelial (RPE) thickening, macular oedema, serous retinal detachment, macular haemorrhages and vasculitis.
For the Zika virus, the most serious complications are found in infants who have microcephaly. Ocular involvement may include conjunctivitis and anterior uveitis, gross macular pigment mottling, chorioretinal atrophy, optic nerve abnormalities and lens subluxation.
Ocular symptoms for patients with the Ebola virus include conjunctivitis and subconjunctival haemorrhage in early stages, and uveitis for those in recovery, said Dr Khairallah.
Prophylaxis remains the mainstay of viral disease control, with public health measures being taken to reduce the number of mosquitoes and improve sanitary conditions, he concluded.
Moncef Khairallah: moncef.khairallah@yahoo.fr
