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Hantavirus, originally named after the Hantaan River in Korea, is the aetiologic agent for the Hemorrhagic Fever with Renal Syndrome (HFRS) in the asian region, in the Americas for the Hantavirus Pulmonary Syndrome (HPS). In Middle Europe hantaviruses are responsible for the "Nephropathia Epidemica" (NE), a mild form of HFRS. Hantaviruses belong to the family of Bunyaviridae. Like other members of this family their genome consists of three segments of single stranded RNA (ss-RNA) leading to various subtypes, strongly associated with different rodent hosts. There are two major groups, the hantaan lineage harbored by murine rodents and the Puumala lineage harbored by arvicolidae ("old world") and sigmodontidae ("new world"). Infected rodents may develop chronic infections for months or even life-long and may shed infectious virus with urine and feces. The primary mode of infection of man occurs by inhaling contaminated aerosols or soil particles. The collection of epidemiologic data in the state of Baden-Württemberg was realized in three different steps: Collection and localisation of clinical cases (n = 62): A concentration of clinical cases in the middle of the state was found. The examination of the seroprevalence of exposed persons: By the examination of 4000 sera from forest workers, a seroprevalence with an average of 2.1% was found. In the districts of Reutlingen and Tübingen seroprevalences up to 9% were found. This leads to the assumption that there are endemic areas. Epidemiologic studies of reservoir hosts: Serologic surveys of rodents (n = 1150) in the described areas yielded to a seroprevalence up to 10-30%. Virus carriers were determined with RT-PCR and nested-PCR testing. The prevalence in the rodent population showed an average of 10%. The isolated subtypes were all identified as members of the Puumala-lineage. The origin of sporadic infections with Hantavirus of the Hantaan-lineage in Baden-Wuerttemberg is still unknown.

The prevalence of different genospecies of Borrelia burgdorferi sensu lato in infected ticks could be a determinant for the risk of acquiring Lyme borreliosis (LB) and its clinical presentation. A total of 7373 ticks and 2761 samples from LB patients from the same area in southwest Germany were analyzed by PCR to assess the frequency of the occurrence of LB-associated genospecies. Fifteen percent of the tick samples and 19% of the human samples were found positive for the presence of B. burgdorferi sensu lato. Further identification of 1106 B. burgdorferi sensu lato positive tick samples by reverse line blotting and 125 positive patient samples by nested PCR using species-specific primers revealed the occurrence of B. afzelii, B. burgdorferi sensu stricto, B. garinii and B. valaisiana. Both single-species and mixed infections were noted and a similar distribution of the different genospecies was found in ticks compared with human samples. It was also the purpose of this study to obtain more information about a possible correlation between the distribution of Borrelia species and clinical syndromes of LB. Skin biopsies of 59 patients with acrodermatitis chronica atrophicans and cerebrospinal fluid samples from 78 patients with possible neuroborreliosis were analyzed. In conclusion, the distribution of the different genospecies in ticks is the decisive factor for the occurrence of the different Borrelia genospecies in samples from LB patients. Borrelia afzelii is the predominant genospecies in all kind of samples from the observed area and there seems to be no association of particular Borrelia genospecies with distinct clinical manifestations of LB.

The risk of Borrelia burgdorferi infection and the value of antibiotic prophylaxis after tick bite are controversial. In this study, performed in two areas of southwestern Germany, ticks were collected from 730 patients and examined by the polymerase chain reaction (PCR) for B. burgdorferi. To assess whether transmission of B. burgdorferi occurred, the patients were clinically and serologically examined after tick removal and during follow-up examinations. Data from all tick bites gave a total transmission rate of 2.6% (19 patients). Eighty-four ticks (11.3%) were PCR positive. Transmission occurred to 16 (26.7%) of 60 patients who were initially seronegative and could be followed up after the bite of an infected tick. These results indicate that the transmission rate from infected ticks in Europe is higher than previously assumed. Examination of ticks and antibiotic prophylaxis in the case of positivity appears to be indicated.

