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Biomedical subjects

H J Gerth

Publications and source records attributed to H J Gerth.

At least 19 recordsLinked to original sources
PubMed1995

Roe deer as sentinels for endemicity of tick-borne encephalitis virus.

The suitability of serological surveys of roe deer (Capreolus capreolus) in determining the spread of tick-borne encephalitis virus (TBEV) was tested in a south German area with a low risk of TBEV infection to humans. Sera obtained from 192 hunted roe were screened by an haemagglutination-inhibition test (HAI) and in an ELISA developed in our laboratory. Those found positive were tested in a neutralization test (NT). Fifty (26.0%) sera reacted positive by ELISA and 43 (86.0%) of these were confirmed by HAI or NT. Forty-seven (24.5%) samples were positive by HAI, 44 (93.6%) of which were also positive in NT or ELISA. Only insignificant increase of the antibody prevalence with age (P = 0.17 for HAI antibodies) suggests that most infections occur at an early age in scattered natural foci. The antibody prevalence in females was lower than in males (OR = 0.63; P = 0.02 for HAI antibodies). In determining the distribution of seropositive roe we increased the sample size to 235 sera. No antibodies were detected in 56 (23.8%) sera collected in the eastern third of the county. The areas of high antibody prevalence in roe match those in which humans have been infected. We conclude that serosurveys of roe deer are useful in marking out areas in which humans face the risk of infection, provided that an adequate number of sera, preferably from males, is available.

Age Distribution↗
PubMed1995

[Poliomyelitis].

The epidemiology of poliomyelitis, the poliovaccines and the present state of the WHO campaign for world-wide eradication of the polioviruses until the year 2000 are reviewed. In a second part, the recommendations of the "Ständige Impfkommission (STIKO, immunization task force)" from 1994 for Germany concerning poliovaccination are discussed. In contrast to the industrialized countries, the oral vaccination of infants in protection rates. After changes in vaccination strategy including mass vaccination days, the eradication campaign has succeeded in a considerable number of developing nations. However, because of limited financial resources and organizational difficulties the year 2000 goal for global eradication of polioviruses will hardly be met. The vaccination strategy of the STIKO continues to rely essentially on the trivalent oral poliovirus vaccine. The enhanced-potency inactivated polio vaccine is recommended for immunodeficient and all HIV-positive vaccinees as well as vaccinees with immunodeficient or HIV-positive contacts. Combined use of oral live vaccine and inactivated poliovirus vaccine induces an excellent local and systemic immunity. A combined vaccination strategy should be of particular interest in situations where other strategies fail.

Adult↗
PubMed1993

Disseminated BK type polyomavirus infection in an AIDS patient associated with central nervous system disease.

A 27-year-old man with hemophilia type A and acquired immunodeficiency syndrome developed a subacute meningoencephalitis, associated with a normotensive internal hydrocephalus, 14 weeks before his death. From cerebrospinal fluid and brain autopsy material, a virus could be isolated and was classified by Southern blot analysis and restriction endonuclease reactions as the human polyomavirus BK. The postmortem findings of polyomavirus antigen and BK virus DNA in various cell types of the kidneys, lungs, and central nervous system strongly suggest that BK virus was the causative agent of a tubulointerstitial nephropathy, an interstitial desquamative pneumonitis, and a subacute meningoencephalitis with accentuation of the ventricular and meningeal surfaces of the brain. Besides distinctive cytopathic effects, the presence of intranuclear inclusions was a prominent histopathological feature. Therefore, the human polyomavirus BK should be regarded as a new candidate on the still growing list of opportunistic pathogens in acquired immunodeficiency syndrome.

AIDS-Related Opportunistic Infections↗
PubMed1992

Direct detection of influenza virus antigen in nasopharyngeal specimens by direct enzyme immunoassay in comparison with quantitating virus shedding.

We developed a direct enzyme immunoassay [EIA; Enzygnost Influenza A(Ag) and Enzygnost Influenza B(Ag)] for the direct detection of influenza A and B virus antigens in nasopharyngeal secretion specimens (NPS). The test is performed without sonification of specimens, and results are obtained within 4 h. A direct comparison between direct EIA and quantitation of virus shedding for influenza A and B virus antigen detection was carried out. A total of 210 NPS and 98 nasopharyngeal wash specimens (NPW) were investigated. We isolated influenza A viruses from 79 (37.6%) of 210 NPS; of these 79 cell-culture-positive NPS, 70 (88.6%) were also positive by direct EIA. Of 29 (13.8%) NPS from which influenza B virus was isolated, 24 (82.8%) NPS were positive by direct EIA. Virus shedding was determined quantitatively in 48 NPS from patients with influenza A and in 24 NPS from patients with influenza B. Only a crude correlation between optical density values and virus concentrations was observed. Detection of influenza virus antigens in NPS by direct EIA showed sensitivities of 89.7% for influenza A virus and 87.9% for influenza B virus and specificities of 99.3% for influenza A virus and 100% for influenza B virus. With direct EIA, all NPW were negative for influenza A virus, although virus was isolated from 21 (21.4%) NPW. Of 15 NPW from which influenza B virus was isolated, 7 showed positive results in direct EIA. In addition, direct EIA is suitable for detecting influenza A and B viruses in cell cultures before the appearance of any cytopathic effects and can be used as a cell culture confirmation test.

