Frequency and diversity of molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients of a South West German teaching hospital.

We have determined the frequency and the genetic diversity of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from inpatients of a South West German teaching hospital. The frequency of primary MRSA isolates remained constant over the two-year surveillance period: 108 of the total number of 1450 S. aureus isolates (7.5%) were MRSA in 2001 and the corresponding figures were 110 MRSA out of 1412 S. aureus isolates (7.8%) in 2002. Six clusters of nosocomial MRSA infection were observed during 2001 and 2002. Cluster infections involved 65 patients on four different wards. Molecular typing of the 65 cluster isolates demonstrated that 51 (79%) belonged to a single predominant clone. The remaining 14 isolates represented seven genetically unrelated MRSA clones. Molecular typing of 50 additional non-cluster, sporadic isolates demonstrated 37 different pulsed-field gel electrophoresis (PFGE) banding patterns. Our results demonstrate that primary MRSA strains from hospitalized patients show a high degree of genetic heterogeneity. In contrast, however, MRSA isolates from nosocomial clusters were mostly derived from a single predominant clone, thus indicating a significant intra-ward and intra-hospital distribution. Molecular typing methods may lead to an improved understanding of MRSA epidemiology and thus allow the establishment of effective preventive measures.

Prevalence of antimicrobial resistance of Streptococcus pneumoniae in southwest Germany as determined by the E test.

We have studied the prevalence of anti-microbial resistance of Streptococcus pneumoniae in Southwest Germany. One hundred seventy-four clinical isolates of pneumococci collected from hospitalized patients between October 1992 and April 1994 were used for MIC determinations. MICs for penicillin, ceftriaxone, erythromycin, and rifampicin were assessed by the E test. Eleven of the 174 strains (6.3%) were intermediately resistant to penicillin (MIC between 0.1 and 1.0 microgram/ml) and four of the 174 strains (2.3%) were intermediately resistant to ceftriaxone (MIC between 0.1 and 1.0 microgram/ml). All four isolates with a reduced susceptibility to ceftriaxone also demonstrated intermediate resistance to penicillin. Six of the 174 strains (3.5%) were highly resistant (MIC > or = 8 micrograms/ml) to erythromycin. Resistance to rifampicin was not observed. Our results demonstrate that pneumococcal resistance to penicillin and erythromycin has increased markedly in Germany over the last decade. Our findings underline the need for continuous surveillance of antimicrobial resistance of Streptococcus pneumoniae.

[Prevalence of hepatitis A virus antibodies in hospital personnel]. / Prävalenz von Hepatitis-A-Virus-Antikörpern bei Krankenhauspersonal.

We screened 351 employees of a county hospital for the presence of antibodies against hepatitis A virus (anti-HAV). Hospital staff tested was from the department of paediatrics, infectious diseases unit, institute of microbiology, hospital kitchen, and the day-care centre. 292 donors from the hospital blood bank served as a control group. The prevalence of anti-HAV in indigenous hospital staff less than 30 years of age was extremely low, but showed an age-dependent increase to 69 per cent in personnel more than 50 years of age. The anti-HAV prevalence rate of indigenous health-care workers did not show significant differences from that of volunteer blood donors. The high prevalence of anti-HAV in non-indigenous employees with almost total exposure in persons more than 40 years of age most probably reflects the high risk of childhood infection in endemic regions. We conclude that the risk of occupational exposure to HAV in the hospital setting appears to be small. Active immune prophylaxis with hepatitis A vaccine should be restricted to employees with frequent contact with HAV-contaminated faeces. Pre-vaccination screening for anti-HAV is cost effective in indigenous hospital staff more than 30 years of age and in all non-indigenous employees.

[Prevalence of hepatitis C virus antibodies in hospital personnel and the general population]. / Durchseuchung mit Hepatitis C-Virus-Antikörpern bei Krankenhauspersonal und Allgemeinbevölkerung.

The recent cloning of the genome of a parenterally transmitted non-A, non-B hepatitis virus, designated the hepatitis C virus (HCV), has been used for the development of an enzyme immunoassay for the detection of antibodies against HCV (anti-HCV). We have employed this assay to evaluate the prevalence of HCV antibodies in hospital personnel and voluntary blood donors. Twelve of 1018 sera (1.2 percent) from health care workers were repeatedly reactive in the enzyme immunoassay for anti-HCV. Specificity testing with a modification of the enzyme immunoassay (additional wash cycle with 8 mol/l urea) and a recombinant immunoblot assay demonstrated HCV antibodies in only 6 of the 12 sera. Thus, the true prevalence of anti-HCV in hospital personnel was 0.6 percent. Nine of 1046 sera (0.9 percent) from blood donors were reactive in the enzyme immunoassay for anti-HCV. In none of the 9 sera the presence of HCV antibodies could be confirmed by additional testing with the urea wash modification or the recombinant immunoblot assay. The true prevalence of anti-HCV in blood donors thus appears to be lower than 0.1 percent. Our results indicate that the risk of HCV transmission in the hospital setting appears to be low, but is significantly higher than that of the general population.

