Diagnosis of Streptococcus suis Meningoencephalitis with metagenomic next-generation sequencing of the cerebrospinal fluid: a case report with literature review.

BACKGROUND: Streptococcus suis meningoencephalitis is a zoonotic disease that mostly infects slaughterhouse workers. Rapid diagnosis of Streptococcus suis meningoencephalitis is critical for effective clinical management of this condition. However, the current diagnostic techniques are not effective for early diagnosis of this condition. To the best of our knowledge, the use of cerebrospinal fluid metagenomic next generation sequencing in the diagnosis of Streptococcus suis meningoencephalitis has been rarely reported. CASE PRESENTATION: Here, we report a case of Streptococcus suis meningoencephalitis in a 51-year-old female patient. The patient had a history of long-term contact with pork and had a three-centimeter-long wound on her left leg prior to disease onset. Conventional tests, including blood culture, gram staining and cerebrospinal fluid culture, did not reveal bacterial infection. However, Streptococcus suis was detected in cerebrospinal fluid using metagenomic next generation sequencing. CONCLUSIONS: Metagenomic next generation sequencing is a promising approach for early diagnosis of central nervous system infections. This case report indicates that cases of clinical meningeal encephalitis of unknown cause can be diagnosed through this method.

Ongoing activity of Toscana virus genotype A and West Nile virus lineage 1 strains in Turkey: a clinical and field survey.

Toscana virus (TOSV), West Nile virus (WNV) and tickborne encephalitis virus (TBEV) are among major viral pathogens causing febrile disease and meningitis/encephalitis. The impact of these viruses was investigated at a referral centre in Ankara Province, Central Anatolia in 2012, where previous reports suggested virus circulation but with scarce information on clinical cases and vector activity. Serum and/or cerebrospinal fluid samples from 94 individuals were evaluated, in addition to field-collected arthropod specimens that included 767 sandflies and 239 mosquitoes. Viral nucleic acids in clinical samples and arthropods were sought via specific and generic nested/real-time PCRs, and antibody responses in clinical samples were investigated via commercial indirect immunofluorescence tests (IIFTs) and virus neutralization. A WNV antigen assay was also employed for mosquitoes. WNV neuroinvasive disease has been identified in a 63-year-old male via RNA detection, and the WNV strain was characterized as lineage 1. TOSV infections were diagnosed in six individuals (6.3%) via RNA or IgM detection. Partial sequences in a 23-year-old female, presented with fever and transient pancytopenia, were characterized as TOSV genotype A. Febrile disease with arthralgia and/or peripheral cranial nerve involvement was noted in cases with TOSV infections. Previous WNV and TOSV exposures have been observed in 5.3% and 2.1% of the subjects, respectively. No confirmed TBEV exposure could be identified. Morphological identification of the field-collected mosquitoes revealed Culex pipiens sensu lato (74.4%), Anopheles maculipennis (20.9%), An. claviger (2.1%) and others. Sandfly species were determined as Phlebotomus papatasi (36.2%), P. halepensis (27.3%), P. major s. l. (19.3%), P. sergenti (8.9%), P. perfiliewi (4.4%), P. simici (2.6%) and others. Viral infections in arthropods could not be demonstrated. TOSV genotype A and WNV lineage 1 activity have been demonstrated as well as serologically proven exposure in patients. Presence of sandfly and mosquito species capable of virus transmission has also been revealed.