Hepatitis C virus infection among institutionalised psychiatric patients: a regression analysis of indicators of risk.

BACKGROUND/AIMS: Institutionalised psychiatric patients are at increased risk of developing chronic infection with hepatitis B virus (HBV). However, little information is available on transmission and epidemiology of hepatitis C virus (HCV) in this setting. The aim of this study was to identify potential risk factors of acquiring HCV infection in two large psychiatric institutions in northern Italy. METHODS: We designed a case-control study using randomly selected controls from the same study database, consisting of a total of 1180 patients, in order to satisfy the principle that both cases and controls should be representative of the same base experience. A multiple regression logistic analysis was used to identify features that could predict exposure to HCV as evidenced by the presence of circulating anti-HCV antibodies. RESULTS: Anti-HCV was detected in 79 patients (6.7%). The prevalence of viraemia and the distribution of genotypes were very similar to those found in subjects with chronic HCV infection drawn from the same geographical area. Multivariate analysis indicated that a diagnosis of psychosis and a history of trauma were statistically significant independent risk factors associated with a positive anti-HCV result (OR 2.615, 1.273-5.373 95% CI and OR 2.096, 1.133-3.877 95% CI, respectively). CONCLUSIONS: The findings of this large epidemiological study show for the first time that prolonged residence in psychiatric institutions does not entail per se a significant risk of acquiring HCV infection. Since transmission of HCV in this setting appears to occur predominantly via classical parenteral routes, simple prophylactic measures appear to be adequate to prevent infection.

In-vitro and in-vivo activity of rifabutin against Toxoplasma gondii.

The activity of rifabutin against Toxoplasma gondii was investigated in vitro and in vivo. One set of in-vitro studies used either a low virulence or a high virulence T. gondii strain subcultured in drug-free conditions after exposure to various drug concentrations. No parasite growth was observed after subculture at 1 month after exposure to 6 mg/L of rifabutin for the low virulence and 12 mg/L for the high virulence strain. The IC50 of rifabutin was 26.5 mg/L in a different series of experiments using an enzyme-linked immunoassay) and the T. gondii high virulence strain. In similar experiments with clarithromycin, low virulence and high virulence parasites grew in drug-free subcultures following exposure to drug concentrations as high as 100 mg/L; the IC50 of clarithromycin exceeded 100 mg/L for the high virulence strain. In the acute toxoplasmosis murine model, mice received a 12 day treatment starting 5 days before infection with high virulence parasites. Survival was significantly improved compared with untreated controls in response to 50, 100 and 200 mg/kg/day rifabutin and 100 and 200 (but not 50) mg/kg/day clarithromycin, and with the combination of the two drugs at 25, 50 and 100 mg/kg/day. Survival was significantly improved when combination therapy was administered. The calculated ED50 values (mg/kg/day) were 160.5 for rifabutin, 119.4 for clarithromycin, and 114.8 for the combination. In the present experimental conditions rifabutin proved effective in vitro and in vivo against T. gondii and showed potentiation with clarithromycin in vivo.

Asymptomatic genitourinary Chlamydia trachomatis infection in women seropositive for human immunodeficiency virus infection.

