Hepatitis B virus infection in hospital staff: epidemiology and persistence of vaccine-induced antibodies.

To establish the epidemiology of viral hepatitis B (HBV) infection in hospital staff the sera of 2462 workers and 176 professional nursing students were examined. The prevalences of HBsAg and anti-HBs among the workers were 4.5 and 42.2% and among the students were 2.3 and 15.3%, respectively. The risk of infection showed a correlation with the profession of the hospital workers, the various jobs carried out in different departments, age, and the number of working years. The anti-hepatitis vaccination with HBVax and HEVAC-B vaccines was used on 142 professional students and 996 hospital workers. Five years after the beginning of the vaccine cycle the percentage of responders observed among the students was 75 (HBVax) and 79% (HEVAC-B). Among the hospital staff the response registered was 66 and 71%, respectively. The best recorded response among the youngest subjects suggests that the anti-hepatitis vaccination should be obligatory for hospital workers at the beginning of their working period or professional training.     

The anti-idiotypic antibody to chlamydial glycolipid exoantigen (GLXA) protects mice against genital infection with a human biovar of Chlamydia trachomatis.

Despite more than three decades of anti-chlamydial vaccine research and improved vaccine strategies with new technologies, no vaccine candidate has protected against heterologous challenge, nor at more than one site of infection. The majority of experimental anti-chlamydial vaccines to date have targeted the chlamydial major outer membrane protein (MOMP). Many MOMP-directed vaccine candidates have been highly immunogenic, but have failed to protect against infectious challenge. We have extended our previous studies of a different anti-chlamydial vaccine, a monoclonal anti-idiotypic antibody (anti-Id; mAb2) which is a molecular mimic of the chlamydial glycolipid exoantigen (GLXA). The present studies demonstrate that the mAb2 vaccine is protective in a murine genital infection model utilizing a human urogenital strain. After either mucosal (oral or intranasal) or systemic (subcutaneous) immunization with the poly (lactide) encapsulated-mAb2 to GLXA, C3H/HeJ mice were significantly protected against topical vaginal challenge with Chlamydia trachomatis (K serovar; UW-31). Reduced vaginal shedding of organism and genital tract inflammation were associated with GLXA-specific and/or anti-EB neutralizing serum antibody. Our results demonstrate that the anti-Id (mAb2) vaccine is protective against an additional human biovar of C. trachomatis in C3H/HeJ mice, which are allogeneic to the source of mAb2 (BALB/c).     

Concomitant infection of HTLV-I and HIV-l: Prevalence of IgG and IgM antibodies in Washington,D.C. area

Serum samples collected from four groups of individuals in the Washington, D.C. area were examined for the presence of IgG and IgM classes of antibody reacting against HTLV-1 and HIV-1. These four groups were: (1) healthy adults with negative premarital VDRL test for syphilis (n=113), (2) miscellaneous common disease patients (n=155), (3) drug abusers (n=130), and (4) homosexual men (n=187). The former two groups are considered to be low-risk groups, and the latter two, high-risk groups. The prevalence of IgG antibody on ELISA/Western blot tests for these groups were respectively: (1) 5.3%/1.8%, (2) 5.2%/1.9%, (3) 13.9%/4.6%, and (4) 4.3%/1.6% for HTLV-1, and (1) 2.7%/0.9%, (2) 4.5%/0%, (3) 12.3%/5.4%, and (4) 8.0%/5.9% for HIV-1. Instances of possible concomitant infection as shown by the presence of antibodies against both HTLV-I and HIV-1 were found only in the latter two high-risk groups, i.e. two (1.5%) in group (3), and three (1.6%) in group (4) as confirmed by both Western blot and immunofluorescence tests. Out of 97 sera collected from drug abusers in 1985-86 which had IgG antibody by Western blot test against HIV-1, 23 (23.7%) were HTLV-I antibody positive by ELISA test (Group 5), and 8 of these were confirmed by Western blot test. Among these 8 persons, IgM antibody against HTLV-I was found in 2, while that against HIV-1 was positive in 7 persons. This fact suggests that the exposure to HIV-1 occurred more recently than that with HTLV-I in most of those persons who were dually infected. By cross-absorption studies, it was shown that the dual antibody reactivities were not due to cross-reactivity between HTLV-I and HIV-1.     

