Chlamydia pneumoniae IgA seropositivity and sudden sensorineural hearing loss.

A prospective study was designed to evaluate a possible role of an endured infection with Chlamydia pneumoniae or Chlamydia trachomatis as a cause for sudden sensorineural hearing loss. For this in 60 patients with a first episode of a sensorineural hearing loss and-60 sex-matched and aged-matched controls, following a complete otoneurological diagnosis blood tests for IgA, IgM and IgG with regard to Chlamydia pneumoniae and trachomatis were evaluated. We found a statistically significant higher prevalence of IgA positivity of Chlamydia pneumoniae in patients with sudden sensorineural hearing loss (chi2-test, p < 0.017). For this, Chlamydia pneumoniae may be a possible cause for sudden sensorineural hearing loss. A targeted antibiotic therapy, as it has been discussed for myocardial infarction, might possibly open an additional treatment option for sudden sensorineural hearing loss.

[Q Fever in pregnancy: a case report and review of the literature]. / Q-Fieber in der Schwangerschaft: Therapie und Handling des Krankheitsbildes anhand eines Fallberichtes.

Endemic occurrence of Q fever among persons in close contact with domestic animals is well known in some rural regions of Germany. The prevalence of antibodies indicating acute Q fever in pregnancy reported in the literature varies between 0.2 % and 4.7 % of the screened population. Q fever in pregnancy initially manifests as placentitis and often leads to premature birth (30 %), growth restriction (46 %), spontaneous abortion (22 %) or fetal death in utero (7 %). Some impairment of pregnancy is observed in over 70 % of cases with seroconversion during pregnancy. Thus Q fever serology should be tested in all pregnant women presenting with atypical pneumonia and/or prolonged fever of unknown etiology. It is of interest that medical staff members in contact with Cociella burnetii infected pregnant women are also at risk of acquiring an acute Q fever infection. We report about a patient presenting with confirmed acute and later chronic Q fever during pregnancy in whom antibiotic treatment with rifampicin and clarithromycin proved to be effective and led to the vaginal delivery of a premature but healthy infant. We believe that maternal serum screening for transmissible infections should also include Q fever serology in certain rural regions.

Hemorrhagic fever with renal syndrome: diagnostic problems with a known disease.

Hemorrhagic fever with renal syndrome (HFRS), caused by different hantaviruses, is a distinct clinical syndrome endemic in several parts of Asia and Europe. However, the clinical picture can sometimes be indistinguishable from that of other infectious or noninfectious diseases. In this report we describe a clinical case, which is a rare occurrence but is a prime example of the difficulties in the diagnosis of HFRS in areas with a low prevalence of the disease.

Ebola and Marburg virus antibody prevalence in selected populations of the Central African Republic.

With the natural history of the filovirus family seemingly unknown, filovirus ecology in its natural environment remains a rudimentary field of research. In order to investigate the maintenance cycle of filovirus in Central Africa, a study was conducted within the rain forest of the Central African Republic. The epidemiological study determines the frequency and distribution of filovirus seroprevalence in a selected human population. Using an ELISA, serum samples from Pygmy and non-Pygmy populations were tested for Ebola-Zaire virus and Marburg (MBG) virus antibody. Filovirus antibody reacting sera were found in all zones investigated, and in all populations studied (Ebola virus IgG 5.3%; Marburg virus IgG 2.4%). Pygmies appeared to have a significantly higher seroprevalence (P < 0.03) against Ebola-Zaire virus (7.02%) than non-Pygmies (4.2%). MBG virus or related unknown filovirus strains also seem to be present in the western part of Central Africa. MBG virus antibodies were present in different Pygmy groups (ranging from 0.7 to 5.6%, mean 2.05%) and in several non-Pygmy populations (ranging from 0.0 to 3.9%, mean 3.4%) without an overall significant difference between the two groups (P = 0.14). The potentialities of nonpathogenic filovirus strains circulating in the Central African Republic are discussed.

[Early summer meningoencephalitis. Extension of the endemic area to mid-Hessia]. / Frühsommermeningoenzephalitis (FSME). Ausbreitung des Endemiegebietes nach Mittelhessen.

Tick-borne encephalitis (TBE) is the most severe arbovirus disease transmitted by ticks. The mortality of the central European form is 0.7-2%. Active immunisation is recommended for endemic regions. We report on 4 patients with TBE acquired in Middle-Hessen between 1994 and 1997 (2 in 1997). After repeated CSF and serum testing the TBE-specific antibodies were found in all 4 cases. In one case there was also evidence for a prior infection with borrelia burgdorferi. The results of the initial CSF-analysis were atypical in 2 cases (high cell count of 136 cells/mm3, total protein up to 1.5 g/l). The endemic region for TBE has expanded in northern direction into Middle-Hessen, a region in which Lyme borreliosis is also endemic. Thus, true double infections are possible. This and the initially frequently atypical CSF-findings make the differential diagnosis difficult. Therefore, repetitive CSF and blood examinations are recommended.