OBJECTIVE: To evaluate the prevalence of asymptomatic Chlamydia trachomatis genitourinary infection in women with human immunodeficiency virus (HIV) infection. METHODS: The prevalence of asymptomatic chlamydial genitourinary infection in HIV-seropositive women was compared with both HIV-seronegative controls and women with unknown HIV status. Chlamydia trachomatis was isolated in cell culture from endocervical and urethral specimens. RESULTS: The prevalence of genitourinary C trachomatis infection among HIV-seropositive women was 18.3% (21 of 115), a rate significantly higher than in both HIV-negative women (11 of 136; P = .016) and controls with unknown HIV status (18 of 326; P = .0001). Crude odds ratios for endocervical and urethral chlamydial infection in HIV-seropositive women compared to HIV-seronegative controls were 2.6 (95% confidence interval [CI] 1.13-6.08) and 3.3 (95% CI 1.15-9.67), respectively. After adjustment for variables related to sexual habits, there was no difference in the risk of cervical C trachomatis infection between HIV-seropositive cases and HIV-seronegative controls (Mantel-Haenszel odds ratio 1.04, 95% CI 0.93-1.14; P = .41). Finally, in HIV-seropositive patients, both the severity of immunosuppression evaluated by CD4+, CD8+, and total lymphocyte counts and the detection of p24 HIV-related antigen did not correlate with the presence of chlamydial infection. CONCLUSIONS: Women infected with HIV are at high risk for asymptomatic genitourinary chlamydial colonization. To prevent a possible "epidemic" of pelvic inflammatory disease, appropriate screening programs and therapeutic strategies should be planned.

Prevalence of chlamydial antibody in pregnancy. A matched-pair study.

In this matched-pair study 139 pregnant women were matched on the basis of age to an equal number of non-pregnant women with no signs of genital infection. The mean age was 28.7 years (range 20-41). The cut-offs used for detection of chlamydial antibody were 1:64 and 1:128 for IgG and 1:16 for IgA. IgG antibody at 64 was detected in 37.4% of pregnant women, compared to 46% of controls (p = 0.145). There was, however, a statistically significant difference between the groups for IgG at 128 (gravidae = 15.8%; controls = 28%; p = 0.014). IgA were detected in 8.6% and 16.5% of subjects, respectively (p = 0.047). IgG levels did not vary with increasing age among the pregnant women, but rose significantly with age in non-pregnant controls (logistic regression p-values = 0.011 and 0.006, for IgG at 64 and 128, respectively). IgG-positive women in the control group tended to be older than pregnant IgG-positive women (p = 0.06). These differences could not be explained by marital status, parity or use of oral contraceptives. In view of the lack of epidemiological differences, biological explanations might be invoked.

Toxoplasma gondii virulence: changing pattern under different maintenance conditions.

Toxoplasma gondii parasites were isolated in vitro and in vivo from a hare that had died of disseminated toxoplasmosis. Intraperitoneal inoculation of either homogenate of hare organs or parasites isolated on culture produced chronic infection in mice. However, a progressive increase of virulence following subsequent mouse-to-mouse transfections was observed. These findings suggest that host-parasite interaction plays a major role in determining the degree of pathogenicity, and that in vitro and in vivo isolation, if not followed by subsequent passages, may fail to reveal major differences in virulence between isolates.

Chlamydia trachomatis infection in "sine causa" recurrent abortion.

One hundred and one women suffering from "sine causa" recurrent abortion were screened for Chlamydia trachomatis (C.T.) infection by using direct examination, cultural and serological procedures. In this series, C.T. infection did not appear to be related to increased risk of recurrent abortion. The culture-positive and serology-positive rates (14.85% and 34.65%, respectively) did not differ from other unselected populations. Neither time from last abortion nor type of abortion were significantly related to C.T. infection. Nonetheless, the women who underwent examination within one year from last abortion and had a culture-positive partner as well, were more likely to present with a C.T.-positive culture.

Chlamydia trachomatis infection in primary unexplained infertility.

In recent years Chlamydia trachomatis has emerged as a significant cause of acute salpingitis and reproductory failure. In this study, 85 women suffering from primary infertility and 85 parous women as control group were screened for C. trachomatis genital infection by means of cell culture and antigen detection on genital samples as well as the detection of anti-chlamydial antibodies in blood. C. trachomatis was detected in 31.8% of infertile women and 5.8% of fertile subjects. Isolation of C. trachomatis in cell culture proved to be the most reliable diagnostic tool when compared to immunofluorescence staining on smears and serology. Although the latter may be considered of great value in epidemiological researches, culture isolation should be associated for the diagnosis of active infection.