Relapse of herpes simplex encephalitis in a patient with metastatic small cell lung cancer following scalp sparing whole brain radiotherapy.

Herpes simplex virus is the most common cause of severe and potentially fatal sporadic encephalitis worldwide. Recurrence of neurologic symptoms after resolution of the initial episode of HSV encephalitis and despite adequate treatment with intravenous acyclovir is well recognized albeit rare. Most of these recurrences had no evidence of replicating virus and are immune in nature with only a minority of these recurrences representing true virologic relapses. Immunocompromised patients are predominantly at greater risk for virologic relapse of HSV encephalitis with potentially severe and at times fatal consequences. We describe a patient with small cell lung cancer and brain metastasis who underwent chemotherapy, treatment with dexamethasone and whole brain radiotherapy who subsequently suffered two episodes of HSV encephalitis three months and seven months after completion of radiotherapy and while on dexamethasone treatment.

Laboratory test performance in young adults during influenza outbreaks at World Youth Day 2008.

BACKGROUND: The performance of influenza laboratory diagnostics in young adults and in the setting of outbreaks during mass gatherings has not been well studied. OBJECTIVES: We compare the performance of point-of-care tests (POCTs) and immunofluorescence assays (IFAs) with nucleic acid tests (NATs) and viral culture in pilgrims attending influenza clinics established during a large influenza outbreak (World Youth Day, Sydney, Australia, 2008) to assess their performance under the real-life pressures of a mass influenza outbreak. STUDY DESIGN: Patients with an influenza-like illness (ILI) underwent respiratory specimen sampling. Combined deep nares and throat swabs were collected for POCT by trained or untrained clinic staff; type-specific IFA; NAT and viral culture. Laboratory-confirmed influenza occurred if viral culture and/or NAT were positive; the performance of laboratory tests was calculated against this 'gold standard'. RESULTS: A total of 230 samples were collected from 227 patients (median age, 20 years; interquartile range, 18-28 years), with 95 samples (41.3%) having laboratory-confirmed influenza infection (influenza A, 57; influenza B, 38). IFA and POCT sensitivities were 74.5% and 55%, respectively. Four of 51 (8%) culture-positive specimens were negative by NAT, and several errors in influenza virus typing occurred with IFA, POCT and NAT. A non-significant trend towards better POCT performance with increased operator training was demonstrated. CONCLUSION: Different environments, patient populations, operator experience, laboratory access and practicalities associated with performing tests during mass influenza outbreaks may affect performance of influenza-specific laboratory tests.