Duplicates and misclassification of tuberculosis notification records in Brazil, 2001-2007.

OBJECTIVE: To evaluate the change in tuberculosis (TB) notification rates due to the removal of unwanted duplicate records from the Brazilian notification system (2001-2007, data extracted in October 2008), and therefore extending the period of investigation of the previous study using the same methodology (2000-2004, data extracted in February 2006). METHODS: Repeat records were identified using a probabilistic record linkage, classified into six mutually exclusive categories, and then kept, combined or removed from the database. RESULTS: In the TB database, 22.7% of all records belonged to patients with multiple records. When we excluded the first record of every patient in this group, 43.7% were classified as transfers, 29% as returns after default, 16.3% as relapses and 6.6% as true duplicates, while 2.9% were inconclusive and 1.5% had missing data. Removal of unwanted duplicate records reduced the notification rates of new cases by 4% to 6.3%, and increased the proportion cured by 3.4% to 4.9%. DISCUSSION: Linkage of records within the TB notification database and the implementation of procedures to distinguish between new and retreatment or transfer-in records yielded better data. Recommendations are provided on how to prevent duplicates and misclassifications in national TB databases.

Aseptic meningitis after posterior fossa surgery treated by pseudomeningocele closure.

Aseptic meningitis is a recognised complication after posterior fossa surgery. It is often self limiting but occasionally runs a protracted course requiring repeated CSF examination to exclude infection, and treatment with systemic steroids. A patient is described with aseptic meningitis after posterior fossa surgery who underwent posterior fossa re-exploration nearly 3 years after the initial operation. This disclosed a pseudomeningocele, which was closed. The patient remains symptom free almost 2 years after closure. In this case of chronic aseptic meningitis after posterior fossa surgery, closure of the pseudomeningocele found at exploratory surgery led to resolution of the symptoms.