Evaluation and optimisation of commercial Zika IgG avidity assay

BACKGROUND

ZIKV infection has potentially severe consequences particularly in fetuses/newborns born to mothers that were infected early in pregnancy. Diagnosis relies on the detection of ZIKV IgM that can also be detected due to cross reactivity or to nonspecific polyclonal activation of the immune system. Therefore, in case of ZIKV IgM detection, identification of a recent infection can be of major importance for the optimal management of pregnant women.

OBJECTIVE

This study evaluates the performances of a commercially available assay to measure ZIKV-IgG avidity.

STUDY DESIGN

A total of 110 serum or plasma samples collected from symptomatic or asymptomatic patients living or returning from a ZIKV endemic area were classified according to epidemiological and clinical information, and to serology and molecular assays' results. Samples were tested with the IgG ZIKV Avidity Test (DIA.PRO®) according to manufacturer's instruction and with a modified protocol.

RESULTS

By using the manufacturer's Avidity Index cut-off, distinction between recent and past infection was unclear with similar AIs in the two situations (p = 0.8872). Sensitivity and specificity in identifying recent infection were poor, 67.3 % and 4.5 % respectively. By using a modified protocol, a better discrimination was observed with significant differences between mean AIs (p = 0.0318), and with higher sensitivity and specificity, respectively 87.8 % and 100 %.

CONCLUSION

Our results highlight that IgG ZIKV Avidity Test DIA.PRO® assay is not reliable enough to be used in clinical practice without modifications.

New HIV-1 circulating recombinant form 94: from phylogenetic detection of a large transmission cluster to prevention in the age of geosocial-networking apps in France, 2013 to 2017

BackgroundEnding the HIV pandemic must involve new tools to rapidly identify and control local outbreaks and prevent the emergence of recombinant strains with epidemiological advantages.AimThis observational study aimed to investigate in France a cluster of HIV-1 cases related to a new circulating recombinant form (CRF). The confirmation this CRF's novelty as well as measures to control its spread are presented.MethodsPhylogenetic analyses of HIV sequences routinely generated for drug resistance genotyping before 2018 in French laboratories were employed to detect the transmission chain. The CRF involved was characterised by almost full-length viral sequencing for six cases. Cases' clinical data were reviewed. Where possible, epidemiological information was collected with a questionnaire.ResultsThe transmission cluster comprised 49 cases, mostly diagnosed in 2016-2017 (n = 37). All were infected with a new CRF, CRF94_cpx. The molecular proximity of this CRF to X4 strains and the high median viraemia, exceeding 5.0 log₁₀ copies/mL, at diagnosis, even in chronic infection, raise concerns of enhanced virulence. Overall, 41 cases were diagnosed in the Ile-de-France region and 45 were men who have sex with men. Among 24 cases with available information, 20 reported finding partners through a geosocial networking app. Prevention activities in the area and population affected were undertaken.ConclusionWe advocate the systematic use of routinely generated HIV molecular data by a dedicated reactive network, to improve and accelerate targeted prevention interventions. Geosocial networking apps can play a role in the spread of outbreaks, but could also deliver local targeted preventive alerts.

Evaluation of the cobas® GT hepatitis C virus genotyping assay in G1-6 viruses including low viral loads and LiPA failures

Direct-acting antiviral (DAA) drug performances depend on the viral genotype. So international recommendations give typing of the virus a prerequisite for treatment choice and patient management. Commercially available HCV genotyping kits are scarce and this analysis is often in-house using tedious PCRs and Sanger sequencing, leading to a lack of standardization. A newly commercialized HCV genotyping assay based on real-time PCR has been developed by Roche Diagnostics (Mannheim, Germany). We compared this new assay with our in-house PCRs -sequencing technique on 101 regular samples and 81 LiPA failures or low viral load samples. No genotype or 1a/1b subtype mismatch was observed. Two samples were misidentified at the subtype level without clinical impact. Three genotype 1b and two genotype 1a samples with low viral load could not be subtyped. Nevertheless, 13 (13%) samples from the regular panel and 35 (43%) from the more difficult-to-type panels failed to give results on first pass with the Roche kit. Failures were mostly associated with genotype 3 subtype a, with genotype 4 subtype non-a, or with viral loads <200 IU/mL (p = 0.0061). The workflow allowed a non-specialized technician to obtain results in less than 4 hours whereas 2 to 3 days and experienced staff were required with the in-house assay. In conclusion, the Roche cobas^® HCV GT kit is easy and rapid to use and provides reliable results. The high rate of uninterpretable results particularly for low viral load samples and less frequent genotypes, and the absence of subtyping for non-genotype 1 could require sending complex samples to a specialized laboratory.

Screening test for neutralizing antibodies against yellow fever virus, based on a flavivirus pseudotype

Given the possibility of yellow fever virus reintroduction in epidemiologically receptive geographic areas, the risk of vaccine supply disruption is a serious issue. New strategies to reduce the doses of injected vaccines should be evaluated very carefully in terms of immunogenicity. The plaque reduction test for the determination of neutralizing antibodies (PRNT) is particularly time-consuming and requires the use of a confinement laboratory. We have developed a new test based on the use of a non-infectious pseudovirus (WN/YF17D). The presence of a reporter gene allows sensitive determination of neutralizing antibodies by flow cytometry. This WN/YF17D test was as sensitive as PRNT for the follow-up of yellow fever vaccinees. Both tests lacked specificity with sera from patients hospitalized for acute Dengue virus infection. Conversely, both assays were strictly negative in adults never exposed to flavivirus infection or vaccination, and in patients sampled some time after acute Dengue infection. This WN/YF17D test will be particularly useful for large epidemiological studies and for screening for neutralizing antibodies against yellow fever virus.

