Occupational risk of human Cytomegalovirus and Parvovirus B19 infection in female day care personnel in the Netherlands; a study based on seroprevalence

Cytomegalovirus (CMV) and Parvovirus B19 infections acquired during pregnancy may result in developmental disabilities of the foetus. This study evaluates the occupational risk of these infections in female day care personnel. IgG seroprevalence was determined in 310 Dutch day care workers and 158 nursing school students. CMV seroprevalence was age-related, starting at 21% in those <20 years and reaching 65% in those >35 years. Between the ages of 20 and 24 years the CMV prevalence was higher in day care personnel than in controls, 50% versus 31% (p = 0.03). In the first 2 years of employment the risk of attracting CMV was significantly increased (OR(adj) = 3.80; p < 0.001) and the occupational risk was also increased (OR(adj) 2.19; p < 0.001). Parvovirus seropositivity (71-77%) was not related to age or working at a day care centre. In conclusion, an occupational risk was observed for CMV, but not for Parvovirus infection in female day care personnel.

Evaluation of a rapid one-step immunochromatographic test and two immunoenzymatic assays for the detection of anti-Treponema pallidum antibodies

BACKGROUND

The control of syphilis depends on screening of the population at risk and is usually performed using the Treponema pallidum particle agglutination test (TPPA). Outside Europe the rapid plasma reagin test (RPR) or venereal disease research laboratory test is most often used for screening purposes. Because of the drawbacks in current diagnostic procedures, ie, long turnaround time, the need is felt for a rapid and simple test that can potentially be performed on whole blood.

OBJECTIVE AND STUDY DESIGN

In this study a one-step immunochromatographic test (Biorapid Syphilis) and two ELISA, the Bioelisa Syphilis 3.0 and ETI-Treponema Plus, were evaluated.

METHODS

Serum samples were collected between February 2000 and May 2006 at the University Hospital in Maastricht, The Netherlands. 145 TPPA-positive sera, confirmed by fluorescent treponemal antibody absorption (FTA-Abs, treponemal test) and/or RPR (non-treponemal) were included. Furthermore, 41 sera from healthy controls and 144 TPPA-negative sera from controls with underlying conditions that might interfere with T pallidum serology were collected.

RESULTS

The sensitivity and specificity of the Biorapid Syphilis, Bioelisa Syphilis 3.0 and ETI-Treponema Plus were 92% and 79%, 100% and 100% and 100% and 100%, respectively, with our selected sera.

CONCLUSIONS

The performance of both ELISA was excellent in our study and is favoured over the TPPA because of its ability to be run on an automated system. The sensitivity and specificity of the Biorapid Syphilis were considered too low to implement the test in a hospital laboratory in a developed country but it might be useful in primary healthcare settings in developing countries.

Comparison of five different immunoassays for the detection of Borrelia burgdorferi IgM and IgG antibodies

The performances of five commercially available enzyme immunoassays were compared for the detection of Borrelia burgdorferi IgM and IgG antibodies. Sensitivity was assessed with European serum samples collected from 45 patients with clinically defined Lyme disease in conjunction with a positive immunoblot (n = 44) or other serological test (n = 1). Sensitivities for the detection of IgM and IgG with each test were: Dako IgM 64%; Dako IgG 53%; Serion IgM 89%; and Serion IgG 88%. The Immunetics assay makes no distinction between IgM and IgG antibodies and had a sensitivity of 91%. Specificity was calculated by testing a control group comprising 40 patients with acute Epstein-Barr virus infection, cytomegalovirus infection, syphilis or rheumatoid factor positivity. The specificities achieved for each test were: Dako IgM 78%; Dako IgG 100%; Serion IgM 52%; Serion IgG 92%; and Immunetics 92%. The discriminatory power between control and patient samples appeared highest for the Immunetics assay. Between-run variation was comparable for the five tests and did not exceed 13%. When the Immunetics assay was used as an initial screening test, with low-titre positive results confirmed by an immunoblot, a sensitivity of 91% and a specificity of 100% were achieved. To attain maximal sensitivity, the Serion IgM and IgG tests were also performed on samples with negative Immunetics results. All positive Serion IgM and IgG results were also confirmed by immunoblot. In conclusion, the Immunetics assay, based on a synthetic C6 peptide, can be used reliably as an initial screening test for the serodiagnosis of Lyme disease.

