Comparison of international guidelines for CT prior to lumbar puncture in patients with suspected meningitis.

PURPOSE: To compare the performance of multiple international guidelines in selecting patients for head CT prior to lumbar puncture (LP) in suspected meningitis, focusing on identification of potential contraindications to immediate LP. METHODS: Retrospective study of 196 patients with suspected meningitis presenting to an emergency department between March 2013 and March 2023 and undergoing head CT prior to LP. UK Joint Specialist Society Guidelines (UK), European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and Infectious Diseases Society of America (IDSA) guidelines were evaluated by cross-referencing imaging criteria with clinical characteristics present at time of presentation. Sensitivity of each guideline for recommending neuroimaging in cases with brain shift on CT was evaluated, along with the number of normal studies and incidental or spurious findings. RESULTS: 2/196 (1%) patients had abnormal CTs with evidence of brain shift, while 14/196 (7%) had other abnormalities on CT without brain shift. UK, ESCMID and IDSA guidelines recommended imaging in 10%, 14% and 33% of cases respectively. All three guidelines recommended imaging pre-LP in 2/2 (100%) cases with brain shift. IDSA guidelines recommended more CT studies with normal findings (59 vs 16 and 24 for UK and ESCMID guidelines respectively) and CT abnormalities without brain shift (4 vs 1 and 2 respectively) than the other guidelines. CONCLUSION: UK, ESCMID and IDSA guidelines are all effective at identifying the small cohort of patients who benefit from a head CT prior to LP. Following the more selective UK/ESCMID guidelines limits the number of normal studies and incidental or spurious CT findings.

Neonatal sepsis with meningitis, ventriculitis and brain abscess caused by Edwardsiella tarda.

A case of neonatal sepsis caused by Edwardsiella tarda, an uncommon pathogen typically associated with aquatic lifeforms, is described. The infant presented in septic shock with seizures and respiratory failure and was found to have meningitis, ventriculitis and a brain abscess requiring drainage. Only a small number of case reports of neonatal E. tarda infection, several with sepsis with poor auditory or neurodevelopmental outcomes or meningitis, have been described in the literature. This case report suggests that E. tarda, while uncommon, can be a cause of serious central nervous system disease in the neonatal population and that an aggressive approach to pursuing and treating complications may lead to improved neurodevelopmental outcomes.

Meningitis in Children: Still a Can't-Miss Diagnosis.

Although vaccination and antimicrobial treatment have significantly impacted the frequency and outcomes of meningitis in children, meningitis remains a critical can't-miss diagnosis for children, where early recognition and appropriate treatment can improve survival and neurologic outcomes. Signs and symptoms may be nonspecific, particularly in infants, and require a high index of suspicion to recognize potential meningitis and obtain the cerebrospinal fluid studies necessary for diagnosis. Understanding the pathogens associated with each age group and specific risk factors informs optimal empirical antimicrobial therapy. Early treatment and developmental support can significantly improve the survival rates and lifelong neurodevelopment of children with central nervous system infections.

Six Year Old With Chronic Headache: An Unexpected Meningitis Mimic.

The constellation of fevers accompanied by headache and vomiting is a red flag for clinicians that appropriately triggers evaluation for meningitis and other life-threatening diagnoses. When symptoms persist even after these conditions are ruled out, patient care becomes more challenging. We present the case of a 6-year-old male with a history of autism spectrum disorder who presented with 6 months of headaches and associated vomiting and intermittent fevers with negative infectious workup despite cerebrospinal fluid pleocytosis. Serial neuroimaging and laboratory evaluation ultimately led to a diagnosis of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) presenting as aseptic meningitis. The clinical and radiographic findings of MOGAD are widely variable and overlap with several other inflammatory conditions, which makes diagnosis challenging. This case highlights the importance of recognizing this rare MOGAD presentation as an infectious meningitis mimic.

A live attenuated vaccine to prevent severe neonatal Escherichia coli K1 infections.