Evaluation of a new random-access HBV DNA molecular assay: The VERIS HBV assay

BACKGROUND

Detection and quantification of HBV DNA are essential to diagnose chronic HBV infection, monitor the virological response to treatment and the possible selection of resistant viruses in order to tailor therapy. The VERIS/MDx System HBV Assay is a random-access system that quantifies HBV DNA in clinical samples using unique single sample and reagent access during the workflow process without the need to reload other tests and delivers results within 1.2h following sampling.

OBJECTIVE AND STUDY DESIGN

The goal of this study was to evaluate the analytical performance of the VERIS HBV assay for HBV DNA detection and quantification in clinical samples from a series of patients chronically infected with different HBV genotypes.

RESULTS

The specificity of the VERIS HBV assay was estimated to be over 99.5%. The limit of detection (LOD) was estimated to be 4.1IU/mL (95%CI: 3.20-5.90IU/mL). Using an HBV linearity panel and controls (Seracare LifeScience), intra-assay and inter-assay coefficients of variation ranged from 0.12% to 3.64% and from 1.05% to 7.35%, respectively. The influence of the HBV genotype was evaluated from 120 clinical specimens containing HBV genotypes A to G tested in parallel with the VERIS HBV assay and the COBAS AmpliPrep/COBAS TaqMan HBV v2.0 assay. A linear relationship between the HBV DNA levels measured with both assays was found. A modest bias of HBV DNA levels was observed in the VERIS assay as compared to CAP/CTM HBV v2.0 in most of the samples tested (mean VERIS minus CAP/CTM difference: -0.395 log IU/mL). Overall, the VERIS HBV assay is well suited to monitoring clinical HBV DNA levels in infected patients according to current clinical practice guidelines.

Direct genotyping of Toxoplasma gondii from amniotic fluids based on B1 gene polymorphism using minisequencing analysis

Background

Because some Toxoplasma gondii genotypes may be more virulent in pregnant women, discriminating between them appears valuable. Currently, the main genotyping method is based on single copy microsatellite markers, which limit direct genotyping from amniotic fluids (AFs) to samples with a high parasitic load. We investigated whether the multicopy gene B1 could type the parasite with a higher sensitivity. To estimate the amplifiable DNA present in AFs, we first compared three different PCR assays used for Toxoplasma infection diagnosis: the P30-PCR, targeting the single copy gene P30; the B1-PCR, targeting the repeated B1 gene; and RE-PCR, targeting the repeated element.

Results

Of the 1792 AFs analyzed between 2008 and 2011, 73 were RE-PCR positive. Of those, 49 (67.1%) were P30-PCR and B1-PCR positive, and 14 (19.2%) additional AFs were B1-PCR positive only.

All 63 BI-positive AFs (France n = 49; overseas n = 14) could be genotyped based on an analysis of eight nucleotide polymorphisms (SNPs) located within the B1 gene. Following high-resolution melting (HRM) analysis, minisequencing was carried out for each of the eight SNPs. DNA from six reference strains was included in the study, and AFs were assigned to one of the three major lineages (Types I, II, and III). In total, 26 genotypes were observed, and the hierarchical clustering distinguished two clades in lineages II (IIa, n = 30 and IIb, n = 4) and III (IIIa n = 23 and IIIb n = 6). There was an overrepresentation of overseas isolates in Clade IIb (4/4, 100%) and Clade IIIa (8/22; 36.4%) (p <0.0001), whereas medical interruption and fetal death were overrepresented in Clade IIb (2/4, 50%) and Clade IIIa (4/23, 17.4%) (p = 0.049).

Conclusions

Although the current genotyping system cannot pretend to replace multilocus typing, we clearly show that targeting the multicopy B1 gene yields a genotyping capacity of AFs around 20% better than when single copy targets are used. The present genotyping method also allows clear identification of genotypes of potential higher virulence.

The Cobas AmpliPrep/Cobas TaqMan HCV test, version 2.0, real-time PCR assay accurately quantifies hepatitis C virus genotype 4 RNA

Accurate hepatitis C virus (HCV) RNA quantification is mandatory for the management of chronic hepatitis C therapy. The first-generation Cobas AmpliPrep/Cobas TaqMan HCV test (CAP/CTM HCV) underestimated HCV RNA levels by >1-log10 international units/ml in a number of patients infected with HCV genotype 4 and occasionally failed to detect it. The aim of this study was to evaluate the ability of the Cobas AmpliPrep/Cobas TaqMan HCV test, version 2.0 (CAP/CTM HCV v2.0), to accurately quantify HCV RNA in a large series of patients infected with different subtypes of HCV genotype 4. Group A comprised 122 patients with chronic HCV genotype 4 infection, and group B comprised 4 patients with HCV genotype 4 in whom HCV RNA was undetectable using the CAP/CTM HCV. Each specimen was tested with the third-generation branched DNA (bDNA) assay, CAP/CTM HCV, and CAP/CTM HCV v2.0. The HCV RNA level was lower in CAP/CTM HCV than in bDNA in 76.2% of cases, regardless of the HCV genotype 4 subtype. In contrast, the correlation between bDNA and CAP/CTM HCV v2.0 values was excellent. CAP/CTM HCV v2.0 accurately quantified HCV RNA levels in the presence of an A-to-T substitution at position 165 alone or combined with a G-to-A substitution at position 145 of the 5' untranslated region of HCV genome. In conclusion, CAP/CTM HCV v2.0 accurately quantifies HCV RNA in genotype 4 clinical specimens, regardless of the subtype, and can be confidently used in clinical trials and clinical practice with this genotype.