Prevalence of hepatitis C virus antibodies in hospital personnel.

We have used a recently developed enzyme immunoassay to evaluate the prevalence of hepatitis C virus antibodies (anti-HCV) in patient groups and hospital personnel. The prevalence of anti-HCV in haemophiliacs, intravenous drug users, male homosexuals, and haemodialysis patients was 86, 63, 28, and 9 percent, respectively. Eight of 738 (1.1 percent) sera from health care workers were positive for anti-HCV. Only two of the 8 employees which were seropositive for anti-HCV also demonstrated serological markers of a previous infection with hepatitis B virus. The reported seroepidemiological data may not correctly reflect the risk of HCV transmission in the hospital setting, since the currently available assay shows a high sensitivity only for the detection of persistent HCV infections. There is an urgent need for the development of HCV antibody assays with increased sensitivity.

[Detection of antibodies to Helicobacter pylori with the immunoenzyme test and indirect immunofluorescence]. / Nachweis von Antikörpern gegen Helicobacter pylori mit Enzymimmuntest und indirekter Immunfluoreszenz.

Sera from 56 adult patients were screened for the presence of IgG antibodies against Helicobacter pylori by enzyme immunoassay and indirect immunofluorescence. In addition, the detection of Helicobacter pylori in antral biopsy specimens was attempted by culture and histological methods. Colonisation of the antrum mucosa with Helicobacter pylori was observed in 39 of the 56 patients. IgG antibodies against Helicobacter pylori were detected by enzyme immunoassay in 34 of 39 infected patients. Thus, the enzyme immunoassay showed a sensitivity of 87.2 percent and a specificity of 82.4 percent. IgG antibodies against Helicobacter pylori were further detected by indirect immunofluorescence in 28 of 39 infected patients. Thus, indirect immunofluorescence showed a sensitivity of 66.7 percent and a specificity of 88.2 percent. Our results demonstrate that the enzyme immunoassay for IgG antibodies and other invasive or noninvasive methods for the detection of infection with Helicobacter pylori appear to be of equal sensitivity and specificity.

Interferon alpha in hepatitis type B and non-A, non-B. Defective production by peripheral blood mononuclear cells in chronic infection and development of serum interferon in acute disease.

The production in vitro of interferon alpha and gamma by peripheral blood mononuclear cells of 25 patients with chronic hepatitis B and 13 patients with chronic hepatitis non-A, non-B was compared to that of healthy controls. Following induction by Molt 4 leukemia cells (P less than 0.001) and influenza A/X31 virus (P less than 0.01), there was a significantly lower interferon alpha response in patients with chronic hepatitis B and chronic hepatitis non-A, non-B. Yields of interferon gamma in patients with chronic hepatitis were comparable to those of normal individuals. The degree of interferon deficiency did not correlate with severity of liver disease. In patients with chronic hepatitis B, viral replication (presence or absence of HBeAg) was not related to the defect in interferon alpha production. Three of 10 patients with acute hepatitis B had measurable antiviral activity in the serum for 3-5 days after the onset of jaundice.

HIV antigen, HIV antibody and serum interferon in a patient with encephalopathy.

Acute encephalopathy was associated with the presence of human immunodeficiency virus type I (HIV I) antigen and seroconversion to anti-HIV I in a 27-year-old homosexual man. Examination of consecutive sera from the patient revealed circulating interferon (IFN) alpha which became detectable with the appearance of HIV I antigen but before development of anti-HIV I. Serum IFN was present for only a limited time and was not demonstrable after neurological symptoms resolved. It may be speculated that circulating antiviral activity contributed to the clinical manifestations of acute HIV I infection.

Determination of antibodies against LAV/HTLV III: comparative evaluation of four different commercial test kits.

Four different, commercially available ELISA tests for the detection of antibodies against LAV/HTLV III were evaluated for specificity and sensitivity. The relative specificity of the kits was determined by investigating a test panel of 76 sera collected from asymptomatic or symptomatic homosexual men. Completely concordant results were obtained for sera from asymptomatic male homosexuals (11% positive for Anti-LAV/HTLV III) or from patients with the AIDS-related complex (91% positive for Anti-LAV/HTLV III). Differences between the ELISA test kits, however, were observed with sera obtained from patients with AIDS. While Anti-LAV/HTLV III was detected by the Abbott, Electro-Nucleonics, and Organon test in all 17 sera from AIDS patients, the Pasteur test failed to detect Anti-LAV/HTLV III in 7 consecutive sera from an individual patient with late-stage AIDS. The relative sensitivity of the ELISA tests was determined by endpoint titration of confirmed Anti-LAV/HTLV III positive sera from donors of different risk groups for AIDS. The titration experiments demonstrated that the Abbott test clearly was the most sensitive of the ELISA tests studied, followed by the Electro-Nucleonics, Pasteur, and Organon test. The results further indicate that most of the differences of specificity and sensitivity observed between the Anti-LAV/HTLV III tests could be abolished by a modified definition of minimum positive absorbance values.

