Contribution of NADH dehydrogenase subunit I and cytochrome C oxidase subunit I sequences toward identifying a case of human coenuriasis in France.

Coenuriasis is a parasitic disease induced by larval taeniid tapeworms that is rarely observed in humans. In December 2005, a case was diagnosed in Nancy, France, after surgical excision of a cyst on a 24-yr-old woman returning from the Côte d'Ivoire. Morphological and epidemiological criteria suggested that the infection was due to Taenia serialis. Molecular analysis of NADH dehydrogenase subunit I (NDI) and cytochrome c oxidase subunit I (COI) sequences was also in favor of T. serialis identification, but the absence of available genetic data on T. brauni and T. glomeratus and the small number of published sequences for T. serialis and T. multiceps must be considered with caution. The NDI partial sequences presented more variations within species of Taenia than the COI sequences, which make them more useful targets for species identification and analysis of intraspecific polymorphisms. The present study points to the usefulness of molecular biology tools to help make up for the shortcomings of the commonplace parasitological diagnosis for coenuriasis.

Ocular toxoplasmosis after the fifth decade.

PURPOSE: To describe the clinical features in patients presenting with ocular toxoplasmosis after the fifth decade and to analyze laboratory findings in comparison to uveitis history and clinical data. DESIGN: Prospective consecutive observational case series. METHODS: A prospective clinical analysis of 27 consecutive patients older than 50 years of age with primary or recurrent ocular toxoplasmosis was performed during a period of 8 years. These cases account for 12% of all ocular toxoplasmosis cases irrespective of age indexed in our institution during the same period. Paired serum and aqueous humor samples were tested for anti-Toxoplasma gondii IgG, IgM, and IgA antibodies. The presence of T. gondii DNA in aqueous humor was determined by polymerase chain reaction followed by DNA hydridization method. RESULTS: Although similar in age, two groups were distinguished clinically: 12 patients (44%) presented with usual forms of retinochoroiditis (mean +/- SD, 1.6 +/- 0.5 disk areas [DA] in size); 15 patients (56%) presented with atypical lesions, greater than 3 DA in size (mean +/- SD, 5.0 +/- 2.0 DA). The second group showed a higher rate of complications (P =.028) and a poorer visual outcome (P =.015). Twenty-four patients (89%) had intraocular IgG production, 17 (63%) had intraocular IgA production, 3 (11%) had intraocular IgM production, and 12 (44%) had a positive T. gondii DNA detection. CONCLUSIONS: After the fifth decade, ocular toxoplasmosis remains an important cause of posterior uveitis. The combination of antibody detection by immunocapture tests with T. gondii DNA detection, both in aqueous humor, allowed the diagnosis of toxoplasmic infection in the atypical cases with large ocular lesions.

Contribution of human herpesvirus 6 (HHV-6) viral load in whole blood and serum to investigate integrated HHV-6 transmission after haematopoietic stem cell transplantation.

BACKGROUND: Human herpesvirus 6 (HHV-6) is susceptible to latency and recurrence. A less-frequent form of HHV-6 persistence is the integration of viral DNA into host chromosomes. OBJECTIVES: To investigate HHV-6 viral load after haematopoietic stem cell transplantation (HSCT) in whole blood (WB) and serum with regard to integrated HHV-6 transmission diagnosis. STUDY DESIGN: HHV-6 DNA quantitation in serum and WB was performed using quantitative polymerase chain reaction for the follow-up of a 16-year-old girl after HSCT. In whole blood, results were expressed as HHV-6 genomic equivalent copies (gec) per milliliter of WB or per million cells. RESULTS: HHV-6 viral load (undetectable before HSCT) increased up to 3.05 x 10(7)gec/10(6)cells. HHV-6 viral load in the donor sample (3.44 x 10(6)gec/10(6)cells) was in favor of viral transmission through HSCT. The correlation between viral load in WB and serum was significant (p=0.0005). Viral load results expressed as gec/10(6)cells in WB was more reliable than results expressed as gec/ml of whole blood. CONCLUSION: These findings indicate that HHV-6 may be transmitted during HSCT as integrated virus contained in the graft. This reiterates that in the setting of HSCT, HHV-6 viral load must be correctly interpreted. Using HHV-6 viral load expressed as gec/10(6) cells may be more suitable for the follow-up of patients with integrated HHV-6.

Potential of beta-galactosidase-expressing Toxoplasma gondii for in situ localization and observation of rare stages of the parasite life cycle.

A cyst-forming strain of Toxoplasma gondii was transfected with the Escherichia coli LacZ gene and expressed beta-galactosidase constitutively. This strain has been used to localize and analyze the early stages of development and reactivation of T. gondii in mice. The chromogenic detection of the enzyme allows an easy detection of the parasites after light fixation and therefore allows a submacroscopic analysis of tissue distribution within the organism. Also, it allows further embedding and retrieval of rare stages for electron microscopic observation. that detect the presence of the parasite and initiate the response, and (2) the early stages of reactivation, when the cysts are supposed to break open and release the infectious bradyzoïtes. We have taken advantage of the possibility of detecting the enzymatic activity of beta-galactosidase (beta-gal) in transfected parasites to show that one could perform a semi-macroscopic detection and that this was compatible with further analysis by histological or electron microscopic techniques, being therefore able to detect the rare events and then to analyze them further with more refined morphological techniques.

Development of an immunoenzymatic assay using a monoclonal antibody against a 50-kDa catabolite from the P126 Plasmodium falciparum protein to the diagnosis of malaria infection

The WHO criterion of defering any donation of blood by a confirmed case of malaria for three years after cessation of therapy can not be applied in areas where malaria in endemic. For this reason we developed an immunoenzymatic assay for the detection of plasmodial antigens for blood screening in malararial endemic areas. So, we tested sera from 191 individuals. Among patients with active disease 100% of the cases of Plasmodium falciparum or mixed infections and 91.7% of those with P. vivax were positive for the presence of plasmodial antigens. The lower parasitaemia detected was 0.0003% for P. vivax malária. When the frequency of positive circulating malarial antigens was evaluated among asymptomatic and symptomatic individuals with negative TBS, positive results were found in respectively 38.7% and 17.7% of the individuals studied in the 30 days after confirmed malaria attack. Data provide by these assays have shown that ELISA seemed to be more sensitive than parasitological examination for malaria diagnosis. This test by virtue of its high sensivity and the facilities in processing a large number of specimens, can prove to be useful in endemic areas for the recognition of asymptomatic malaria and screening of blood donors