Release of viral glycoproteins during Ebola virus infection.

Maturation and release of the Ebola virus glycoprotein GP were studied in cells infected with either Ebola or recombinant vaccinia viruses. Significant amounts of GP were found in the culture medium in nonvirion forms. The major form represented the large subunit GP1 that was shed after release of its disulfide linkage to the smaller transmembrane subunit GP2. The minor form were intact GP1,2 complexes incorporated into virosomes. Vector-expressed GP formed spikes morphologically indistinguishable from spikes on virus particles, indicating that spike assembly is independent of other viral proteins. Analysis of a truncation mutant revealed an early and almost complete release of GP1,2 molecules, showing that membrane anchoring is mediated by the carboxy-terminal hydrophobic domain of GP2. We have also compared wild-type virus which requires transcriptional editing for synthesis of full-length GP with a variant that does not depend on editing. Both viruses released comparable amounts of GP1, but the variant expressed only minute amounts of the small, soluble GP which is the expression product of nonedited mRNA species of the GP gene. The abundant shedding of soluble GP1 may play an important role in the immunopathology of Ebola hemorrhagic fever in experimentally and naturally infected hosts.

Parainfluenza-3-virus infection enhances allergic sensitization in the guinea-pig.

BACKGROUND: Viral respiratory tract infections have been previously considered to be associated with induction of allergic sensitization. OBJECTIVE AND METHODS: In order to investigate this relationship in an animal model, guinea-pigs were inoculated intranasally with Parainfluenza-3-(PI-3) virus (n = 16) or virus-free culture medium (controls, n = 12), sensitized at day 4 with inhaled ovalbumin (OA) and challenged 3 weeks later with inhaled OA using specific bronchial provocation testing with body plethysmographic measurement of compressed air (CA). Furthermore, specific anti-OA-IgG1-antibodies in serum before challenge were determined by enzyme linked immunosorbent assay (ELISA). For investigation of airway epithelium permeability horseradish peroxidase (HRP) was inhaled at day 4 after inoculation by six animals, and HRP serum concentrations were determined by a direct ELISA 30 min after inhalation. RESULTS: PI-3 infected animals were found to be significantly more sensitized to OA compared with controls, with higher CA values (P < 0.001) on specific bronchial provocation and with increased specific anti-OA-IgG1 titers. Serum-HRP concentrations were about 20 times higher in the infected animals compared with controls. PI-3 infected and sham-infected animals had comparable bronchial reactions on specific provocation with OA when sensitized systemically. CONCLUSIONS: We conclude that viral respiratory tract infection with PI-3 virus enhances inhalative allergic sensitization in the guinea-pig. Increased mucosal permeability to antigens may be an important pathophysiological mechanism.

Emerging and reemerging of filoviruses.

Filoviruses are causative agents of a hemorrhagic fever in man with mortalities ranging from 22 to 88%. They are enveloped, nonsegmented negative-stranded RNA viruses and are separated into two types, Marburg and Ebola, which can be serologically, biochemically and genetically distinguished. In general, there is little genetic variability among viruses belonging to the Marburg type. The Ebola type, however, is subdivided into at least three distinct subtypes. Marburg virus was first isolated during an outbreak in Europe in 1967. Ebola virus emerged in 1976 as the causative agent of two simultaneous outbreaks in southern Sudan and northern Zaire. The reemergence of Ebola, subtype Zaire, in Kikwit 1995 caused a worldwide sensation, since it struck after a sensibilization on the danger of Ebola virus disease. Person-to-person transmission by intimate contact is the main route of infection, but transmission by droplets and small aerosols among infected individuals is discussed. The natural reservoir for filoviruses remains a mystery. Filoviruses are prime examples for emerging pathogens. Factors that may be involved in emergence are international commerce and travel, limited experience in diagnosis and case management, import of nonhuman primates, and the potential of filoviruses for rapid evolution.

Marburg virus gene 4 encodes the virion membrane protein, a type I transmembrane glycoprotein.

Gene 4 of Marburg virus, strain Musoke, was subjected to nucleotide sequence analysis. It is 2,844 nucleotides long and extends from genome position 5821 to position 8665 (EMBL Data Library, emnew: MVREPCYC [accession no. Z12132]). The gene is flanked by transcriptional signal sequences (start signal, 3'-UACUUCUUGUAAUU-5'; termination signal, 3'-UAAUUCUUUUU-5') which are conserved in all Marburg virus genes. The major open reading frame encodes a polypeptide of 681 amino acids (M(r), 74,797). After in vitro transcription and translation, as well as expression in Escherichia coli, this protein was identified by its immunoreactivity with specific antisera as the unglycosylated form of the viral membrane glycoprotein (GP). The GP is characterized by the following four different domains: (i) a hydrophobic signal peptide at the amino terminus (1 to 18), (ii) a predominantly hydrophilic external domain (19 to 643), (iii) a hydrophobic transmembrane anchor (644 to 673), and (iv) a small hydrophilic cytoplasmic tail at the carboxy terminus (674 to 681). Amino acid analysis indicated that the signal peptide is removed from the mature GP. The GP therefore has the structural features of a type I transmembrane glycoprotein. The external domain of the protein has 19 N-glycosylation sites and several clusters of hydroxyamino acids and proline residues that are likely to be the attachment sites for about 30 O-glycosidic carbohydrate chains. The region extending from positions 585 to 610 shows significant homology to a domain observed in the envelope proteins of several retroviruses and Ebola virus that has been suspected to be responsible for immunosuppressive properties of these viruses. A second open reading frame of gene 4 has the coding capacity for an unidentified polypeptide 112 amino acids long.