Preterm birth is currently the leading cause of neonatal morbidity and mortality. Genetic, immunological and infectious causes are suspected. Preterm infants have a higher risk of severe bacterial neonatal infections, most of which are caused by Escherichia coli an in particular E. coli K1strains. Women with history of preterm delivery have a high risk of recurrence and therefore constitute a target population for the development of vaccine against E. coli neonatal infections. Here, we characterize the immunological, microbiological and protective properties of a live attenuated vaccine candidate in adult female mice and their pups against after a challenge by K1 and non-K1 strains of E. coli. Our results show that the E. coli K1 E11 ∆aroA vaccine induces strong immunity, driven by polyclonal bactericidal antibodies. In our model of meningitis, mothers immunized prior to mating transfer maternal antibodies to pups, which protect newborn mice against various K1 and non-K1 strains of E. coli. Given the very high mortality rate and the neurological sequalae associated with neonatal E. coli K1 meningitis, our results constitute preclinical proof of concept for the development of a live attenuated vaccine against severe E. coli infections in women at risk of preterm delivery.

High-risk Escherichia coli clones that cause neonatal meningitis and association with recrudescent infection.

Neonatal meningitis is a devastating disease associated with high mortality and neurological sequelae. Escherichia coli is the second most common cause of neonatal meningitis in full-term infants (herein NMEC) and the most common cause of meningitis in preterm neonates. Here, we investigated the genomic relatedness of a collection of 58 NMEC isolates spanning 1974-2020 and isolated from seven different geographic regions. We show NMEC are comprised of diverse sequence types (STs), with ST95 (34.5%) and ST1193 (15.5%) the most common. No single virulence gene profile was conserved in all isolates; however, genes encoding fimbrial adhesins, iron acquisition systems, the K1 capsule, and O antigen types O18, O75, and O2 were most prevalent. Antibiotic resistance genes occurred infrequently in our collection. We also monitored the infection dynamics in three patients that suffered recrudescent invasive infection caused by the original infecting isolate despite appropriate antibiotic treatment based on antibiogram profile and resistance genotype. These patients exhibited severe gut dysbiosis. In one patient, the causative NMEC isolate was also detected in the fecal flora at the time of the second infection episode and after treatment. Thus, although antibiotics are the standard of care for NMEC treatment, our data suggest that failure to eliminate the causative NMEC that resides intestinally can lead to the existence of a refractory reservoir that may seed recrudescent infection.

Occludin and collagen IV degradation mediated by the T9SS effector SspA contributes to blood-brain barrier damage in ducks during Riemerella anatipestifer infection.

Riemerella anatipestifer infection is characterized by meningitis with neurological symptoms in ducklings and has adversely affected the poultry industry. R. anatipestifer strains can invade the duck brain to cause meningitis and neurological symptoms, but the underlying mechanism remains unknown. In this study, we showed that obvious clinical symptoms, an increase in blood‒brain barrier (BBB) permeability, and the accumulation of inflammatory cytokines occurred after intravenous infection with the Yb2 strain but not the mutant strain Yb2ΔsspA, indicating that Yb2 infection can lead to cerebrovascular dysfunction and that the type IX secretion system (T9SS) effector SspA plays a critical role in this pathological process. In addition, we showed that Yb2 infection led to rapid degradation of occludin (a tight junction protein) and collagen IV (a basement membrane protein), which contributed to endothelial barrier disruption. The interaction between SspA and occludin was confirmed by coimmunoprecipitation. Furthermore, we found that SspA was the main enzyme mediating occludin and collagen IV degradation. These data indicate that R. anatipestifer SspA mediates occludin and collagen IV degradation, which functions in BBB disruption in R. anatipestifer-infected ducks. These findings establish the molecular mechanisms by which R. anatipestifer targets duckling endothelial cell junctions and provide new perspectives for the treatment and prevention of R. anatipestifer infection.

Neonatal Elizabethkingia anophelis meningitis originating from the water reservoir of an automated infant milk dispenser, the Netherlands, February 2024.

Elizabethkingia anophelis is a multidrug-resistant pathogen causing high mortality and morbidity in adults with comorbidities and neonates. We report a Dutch case of E. anophelis meningitis in a neonate, clonally related to samples taken from an automated infant milk dispenser located at the family's residence. We inform about the emergence of E. anophelis and suggest molecular surveillance in hospitals and other health settings. This is the first case connecting an automated formula dispenser to an invasive infection in a neonate.

Identifying high-risk neurological phenotypes in adult-onset classic monogenic autoinflammatory diseases: when should neurologists consider testing?