Different profiles of cytomegalovirus RNA transcripts and anti-cytomegalovirus IgM antibodies in renal transplant recipients

BACKGROUND

A difference in anti-cytomegalovirus IgM antibody profile has been found between sera from acutely cytomegalovirus (CMV)-infected patients and sera from CMV-infected patients with subclinical infection.

OBJECTIVES

The aim of this study is to investigate whether such different IgM antibody responses are correlated with differences in the expression of CMV immediate early and late mRNAs.

STUDY DESIGN

We have investigated the anti-CMV IgM response in 46 renal transplant recipients by employing two commercially available IgM kits (AxSYM and IMX) as well as two novel enzyme-linked immunosorbent assays (ELISAs), which were developed using recombinant ppUL32 (pp150) and pUL80a (p38), respectively. The results were compared with four direct CMV diagnostic tests: pp65 antigenemia, viral culture and nucleic acid sequence-based amplification (NASBA), detecting either CMV immediate early 1 (IE1) mRNA (IE1-NASBA), or CMV pp67 (late) mRNA (pp67-NASBA).

RESULTS

Analysis of all CMV-infected recipients (n=28) showed that in 16 recipients (group I) more than one direct test became positive after transplantation, while in the other 12 recipients (group II), IE1-NASBA was the only direct test to become positive. In group I, 100, 81, 100 and 50% of the recipients were IgM-positive with AxSYM, IMX, p38 and pp150, respectively. In group II, 100, 83, 17 and 83% of the recipients were IgM-positive with AxSYM, IMX, p38 and pp150, respectively.

CONCLUSIONS

Our data indicate that the IgM-response against p38 and pp150 differs significantly (P<0.01) between group I recipients with productive CMV infection, and group II recipients with a non-productive CMV infection which may be of diagnostic and prognostic relevance.

Screening of patients with complex regional pain syndrome for antecedent infections

OBJECTIVE

This study was designed to investigate whether Complex Regional Pain Syndrome type I (CRPS I) could be linked to any previous infection.

PATIENTS

Fifty-two patients with CRPS I of one extremity were screened for the presence of antibodies against mostly neurotropic microorganisms.

RESULTS

Of these 52 patients, none had antibodies against Treponema pallidum, Borrelia burgdorferi, or HTLV-1. Only four patients were positive for Campylobacter jejuni. For cytomegalovirus, Epstein-Barr virus, herpes simplex virus, and Toxoplasma gondii, seroprevalences were similar to control values. The total seroprevalence of Parvovirus B 19 in our CRPS population was 77%, which was significantly higher than in an independent Dutch population group (59%). Seroprevalence in lower extremity CRPS 1 (94%) was significantly higher than in upper extremity CRPS I patients (68%). In this study all patients were seropositive for varicella zoster virus (VZV) antibodies, but a high prevalence of VZV antibodies is similar to its prevalence in a normal population (>90%).

CONCLUSIONS

In this study we found a significantly higher seroprevalence of Parvovirus B19 in CRPS I and this is most striking in lower extremity CRPS I patients. Further serologic research in other geographic areas is needed to provide additional information about a potential role of Parvovirus B 19 or other microorganisms in the etiopathogenesis of CRPS I.