The relationship between ocular toxoplasmosis and levels of specific toxoplasma antibodies.

The relationship between ocular toxoplasmosis and levels of toxoplasma specific antibodies was examined in 195 patients. Using clinical information collected by questionnaires, patients were divided into: 97 with ocular toxoplasmosis (group 1) and 98 with ocular lesions not due to toxoplasma (group 2). The geometric mean of dye test titres (+/-S.D. natural log titre) in group 1 was 53.2 (+/-0.95) compared with 24.6 (+/-1.11) in group 2 (P < 0.001). Young females tended to have more active lesions compared with young males (P < 0.05). There was an age-dependent difference in dye test titres between the groups (P < 0.001). Group 1 showed a decline in titre with age compared with an increase in group 2. Ocular toxoplasmosis was diagnosed most frequently among 21-30 year olds. More group 1 patients had dye test titres > or = 65 iu/ml than group 2 (P < 0.05). Dye test titres > or = 65 iu/ml support a diagnosis of ocular toxoplasmosis whereas lower titres suggest other causes for eye lesions.     

IgG与IgM抗体测定在麻疹病例确诊中的作用

目的了解IgG与IgM抗体检测以及病毒分离培养的结果对麻疹病例诊断的作用。方法应用商品ELISA试剂盒检测可疑病人血清中的麻疹特异性IgG与IgM抗体;应用细胞培养法分离培养可疑病人早期咽拭子中的麻疹病毒。结果应用双份血清检测麻疹特异性IgG抗体的方法,一个暴发点的22名发热患者中11人确诊为麻疹,其中5人IgM抗体阳性、2人分离出麻疹病毒(其中1人IgM抗体阴性)。结论 IgM抗体检测对麻疹病例诊断漏诊率相当高,病毒分离培养法漏诊率更高,可靠的方法是检测双份血清中的IgG抗体。     

Serum IgG antibodies to human herpesvirus-6 (HHV-6) do not predict the progression of HIV disease to AIDS

Objectives: To evaluate if different levels of human herpesvirus 6 (HHV-6) antibodies can predict HIV disease progression. Design: Longitudinal study of individuals with a documented date of HIV seroconversion. Setting: Clinical centers located throughout Italy. Patients: Individuals who serconverted for HIV between 1983 and 1995 in Italy. Methods: Sera were tested for IgG antibodies to HHV-6 using a commercial enzyme immunoassay. A serum sample with an optical density (OD) 242 (i.e. the mean value of 10 negative controls+ 4×standard deviation) was considered as HHV-6 positive; the progression of HIV disease was evaluated estimating the relative hazards (RH) of AIDS (by Cox models) for individuals with higher levels vs. lower levels of HHV-6 antibodies or considering levels of antibodies based on 10% increase of the distribution (deciles). Rates of CD4 decline fitting linear regression were also estimated. Results: A total of 381 persons were followed for a median time of 4 years (range: 0.15–9 years) following the date of collection of the serum sample. The median OD value of HHV-6 antibodies was 306, with an interquartile range of 241–440 and a range of 48–2330. A slight inverse correlation was found between HHV-6 antibody levels and age of the individual at the time of serum collection (Spearman rank correlation coefficient, –0.16; p = 0.0013). No association was found between HHV-6 and CD4 level or between HHV-6 and CD8 level at the date of serum collection. The unadjusted RH of progression to AIDS was 0.63 (95% CI: 0.42–0.96) for HHV-6 positive individuals vs. HHV-6 negative; when adjusting for possible confounders (CD4, age, pre-AIDS HIV-related pathologies at the date of sera collection, and previous anti-herpes treatment), the RH of AIDS increased to 0.80 (95% CI: 0.51–1.23). No particular association with HIV disease progression was found when using the deciles of the distribution of HHV-6 antibodies. The median CD4 cell loss was 5.0 × 106 cells/l per month among HHV-6 positive individuals and 5.7 × 106 cells/l per month among the others. Conclusions: The presence of high levels of HHV-6 antibodies does not seem to predict the clinical or immunologic progression of HIV disease.     