BACKGROUND: Monogenic autoinflammatory disorders result in a diverse range of neurological symptoms in adults, often leading to diagnostic delays. Despite the significance of early detection for effective treatment, the neurological manifestations of these disorders remain inadequately recognized. METHODS: We conducted a systematic review searching Pubmed, Embase and Scopus for case reports and case series related to neurological manifestations in adult-onset monogenic autoinflammatory diseases. Selection criteria focused on the four most relevant adult-onset autoinflammatory diseases-deficiency of deaminase 2 (DADA2), tumor necrosis factor receptor associated periodic fever syndrome (TRAPS), cryopyrin associated periodic fever syndrome (CAPS), and familial mediterranean fever (FMF). We extracted clinical, laboratory and radiological features to propose the most common neurological phenotypes. RESULTS: From 276 records, 28 articles were included. The median patient age was 38, with neurological symptoms appearing after a median disease duration of 5 years. Headaches, cranial nerve dysfunction, seizures, and focal neurological deficits were prevalent. Predominant phenotypes included stroke for DADA2 patients, demyelinating lesions and meningitis for FMF, and meningitis for CAPS. TRAPS had insufficient data for adequate phenotype characterization. CONCLUSION: Neurologists should be proactive in diagnosing monogenic autoinflammatory diseases in young adults showcasing clinical and laboratory indications of inflammation, especially when symptoms align with recurrent or chronic meningitis, small vessel disease strokes, and demyelinating lesions.

Streptococcus intermedius causing primary bacterial ventriculitis in a patient with severe periodontitis - a case report.

BACKGROUND: Streptococcus intermedius is a member of the S. anginosus group and is part of the normal oral microbiota. It can cause pyogenic infections in various organs, primarily in the head and neck area, including brain abscesses and meningitis. However, ventriculitis due to periodontitis has not been reported previously. CASE PRESENTATION: A 64-year-old male was admitted to the hospital with a headache, fever and later imbalance, blurred vision, and general slowness. Neurological examination revealed nuchal rigidity and general clumsiness. Meningitis was suspected, and the patient was treated with dexamethasone, ceftriaxone and acyclovir. A brain computer tomography (CT) scan was normal, and cerebrospinal fluid (CSF) Gram staining and bacterial cultures remained negative, so the antibacterial treatment was discontinued. Nine days after admission, the patient's condition deteriorated. The antibacterial treatment was restarted, and a brain magnetic resonance imaging revealed ventriculitis. A subsequent CT scan showed hydrocephalus, so a ventriculostomy was performed. In CSF Gram staining, chains of gram-positive cocci were observed. Bacterial cultures remained negative, but a bacterial PCR detected Streptococcus intermedius. An orthopantomography revealed advanced periodontal destruction in several teeth and periapical abscesses, which were subsequently operated on. The patient was discharged in good condition after one month. CONCLUSIONS: Poor dental health can lead to life-threatening infections in the central nervous system, even in a completely healthy individual. Primary bacterial ventriculitis is a diagnostic challenge, which may result in delayed treatment and increased mortality.

Factors associated with meningitis vaccine awareness and engagement among Latino men who have sex with men in South Florida.

Awareness and uptake of the meningitis vaccine remains low among marginalized groups, such as Latino men who have sex with men (LMSM), potentially due to structural and psychosocial barriers in accessing preventative healthcare. The current study explored awareness and uptake of meningitis vaccines among a group of LMSM (N = 99) living in South Florida. A three-pronged variable selection approach was utilized prior to conducting regression models (linear and logistic). Overall, 48.5% of the participants reported little to no knowledge about meningitis vaccines, and 20.2% reported being vaccinated. Living with HIV (OR = 10.48) and time since outbreak (OR = 1.03) were significant predictors of meningitis vaccine uptake. No significant correlates of meningitis vaccine awareness were identified. More research is needed to identify other important factors associated with meningitis vaccine awareness and uptake among LMSM, a multiple marginalized group.

Feasibility, safety, and impact of the RTS,S/AS01E malaria vaccine when implemented through national immunisation programmes: evaluation of cluster-randomised introduction of the vaccine in Ghana, Kenya, and Malawi.

