Case 1: Headache after a European vacation

A previously healthy five-year-old girl presented to a local emergency department with a three-day history of new-onset headache and neck stiffness. Her parents reported that she may have felt warm but they had not measured her temperature. She demonstrated no associated upper respiratory symptoms, vomiting, diarrhea, urinary symptoms or rashes, and had no known sick contacts. Five days previously, she had travelled briefly with her family to Jasper, Alberta, and one week before had returned from a two-and-a-half-month trip to Norway. While in Norway, the girl's parents had removed several ticks, including one found on the back of her head. All of her immunizations were up to date, and she was developmentally normal. Her medical history was unremarkable, and the family history revealed that her father suffered from migraine headaches. On initial assessment, the patient was oriented and interactive. Her vital signs revealed a temperature of 37.5°C, a heart rate of 118 beats/min, a respiratory rate of 22 breaths/min and a blood pressure of 119/72 mmHg. Her neck was supple, but tender when palpated. The rest of the physical examination was normal. Initial laboratory studies revealed a normal complete blood count, and normal electrolytes, creatinine and serum glucose levels. Cerebrospinal fluid (CSF) analysis revealed a leukocyte count of 61×106/L (no differential obtained due to inadequate sample volume) and a red blood cell count of 3.3×108/L. CSF glucose and protein levels were normal. A CSF Gram stain revealed no organisms or neutrophils, and a CSF sample was sent for routine bacterial cultures and molecular viral testing. The working diagnosis was aseptic meningitis, and the patient was referred to the regional paediatric tertiary care centre for additional workup and admission. The patient was started on intravenous ceftriaxone pending CSF culture results. The CSF culture, blood cultures, throat swabs for enterovirus and respiratory viruses, and CSF polymerase chain reaction analysis for enterovirus, herpes simplex virus types 1 and 2, and West Nile virus, were all negative. Additional laboratory tests confirmed the diagnosis. Lyme disease, also known as Lyme borreliosis, is caused by species of the spirochete bacteria genus Borrelia. The most common Borrelia species implicated in Lyme disease in North America is Borrelia burgdorferi, while in Europe the most common are B burgdorferi, Borrelia afzelii and Borrelia garini (1). Borrelia species are transmitted to humans by vector ticks. The present patient's tick exposure history prompted thorough antibody testing for both North American and European Borrelia species. Results demonstrated a recent infection with European Borrelia species. Lyme disease is defined as endemic in regions where Borrelia species are being demonstrably transmitted by an established population of vector ticks (1). In Canada, these regions include southeastern Manitoba, southern Ontario along Lake Erie and Lake Ontario, regions of coastal New Brunswick and Nova Scotia, as well as Vancouver Island and lower mainland British Columbia (1,2). Additionally, migratory birds distribute vector ticks throughout North America, and approximately 10% of these ticks are infected with B burgdorferi (2). Therefore, there is a small risk of acquiring Lyme disease with any vector tick bite, even outside of endemic regions (2). In Europe, many countries, including Norway, have high and increasing incidences of Lyme disease (3). Indeed, the endemic regions of Lyme disease may be expanding worldwide as the range of the tick vector increases – a phenomenon that is believed to be accelerated by climate change (1,3). Clinically, Lyme disease is divided into three stages: early localized (one to 32 days), early disseminated (three to 10 weeks) and late (two to 12 months). Typically, Lyme meningitis presents during the early disseminated stage, and patients may experience symptoms that are difficult to distinguish from other causes of aseptic meningitis including headache, neck stiffness and elevated levels of CSF leukocytes (4). Because antimicrobial therapy is indicated for Lyme disease, but not viral causes of aseptic meningitis, clinical decision-making models have been created to help with the classification of meningitis etiology (2). In North America, a child in an endemic area presenting with less than seven days of headache, absence of a seventh cranial nerve palsy and less than 70% mononuclear cells has a less than 10% chance of contracting Lyme meningitis (2). Similarly, a retrospective analysis in Europe (3) found that a longer duration of headache, the presence of cranial neuropathies, lower CSF neutrophil counts and elevated CSF protein levels increases the likelihood of Lyme – rather than viral – aseptic meningitis. The history and physical examination should guide the physician to consider Lyme disease. Confirmation is based on the presence of immunoglobulin (Ig) proteins within the CSF (4). In North America, testing is often limited to the use of kits that detect the North American strains. Failure to detect cases due to European Borrelia species is highly likely if the laboratory is not notified of the pertinent travel history. In the present case, initial testing for North American Borrelia species was negative, prompting referral to the reference laboratory. Results from the reference laboratory were highly suggestive of recent infection with European Borrelia species (IgM was positive, but IgG was negative). When retested eight weeks later, IgG was positive, indicating seroconversion (Table 1). Early treatment can blunt the serological response, resulting in a delay of the production of IgG and, thereby, making results difficult to interpret. If serological results are inconsistent with the clinical presentation, it may be worthwhile to revisit exposure history and consult with reference laboratory microbiologists. Summary of serological test results for Lyme disease At the Public Health Agency of Canada's National Microbiology Laboratory (Winnipeg, Manitoba), extensive testing for European Lyme disease serology included Borrelia afzelii, Borrelia garinii and Borrelia burgdorferi. The Euroimmun ELISA immunoglobulin (Ig) M test was positive and the Immunetics C6 IgM/IgG test was equivocal, which is highly suggestive of a recent European Borrelia species infection. Follow-up testing two months later revealed that the Immunetics C6 IgG/IgM test was positive, indicating seroconversion. EIA Enzyme immunoassay Summary of serological test results for Lyme disease At the Public Health Agency of Canada's National Microbiology Laboratory (Winnipeg, Manitoba), extensive testing for European Lyme disease serology included Borrelia afzelii, Borrelia garinii and Borrelia burgdorferi. The Euroimmun ELISA immunoglobulin (Ig) M test was positive and the Immunetics C6 IgM/IgG test was equivocal, which is highly suggestive of a recent European Borrelia species infection. Follow-up testing two months later revealed that the Immunetics C6 IgG/IgM test was positive, indicating seroconversion. EIA Enzyme immunoassay Although many manifestations of Lyme disease are self-limiting, antibiotic therapy is recommended because it shortens the clinical course and prevents complications (4). The present patient received intravenous ceftriaxone (100 mg/kg every 24 h) for 14 days and has remained well. While Lyme disease is not endemic in most of Canada, headache accompanied by a history of travel and exposure to ticks in endemic areas should prompt a clinician to consider Lyme meningitis in the differential diagnosis. Routine and specialized testing of CSF and blood for Borrelia species will help confirm the diagnosis of neuroborreliosis. Routine laboratory tests for Lyme disease in Canada will not detect European Lyme disease. A microbiologist should be consulted to facilitate testing for European Lyme disease.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.