HCV-GenoFibrotest: a combination of viral, liver and genomic (IL28b, ITPA, UGT1A1) biomarkers for predicting treatment response in patients with chronic hepatitis C

BACKGROUND AND AIM

Three gene polymorphisms, interferon-lambda-3 (IL28B), inosinetriphosphatase (ITPA) and bilirubinuridine diphosphate-glucuronosyltransferase (UGT1A1) are associated with treatment (interferon and ribavirin) efficacy and adherence in patients with chronic hepatitis C. The hypothesis was that fibrosis stage estimated with FibroTest instead of biopsy was still an independent predictive factor of sustained virologic response (SVR) when these new polymorphisms were assessed.

METHODS

Patients receiving standard of care treatment were retrospectively analyzed with determination of IL28B, ITPA, and UGT1A1 polymorphisms. Baseline prognostic factors were combined using logistic regression analysis in a training group (157 patients) and validated in avalidation group (79 patients).

RESULTS

The combination of the five most predictive factors (HCV genotype 2/3, IL28B genotype, FibroTest, ActiTest and viral load) in the training population had AUROC for SVR=0.743 (0.655-0.810; P<0.0001 vs. random), which was validated in the validation population, AUROC=0.753 (0.616-849; P=0.0007 vs. random, not different from training P=0.88). FibroTest remained significant [OR=4.20 (2.59-12.50); P=0.03] after assessment of the IL28B CC, HCV genotype and viral load.

CONCLUSION

Fibrosis stage assessed by FibroTest is an independent predictor of SVR, after accounting for the IL28B genetic polymorphism. A combination of five baseline biomarkers could simplify the baseline prediction of SVR.

Usefulness of specific IgG avidity for diagnosis of hepatitis A infection

AIM

Diagnosis of acute hepatitis A virus (HAV) infection is classically based on the detection of HAV-IgM. Nevertheless, HAV-IgM can be positive for patients with polyclonal stimulation of their immune system (i.e. immune reactivation). To improve the diagnostic yield, an avidity test for HAV-IgG antibodies was developed and tested.

METHODS

Avidity tests were performed in 128 sera: 11 selected samples from patients with past infection, 15 acute hepatitis A, 10 vaccinated subjects and 4 patients with immune reactivation as well as 84 HAV-IgM positive unselected sera, provided by routine laboratories.

RESULTS

Patients with past infection had avidities over 70%, whereas avidities in patients with acute hepatitis A were below 50% during the first month following the onset of symptoms. As expected, patients with immune reactivation had avidities over 70% consistent with past infection. The results obtained for the 84 unselected sera allowed reconsidering the diagnosis of acute hepatitis A for nearly a third of patients.

CONCLUSION

This test could improve the diagnosis of acute hepatitis A infection, particularly in elderly patients.

Diagnostic relevance of immunoglobulin G avidity for hepatitis A virus

Diagnosis of acute hepatitis A virus (HAV) infection is based on the detection of HAV immunoglobulin M (IgM). However, IgM could be detected due to nonspecific polyclonal activation of the immune system. An avidity test for anti-HAV IgG was developed to distinguish acute infection, where low-avidity antibodies are detected, from immune reactivation. The assay was tested on 104 samples, including 11 sera from patients with past infection, 15 sera from patients with acute infection and 4 collected after recovery, 10 sera from vaccinated subjects, 4 sera from patients with suspected immune reactivation, and 60 unselected HAV-IgM positive sera, collected over 1 year in a routine laboratory. The avidity index (AI) was expressed as percentage. The results were provided as the mean +/- one standard deviation. Patients with a history of prior infection had AIs of >70% (mean, 86% +/- 10), whereas the mean AI was 36% +/- 16 during acute HAV infection (P < 0.001). Within the first month after the onset of hepatitis, avidity was either noncalculable due to a very low IgG titer or <50%. In patients with immune reactivation, avidity was >70% (88% +/- 10%), a finding consistent with a prior infection. Among the 60 unselected sera, 35 (58%) had a noncalculable or <50% avidity, and most of them had a detectable HAV RNA, confirming HAV infection. In contrast, 16 (27%) had an avidity of >70%, and none was reverse transcription-PCR positive, suggesting immune reactivation. These 16 patients were significantly older than the others (50 +/- 16 years versus 26 +/- 14 years). The new anti-HAV IgG avidity assay we developed could improve HAV infection diagnosis, particularly in elderly patients.