Chromosomal DNA from three individuals with familial hemoglobin M (Hb M) Milwaukee was studied by restriction endonuclease analysis. The segregation of the mutant beta-globin gene could be followed through three generations by direct Sst I analysis at the gene level. Various restriction endonucleases were used to confirm the positions of Sst I sites in the delta-beta A- and delta-beta Mi-globin gene regions.

Nuclear DNA has been analyzed by means of restriction endonuclease mapping procedure to identify chromosomes that carry mutant Hb Köln beta-globin genes in a family with individuals heterozygous for this disease. Inherited DNA polymorphisms within the beta-globin gene cluster yielded a direct linkage of the Hb Köln mutation to haplotype constellations that are diagnostic for further offspring.

Restriction endonuclease mapping of cellular DNA has been used to identify chromosomes that carry the mutant Hb Presbyterian beta-globin genes in a family with individuals heterozygous for this disease. The presence of the polymorphic Hind III restriction site in the G gamma-globin gene and its absence in the A gamma-globin gene were shown to be in phase with the Hb Presbyterian mutation yielding a haplotype constellation that is diagnostic for any further affected offspring.

The admixture of maternal tissue is a possible hazard of prenatal diagnosis from chorionic villi. Therefore the tolerable degree of maternal DNA contamination in prenatal diagnosis of sickle cell anemia was investigated by mixing various amounts of DNA from HbS carriers with DNA from normal individuals and sickle cell anemia patients. The results indicate that lower rate of admixed maternal DNA does not prevent an exact direct DNA-diagnosis of sickle cell anemia.

Thalassemia major is a rare disorder in the German population. We describe here the characterization of the beta-globin genes of a German patient homozygous for beta-thalassemia. Gene cloning and sequencing revealed a G to T transversion at the intron 1 donor site of the beta-globin gene on both chromosomes.

The molecular defect leading to Hb Köln has been analyzed by synthetic oligonucleotides. Thus, DNA of 19 nucleotides, in length corresponding to the normal and mutant beta-globin gene sequences, were used to develop a direct assay for the beta k-gene that codes for this most common form of the unstable hemoglobins. The use of synthetic oligonucleotides established that the Hb Köln mutation is due to a G-to-A transition. The conditions described here should result in the determination of all Hb Köln genotypes with a high level of confidence.

DNA haplotype constellations of the beta-globin gene cluster have been analyzed in German families with hemoglobinopathies (Hb Freiburg, Hb Köln, Hb Presbyterian) and beta-thalassemias. The polymorphic patterns obtained were compared to those found in families from Greece, Italy, and Turkey affected by beta-thalassemia syndromes. With the combined analysis of seven restriction site polymorphisms a DNA-diagnostic prediction for additional offspring could be made with an overall frequency of 75% in the four ethnic groups.

The molecular defect leading to Haemoglobin (Hb) Freiburg has been analysed using synthetic oligonucleotides. Oligonucleotide probes 19 residues and 16 residues long, corresponding to the normal and mutant beta-globin gene sequences, respectively, were used to develop a direct assay for the beta F-globin gene, which codes for an unstable haemoglobin. Under the conditions described here the use of the respective synthetic oligonucleotides should aid in the determination of all Hb Freiburg genotypes in families at risk with a high level of confidence.

After an extensive educational campaign for the medical community in the area of the Westf. Wilhelms-University Münster five pregnancies at risk for sickle cell anemia and thalassemias were investigated during the first trimester of pregnancy. Following chorionic villi sampling in one case a sickle cell anemia and in two other cases a beta-thalassemia could be excluded. In two additional cases a homozygous beta-thalassemia was proven and in one of the cases the first trimester diagnosis was confirmed in the second trimester by fetal blood sampling. Because of the migration patterns in Europe there is currently a considerable demand for prenatal diagnosis of beta-thalassemias in West-Germany after proper information of the population at risk.