Coinfection withRickettsia helveticaand Herpes Simplex Virus 2 in a Young Woman with Meningoencephalitis

Abstract

Herpes virus type 2 DNA was detected by PCR in the cerebrospinal fluid in a young woman presenting with headache, stiff neck and pleocytosis, and serological findings consistent with reactivation. Since she was exposed to ticks, Lyme disease and tick-borne encephalitis were excluded. Further investigation in an ongoing project, using PCR and sequencing of the amplified products, showed the presence of Rickettsia helvetica in the cerebrospinal fluid. The bacteria were also isolated in Vero cell culture, and microimmunofluorescence confirmed the development of antibodies against Rickettsia spp. with predominance of IgM reactivity consistent with recent infection. She was treated with antibiotics and improved rapidly. The patient could easily have been judged to have isolated herpes meningitis. Because Sweden and other European countries are endemic areas for rickettsioses, the paper reaffirms the importance of investigating for the presence of rickettsial infections in endemic areas in cases of meningitis of uncertain aetiology.

Update on Tick-Borne Rickettsioses around the World: a Geographic Approach

“…However, since 2005, no definitive, convincing cases have been published. In particular, recent reports by the same team remain dubious (313)(314)(315)(316).…”

Evaluation of Disease Causality of Rare Ixodes ricinus-Borne Infections in Europe

“…However, proof found of a Rickettsia infection does not imply or translate to symptomatic disease. Therefore the evidence should not be mistaken for disease causation, which has not been demonstrated [22,131]. Interestingly, R. helvetica has been detected as a co-infection with Lyme neuroborreliosis both in patient blood and CSF in a Dutch study [24].…”

“…Three R. helvetica case reports were included [22,130,131]. All these cases developed fever and headache.…”

“…R. helvetica has been cultivated in African green monkey kidney fibroblast cells (VERO) from CSF of two Swedish cases included in this study [22,131], of which one was also infected by Herpes simplex virus. The bacterium has also been successfully cultured and sequenced from questing I. ricinus ticks in VERO cells [135,136].…”

“…One of the cases presented with subacute meningitis [22] and although the diagnosis of neuroborreliosis was rejected based on serology, the test was performed in an early disease stage when test sensitivity infamously falls short. Another case presented with meningoencephalitis [131] and was positive for Herpes Simplex Virus 2, which could account for the clinical picture. In the three case reports included in the study R. helvetica was either isolated and cultivated or isolated, accompanied by seroconversion indicating that this microorganism can cause infection in humans.…”