BACKGROUND: The RTS,S/AS01E malaria vaccine (RTS,S) was introduced by national immunisation programmes in Ghana, Kenya, and Malawi in 2019 in large-scale pilot schemes. We aimed to address questions about feasibility and impact, and to assess safety signals that had been observed in the phase 3 trial that included an excess of meningitis and cerebral malaria cases in RTS,S recipients, and the possibility of an excess of deaths among girls who received RTS,S than in controls, to inform decisions about wider use. METHODS: In this prospective evaluation, 158 geographical clusters (66 districts in Ghana; 46 sub-counties in Kenya; and 46 groups of immunisation clinic catchment areas in Malawi) were randomly assigned to early or delayed introduction of RTS,S, with three doses to be administered between the ages of 5 months and 9 months and a fourth dose at the age of approximately 2 years. Primary outcomes of the evaluation, planned over 4 years, were mortality from all causes except injury (impact), hospital admission with severe malaria (impact), hospital admission with meningitis or cerebral malaria (safety), deaths in girls compared with boys (safety), and vaccination coverage (feasibility). Mortality was monitored in children aged 1-59 months throughout the pilot areas. Surveillance for meningitis and severe malaria was established in eight sentinel hospitals in Ghana, six in Kenya, and four in Malawi. Vaccine uptake was measured in surveys of children aged 12-23 months about 18 months after vaccine introduction. We estimated that sufficient data would have accrued after 24 months to evaluate each of the safety signals and the impact on severe malaria in a pooled analysis of the data from the three countries. We estimated incidence rate ratios (IRRs) by comparing the ratio of the number of events in children age-eligible to have received at least one dose of the vaccine (for safety outcomes), or age-eligible to have received three doses (for impact outcomes), to that in non-eligible age groups in implementation areas with the equivalent ratio in comparison areas. To establish whether there was evidence of a difference between girls and boys in the vaccine's impact on mortality, the female-to-male mortality ratio in age groups eligible to receive the vaccine (relative to the ratio in non-eligible children) was compared between implementation and comparison areas. Preliminary findings contributed to WHO's recommendation in 2021 for widespread use of RTS,S in areas of moderate-to-high malaria transmission. FINDINGS: By April 30, 2021, 652 673 children had received at least one dose of RTS,S and 494 745 children had received three doses. Coverage of the first dose was 76% in Ghana, 79% in Kenya, and 73% in Malawi, and coverage of the third dose was 66% in Ghana, 62% in Kenya, and 62% in Malawi. 26 285 children aged 1-59 months were admitted to sentinel hospitals and 13 198 deaths were reported through mortality surveillance. Among children eligible to have received at least one dose of RTS,S, there was no evidence of an excess of meningitis or cerebral malaria cases in implementation areas compared with comparison areas (hospital admission with meningitis: IRR 0·63 [95% CI 0·22-1·79]; hospital admission with cerebral malaria: IRR 1·03 [95% CI 0·61-1·74]). The impact of RTS,S introduction on mortality was similar for girls and boys (relative mortality ratio 1·03 [95% CI 0·88-1·21]). Among children eligible for three vaccine doses, RTS,S introduction was associated with a 32% reduction (95% CI 5-51%) in hospital admission with severe malaria, and a 9% reduction (95% CI 0-18%) in all-cause mortality (excluding injury). INTERPRETATION: In the first 2 years of implementation of RTS,S, the three primary doses were effectively deployed through national immunisation programmes. There was no evidence of the safety signals that had been observed in the phase 3 trial, and introduction of the vaccine was associated with substantial reductions in hospital admission with severe malaria. Evaluation continues to assess the impact of four doses of RTS,S. FUNDING: Gavi, the Vaccine Alliance; the Global Fund to Fight AIDS, Tuberculosis and Malaria; and Unitaid.

A Review of the Current Management of Intracranial Infections of Neurosurgical Importance.

Surgically treated intracranial infections are among the common disease entities seen in neurosurgical practice. Several microbiological agents such as bacteria and fungi have been identified as responsible for intracranial infection. It affects all age groups, though microbial agents and risk factors vary with age. Presentation is non-specific and it requires a high index of suspicion, especially with a background febrile illness such as in the setting of poorly-treated meningitis and immunosuppressive conditions such as retroviral illness. Contrast-enhanced magnetic resonance imaging (MRI) scan is the diagnostic tool of choice; it helps to confirm the diagnosis and exclude other ring-enhancing lesions such as glioblastoma and metastatic brain tumours. Treatment involves medical and/or surgical treatment with clear indications. Surgical treatment includes the drainage of abscess via a twist drill or burrhole craniostomy, and craniotomy for recurrent cases. The advances recorded in the evolution of antibiotics and neuroimaging have helped to improve the outcomes of these patients with intracranial infection.

