Molecular evolution of puumala hantavirus in Fennoscandia: phylogenetic analysis of strains from two recolonization routes, Karelia and Denmark.

Like other members of the genus HANTAVIRUS: in the family BUNYAVIRIDAE:, Puumala virus (PUUV) is thought to be co-evolving with its natural host, the bank vole Clethrionomys glareolus. To gain insight into the evolutionary history of PUUV in northern Europe during the last post-glacial period, we have studied wild-type PUUV strains originating from areas along two postulated immigration routes of bank voles to Fennoscandia. Full-length sequences of the S RNA segment and partial sequences (nt 2168-2569) of the M segment were recovered by RT-PCR directly from bank vole tissues collected at three locations in Russian Karelia and one location in Denmark. Phylogenetic analysis showed that strains from Karelia and Finland belong to the same genetic lineage, supporting the hypothesis that PUUV spread to present Finland via a Karelian land-bridge. The Danish PUUV strains showed no particularly close relatedness to any of the known PUUV strains and formed a distinct phylogenetic lineage on trees calculated for both S and M segment sequences. Although no direct link between the Danish PUUV strains and those of the southern Scandinavian lineage was found, within the S segment of Danish PUUV strains, two regions with higher similarity to either northern Scandinavian or - to a less extent - southern Scandinavian genetic lineages were revealed, suggesting evolutionary connections of their precursors.

Analysis of puumala hantavirus genome in patients with nephropathia epidemica and rodent carriers from the sites of infection.

Reverse transcription-polymerase chain reaction (RT-PCR) followed by sequence and phylogenetic analyses were used to study specimens from nine Finnish nephropathia epidemica (NE) patients admitted to hospital during the epidemic in winter 1996-1997. Blood samples from six patients were found to be positive for the partial M- and/or S-segment sequences of Puumala hantavirus (PUUV). Analyses of these sequences (nt 2168-2610 for the M segment, and nt 819-1082 for the S segment) revealed six distinct PUUV strains showing highest similarity to previously described PUUV strains from Finland: 90-95% for the S segment, and 90-99% for the M segment. Accordingly, on the phylogenetic trees calculated for both viral segments, all six human strains were placed within the Finnish genetic lineage of PUUV. Attempts were made to trace five RT-PCR-positive patients to local bank voles (Clethrionomys glareolus) infected with wild-type PUUV, and for two patients a comparative analysis of human- and rodent-originated viral sequences was undertaken. Whereas in the first case the differences between the sequences were substantial (5. 7% for the S segment, and 10.8%, for the M segment), in the other case the M segment sequence recovered from the clinical specimen was 100% identical to three sequences recovered from rodent lungs, and the S sequences differed by one silent substitution only. This is the first finding of virtually identical PUUV sequences in an NE patient and a natural rodent host from the site of infection.

Primary and secondary infections by human parvovirus B19 following bone marrow transplantation: characterization by PCR and B-cell molecular immunology.

Due to the preparative regimen necessary, bone marrow transplantation (BMT) consistently results in severe immunodeficiency, often associated with anaemia, leukopenia and thrombocytopenia. Parvovirus B19 replicates in red blood cell precursors in the bone marrow and causes erythema infectiosum ('fifth disease'), anaemia, arthritis and foetal death. We assessed the significance of B19 infections as a cause of post-BMT complications. Over 900 serial serum samples from 201 allogeneic bone marrow recipients were studied by polymerase chain reaction (PCR) and by modern serodiagnostic methods. During the first 6 months after transplantation all BMT recipients remained B19 PCR-negative. Antibody screening for B19 infections was performed up to 36 months post-transplantation. Three cases of acute B19 infection were diagnosed during the second year post-BMT. To characterize the adoptively transferred immune system we measured subclasses and avidity of anti-VP1 IgG and epitope-type specificity (ETS) of anti-VP2 IgG, which allowed functional differentiation of primary and secondary B-cell responses long after BMT. The profile of the immune response was that of a primary infection in 1 and of reinfection in 2 of the 3 acute cases. Both types were clinically mild. Infection by human parvovirus B19 is not a frequent cause of post-BMT cytopenias. The findings with the new B19 antibody markers support the concept that the donated marrow determines the type of antiviral B-cell responses.

Costs and cost-effectiveness in hip and knee replacements. A prospective study.