Chlamydia pneumoniae and screening for tubal factor subfertility

Chlamydia antibody testing (CAT) by micro-immunofluorescence (MIF) tests has been introduced into the fertility work-up as a screening test for tubal factor subfertility. In this study the role of C. pneumoniae antibodies, as a cause for false positive CAT results due to cross-reactivity with C. trachomatis antibodies in the MIF test, has been evaluated. In 240 subfertile women serological data were compared to laparoscopy findings. The prevalence of C. pneumoniae antibodies using enzyme-linked immunosorbent assay (ELISA) was 75% and did not differ between patients with and without tubal pathology. C. pneumoniae antibodies were found in 87% of women with a positive MIF test (> or =32), and in 66% with a negative MIF test (P < 0.0005). Using ELISA instead of MIF for the detection of C. trachomatis antibodies, C. pneumoniae antibodies were found in 87% of C. trachomatis positive women, and in 69% of C. trachomatis negative women (P < 0.0005). Patients without tubal factor subfertility but a positive MIF test showed C. pneumoniae antibodies more frequently than patients without tubal factor subfertility and a negative MIF test. Therefore it was suggested that C. pneumoniae antibodies may be the cause of false positive CAT results. Remarkably, tubal pathology was more common in patients who had antibodies to both C. trachomatis and C. pneumoniae.

Diagnostic implications of human cytomegalovirus immediate early-1 and pp67 mRNA detection in whole-blood samples from liver transplant patients using nucleic acid sequence-based amplification

Nucleic acid sequence-based amplification (NASBA) was used for detection of the human cytomegalovirus (CMV) immediate early-1 (IE) and the late pp67 mRNA in 353 blood samples collected from 34 liver transplant patients. The diagnostic value of these assays was compared to that of the pp65 antigenemia assay. Overall, 95 and 42% of the antigenemia-positive samples were IE NASBA and pp67 NASBA positive, respectively. Although the results from pp67 NASBA and the antigenemia assay appeared to correspond poorly, a clear correlation was seen between pp67 NASBA-negative results and low numbers of pp65 antigen-positive cells. Twenty patients (59%) were treated with ganciclovir after the diagnosis of symptomatic CMV infection. Before initiation of the antiviral therapy, the antigenemia assay detected the onset of symptomatic infection in all patients, whereas 95 and 60% of these patients were IE NASBA and pp67 NASBA positive, respectively. Although the sensitivity of IE NASBA was very high, the positive predictive value (PPV) of this assay for the onset of a symptomatic infection was only 63%. The PPV of the antigenemia assay as well as pp67 NASBA was considerably higher (80 and 86%, respectively). Thus, the detection of IE mRNA using NASBA appears to be particularly useful as a marker for early initiation of antiviral therapy in patients at high risk for the development of a symptomatic infection. Also, IE NASBA was found to be more sensitive than the antigenemia assay for monitoring CMV infection during antiviral therapy. On the contrary, pp67 NASBA did not appear to have additional diagnostic value compared to the antigenemia assay.

Diagnostic value of nucleic-acid-sequence- based amplification for the detection of cytomegalovirus infection in renal and liver transplant recipients

To evaluate the diagnostic value of nucleic-acid-sequence-based amplification (NASBA) for the detection of cytomegalovirus (CMV) infection in transplant recipients, we compared immediate early 1 (IE1) and late pp67 mRNA detection by NASBA with the antigenemia assay, PCR and viral culture in 72 renal transplant (RTx) recipients and with antigenemia and serology in 25 liver transplant (LTx) recipients. Antigenemia, viral culture and pp67 NASBA were almost equivalent for the detection of CMV in RTx recipients. In LTx recipients, antigenemia detected more positive samples and more positive recipients compared to pp67 NASBA. In RTx recipients, PCR detected more positive samples and positive recipients compared to pp67 NASBA, antigenemia and viral culture. Also the first day of detection was slightly earlier for PCR. However, IE1 NASBA was the most sensitive test and detected 96% of all positive samples and positive transplant recipients. In addition, IE1 NASBA preceded PCR and all other positive results. This makes IE1 NASBA a very attractive screening test for the early detection of CMV infection.

Early detection of human cytomegalovirus infection after kidney transplantation by nucleic acid sequence-based amplification

BACKGROUND

The early detection of human cytomegalovirus infection after organ transplantation is a prerequisite for effective antiviral therapy. We evaluated the diagnostic value of monitoring the viral immediate-early (IE) 1 mRNA expression in blood leukocytes by nucleic acid sequence-based amplification (NASBA).

METHODS

Nucleic acids were isolated from 489 blood samples collected from 42 kidney transplant recipients and subjected to amplification by IE NASBA. The IE NASBA results were compared to those from pp67 NASBA, pp65 antigenemia, cell culture (DEAFF and CPE), and serology.