Frequency of herpes simplex virus, cytomegalovirus and human papillomavirus DNA in semen

Herpes simplex virus (HSV-2) and cytomegalovirus (CMV) infections produce brain damage in the newborn, and human papillomavirus (HPV) plays a role in cervical carcinogenesis. To assess the frequency of herpes virus and HPV in semen and its role in transmission, semen from 111 male partners of women with histologically-detected genital HPV infection was analysed for HSV, CMV and HPV infection. We used cell culture to detect HSV and CMV, and polymerase chain reaction (PCR) for HPV. Virological findings in the sperm were correlated to the presence or absence of HPV-associated genital lesions and to the viral type. Viral cultures yielded HSV-2 DNA in 9% and CMV DNA in 6.3% of cases. No correlation was established with a history of clinically apparent infection for HSV. HPV-DNA was detected in 23.4% of semen by PCR techniques: in 48% of subjects with urethral lesions, in 22% of patients with penile lesions, in 2% of patients without HPV-associated lesions. HPV-DNA type 16 was detected in 3.6% of cases. Patients with a positive HPV semen sample and penile or urethral lesions had the same HPV type detected in the two specimens. The study shows a high detection of clinically inapparent HSV and CMV, but does not confirm high HPV prevalence in semen from men without detectable lesions. Our study also suggests that the mechanism for semen contamination by HPV is the exfoliation of infected cells from urethral lesions during semen ejaculation, and probably, by abrasion from penile lesions. This could result in the contamination of semen used in assisted reproductive technology.

Cervical squamous intraepithelial lesions in HIV-infected women: prevalence, incidence and regression. European Study Group on Natural History of HIV Infection in Women

OBJECTIVES

To assess the impact of HIV-related immunodeficiency and antiretroviral treatment on the occurrence and evolution of abnormal Papanicolaou tests.

STUDY DESIGN

Cohort of 485 HIV-infected women with a known date of infection, enrolled during May 1993-April 1998 in 23 centres (gynaecology, infectious disease or STD clinics, or drug treatment centres) in 12 European countries; in 21 centres, follow-up was performed every 6 months (median follow-up: 2 years).

METHODS

Human papillomavirus (HPV) was detected at inclusion by Southern blot and PCR. The prevalence of squamous intraepithelial lesions (SIL), the incidence of SIL and regression from low-grade SIL were studied according to CD4 count after controlling for HPV detection results.

RESULTS

Compared with women with CD4 cell counts > 500 x 10(6)/l, women with CD4 cell counts < 200 x 10(6)/l had a twofold increase in both prevalence and incidence of SIL and in non-regression from untreated low-grade SIL; in addition, these women had a lower response rate to treatment of high-grade cervical intraepithelial neoplasia. The increase in SIL incidence associated with a low CD4 cell count was significant in women not receiving antiretroviral treatment (relative risk, CD4 cell count 200-499 x 10(6)/l, 1.9; CD4 cell count < 200 x 10(6)/l, 2.9; CD4 cell count > 500 x 10(6)/l, reference), whereas it was less marked and not statistically significant in treated women.

CONCLUSIONS

Severe HIV-related immunodeficiency strongly increases the risk of occurrence of SIL; antiretroviral treatment may reduce this risk, probably by restoring or at least preserving immune function.

Lessons from a multicentre study of the detectability of viral genomes based on a two-round quality control of GB virus C (GBV-C)/hepatitis G virus (HGV) polymerase chain reaction assay

The aim of this study was to determine whether multicentre quality controls for the detectability of viral genomes could contribute to the improvement of diagnostic performance in the participating laboratories. The study was carried out during two successive rounds, during which 18 laboratories specialized in nucleic acid testing analyzed, through a polymerase chain reaction (PCR) assay, a common panel of GB virus C (GBV-C)/hepatitis G virus (HGV) RNA-positive and -negative samples. During the first round, the laboratories used either an 'in-house' PCR procedure or a partly standardized commercial test. After decoding the results of the first round, the procedures of the participating laboratories were compared in order to establish a consensus procedure deduced from those of the laboratories which provided the best results. During the second round, each participating laboratory could use the resulting consensus procedure, or its own procedure, or both. The results of this quality control study indicated that, whatever method used, even specialized and trained laboratories may give false-negative or false-positive results. The commercial assay did not guarantee a systematic high quality level of results. The striking heterogeneity of results observed among laboratories using the same commercial assay confirm that molecular biology methods need skilled technicians. The results of this quality control study suggest that full standardization of viral genome detection, including all steps of the procedure, is necessary and that the laboratories performing PCR should participate in repeated quality control studies, whatever technique is being used.

[Detection of human papillomavirus in cutaneous extragenital Bowen's disease in immunocompetent patients]

INTRODUCTION

A specific link between human papillomavirus (HPV) types 16, 18, 31, and 33 and genital carcinomas and between HPV type 5 and cutaneous extragenital carcinomas in patients with epidermodysplasia verruciformis and renal transplant has been previously found. The aim of this prospective study was to detect HPV in cases of cutaneous extragenital Bowen's disease (BD) from non-immunosuppressed patients.

