[Congenital human cytomegalovirus infection: value of human cytomegalovirus DNA quantification in amniotic fluid]

A quantitative PCR assay (RS Elosa CMV, Lambdatech) was used to quantitate HCMV DNA in maternal amniotic fluid of 12 fetuses with congenital infection (group 1) and of 10 fetuses without congenital infection (group 2). HCMV detection was performed for both groups using culture and qualitative PCR. Histologic examinations of fetal tissues and placenta were carried out for 9 patients from group 1. The amniotic fluid viral loads were negative in all patients of group 2. In group 1, all viral loads were high (from 1.105 to > 107 cop/mL) and no difference was observed between symptomatic and asymptomatic foetuses. Further evaluation on larger samples is needed to define more precisely the pronostic value of HCMV DNA quantification in amniotic fluid.

[Detection of human papillomavirus DNA by molecular hybridization in tube: interest in cervical neoplasia]

The presence of human papillomavirus (HPV) DNA in 79 cervical specimens obtained from 70 patients was studied by using a molecular hybridization technique performed in tube. The results were compared to those of the cytological and histological studies. The molecular hybridization technique in tube (Hybrid Capture I) detects two groups of HPV types. One group is highly associated with the development of cancer (types 16, 18, 31, 33, 35, 45, 51, 52, 56) whereas the second group (types 6, 11, 42, 43, 44) is not. Among 42 patients with cervical lesions before any treatment, high risk DNA of HPV was found in 50% of those with low grade cytology and 90% with high grade cytology. In total, 32 out of the 42 patients (76%) who presented histological lesions, were actually infected by HPV. Samples were obtained before and after treatment from 9 patients. Seven out of 9 presented high grade cervical intraepithelial neoplasia (CIN) and 2 other patients had low grade CIN. HPV DNA was not detected in any of the patients after treatment. Detection of HPV DNA by molecular hybridization in tube is simple, sensitive, standardized, inexpensive and is well adapted to screening programs. It can be used in complement of the cytological diagnosis, in the surveillance of equivocal cytological abnormalities, and in the follow-up of treated patients.

[ParaSight F in the diagnosis of Plasmodium falciparum malaria]

The ParaSight F is a new diagnostic test for Plasmodium falciparum infections and is based on the detection of a trophozoite-derived antigen, the histidine rich protein II (HRP-II). To assess the usefulness of this test, we conducted a prospective study and analyzed 62 blood specimens from 38 patients, using thin blood films, thick blood films and the ParaSight F test. Compared to thick blood film, on samples taken before and during treatment, the ParaSight F test had 86.4% sensitivity and 100% specificity. In 31.5% of P. falciparum infected patients, parasitemia was lower than 1 parasite/1000 red blood cells, with all specimens being positive by the ParaSight F test. In 15 cases, specimens were negative by thin blood film, but were positive by thick blood film and by the ParaSight F test. Two patients had, after their treatment was started, positive results by ParaSight F and negative results by thick blood film. Cross-reactivity occurred neither with other Plasmodium species, nor in cases of severe inflammatory syndrome. Persistence of antigenemia was monitored in 14 patients receiving quinine. At day five of treatment, antigenemia persisted in seven patients. In conclusion, the ParaSight F test does not allow following up the efficacy of treatment, identifying other Plasmodium species, or assessing parasitemia. However, because this test is easy to perform and has good sensitivity and specificity, it is a useful tool in emergent context, in cases of parasitemia lower than the thin blood film threshold, and in cases morphologically difficult to decipher.

[PCR value in the diagnosis of feto-placental human parvovirus B19 hydrops fetalis: apropos of 10 cases]

Human parvovirus B19 primary infection during pregnancy is responsible for 27% of non autoimmune hydrops fetalis. Parvovirus B19 antigen detection and parvovirus B19 IgM and IgG antibody determination using enzyme immunoassays are not reliable for diagnostic purposes and lack of specificity. Parvovirus B19 DNA detection in amniotic fluid, fetal blood, ascitic fluid, and fetal biopsies or placenta specimens seems to be the best method for the diagnosis. Ninety-seven samples from 70 cases of spontaneous abortions after fetal death or hydrops fetalis were examined using PCR. A 270-bp length fragment of the NSI gene was amplified using PCR followed by electrophoresis, by Dot-blot hybridization assay using a biotinylated probe and by Southern-blot hybridization assay using a horseradish peroxidase-labelled probe followed by chemiluminescent assay. The Southern-blot hybridization assay was the longest test but the most sensitive. The parvovirus B19 genome was identified in 10 cases. In two cases, intrauterine blood transfusions led to the cessation of symptoms and to the birth of normal babies.