on may 28 , 2006 , a 70-year - old farmer , living in the area of bordeaux , southwestern france , was admitted , febrile and comatose , to the intensive care unit of the  pellegrin hospital  in bordeaux .
he had no relevant medical history and had not traveled abroad during the previous year .
the fever had begun 36 hours earlier , accompanied by headache , nausea , and vomiting .
he exhibited normal osteotendinous and cranial nerve reflexes , had no babinski sign but had notable nuchal rigidity .
a blood sample was collected at admission and showed the following : leukocyte count 10,300/mm ( neutrophils 7,180/mm , lymphocytes 1,140/mm ) ; hemoglobin 14.2 g / l , platelet count 209,000/mm , creatinine 158 mol / l , prothrombin rate 94% .
the cerebrospinal fluid ( csf ) findings were consistent with viral meningoencephalitis : leukocyte count 620 cells / mm , 45% lymphocytes , protein 1.25 g / l , glucose 0.6 g / l .
the patient was treated with 12 g / day intravenous amoxicillin and acyclovir . on day 4 ,
the glasgow coma score was 15 , but the patient exhibited hypotonic tetraplegia with no osteotendinous reflexes .
ten days later , rapid motor improvement of lower extremities was observed , and the patient was transferred on day 15 to a rehabilitation center .
, enterovirus , adenovirus , varicella - zoster virus , herpes simplex virus , epstein - barr virus , and cytomegalovirus .
igm capture and igg indirect in - house assays with native antigen ( from hypr 1953 tbev strain , kindly provided by f. heinz ) were performed to detect igm and igg tbev antibodies .
the cut - offs were as follows : igg cut - off 0.05 ; igm cut - off 0.2 . an 80% plaque - reduction neutralization test ( prnt80 )
was performed by using the hypr 1953 strain to determine the titer of tbev neutralizing antibodies .
rising tbev igg optical density values were detected in a single assay between the earliest and the latest serum specimen ( table ) .
high titers of tbev neutralizing antibodies were detected on days 11 and 24 after clinical onset of disease ( table ) . a nested reverse transcription 
pcr ( 10 ) for tbev in early serum and csf ( days 3 and 4 ) showed negative results .
* tbev , tickborne encephalitis virus ; igm , immunoglobulin m ; od , optical density ; prnt80 : plaque - reduction neutralization test ( 80% ) ; rt - pcr , reverse transcription  pcr ; csf , cerebrospinal fluid ; nd , not done .
igm capture and igg indirect in - house assay were performed to detect igm and igg tbev antibodies .
the cut - offs were as follows : igg cut - off 0.05 ; igm cut - off 0.2 .
a prnt was performed using the hypr tbev strain to determine the titer of tbev - neutralizing antibodies .
we describe , to our knowledge , the first case of tickborne encephalitis in southwestern france .
high levels of tbev igm were observed in serum and csf samples , as is usually observed in tbe neurologic cases ( 9 ) .
in addition , the high titers of tbev - specific antibodies , determined by prnt , reinforces the conclusion that tbev is the probable cause of the encephalitis - like condition of the patient . however , no virus was isolated and no genome detected .
early csf and serum specimens had not been immediately tested for tbev , and the successive freezing and thawing may explain the negative results .
another explanation could be that the first phase of the disease was not recognized by the patient and that the viremic phase was already finished when the patient was hospitalized , as suggested by the presence of high titers of tbev - neutralizing antibodies on day 8 after admission .
this explanation is compatible with the chronic exposure of the farmer to tick bites . as a differential diagnosis , infection by borrelia garinii , which is also transmitted by i. ricinus ,
could be excluded because no specific igm and igg were detectable by serologic testing and no dermatologic signs characteristic of lyme disease were visible .
however , 2 other tickborne viruses , genetically related to tbev , could not be formally excluded : louping ill virus and spanish sheep encephalitis virus . to date ,
in france most tbe cases have been reported from alsace - lorraine . however , in 2003 , 3 cases were reported from the french alpen region ( 5 ) , likely linked to goat cheese consumption .
these new cases raised the question of the extension of tbev that is endemic in france , as has been observed in germany and switzerland . since 2003 , however , patients from this region with meningitis and encephalitis have been more systematically screened for tbev , and no other case has been identified ( i. schuffenecker , unpub . data ) .
the discovery of the first tbe case in southwestern france raises the question of the mode of emergence of the virus in this region .
the viral cycle involves mainly rodents or deer and ticks with humans as accidental hosts .
one hypothesis to the emergence could be the introduction of infected ticks through animal transportation or bird migration .
a field survey in the close vicinity of the farmer s house and fields could yield valuable results .
collecting ticks and rodents could provide the opportunity to identify the circulating strains ( as recently was done in finland and estonia ) ( 11 ) .
also , a seroprevalence study on domestic animals could provide information on the level of circulation of flaviviruses .
finally , tbev should be more systematically screened for in patients with encephalitis and meningitis in the absence of any other etiologic diagnosis . because this finding has implications for expanding vaccine coverage to forestry and agriculture workers , additional epidemiologic data about tbev circulation in southwestern france should be obtained .
 we report an autochthonous human case of tickborne encephalitis ( tbe ) in the bordeaux area , southwestern france . 
 the patient was a farmer who had severe encephalomyelitis . 
 elisa and neutralization assay of serum and cerebrospinal fluid established the diagnosis . 
 this potential new endemic focus for tbe virus should be further investigated . 
The Case
Conclusions