Les infections intracrâniennes traitées chirurgicalement font partie des entités pathologiques courantes rencontrées en pratique neurochirurgicale. Plusieurs agents microbiologiques tels que les bactéries et les champignons ont été identifiés comme responsables des infections intracrâniennes. Cela affecte tous les groupes d'âge, bien que les agents microbiens et les facteurs de risque varient avec l'âge. La présentation est non spécifique et nécessite un haut degré de suspicion, surtout en présence d'une maladie fébrile sous-jacente, comme dans le cas d'une méningite mal traitée et de conditions immunosuppressives telles que l'infection rétrovirale. L'imagerie par résonance magnétique (IRM) avec contraste est l'outil diagnostique de choix ; elle aide à confirmer le diagnostic et à exclure d'autres lésions à rehaussement annulaire telles que le glioblastome et les tumeurs cérébrales métastatiques. Le traitement implique un traitement médical et/ou chirurgical avec des indications claires. Le traitement chirurgical comprend le drainage de l'abcès par une trépanation ou une craniostomie à trou de trepan, et la craniotomie pour les cas récurrents. Les progrès enregistrés dans l'évolution des antibiotiques et de la neuro-imagerie ont contribué à améliorer les résultats de ces patients atteints d'infections intracrâniennes. MOTS-CLÉS: intracrânien, infection, abcès, antibiotiques, chirurgie.

Demographic analysis of hearing impairment based on various parameters in patients with cochlear implant.

Objectives: To analyse the demographic and clinical variables in children having undergone cochlear implant surgery because of deafness. METHODS: The cross-sectional study was conducted from January to November 2022 at the Centre for Research in Experimental and Applied Medicine laboratory of the Department of Biochemistry and Molecular Biology, Army Medical College, Rawalpindi, Pakistan, in collaboration with the Ear, Nose and Throat Department of Combined Military Hospital, Rawalpindi, and comprised children of eith gender aged up to 10 years who had received cochlear implant. Data was collected through questionnaire-based detailed interviews. Syndromic Hearing Loss, Non-Syndromic Hearing Loss, and Acquired Hearing Loss were identified among the subjects. Data was analysed using SPSS 22. RESULTS: Of the 250 cases, 147(58.8%) were boys, 146(58.4%) were aged 0-5 years, 219(87.6%) had prelingual onset of disease, and 202(80.8%) had a non-progressive disease course. In 203(81.2%) cases, normal developmental milestones were seen. Parental consanguinity was observed in 219(87.6%) cases. However, 63(25.2%) patients had a first-degree relative who had a history of deafness. In 170(68%) cases, hearing loss was hereditary, whereas in 80(32%) it was acquired. Meningitis was the most commonly identified risk factor 55(68.75%). Acquired risk factors and family history had significant association with hearing loss (p<0.05). Speech perception significantly improved in all 219(100%) patients with prelingual hearing loss who underwent cochlear implantation. CONCLUSIONS: Majority of the cases were found to be male, had a prelingual disease onset and a non-progressive disease course. Family history was a significant factor, while meningitis was the most common acquired cause of hearing loss.

[Emergencies in infectious diseases]. / Infektiologische Notfälle.

This article aims to provide an overview of common and high-impact medical emergencies that require prompt and effective infectious diseases management. In the described clinical scenarios of malaria, sepsis, necrotizing fasciitis, and meningitis the authors have emphasized the crucial importance of rapid and accurate diagnosis, as well as appropriate treatment from the perspective of infectious diseases. All of these emergencies demand a high degree of clinical suspicion for accurate diagnosis. Some of them also necessitate the involvement of other medical disciplines, such as neurology in the case of meningitis or surgery for necrotizing fasciitis. Additionally, implementing the right empiric antibiotic regimen or, in the case of malaria, antiparasitic treatment is crucial for improving patient outcomes. As patients with these diagnoses may present at any outpatient department, and efficient and quick management is essential, a deep understanding of diagnostic algorithms and potential pitfalls is of the utmost importance.

An intervention to improve lumbar puncture rates for meningitis surveillance in children at four secondary health facilities in Malawi: A before/after analysis.

