[Bacterial meningitis in adults: a retrospective multicentric study in Tuscany (Italy)]. / Le meningiti batteriche dell'adulto: studio retrospettivo multicentrico della Toscana.

The Infectious Diseases Unit of Lucca Hospital conducted a multicentric retrospective study to evaluate the epidemiological and clinical features of adult patients affected by bacterial meningitis attending all the Infectious Diseases Units of Tuscany (Italy) from July 1999 to June 2004. A specific questionnaire was sent to all the units to collect information about each case of bacterial meningitis occurring in patients older than sixteen. Patients with meningitis by Mycobacterium tuberculosis were excluded from the analysis. Nine out of 12 Infectious Diseases Units of Tuscany took part in the study and 197 cases were identified. Most cases of meningitis occurred during 2002 with a slight reduction in cases in subsequent years. Streptococcus pneumoniae and Neisseria meningitidis were the most frequently isolated pathogens with an increase in diagnosis from 1999 to 2004; in 23.8% of patients no pathogens were isolated, with a reduction in meningitis from unknown aetiology from 1999 to 2004. Most patients were treated with a combination of two antibiotics, and corticosteroid drugs were added to the therapy; in the group of patients treated with corticosteroid drugs invalidating complications occurred in 23% of cases and 5% of patients died. In all, 27 out of 197 subjects (13.7%) developed invalidating complications and 20 out of 197 patients (10.2%) died.

Strongyloides stercoralis: ultrastructural study of newly hatched larvae within human duodenal mucosa.

AIM: To investigate the ultrastructural features of the newly hatched larvae of Strongyloides stercoralis in human duodenal mucosa. METHODS: Duodenal biopsies from an AIDS patient were studied by transmission electron microscopy to investigate morphology, location, and host-worm relations of newly hatched larvae. RESULTS: Newly hatched larvae were found in the Lieberkuhn crypts within the tunnels formed by migration of parthenogenic females. Delimiting enterocytes were compressed. Release of larvae into the gut lumen was also documented. It was shown that both a thin and a thick membrane surrounded the eggs and larvae, as a tegument derived respectively from parasite and host. Segmentary spike-like waves, caused by contractures of worm body musculature, were observed on the surface of newly hatched larvae, and their intestinal lumen was closed and empty, with no budding microvilli. Immaturity of the cuticle and some degree immaturity of amphidial neurones were found, but there was no evidence of either immaturity or signs of damage to other structures. CONCLUSIONS: Newly hatched larvae of S stercoralis appear to be a non-feeding immature stage capable of active movement through the epithelium, causing mechanical damage. The tegument resulting from the thin and the thick membrane may protect the parasite and reduce any disadvantage caused by immaturity.

Extent of human immunodeficiency virus type 1 drug resistance as a predictor of virological failure after genotype-guided treatment switch.

Little is known about factors involved in virological response to treatment changes guided by genotyping in patients whose highly active antiretroviral therapy (HAART) fails. A 12-month observational study was conducted of 45 patients infected with human immunodeficiency virus (HIV)-1, who underwent a new genotype-guided HAART regimen following virological treatment failure. Logistic regression models were used to define factors predictive of virological response to genotype-assisted treatment switches. Virological response was defined as achievement of a level of plasma HIV-1 RNA <1000 copies/mL at the end of the follow-up. Drug-resistance mutations were detected at baseline in 30 patients (66.7%). A sustained virological response to new treatment occurred in 13 (43.3%) of these, as opposed to 11 (73.3%) of the 15 patients harboring drug-susceptible virus at baseline (P=.07). In multivariate logistic regression analysis, the number of drug classes where there was resistance at baseline was the only independent predictor of virological failure (P=.0313). Lack of virological response to genotype-guided treatment changes is primarily due to complex baseline resistance patterns. Benefits of antiretroviral resistance testing may be seriously limited by the lack of subsequent treatment options for heavily pretreated patients.

Encephalitis caused directly by Mycoplasma pneumoniae.

A case of non-fatal encephalitis in a 21-y-old immunocompetent woman is described. High titre serum antibodies against Mycoplasma pneumoniae were found. In addition, Mycoplasma pneumoniae DNA was detected in the cerebrospinal fluid by polymerase chain reaction. Neuroimaging findings by magnetic resonance and computed tomographic scanning of the brain, and laboratory investigations, including a search for serum antibodies to gangliosides, did not support an immune-mediated mechanism. No other pathogens were found. These results strongly suggest that the encephalitis was caused directly by Mycoplasma pneumoniae invasion of the central nervous system. They also indicate that such pathogenetic mechanism may sometimes be sufficient to explain neurological manifestations occurring during the course of Mycoplasma pneumoniae infection. The consequences for therapy are discussed.

Encephalitis without meningitis due to sandfly fever virus serotype toscana.

The role of Toscana (TOS) virus in producing encephalitis without meningitis is uncertain. We studied 2 cases of TOS virus encephalitis without meningitis by means of nested polymerase chain reaction assay and DNA sequencing. Findings confirm that TOS virus may directly cause encephalitis and suggest the usefulness of DNA sequencing in investigating relationships between TOS virus molecular patterns and the spectrum of neurological involvement.