高原自然地理环境对人体健康与防护措施的研究进展

青藏高原有"世界屋脊"之称,平均海拔4 000m以上,是全球最高最大的高原。随着2006年青藏铁路的正式运营,数百万游客前往西藏旅游,在增加西藏旅游业发展的同时,高原疾病的发病率也逐渐上升。本文就特殊高原地理环境对人体健康及其防护措施加以探讨。     

Antileishmanial antibodies in an outbreak of visceral leishmaniasis in eastern Sudan: high antibody responses occur in resistant subjects and are not predictive of disease

A 3-year longitudinal survey was carried out from 1998 to 2000 in a village in eastern Sudan where a visceral leishmaniasis (VL) outbreak occurred. Leishmania-specific antibodies were analysed by enzyme-linked immunosorbent assay and immunoblotting. Immunoblot analysis detected antibodies to Leishmania in 80% of the healthy subjects and half of them harboured high immunoglobulin (Ig) G antibody levels, similar to those of VL patients. These antibodies belonged to the IgG1 and IgG3 subclasses but neither their respective levels nor the immunoblot recognition patterns were predictive of VL. During this epidemic, a large proportion of subjects had a high antileishmanial antibody response, indicating that they were infected by Leishmania though most of them remained healthy during the whole study period. These results obtained in the context of an outbreak contrast with those obtained from studies performed in endemic areas characterized by lower parasite transmission levels. Furthermore, the clinical and serological follow-up of our study subjects showed that VL occurred mainly in subjects who had been serologically positive for 5-24 months rather than resulting from primo infection by the parasite.     

The epidemiology of Salmonella dublin infection in a dairy herd: I. Excretion and persistence of the organism

This paper describes the epidemiologically relevant events that took place in a dairy herd infected by Salmonella dublin. The evidence presented indicates that it may be possible to eliminate infection from the farm and that residual infection or persistent excretion are uncommon. In two animals infection persisted, in one instance in the tonsil and in the other in the gall bladder. In this latter case the infection remained from the neonatal period until adulthood. It is possible that both these animals are relevant in a more general context and are indicative of the source of infection in outbreaks in which the origin of infection cannot be determined by more routine examinations.     

The protective effect of condoms and nonoxynol-9 against HIV infection.

OBJECTIVES: Whether or not spermicides can reduce the risk of human immunodeficiency virus (HIV) transmission remains an important question for the control of heterosexual HIV transmission. The authors provide estimates from a reanalysis of one of the few observational studies on the efficacy of condoms and spermicides, used separately and together, per vaginal contact. METHODS: In this reanalysis, three different models were used to assess the efficacy of spermicides and condoms: linear (Pearl index), exponential (maximum likelihood), and monotonic (marginal likelihood). RESULTS: Reported use of barrier methods among 27,432 contacts was as follows: condoms plus nonoxynol-9, 39%; condoms alone, 25%; nonoxynol-9 alone, 24%; and unprotected, 11%. Under all three models, the results indicate a strong protective effect for spermicidal suppositories. The Pearl index indicated that spermicide alone is apparently efficacious, but the efficacy per contact cannot be quantified with this approach. Maximum likelihood estimates for the efficacy of nonoxynol-9 alone and condoms (with or without nonoxynol-9) were 100% (95% confidence interval [CI95] = 43%, 100%) and 92% (95% CI95 = 79%, 100%), respectively. CONCLUSIONS: The data from this observational study suggest that spermicides may be efficacious in reducing the risk of HIV transmission.