[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.

Discrepancy in virological and biochemistry response of patients with chronic hepatitis HCV positive on treatment with PEG-IFN plus ribavirin.

Combination therapy of PEG-IFN alpha-2a o alpha-2b plus ribavirin represents a further improvement in treatment of chronic hepatitis HCV+ with a sustained virological response (SVR) either in monotherapy (25-39%) either in association with ribavirin (59-56%). SVR is highly predictable: 75% of all patients who achieve viral clearance at week 12 (EVR), if they had an adherence > 80% of planned therapy, they become sustained viral responders. In spite of virological response, 16-34% of patients on PEG-IFN monotherapy have high value of ALT, and this make them to reduce adherence. 62 patients whith chronic hepatitis HCV+ and no corrhosis, have been treated for 48 weeks with PEG-IFN and ribavirin to evaluate discrepancy incidence between virological (HCVRNA < 200UI) and biochemical (normal value of ALT) response of patients treated with PEG-IFN plus ribavirin and to verify the impact that stuch discrepancy can produce on SVR of treated patients. Our preliminary data confirm that PEG-IFN bring a superior virological response than biochemical one, either on naive patients either on experienced ones even with ribavirin in association. It will be useful to verify if this discepancy cause a superior SVR as already reported by several studies. Even the follow-up of our 5 discordant patients confirm this trend.

Mucosal and systemic immune activation is present in human immunodeficiency virus-exposed seronegative women.

Immune parameters were analyzed in peripheral blood mononuclear cells (PBMC) and cervical mucosa biopsy specimens of human immunodeficiency virus (HIV)-seronegative women sexually exposed to HIV (exposed seronegative [ESN]), HIV-infected women, and healthy women without HIV exposure. HIV was not detected in PBMC or cervical mucosa biopsy specimens of ESN women. However, interleukin (IL)-6, IL-10, IL-12, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha and -beta mRNA were elevated in PBMC and cervical mucosa biopsy specimens of ESN and HIV-infected women; CCR5 and CXCR4 mRNA were augmented in cervical mucosa biopsy specimens, but not in PBMC, of ESN and HIV-infected women; HIV-specific IFN-gamma-secreting cells were detected in vaginal washes of ESN and HIV-infected women; and phenotypic alterations were present in PBMC of ESN women. These results suggest that active HIV infection is not required for T cell activation; immune alterations occur in women in whom HIV infection cannot be detected virologically or clinically.

A role for mucosal immunity in resistance to HIV infection.

In a recent, thought-provoking novel by Elizabeth McCracken (The Giant's House. Avon Books, New York, 1997), two characters discuss love and its impossibilities. One brashly claims to be "immune to love", explaining the concept to his perplexed interlocutor, "...people become immune to love like they become immune to any disease. Either they had it bad early in life, like chicken pox and that's that; or they keep getting exposed to it in little doses and build up an immunity; or somehow they just don't catch it, something in'em is born resistant. I'm the last type. I'm immune to love and poison ivy". (p. 275) (E. McCracken, The Giant's House. Avon Books, New York, 1997). Substitute the words 'HIV infection' for 'love' and this intriguing metaphor summarizes the state of the art working hypotheses for the phenomenon of resistance to HIV infection in HIV-exposed individuals who, against all odds, do not seroconvert. These hypotheses will be discussed hereafter and particular emphasis will be placed upon a possible role for mucosal immunity in this phenomenon.

HIV-specific mucosal and cellular immunity in HIV-seronegative partners of HIV-seropositive individuals.

HIV-specific mucosal and cellular immunity was analyzed in heterosexual couples discordant for HIV status in serum and in HIV-unexposed controls. HIV-specific IgA but not IgG was present in urine and vaginal wash samples from HIV-exposed seronegative individuals (ESN), whereas both IgA and IgG were observed in their HIV-seropositive partners; antibodies were not detected in low-risk controls. Envelope protein (Env) peptide-stimulated interleukin-2 (IL-2) production by peripheral blood mononuclear cells (PBMCs) was detected in 9 out of 16 ESNs, 5 out of 16 HIV-infected patients and 1 out of 50 controls. Env peptide-stimulated PBMCs of ESNs produced more IL-2 and less IL-10 compared with those of HIV-infected individuals; no differences were observed in chemokine production or in CCR5 expression. These data demonstrate that a compartmentalized immune response to pathogens is possible in humans and raise the possibility of protective roles for cell-mediated immunity and mucosal IgA in HIV-seronegative individuals exposed to HIV.

Serological survey of hepatitis B infection in Tanzania.

In 1992, the prevalence of hepatitis B virus (HBV) markers was evaluated in 1004 subjects aged one to 76 years living in urban and rural areas in Tanzania. The overall prevalence rates of hepatitis B surface antigen (HBsAg) and of any HBV marker were 4.4% and 37.0%, respectively. No statistically significant difference by sex was found. The HBsAg prevalence among pregnant women was 4.3% (20/463). The proportion of HBeAg positive among HBsAg positive pregnant women was 10% (2/20). The HBsAg age-specific prevalence was 2.1% in the 1-5 year age-group; peak prevalence (12.1%) occurred in the 6-15 year age-group. Markers of HBV infection were 4.1% by age five years; they increased with advancing age (P < 0.01). Subjects residing in urban areas had statistically significant higher HBV exposure than those residing in rural areas (43.9% vs 27.4%, P < 0.01). Subjects belonging to the largest family size (seven or more members) showed increasing risk (OR 2.9; 95% CI = 1.96-4.28) of HBV exposure. Because maternal HBV transmission early in life appears to be of minor impact and children are mostly infected later in infancy, HBV vaccination at birth is not indicated, while vaccination of all infants at 2-3 months of age with other paediatric vaccinations is the first priority.