PATIENTS AND METHODS

Twelve cases of cutaneous extragenital BD or Bowen's carcinoma (BC), seen in the period 1994-1996 and confirmed by histologic examination, were included in the study. Tissue sections were studied by in situ hybridization with a mixture of HPV DNA probes and specific HPV DNA probes. In addition, study on fresh materiel from 1995 included: Southern blot hybridization with various usual HPV probes (6, 11, 16, 18, 31, 33, 35, 39, 42), polymerase chain reaction (PCR) with hybridization using consensus HPV probes and probes specific for HPV types 6, 11, 16, 18 and 33. In positive samples with conventional PCR, in situ PCR with probes specific for HPV types 6/11 and 16 was performed on tissue sections.

RESULTS

In situ hybridization was negative in all the cases. Southern blot hybridization was negative in our 9 studied cases. Three cases studied by consensus PCR were positive. PCR with specific HPV probes revealed positivity on two of these cases: HPV 6 in one, and HPV 16 in another. In situ PCR was positive with a mixed 6/11 HPV probe in the third positive consensus PCR case.

DISCUSSION

Our study revealed the presence of HPV in 3 out of 12 cases of cutaneous extragenital BD and BC. HPV type 16, found in BC of skull, was the most usually found type in the literature. HPV types 6/11, detected in 2 cases, were rarely found in cutaneous extragenital BD and BC and these results are in favor of the oncogenic effect of these virus types. In our study, in situ hybridization and Southern blot hybridization were negative in all the cases; HPV was only found in 3 cases by conventional PCR and in 1 case by in situ PCR. The low range of detection of HPV in cutaneous extragenital BD may be due to the used methods, to difficulties related to sampling and/or to a low number of copies of the HPV genoma.

Quantification of hepatitis C virus RNA in serum by branched DNA-based signal amplification assays

The objective of the study was to compare the clinical sensitivity and specificity of versions 1.0 and 2.0 of the branched DNA (bDNA)-based hepatitis C virus (HCV) RNA quantification assay, and also to compare the values yielded by the two versions according to the HCV genotype. Serum samples from 268 patients tested routinely by a non-quantitative HCV RNA PCR assay (group A) were tested with version 2.0 of the bDNA assay. Samples from 342 HCV PCR-positive patients with chronic hepatitis C eligible for interferon treatment (group B) were tested with both version 1.0 and version 2.0 of the bDNA assay. Version 2.0 had a clinical sensitivity of 92% (95% confidence interval (CI): 87-97%) in group A and 89% (86-92%) in group B. In group B, the gain in sensitivity with bDNA 2.0 was 16% relative to bDNA 1.0 (P < 0.001). The log values of the two assays correlated with samples positive by both assays (r = 0.83, P < 0.0001), but the distribution of values was larger in samples containing HCV genotypes 2 and 3. The mean ratio of assay 2.0/assay 1.0 values was 1.69 +/- 1.44 (range: 0.33-13.43). The mean ratio was close to 1 with samples containing genotype 1 or 4, but ranged from 0.33 to more than 5. The mean ratio was close to 3 with samples containing genotype 2 or 3, and ranged from 0.5 to more than 13. HCV RNA levels were significantly lower in samples containing genotype 4 than in those containing other genotypes. Sera from 200 anti-HCV-negative, HCV RNA PCR-negative blood donors (group C), and from 164 anti-HCV-negative patients with symptoms of chronic liver disease (group D) were used to assess the clinical specificity of bDNA 2.0. In addition, samples with an HCV RNA titer between 0.2 (assay cutoff) and 0.5 MEq/ml from a group of 546 patients tested routinely for HCV RNA load by bDNA 2.0 (group E) were retested by bDNA 2.0 and by qualitative PCR. The specificity of bDNA 2.0 was 100% (98-100%) in group C and 99% (97-100%) in group D. Among the 41 samples from group E, 38 were positive by bDNA 2.0 retesting (36 were PCR-positive) and three were negative by bDNA 2.0 retesting (all were PCR-positive). It is concluded that version 2.0 of the bDNA assay is markedly more sensitive than version 1.0 and has a good specificity. In contrast with version 1.0, version 2.0 is not influenced by the HCV genotype. The relationship between values obtained with assays 1.0 and 2.0 on clinical specimens is not linear, indicating that HCV RNA titers cannot reliably be calculated from the results of version 1.0.

First case of yellow fever in French Guiana since 1902

The first case of yellow fever in French Guiana since 1902 was reported in March 1998. The yellow fever virus genome was detected in postmortem liver biopsies by seminested polymerase chain reaction. Sequence analysis showed that this strain was most closely related to strains from Brazil and Ecuador.

Identification of Mycobacterium DNA in an Egyptian Pott's disease of 5,400 years old

The antiquity of tuberculosis in the Old World is controversial because the morphology of the lesion in skeletal remains is non-specific. We report the recovery of a DNA fragment from a 5,400-year-old Predynastic Egyptian skeleton that exhibits a kyphotic, 'hunchback' spinal deformity consistent with Pott's disease and suggestive of tuberculous vertebral involvement. The recovered DNA fragment was sequenced and is consistent with an original Mycobacterium sequence. We cannot prove that it is M. tuberculosis, M. bovis or an ancient mycobacteria resembling the two current forms because the observed modifications in the sequence could be attributed to the antiquity of Mycobacterium and/or to the effects of Taq polymerase. This provides the most specific evidence for the antiquity of human Mycobacterium disease in the world.