RESULTS

IE NASBA proved to be the most sensitive assay which detected the onset of both primary and secondary cytomegalovirus infection significantly earlier than the other assays.

CONCLUSIONS

The early detection of cytomegalovirus infection with IE NASBA would enable the start of effective antiviral therapy at an early state of infection to prevent cytomegalovirus disease in patients at risk.

Evaluation of a new method for early detection of active cytomegalovirus infections. A study in kidney transplant recipients

Early detection of active cytomegalovirus (CMV) infection after organ transplantation is necessary to start effective antiviral treatment. In the present study, blood specimens of kidney transplant recipients (n = 38) were monitored for the expression of CMV immediate early (IE) and late (L) mRNA using nucleic acid sequence-based amplification (NASBA). Results were compared with virus isolation, pp65 antigenemia and serology. In patients developing active CMV infection, pp65 antigen and L mRNA were detected simultaneously. At the same time, positive cell culture results could be reported to the clinic. CMV was detected significantly earlier with IE NASBA than with the other assays. However, the specificity of IE NASBA is lower than that of antigenemia, late NASBA and cell culture. Early detection of IE mRNA is especially useful for patients at high risk of developing symptomatic CMV infection in order that early, adequate antiviral therapy may be started. Late NASBA can be used to monitor further development of CMV infection, comparable to antigenemia.

Diagnostic value of monitoring human cytomegalovirus late pp67 mRNA expression in renal-allograft recipients by nucleic acid sequence-based amplification

The diagnostic value of monitoring human cytomegalovirus (HCMV) late pp67 mRNA expression by nucleic acid sequence-based amplification (NASBA) after renal-allograft transplantation was evaluated. RNAs were isolated from 489 whole-blood specimens of 42 patients for the specific amplification of the late pp67 (UL65) mRNA. NASBA results were compared to results from the pp65 antigenemia assay, virus isolation by cell culture, and serology. The sensitivity value for NASBA proved to be higher than that for the antigenemia assay (50 versus 35%) for the detection of HCMV infection, while the sensitivity values of cell culture and NASBA were comparable (54 and 50%, respectively). NASBA detected the onset of HCMV infection simultaneously with cell culture and the antigenemia assay. Both the antigenemia assay and NASBA are very specific (100%) and highly predictive (100%) for the onset of HCMV infection. Antiviral therapy with ganciclovir resulted in negative results for cell culture, the antigenemia assay, and NASBA. In conclusion, monitoring HCMV pp67 mRNA expression by NASBA is a highly specific method for the detection of HCMV infection in renal-allograft recipients and is more sensitive than the antigenemia assay. Furthermore, NASBA can be used to monitor the progression of HCMV infections and the effect of antiviral therapy on viral activity.

How to use Chlamydia antibody testing in subfertility patients

Screening for tubal factor subfertility by means of Chlamydia antibody testing (CAT) was introduced into the initial work-up of subfertile couples several years ago. The results reported, however, are heterogeneous, and no uniformity exists in cut-off levels of titres, or in definitions of tubal factor subfertility. We performed a prospective cohort study to evaluate the implications of varying the definitions of tubal pathology and of modifying the cut-off levels on the clinical impact of CAT in predicting tubal factor subfertility. In 227 consecutive patients who attended our fertility clinic, the Chlamydia IgG antibody titre was determined and related to tuboperitoneal abnormalities at laparoscopy as a reference standard. According to received operating characteristic (ROC) curve analysis, a titre of 16 is the optimum cut-off level. Increasing the cut-off level improves specificity and positive likelihood ratio (LR+), at the expense of sensitivity and negative LR (LR-). Changing the definition of tubal factor subfertility from unspecified tuboperitoneal abnormalities into extensive adhesions and/or bilateral distal tubal occlusion improves LR+, LR- and kappa significantly. We conclude that CAT is more accurate in predicting severe distal tubal pathology than unspecified tuboperitoneal abnormalities. Although from a statistical point of view a titre of 16 is the optimum cut-off level, from a clinical point of view 32 or 64 may be preferable, depending on the aim of screening and the inception cohort.