Serodiagnosis of primary infections with human parvovirus 4, Finland

To determine the prevalence of parvovirus 4 infection and its clinical and sociodemographic correlations in Finland, we used virus-like particle-based serodiagnostic procedures (immunoglobulin [Ig] G, IgM, and IgG avidity) and PCR. We found 2 persons with parvovirus 4 primary infection who had mild or asymptomatic clinical features among hepatitis C virus-infected injection drug users.     

Serodiagnosis of Trichinella spiralis infections in pigs by enzyme-linked immunosorbent assays

Antibodies to Trichinella spiralis are detectable by enzyme-linked immunosorbent assays even in the earliest days after infection. A modification of the test, which is suitable for application in the slaughter-house, is described with horseradish peroxidase as the marker enzyme.     

Serodiagnosis of human Schistosoma mansoni infections: enhanced sensitivity and specificity in ELISA using a fraction containing S. mansoni egg antigens omega 1 and alpha 1

Six fractions of Schistosoma mansoni egg homogenate obtained by cation exchange chromatography were tested in an enzyme-linked immunosorbent assay (ELISA) for their efficacy in serodiagnosis of human S. mansoni infections. One cationic fraction (CEF6) containing egg antigens omega 1 and alpha 1, was found to be highly reactive with a S. mansoni positive reference serum pool. 94 of 95 sera from individuals infected with S. mansoni gave a positive reaction with CEF6, and no cross reactivity was obtained with this antigenic fraction and sera from donors infected with heterologous non-schistosome parasites and cases of avian cercarial dermatitis. Only 10 of 165 sera from patients with S. haematobium and three of 10 sera from patients with S. japonicum were positive with S. mansoni egg CEF6. In one group of patients from West Africa, examined both serologically and parasitologically at a six-monthly interval, the measurement of antibody to CEF6 provided a more sensitive diagnostic aid than stool examination.     

Density-dependent fecundity in Schistosoma mansoni infections in man

An analysis is presented of autopsy data collected by Cheever in 1968 on the association between Schistosoma mansoni worm burdens and faecal egg counts. Significant negative relationships are found between the number of eggs/worm pair/g faeces and both the number of worm pairs and the total number of worms. A general, non-linear, statistical routine is shown to be the most practical method of fitting non-linear models to the observed density-dependent fecundity relationship. The conceptual and practical implications of density-dependence are discussed in the context of epidemiological field studies and chemotherapy programmes.     

Influence of parasite strain on chemotherapy of murine infections with Schistosoma mansoni

The effectiveness of chemotherapy in human schistosomiasis varies from one area to another, and limited data from experimentally infected animals suggest inherent differences in the susceptibility of certain parasites to drugs. In the present study, groups of mice infected with each of several geographic strains of Schistosoma mansoni were treated with one of four selected drugs and parasiticidal effects were compared.     

Schistosomal pigment in human and murine infections with Schistosoma mansoni.

Schistosomal pigment was studied by optical and electron microscopy in liver biopsies of patients with different clinical forms of schistosomiasis and in livers of mice experimentally infected with Schistosoma mansoni. Phagosomal and residual forms of the pigment are described. The quantity of pigment is low in subclinical and in hepatointestinal forms of schistosomiasis; it is high in young patients with the hepatosplenic form, and low in the old ones. The participation of the pigment in the pathogenesis of schistosomal lesions is discussed.     

The interaction between Entamoeba histolytica and Schistosoma mansoni infections in mice

A synergistic relationship between caecal amoebiasis and S. mansoni infections has been demonstrated in the mouse. The interaction affected both the infectivity of an E. histolytica inoculum and also the likelihood of amoebic tissue invasion. There was some correlation with worm load. Prepatent schistosome infections were apparently without effect but animals with unisexual infections were somewhat more susceptible than controls. Possible mechanisms include intramucosal tissue damage produced by schistosome ova and an altered immunological responsiveness.     

Glomerular lesions in experimental infections of Schistosoma mansoni in Cebus apella monkeys

Three monkeys (Cebus apella) experimentally infected with Schistosoma mansoni studied for periods of 19, 14, and 11 months showed deposits containing γ-globulin in subendothelial and subepithelial basal membranes and in basement membranes proper. The glomeruli showed mild reactivity characterized by local hypertrophy and hyperplasia of mesangial cells. Such findings were close to those observed by us in the kidney of hepatosplenic schistosomiasis patients without evidence of renal disease. The distribution of the deposits, both in human and experimental disease, are suggestive of preformed, non-glomerular antigen-antibody complexes that form in a zone of excess antigen and become trapped in the glomerular capillaries.     

Preliminary trials with praziquantel in human infections due to Schistosoma mansoni.

As part of a programme of multicentre trials of the tolerance and therapeutic effect of praziquantel, clinical trials were carried out in Brazil in patients with active Schistosoma mansoni infections, each of whom had a minimum geometric mean egg output of 100 eggs per gram of faeces calculated from multiple pretreatment stool examinations.