Antigens, Viral↗
PubMed1991

[Rapid diagnosis of influenza virus infections from nasopharyngeal secretions].

Since virus isolation consumes a lot of work and time, and virus specific antibodies are not detectable before several days after the onset of illness we developed an enzyme immunoassay (ELISA) for the detection of influenza A and influenza B virus antigen in nasopharyngeal specimens (NPS). This test permits antigen detection within four hours. This ELISA was tested with 119 NPS from children, most of these between 1-12 years old. Virus isolation in MDCK-cells served as control. A total of 67 influenza A/H3N2-, 10 influenza A/H1N1, and 2 influenza B viruses were isolated from cell cultures. 68 (88.3%) of the NPS reacted positive in influenza A virus antigen ELISA, 2 in influenza B virus antigen ELISA, and 9 reacted falsely-negative. The failure to detect antigen could not be solely due to low antigen concentration in the NPS because in 5 materials high concentrations of infectious virus were shown in cell culture. The test allows the rapid diagnosis of influenza virus infections with high efficacy also for laboratories without the facility to perform tissue culture. For accelerating the diagnosis by isolation of viruses in cell cultures, ELISA is useful as cell culture confirmation test, because influenza virus antigen is detectable before a cytopathogenic effect appears.

Adolescent↗
PubMed1988

[Prospective one-year epidemiologic longitudinal study of air pollutants and the incidence of croup].

Among a population of 18,175 children below 7 years of age in medium sized towns and rural areas in south-western Germany 552 (3.03%) cases of croup were registered during a 12 months period in 1984-85 by their physicians. Distributions according to months, sex and age at the onset of the disease were the same as in other recent investigations: The level of the air-pollution measured (SO2, NOx, CO, CO2, ozone and dust) was low (highest monthly means in microgram/m3: SO2 88, NO2 73, NO 119, dust 41). There was no relevant influence of the degree of air pollution on croup-frequency. The rise of croup-frequency shortly after a period of several days of higher pollution was accompanied by an influenza epidemic as proved by virus isolations.

Air Pollutants↗
PubMed1987

Subtype-specific identification of influenza virus in cell cultures with FITC labelled egg yolk antibodies.

We report on results obtained with a direct immunofluorescence test for subtype-specific identification of influenza virus in detached cells of MDCK cultures after inoculation of 281 clinical specimens from patients with influenza-like disease. Influenza virus antibodies were produced in eggs from immunized hens and labelled with FITC. In 157 cases CPE was found in MDCK cells. A total of 57 cases of influenza A (H3N2), 86 cases of influenza A (H1N1), and 14 cases of influenza B were identified. In 33 cases of influenza A (H1N1) infection with massive CPE guinea pig but not chicken erythrocytes were agglutinated by the cell culture supernatants. The single step immunofluorescence test described proved easy to perform and results were obtained within 1 h after CPE was observed in contrast to the conventional HIT which is very time-consuming.

Animals↗
PubMed1987

Infectiousness for humans of Ixodes ricinus containing Borrelia burgdorferi.

We studied the rate of transmission of Borrelia burgdorferi from ticks (Ixodes ricinus) to man under field conditions in a case control study. At a holiday camp in southern Germany 384 ticks were removed from 272 persons. Information on symptoms possibly related to Borrelia infection were obtained by a questionnaire to be sent back six weeks after the tick bite. Ticks were examined by immunofluorescence microscopy (IFT) for Borrelia and 49 (12.8%) were found positive. Blood was obtained from 41 persons bitten by Borrelia positive and 41 age and sex matched persons bitten by Borrelia negative ticks. Sera from age and sex matched patients of local hospitals and clinics served as additional controls. Antibody titers were obtained by indirect IFT about 13 weeks after tick bite. Titers 1 : greater than 32 suggested recent infection and 1 : 32 immunity. In the exposed group there were about half as many persons with titers 1 : less than 32 (n = 14) than in the control group (n = 27) suggesting that either part of the infected ticks was in a non-infectious state or the hosts were immune. In the exposed group there were 46.4% (n = 19) and in the control group, bitten by Borrelia negative ticks, 14.7% (n = 6) persons with titers 1 : greater than 32, but 5/6 of these persons in the control group recalled additional tick bites in 1984. Only one child (in the exposed group) developed an Erythema chronicum migrans, and no other Borrelia related manifestations were reported. The manifestation rate of the Borrelia-related disease was 4%.

Adolescent↗
PubMed1987

Common respiratory and gastrointestinal illness in paediatric student nurses and medical technology students.