Evidence for occurrence of filovirus antibodies in humans and imported monkeys: do subclinical filovirus infections occur worldwide?

In the present serological study 120 monkey sera from different species originating from the Philippines, China, Uganda and undetermined sources and several groups of human sera comprising a total of 1288 specimens from people living in Germany were examined for the presence of antibodies directed against filoviruses (Marburg virus, strain Musoke/Ebola virus, subtype Zaire, strain Mayinga/Reston virus). Sera were screened using a filovirus-specific enzyme-linked immunosorbent assay (ELISA). ELISA-positive sera were then confirmed by the indirect immunofluorescence technique, Western blot technique, and a blocking assay, and declared positive when at least one confirmation test was reactive. Altogether 43.3% of the monkey sera and 6.9% of the human sera reacted positively with at least one of the three different filovirus antigens. The blocking assays show that antibodies, detected in the sera, are directed to specific filovirus antigens and not caused by antigenic cross-reactivity with hitherto unknown agents. Data presented in this report suggest that subclinical filovirus infections may also occur in humans and in subhuman primates. They further suggest that filoviruses are not restricted to the African continent.

Glycosylation and oligomerization of the spike protein of Marburg virus.

The oligosaccharide side chains of the glycoprotein of Marburg virus (MW 170,000) have been analyzed by determining their sensitivity to enzymatic degradation and their reactivity with lectins. It was found that they consist of N- and O-glycans. Studies employing chemical cross-linking showed that the glycoprotein is present as a homotrimer in the viral envelope.

Generation in vitro of alloreactive lymphocytes is suppressed by the addition of spleen cells from mice infected with lymphocytic choriomeningitis virus.

The generation of cytotoxic T cells to alloantigens in mixed lymphocyte culture was suppressed by the addition of spleen cells from adult mice acutely infected with lymphocytic choriomeningitis virus. T cells of surface phenotype Lyt 1+2+ were required for the suppression. Suppressive cells appeared also in lymph nodes, but not in the thymus. In the spleen their number was maximal 6 to 8 days after infection. Infectious virus could not be detected in the suppressive spleen cells. Therefore the virus itself does not seem to cause the effect.

Occurrence of dysplastic epithelium in the murine vagina after transfer of cell-free extracts from carcinoma in situ of the human cervix uteri.

Cell-free extracts were prepared from tissue specimens of intraepithelial carcinoma of the cervix uteri of human patients and subsequently injected into newborn and juvenile mice of NMRI strain via several routes. Cytological controls of vaginal epithelium were carried out in periods of 8--12 wk. Groups of mice were killed at varying intervals for histological examination. After a latency of 4-8 mth dysplastic changes of the vaginal epithelium were found in 67.6% (48 out of 71) of the mice and were graded as hyperplasia, mild and severe dysplasia and carcinoma in situ. Antibody against herpes virus hominis was not detected in the sera of these mice. Only 1 out of 120 control mice had mild dysplasia 16 mth after inoculation of an extract from noninfected human embryo kidney cells. In 9 out of 10 human cases of histologically confirmed cervical carcinoma in situ, injection of extracts into mice was followed by the appearance of dysplastic epithelium in the murine vagina. In the one case in which no positive response was obtained, the observation time had been less than 6 mth.

Rapid purification of lymphocytic choriomeningitis virus by density gradient centrifugation in colloidal silica.

Lymphocytic choriomeningitis virus was purified from cell culture fluid by density gradient centrifugation in colloidal silica. The specific infectivity increased 5000-fold and the recovery of infectivity was about 10%.

Early detection of antigen and estimation of virus yield in specimens from patients with Marburg virus disease.

Autopsy specimens from patients with Marburg disease having at least 10(4.5) TCID(50) of virus per gram of tissue were found to contain sufficient fluorescent antigen-positive cells to make a specific diagnosis possible in less than 3 h. Liver, heart, spleen, and kidney tissues were found to contain significant amounts of virus. Tissue suspensions, as well as blood or serum samples, inoculated into Vero cell cultures produced virus-specific immunofluorescence within 2-5 days. At least one specimen of all virus-positive persons yielded Marburg virus-specific antigen on day 2 or 3 after inoculation. Furthermore, tissues with at least 10(5.5) TCID(50) of virus/g had Marburg antigen of sufficient titre to be used in complement fixation tests.