[Uveitis in Whipple disease: Identification of Trophyrema whippelii by PCR]

Whipple's disease is a multisystem bacterial disease usually characterized by malabsorption, diarrhea and polyarthritis. Ocular manifestations include uveitis, vitreitis, retinis, myositis, papilledema and optic atrophy. We report a case of a chronic bilateral vitreitis in a 63 year-old man who had been treated for a Whipple's disease with gastrointestinal involvement 30 years before. The jejunal biopsy was negative but the polymerase-chain-reaction (PCR) revealed the presence of Trophyrema Whippelii in the vitreous prelevement of both eye. This new, original strategy of PCR is specific and more sensitive than histological diagnosis.

Whipple's syndrome (uveitis, B27-negative spondylarthropathy, meningitis, and lymphadenopathy) associated with Arthrobacter sp. infection

OBJECTIVE

To report an unusual case of Whipple's disease, including uveitis, seronegative spondylarthropathy, meningitis, and lymphadenopathy, associated with an Arthrobacter sp. infection.

DESIGN

Interventional case report.

PATIENT AND INTERVENTION

A 60-year-old white man presenting with severe chronic uveitis and systemic inflammatory manifestations was treated efficiently for Whipple's disease after histopathologic analysis of vitreous and inguinal adenopathy biopsy specimens. The authors performed a retrospective, laboratory-based evaluation of stored tissue specimens.

MEASUREMENTS

Molecular analysis based on 16S ribosomal RNA gene amplification was applied to pretreatment biopsy specimens of inguinal lymph node to identify a causative bacterial agent.

RESULTS

Tropheryma whippelii genome was not detected in these specimens. However, an amplification product was obtained after the first polymerase chain reaction run and subsequently was sequenced. It corresponded to an Arthrobacter sp., a gram-positive agent presenting diagnostic patterns and therapeutic management similar to those of Whipple's disease caused by T. whippelii.

CONCLUSION

The absence of T. whippelii identification by molecular amplification during a clinically and histologically oriented Whipple's syndrome should not rule out the diagnosis. Arthrobacter infection may represent a new bacterial etiology of systemic inflammatory disorders involving the eye and associated with periodic acid-Schiff-positive inclusions.

Comparison of two serological methods and a polymerase chain reaction-enzyme immunoassay for the diagnosis of acute respiratory infections with Chlamydia pneumoniae in adults

Chlamydia pneumoniae is a common respiratory tract pathogen. Serological methods currently used for the diagnosis of C. pneumoniae infection lack specificity, give ambiguous results from a single serum sample and often provide only a retrospective diagnosis. A prospective study was undertaken to assess whether PCR could be a useful addition to the serological techniques routinely practised for diagnosis. This study investigated 68 adult patients with a diagnosis of acute respiratory infection. Acute and convalescent serological determination of antibodies to C. pneumoniae were performed by means of an rELISA test and a micro-immunofluorescence (MIF) test. Nasopharyngeal aspirates or bronchoalveolar lavage specimens and bronchial aspirates obtained from the 68 patients were evaluated by PCR-enzyme immunoassay (PCR-EIA) for the presence of C. pneumoniae and by immunofluorescence assay and cell culture for virus identification. Mycoplasma pneumoniae serology was also performed. Eight patients (11.8%) were positive by either rELISA or PCR-EIA, or both, with an infection rate of 5 (18.5%) of 27 in patients with community-acquired pneumonia, 2 (9%) of 22 in asthmatic patients and 1 (5%) of 19 in patients with an exacerbation of chronic obstructive pulmonary disease. Serological evidence of acute infection was found in four of these patients with the rELISA test and in three others with the MIF test. PCR-EIA detected C. pneumoniae DNA in four specimens, but there were concordant results with both rELISA and PCR-EIA in only one patient A positive PCR-EIA was also obtained in a patient who did not show an antibody response in acute serum. The discrepancy between serological and PCR-EIA results reflects the difficulties in routine laboratory diagnosis of C. pneumoniae infection and the necessity for further studies with optimised techniques.

Comparative prevalence, incidence and short-term prognosis of cervical squamous intraepithelial lesions amongst HIV-positive and HIV-negative women

OBJECTIVE

To investigate the impact of HIV infection on the prevalence, incidence and short-term prognosis of squamous intraepithelial lesions (SIL), in a prospective study with 1-year follow-up.

METHODS

Between 1993 and 1995, 271 HIV-positive and 171 HIV-negative women at high risk of HIV infection were recruited, 365 (82.6%) of whom completed the 1-year follow-up. The women underwent a Papanicolaou smear test at inclusion and at 6 and 12 months. Human papillomavirus (HPV) was detected at inclusion by Southern blot and PCR.

RESULTS

The SIL prevalence ranged from 7.5% for HIV-negative to 31.3% for HIV-positive women with CD4 cell counts < 500 x 10(6)/l (P < 0.001). Other factors associated independently and significantly with SIL prevalence were HPV-16, 18, 33 and related types, HPV-31, -35, -39 and related types, lifetime number of partners, younger age, past history of SIL and lack of past cervical screening. The SIL incidence ranged from 4.9% in HIV-negative women to 27% in HIV-positive women with CD4 cells < 500 x 10(6)/l (P < 0.001). Progression from low- to high-grade SIL during follow-up was detected in 38.1% of HIV-positive women with CD4 cells < or = 500 x 10(6)/l but in no HIV-negative nor HIV-positive women with CD4 cells > 500 x 10(6)/l. HPV-16, 18, 33 and related types were also associated with higher incidence of SIL and progression from low- to high-grade SIL.