The aim of this study was to establish the risk of acquiring common respiratory and gastrointestinal illness for paediatric nurses. Using self-administered questionnaires, student nurses at two children's hospitals and students at one school of medical technology reported biweekly the number of minor illnesses, symptoms, and indicators of severity of infection over a 3-year period (1975-8). Although a systematic bias was evident with some symptoms, others appeared to be quite reliable. The following four syndromes were defined to estimate the risk: upper respiratory syndrome (URS), lower respiratory syndrome (LRS), respiratory and gastrointestinal syndrome (RGS), and gastrointestinal syndrome (GS). Surveillance days were allocated to groups with high- or low-intensity contact with children. The incidence of all illnesses was 2.9 per person-year in the low-intensity contact group and 4.4 per person-year in the high-intensity contact group. The reported incidence of LRS and RGS in the high-intensity contact group was 1.55 times higher than in the low-intensity group (P less than 0.001). LRS and RGS incidence was similar in nurses at both schools. During low contact periods it corresponded to that of the medical technologists.

Adolescent↗
PubMed1987

Seroepidemiological studies on the occurrence of common respiratory infections in paediatric student nurses and medical technology students.

The occupational risk of acquiring minor respiratory infections for paediatric student nurses was estimated by performing serological examinations with influenza A, B, C, parainfluenza, mumps, respiratory syncytial virus, adenovirus and Mycoplasma pneumoniae at 6-month intervals over a period of 4 years in paediatric student nurses at two schools of nursing and students at one school of medical technology. Titre increases against all tested agents occurred 1.86 times more often in the student nurses than in the medical technology students, the most frequent agents in both groups being influenza A and B. No difference in the relative distribution of the agents could be verified in the two occupational groups. Data on the protective value of pre-infectious antibody levels for influenza A, B, and coronavirus OC43 and on the importance of the spread of single agents among classmates are presented.

Adolescent↗
PubMed1987

[The 1985 influenza epidemic in a pediatric practice].

Because it is not possible to distinguish clinically influenza from other respiratory infections, virological methods have to be used to establish the influenza etiology. Nasopharyngeal swabs from 202 children with respiratory symptoms were taken. Influenza A virus (H3N2) was isolated from 44 children, influenza A virus (H1N1) from 61 children and influenza B virus from 13 children. The maximal activity of the two influenza A virus subtypes was different. The following features permitted the classification of 3 groups; monophasic fever greater than or equal to 38.5 degrees C (81.35%), biphasic fever (14.41%), and pseudocroup (4.24%). 16.1% of the children with fever also had gastrointestinal symptoms. No relation between influenza type/subtype and type of manifestation could be established.

Child↗
PubMed1986

Diagnostic significance of influenza subtype-specific IgG, IgA, and IgM antibodies.

Up to now, the complement fixation test (CFT) has been the basis for the serological diagnosis of influenza virus infection in routine laboratories. Generally, low CF titers (1:20 or 1:40) are difficult to interpret. This means that the differentiation between recent and remote influenza infections is not possible by CFTs on single sera. Nonetheless this is generally possible by the subtype- and immunoglobulin class-specific immunofluorescence test (IFT) reported in this paper. Sera from 76 patients with confirmed influenza infection were tested and we obtained the following results: only 27.6% contained antibodies of all immunoglobulin classes, 51% contained IgG and IgA antibodies (without IgM) and 3.9% responded only with the IgG isotype. The IFT-positive and CFT-negative were 5.2% and the IFT-negative and CFT-positive 4%. In 7.9% no antibody rises were detected by CFT or by IFT despite virus isolation. Results from IFT may permit the interpretation of low CF titers. In contrast to CFT, IFT makes possible the differentiation between vaccinated and unvaccinated persons because vaccinated persons regularly produce IgM antibodies against all strains of the vaccine.

Antibodies, Viral↗
PubMed1985

Immunofluorescence test with antigen-loaded erythrocytes: detection of influenza virus specific IgG, IgA, and IgM antibodies.

An immunofluorescence test (IFT) for the detection of influenza virus antibodies was established to supplement the standard serological diagnostical complement fixation test (CFT). Current strains (A/Philippines/2/82, A/Brazil/11/78, B/Singapore/222/79) were loaded on formalinized chicken erythrocytes. In contrast to CFT, we can distinguish specific immunoglobulin classes against influenza virus. Unlike CFT, IFT is subtype-specific. A recent infection can be distinguished from a past infection by the differentiation of specific immunoglobulin classes. Anticomplementary factors and hemolytic sera do not influence the result of the IFT. IFT does not require cell cultures and is easy to read.

Adult↗
PubMed1984

Early diagnosis of Q fever: detection of immunoglobulin M by radioimmunoassay and enzyme immunoassay.

The use of a radioimmunoassay and an enzyme immunoassay for early diagnosis of Q fever is described, both of which are based on the IgM antibody-capture principle. A commercially available phase II antigen and a labeled, purified anti-Q-IgG of human origin were employed. With these tests Q fever antibodies were detected earlier in the course of infection than with the complement fixation test.

Antibodies, Bacterial↗