The extensive benefits of the total hip (THA) and knee (TKA) replacements are well documented, but surprisingly little is known about their economics. We assessed costs, cost-effectiveness (C/E), and patient-related C/E variances in THA and TKA from data on 276 THA and 176 TKA patients. Patients with primary arthrosis, primary operation, and total joint replacement were recruited from seven hospitals between March 1991 and June 1992. Their use of health and other welfare services together with health-related quality of life (HRQoL) were measured before the surgery and at 6, 12, and 24 months postoperatively. HRQoL was assessed by the 15D, a 15-dimensional HRQoL instrument, and the Nottingham Health Profile. Costs were assessed from questionnaire responses, the Finnish Hospital Discharge Register, and Finnish Arthroplasty Register. Total hospital costs per patient were 45,000 FIM (US $10,500) for THA and 49,600 FIM (US $11,500) for TKA. Prosthesis costs comprised 21% of these costs in THA and 24% in TKA. On average, hip patients gained more in terms of HRQoL, and the operations were more cost-effective. The C/E ratio for younger (< or = 60 years) knee patients did not differ from those in all age groups of hip patients, whereas TKAs in those over 60 years had a worse C/E ratio compared with all other patient subgroups. It was concluded that allocation efficiency can be improved by considering not only the intervention but also patient characteristics such as age. Indeed, the C/E ratio varied more across age groups of knee patients than between average THA and TKA patients.

Hepatitis C genotypes in Finland determined by RFLP.

Genotyping of hepatitis C virus (HCV) is important because of its clinical and epidemiological implications. We report here the distribution of HCV genotypes in various patient groups in Finland using a rapid and reliable HCV typing method based on restriction fragment length polymorphism (RFLP) of the amplified DNA from the 5' non-coding region of the genome. The reaction product from the primary, diagnostic PCR (nested, one tube system) was used in genotyping. From 264 Finnish sera we identified HCV genotypes 1a (14%), 1b (24%), 2b (20%). 3a (41%) and 1a + 1b (1%). Only one patient with genotype 2a was identified. From four Egyptian blood donors, types 1b and 4 were found. Genotype 3a was more often associated with i.v. drug abuse and younger age profile (less than 30 years).

Human spumaretrovirus in the etiology of sudden hearing loss.

The etiology of sudden sensorineural hearing loss, so called sudden deafness, has for long puzzled researchers. Recently we have studied the possibility that a hitherto relatively unknown retrovirus group consisting of human spumaretroviridae (HSRV) might be the causative agent of sudden deafness. During the last 3 months we have screened about 30 cases of sudden deafness. In 4 of them antibodies against HSRV were detected. Three of them had suffered from a flu-like condition about 2 weeks before the onset of hearing loss. In 2 cases the hearing of both ears was involved, in 1 case a relapsing hearing loss was observed, and 1 case developed a Meniere-like symptomatology with a fluctuant hearing loss. Vertigo was present in 3 patients and all suffered from tinnitus. Full recovery of hearing was observed in 4 of 6 affected ears whereas 2 ears became practically deaf with poor speech discrimination. At present it seems likely that a significant part of sudden deafness is caused by HSRV infection. The course of infection follows the spontaneous course of sudden deafness described by many authors. We encourage otologic units to screen for HSRV when assessing the etiology of sudden deafness.

Identification of human type D retrovirus as a contaminant in a neuroblastoma cell line.

In this report we describe a type D virus isolated from a human neuroblastoma cell line (Paju). The viral RNA was isolated, partially molecularly cloned and sequenced. Our clones were shown to be identical to a human D-type retrovirus previously isolated from a human lymphoblastoid cell line. However, we obtained no evidence for the virus in earlier passage of the Paju cell line and therefore we must consider this isolate a laboratory contamination. contamination.

Nocardia water soluble mitogen (NWSM), a human B-lymphocyte mitogen.

Nocardia water soluble mitogen (NWSM), which is a peptidoglycan, was prepared from Nocardia opaca. Its effect on human B-lymphocyte proliferation, the number of immunoglobulin secreting B-cells, and bone marrow stem cell growth was studied in vitro. NWSM stimulated the proliferation of B-lymphocytes of all ten healthy subjects studied very effectively (P less than 0.0005). No T-cell activation occurred. NWSM did not increase the amount of antibody producing cells. The growth of bone marrow stem cells was enhanced only in one patient out of the eight studied. Thus NWSM is a B-lymphocyte mitogen with a potential effect on hematopoietic stem cells. However, production of NWSM was faced with difficulties because not all lots prepared had B-cell stimulating activity.