CONCLUSION

HIV-induced immunodeficiency is associated with high prevalence, incidence and persistence/progression of SIL. A pejorative influence of HIV infection without marked immunodeficiency is less clear. HIV-positive women with SIL may thus benefit from early treatment when a useful immune response is still present.

Comparison of clinical, histological, and virological symptoms of HPV in HIV-1 infected men and immunocompetent subjects

OBJECTIVE

We assessed the clinical, histological, and virological features of anogenital human papillomavirus (HPV) infection, according to their immune status in HIV-1 infected men, referred for an anogenital examination or treatment, in comparison with immunocompetent patients.

METHODS

The study population comprised 33 HIV-1 infected heterosexual or homosexual men and 38 HIV negative men seen in a screening and treatment centre for anogenital HPV infections. All patients were examined with a colposcope. Biopsies were carried out on all subjects with anogenital lesions for histological studies and HPV detection by Southern blot.

RESULTS

The HIV infected patients had a balanopreputial HPV infection in 70%, anal in 30%, and urethral in 37%, while HIV negative patients had balanopreputial lesion in 72%, anal in 26%, and urethral in 16%. Diffuse anogenital lesions were present in 33% of the HIV infected cases and in 10.5% of HIV negative cases (p < 0.02). Among the HIV infected patients, the genital HPV lesions were condylomatous in 67.5% of the cases and dysplastic in 57%. HIV negative patients had condylomatous lesions in 86% of the cases and dysplasic in 14%. The condylomatous lesions of HIV infected patients had a low grade malignant histological aspect in 36% of the cases and high grade histological criteria were found in 22% of the dysplasias. Oncogenic HPVs were detected more frequently in HIV infected patients (35% v 12%) and more than one HPV type was found in 21.5% of cases. Neither the anogenital diffusion of the HPV lesions nor their morphological, histological, and virological features differed significantly in patient with CD4 cell counts > or < 200 x 10(6)/l. In contrast, patients with CD4 cell counts < 50 x 10(6)/l had a higher risk of several types of HPVs and of developing a diffuse anogenital infection.

CONCLUSION

HIV-1 infected patients had an increased frequency of high grade anogenital dysplastic lesions and a higher frequency of HPV infection with multiple and diffuse sites of involvement. These characteristics of HPV infection were independent of the patients' immune status up to CD4 cell counts > 50 x 10(6)/l but showed an increased risk when the CD4 cell count was < 50 x 10(6)/l. The higher frequency of diffuse anogenital infections among HIV infected men calls for rapid treatment, laser or surgery, given the association of histological features of intraepithelial neoplasia and the presence of multiple HPV infection sites which may be the consequence of immune disturbances, most of which are transmissible potentially oncogenic HPVs.

Human immunodeficiency virus infection and AIDS in a person with negative serology

A 38-year-old woman resident of Ivory Coast died of AIDS, while remaining human immunodeficiency virus (HIV)-seronegative. She had been regularly tested because her husband was HIV-seropositive. The subject's lack of specific antibodies was assessed using commercial tests and confirmed by a radioimmunoprecipitation assay of the patient's virus. She was unquestionably HIV-1-infected, with a high plasma virus load, and her virus could be isolated. Molecular analyses indicated this retrovirus was clade A, which is common in Africa, and it was highly homologous to the virus isolated from her husband. The subject's seronegative status was thought to be due to rapid depletion of specific CD4+ helper T cells, resulting from accelerated disease progression, and was host-related rather than due to a specific HIV strain.

[Prevalence of Chlamydia trachomatis among men consulting in urology. Comparative study between cell culture and sperm PCR]

OBJECTIVE

Genital Chlamydia trachomatis infection can be difficult to diagnose, depending on the precise site of infection. Given the lack of major clinical signs and symptoms in many cases and the risk of male and female infertility. Chlamydia trachomatis is a public health problem. It can be difficult to detect this pathogen in sperm by means of cell culture, because of seminal fluid toxicity for cell lines. New techniques such as the polymerase chain reaction (PCR) can be used to detect genomic DNA.

STUDY DESIGN

We studies 81 patients by applying the Amplicor CT PCR test to sperm, in comparison with cell culture on sperm and urethral samples.

RESULTS

The prevalence of Chlamydia trachomatis infection was not significantly different (3.7% vs 5%) in the urethral cell culture and PCR methods, respectively (p > 0.05). In contrast, PCR was significantly more sensitive than sperm cell culture (5% vs 1.2%; p < 0.03). Moreover, we have not detected of genital chlamydiose among the infertile men.

CONCLUSION

These findings suggest that PCR detection of Chlamydia trachomatis can dispense with the need for urethral sampling and cell culture in selected male patients.

Genitourinary tuberculosis: rapid diagnosis using the polymerase chain reaction

We present the case of a patient with suspected genitourinary tuberculosis in whom confirmation by direct smear examination was negative. Detection of mycobacterial DNA by use of the polymerase chain reaction (PCR) established the diagnosis, which was confirmed by culture 4 weeks later. Given its very high sensitivity and positivity, PCR may become the method of choice for rapid diagnosis of genitourinary tuberculosis and institution of therapy.