Evaluation of a new confirmatory assay for antibodies against lymphadenopathy-associated virus (LAV)/human T-lymphotropic virus type III (HTLV III).

We have evaluated a newly developed competitive enzyme immunoassay for the specific detection of antibodies against LAV/HTLV III envelope and core proteins. Comparative studies of sera from high-risk donors showed complete concordance between the results of the confirmatory enzyme immunoassay and immunoblot or indirect immunofluorescence techniques. Studies of sera from blood donors with a repeatedly reactive screening test for anti-LAV/HTLV III demonstrated two specimens which were positive by the confirmatory enzyme immunoassay and negative or indeterminable by immunoblotting and immunofluorescence.

Changing biclonal gammopathy due to different lymphocyte clones in acquired immunodeficiency syndrome with Kaposi's sarcoma.

We report the first case of acquired immunodeficiency-syndrome (AIDS) with Kaposi's sarcoma which at the same time has also a changing biclonal gammopathy (initial: double IgG-paraproteinaemia, later on IgA-IgG double-paraproteinaemia) due to different lymphocyte clones. The relationship of a B-cell neoplasia to a concurrent disease of T-cells is discussed.

Treatment of HBsAg-,HBeAg-positive chronic active hepatitis with adenine arabinoside. A case report with clinical remission and seroconversion to anti-HBs.

A 26-year-old patient developed HBsAg-, HBeAg-positive chronic active hepatitis arising from an acute infection 6 months earlier. Treatment with adenine arabinoside (Ara-A), 15 mg/kg/day administered as overnight infusions for three weeks, resulted in clinical and complete biochemical remission with normalisation of aminotransferases, loss of HBsAg, HBeAg and DNA polymerase, and appearance of Anti-HBs during follow-up for 9 months. Treatment of chronic hepatitis B infection using Ara-A for several weeks may be especially effective when initiated early in the course of the disease.

Production of interferon alpha and interferon gamma by peripheral blood leukocytes from patients with chronic hepatitis B virus infection.

Peripheral blood leukocytes from patients with chronic hepatitis B virus (HBV) infection were studied for their capacity to produce interferon (IFN) alpha or IFN gamma. Yields of IFN alpha in leukocyte cultures stimulated with influenza A virus or human leukemic cells were significantly lower than those obtained from healthy controls. Production of IFN gamma in response to induction with protein A of Staphylococcus aureus was also significantly diminished. Defects of IFN production in leukocyte cultures showed no correlation with active viral replication or the degree of severity of HBV-associated liver disease. The demonstration of partial defects of endogenous IFN production provides a rationale for using IFN replacement therapy in patients with chronic HBV infection.

[Prevention and therapy of herpesvirus infections]. / Prophylaxe und Therapie von Herpesinfektionen.

The group of the human-pathogenic herpesviruses comprises five subgroups: Herpes simplex virus type 1 (HSV-1), Herpes simplex virus type 2 (HSV-2), varicella zoster virus (VZV), cytomegalovirus (CMV), and Epstein-Barr virus (EBV). Primary infection with these ubiquitous herpesviruses usually occurs in childhood or during adolescence and frequently remains inapparent. However, it can also give rise to a variety of clinical pictures. Important clinical manifestations of herpesvirus infections are mucocutaneous lesions (HSV-1, HSV-2, VZV) self-limited, lymphoproliferative diseases (CMV, EBV) and congenital malformations (CMV). Primary infection with herpesviruses leads to a persistent infection of the host. This clinically silent condition of latency can be interrupted and may cause pathological symptoms to recur by reactivation of latent herpesviruses. A classical example of the clinical manifestation of herpesvirus reactivation is herpes zoster following an overcome varicella disease. The mechanism of herpesvirus reactivation has not yet been fully clarified. Reactivation of herpesviruses might be attributable to a weakening of the cellular immunodefence. For the control of viral infections mainly two cellular effector systems are responsible: unspecific, cytotoxic, natural killer (NK) cells and specific cytotoxic thymus-dependent (T) lymphocytes. The functional impairment of these cytotoxic active cells my cause herpesvirus reactivation in immunodeficient or immunosuppressed persons. Interference with the immunological control function may also contribute to the genesis of herpesvirus-associated tumours. Such an association between herpesviruses and human tumours is assumed to exist especially in the case of EBV. The frequently life-endangering severity of local or disseminated herpesvirus infections calls for suitable measures ensuring efficient prophylaxis and therapy. However, the possibilities of a specific immunoprophylaxis (vaccine, special immunoglobulins) against herpesvirus infections are still rather limited. The development of antiviral substances has greatly benefited from the introduction of new agents (Acyclovir) and the production of sufficient quantities of interferon (IFN) preparations during the last few years. Impressive results were obtained with the nucleoside-related substance Acyclovir in the prevention and therapy of primary or reactivated HSV-1 or HSV-2 infections. The use of Acyclovir as prophylactic agent produced the effect that recipients of bone-marrow transplants were no longer afflicted by HSV-1 infections.(ABSTRACT TRUNCATED AT 400 WORDS)