Toscana virus meningo-encephalitis: an important differential diagnosis for elderly travellers returning from Mediterranean countries

Abstract

BackgroundElderly patients have a long list of differentials for causes of acute confusion and altered consciousness levels, including infectious agents. In addition, elderly, retired patients often have more time to travel for tourism, particularly to exotic, warmer locations. Mediterranean countries such as Spain and Italy are popular holiday destinations for British and other tourists, especially during the winter months. However, these warm climates allow insect vectors to proliferate, increasing the risk of exposure to endemic vectorborne viral infections whilst on vacation. Such infections may not be routinely considered by geriatric medical teams.Case presentationAn 87-year old gentleman presented with a three-day history of worsening confusion, lethargy, ataxia, and fevers following a trip to Spain, where he may have sustained a sandfly bite. By the time of admission, he had a reduced GCS, was hallucinating, and was incontinent of urine and faeces, though blood pressure and heart rate were normal. He also appeared hyperaesthetic, and found even capillary blood sugar testing extremely painful. He had no history of cognitive defect or other neurological conditions. He had been previously independently active, with frequent trips to Spain where he maintained a holiday home. He probably sustained a sandfly bite during this most recent trip, whilst cleaning out a shed.Acute and convalescent sera demonstrated IgG antibodies to Toscana virus at extremely high titres of ≥1:10,000 by immunofluorescence assay, though no Toscana virus RNA was detectable in these sera by the time of presentation.ConclusionsToscana virus should be included in the differential diagnosis of any patients presenting with meningo-encephalitis who have recently returned from a Mediterranean country. Testing for Toscana virus infection is performed by serological testing on acute/convalescent paired sera, and/or a polymerase chain reaction (PCR) assay on blood or cerebrospinal fluid (CSF) if presenting within 5 days of illness onset. Making a diagnosis of Toscana virus meningitis/encephalitis (where no other pathogen is detected) has additional clinical utility in reducing or preventing unnecessary use of antibiotics, as well as reassuring the patient and family that generally, this illness is generally self-limiting and full recovery within a few weeks is expected, as in the case reported here.

Toscana virus encephalitis in Southwest Germany: a retrospective study

“…As currently no treatment or vaccine is available, no specific treatment can be offered to patients diagnosed with TOSV-neuroinvasive disease. However, identifying TOSV as the causal agent in a patient with meningoencephalitis can help to avoid unnecessary treatment with antibiotics and antiviral agents [ 16 ].…”

Toscana Virus: Ten Years of Diagnostics in Portugal

“…The diagnosis of phleboviruses should be considered in, the warmer months, in cases of neurological disease or febrile syndrome of unknown origin. It is known that treatment often only serves to reduce symptoms; however, as Veater and colleagues have shown (2017), 34 the usefulness of a correct diagnosis of TOSV is that it can reduce and/or prevent the unnecessary use of antibiotics. Furthermore, both patient and family can be reassured that in general, this illness is self-limiting with full recovery expected within a few weeks.…”

Sandfly-Borne Viruses of Demonstrated/Relevant Medical Importance

“…In most countries, where TOSV is endemic, it is not a notifiable disease; this together with the absence of pathognomonic clinical sign, and the very limited number of commercially available diagnostic assay may explain why autochthonous cases are drastically under detected, and that most of reported cases have affected travelers, the diagnosis of which is done when returning to their homeland. TOSV cases in travelers have been reported from Italy [66], France [67], Spain [68,69] and Portugal [64], but also from the Mediterranean islands such as Cyprus [73], Elba [79,80], Sicily [81] and Sardinia [82].…”