Unapparent systemic dissemination of Mycobacterium tuberculosis

A healthy 6-week-old girl exposed to tuberculosis presented a positive DNA amplification for Mycobacterium tuberculosis complex in gastric aspirates and cerebrospinal fluid whereas she had no other clinical or biological symptoms. Cultures were negative. This report underlines the interest of polymerase chain reaction for early diagnosis of tuberculosis and suggests the importance of treating exposed neonates and young infants just as active tuberculosis.

Use of polymerase chain reaction for improved diagnosis of tuberculosis in children

OBJECTIVE

To study the value of a rapid diagnostic method based on the amplification by polymerase chain reaction (PCR) of a fragment of the IS6110 insertion element for the detection of Mycobacterium tuberculosis in children.

DESIGN

We tested 199 specimens obtained from 68 children referred for evaluation of suspected tuberculosis.

RESULTS

In 83.3% of children with active disease and 38.9% with tuberculous infection but no evidence of disease, at least one positive PCR result was observed. No child without tuberculosis had positive PCR results (100% specificity). The sensitivity of the PCR was increased by testing of multiple samples from the same child and use of Chelex particles (Bio-Rad Laboratories, Ivry, France) rather than guanidine isothiocyanate-silica particles for DNA extraction. Bronchoalveolar lavage samples were no more useful than gastric aspirates.

CONCLUSIONS

If appropriate laboratory methods are used, DNA amplification is a reliable method for the early diagnosis of tuberculosis in children and appears to be very helpful in clinical pediatric practice when the diagnosis of active tuberculosis is difficult or needs to be rapidly confirmed.

[Generalized BCG infection after intravesical instillations of Calmette-Guerin bacillus]

BCG has been disappointing as immunotherapy of numerous cancers, but it has been clinically successful in the intravesical treatment of bladder carcinomas sparing the muscle coat; it has indeed become the reference treatment for this type of cancer. However, complications are repeatedly reported, including generalized BCGitis. We report such a case with positive BCG culture. From the cases already published there emerges a homogeneous and often subacute clinical presentation suggestive of an ordinary pathogen. Bacteriology is not very helpful, even when recent techniques are used, and therefore the diagnosis rests on the context and, when samples are taken, on suggestive histological findings. To discuss the physiopathology of BCGitis--generalized immune reaction or multifocal BCG proliferation--is not useless since treatment depends on it. It is probable that these 2 mechanisms working together can be incriminated justifying the prescription of both antibiotics and corticosteroids. When this is done, the prognosis seems to be favourable in most patients. Yet a strict respect of contra-indications and a very careful subsequent radiotherapy should reduce the risks.

Evaluation of nonradioactive DNA probes for identification of mycobacteria

Commercial chemiluminescent DNA probes (Accuprobe; Gen-Probe, San Diego, Calif.) for the identification of Mycobacterium tuberculosis (MTB) complex, M. avium complex (MAC), M. gordonae, and M. kansasii were evaluated with 134 clinical isolates. These included 36 MTB complex, 40 MAC, 27 M. gordonae, 9 M. kansasii, and 22 Mycobacterium spp. The specificity was 100% for the four probes. The sensitivity was 100% for the MTB complex and M. gordonae probes and 95.2% for the MAC probe. Five of the nine M. kansasii isolates tested were not detected with the probe.

Quantitative in situ hybridization using strand specific RNA probes: expression of the bunyavirus Germiston S segment in mosquito cells

Infection of Vero (monkey) cells by Germiston bunyavirus is highly cytopathic with cell lysis and virus production at a high titre, whereas infection of Aedes albopictus C6/36 (mosquito) cells leads, after an acute primary phase, to a persistent non-cytopathic infection with a loss in virus production. In this report we demonstrate that single-stranded RNA probes can be successfully used in an in situ hybridization assay to quantify viral expression during this persistent infection. The steady-state levels of viral S-RNA segment (genomic and messenger sense) during the acute phase were similar to those observed in lytically infected Vero cells, but appeared delayed. Both senses of S-RNA were detected throughout persistent infection but in lower amounts, in less than 10% of the cells and always in the cytoplasm of infected cells. The number of copies per cell of messenger sense S-RNAs remained low during persistent infection whereas a higher fluctuation was observed for genomic S-RNAs. In situ hybridization with specific stranded RNA probes provides both qualitative and quantitative informations, that can lead to a better understanding of virus-cell interactions.

Detection of the bunyavirus Germiston in VERO and Aedes albopictus C6/36 cells by in situ hybridization using cDNA and asymmetric RNA probes

Using Germiston virus infected vertebrate (VERO) and invertebrate (Aedes albopictus C6/36) cells, paraformaldehyde-glutaraldehyde fixative allowed the best preservation of cellular morphology and the highest hybridization signals with cDNA and asymmetric RNA probes against the viral S segment. Asymmetric RNA probes always gave higher sensitivity and better specificity of in situ hybridization than the nick-translated symmetric DNA probe in both vertebrate and invertebrate cells. The study of Aedes albopictus C6/36 cells persistently infected with Germiston virus showed that only a small number of cells contained the S segment, and that the replication and transcription of the S segment took place in the cytoplasm of acutely and persistently infected cells.