OBJECTIVES: A lumbar puncture (LP) procedure plays a key role in meningitis diagnosis. In Malawi and other sub-Saharan African countries, LP completion rates are sometimes poor, making meningitis surveillance challenging. Our objective was to measure LP rates following an intervention to improve these during a sentinel hospital meningitis surveillance exercise in Malawi. METHODS: We conducted a before/after intervention analysis among under-five children admitted to paediatric wards at four secondary health facilities in Malawi. We used local and World Health Organization (WHO) guidelines to determine indications for LP, as these are widely used in low- and middle-income countries (LMIC). The intervention comprised of refresher trainings for facility staff on LP indications and procedure, use of automated reminders to perform LP in real time in the wards, with an electronic data management system, and addition of surveillance-specific clinical officers to support existing health facility staff with performing LPs. Due to the low numbers in the before/after analysis, we also performed a during/after analysis to supplement the findings. RESULTS: A total of 13,375 under-five children were hospitalised over the 21 months window for this analysis. The LP rate was 10.4% (12/115) and 60.4% (32/53) in the before/after analysis, respectively, and 43.8% (441/1006) and 72.5% (424/599) in the supplemental during/after analysis, respectively. In our intervention-specific analysis among the three individual components, there were improvements in the LP rate by 48% (p < 0.001) following the introduction of surveillance-specific clinical officers, 10% (p < 0.001) following the introduction of automated reminders to perform an LP and 13% following refresher training. CONCLUSIONS: This analysis demonstrated a rise in LP rates following our intervention. This intervention package may be considered for planning future facility-based meningitis surveillances in similar low-resource settings.

[A case of liver abscess with meningitis and endophthalmitis: invasive liver abscess syndrome].

A woman in her 70s was hospitalized and was diagnosed with liver abscess and managed with antibiotics in a previous hospital. However, she experienced altered consciousness and neck stiffness during treatment. She was then referred to our hospital. On investigation, we found that she had meningitis and right endophthalmitis concurrent with a liver abscess. Klebsiella pneumoniae was detected from both cultures of the liver abscess and effusion from the cornea. A string test showed a positive result. Therefore, she was diagnosed with invasive liver abscess syndrome. Although she recovered from the liver abscess and meningitis through empiric antibiotic treatment, her right eye required ophthalmectomy. In cases where a liver abscess presents with extrahepatic complications, such as meningitis and endophthalmitis, the possibility of invasive liver abscess syndrome should be considered, which is caused by a hypervirulent K. pneumoniae.

Risk of encephalitis and meningitis after COVID-19 vaccination in South Korea: a self-controlled case series analysis.

BACKGROUND: Several neurological manifestations shortly after a receipt of coronavirus infectious disease 2019 (COVID-19) vaccine have been described in the recent case reports. Among those, we sought to evaluate the risk of encephalitis and meningitis after COVID-19 vaccination in the entire South Korean population. METHODS: We conducted self-controlled case series (SCCS) analysis using the COVID-19 immunization record data from the Korea Disease Control Agency between February 2021 and March 2022, linked with the National Health Insurance Database between January 2021 and October 2022. We retrieved all medical claims of adults aged 18 years or older who received at least one dose of COVID-19 vaccines (BNT162b2, mRNA-1273, ChAdOx1-S, or Ad26.COV2.S), and included only those who had a diagnosis record for encephalitis or meningitis within the 240-day post-vaccination period. With day 0 defined as the date of vaccination, risk window was defined as days 1-28 and the control window as the remainder period excluding the risk windows within the 240-day period. We used conditional Poisson regression to estimate the incidence rate ratios (IRR) with 95% confidence intervals (CI), stratified by dose and vaccine type. RESULTS: From 129,956,027 COVID-19 vaccine doses administered to 44,564,345 individuals, there were 251 and 398 cases of encephalitis and meningitis during the risk window, corresponding to 1.9 and 3.1 cases per 1 million doses, respectively. Overall, there was an increased risk of encephalitis in the first 28 days of COVID-19 vaccination (IRR 1.26; 95% CI 1.08-1.47), which was only significant after a receipt of ChAdOx1-S (1.49; 1.03-2.15). For meningitis, no increased risk was observed after any dose of COVID-19 vaccine (IRR 1.03; 95% CI 0.91-1.16). CONCLUSIONS: Our findings suggest an overall increased risk of encephalitis after COVID-19 vaccination. However, the absolute risk was small and should not impede COVID-19 vaccine confidence. No significant association was found between the risk of meningitis and COVID-19 vaccination.