A Pooled Analysis to Compare the Clinical Characteristics of Human Papillomavirus-positive and -Negative Cervical Precancers.

Given that high-risk human papillomavirus (HPV) is the necessary cause of virtually all cervical cancer, the clinical meaning of HPV-negative cervical precancer is unknown. We, therefore, conducted a literature search in Ovid MEDLINE, PubMed Central, and Google Scholar to identify English-language studies in which (i) HPV-negative and -positive, histologically confirmed cervical intraepithelial neoplasia grade 2 or more severe diagnoses (CIN2+) were detected and (ii) summarized statistics or deidentified individual data were available to summarize proportions of biomarkers indicating risk of cancer. Nineteen studies including 3,089 (91.0%) HPV-positive and 307 (9.0%) HPV-negative CIN2+ were analyzed. HPV-positive CIN2+ (vs. HPV-negative CIN2+) was more likely to test positive for biomarkers linked to cancer risk: a study diagnosis of CIN3+ (vs. CIN2; 18 studies; 0.56 vs. 0.24; P < 0.001) preceding high-grade squamous intraepithelial lesion cytology (15 studies; 0.54 vs. 0.10; P < 0.001); and high-grade colposcopic impression (13 studies; 0.30 vs. 0.18; P = 0.03). HPV-negative CIN2+ was more likely to test positive for low-risk HPV genotypes than HPV-positive CIN2+ (P < 0.001). HPV-negative CIN2+ appears to have lower cancer risk than HPV-positive CIN2+. Clinical studies of human high-risk HPV testing for screening to prevent cervical cancer may refer samples of HPV test-negative women for disease ascertainment to correct verification bias in the estimates of clinical performance. However, verification bias adjustment of the clinical performance of HPV testing may overcorrect/underestimate its clinical performance to detect truly precancerous abnormalities.

HPV DNA testing with cytology triage in cervical cancer screening: Influence of revealing HPV infection status.

BACKGROUND: Knowledge of cervical human papillomavirus (HPV) status might influence a cytotechnician's assessment of cellular abnormalities. The authors compared original cytotechnicians' Papanicolaou (Pap) readings for which HPV status was concealed with Pap rereads for which HPV status was revealed separately for 3 screening populations. METHODS: Previously collected cervical Pap smears and clinical data were obtained from the Canadian Cervical Cancer Screening Trial (study A), the Democratic Republic of Congo Community-Based Screening Study (study B), and the Brazilian Investigation into Nutrition and Cervical Cancer Prevention (study C). Smears were reread with knowledge of HPV status for all HPV-positive women as well as a sample of HPV-negative women. Diagnostic performance of Pap cytology was compared between original readings and rereads. RESULTS: A total of 1767 Pap tests were reread. Among 915 rereads for HPV-positive women, the contrast between "revealed" and "concealed" Pap readings demonstrated revisions from negative to positive results for 109 women (cutoff was atypical squamous cells of undetermined significance or worse) and 124 women (cutoff was low-grade squamous intraepithelial lesions [LSIL] or worse). For a disease threshold of cervical intraepithelial neoplasia of grade 2 or worse, specificity significantly declined at the atypical squamous cells of undetermined significance cutoff for studies A (86.6% to 75.3%) and C (42.5% to 15.5%), and at the LSIL cutoff for study C (61.9% to 37.6%). Sensitivity remained nearly unchanged between readings, except in study C, in which reread performance was superior (91.3% vs 71.9% for the LSIL cutoff). CONCLUSIONS: A reduction in the diagnostic accuracy of Pap cytology was observed when revealing patients' cervical HPV status, possibly due to a heightened awareness of potential abnormalities, which led to more false-positive results.

Effect of vaginal self-sampling on cervical cancer screening rates: a community-based study in Newfoundland.

BACKGROUND: Cervical cancer is highly preventable and treatable if detected early through regular screening. Women in the Canadian province of Newfoundland & Labrador have relatively low rates of cervical cancer screening, with rates of around 40 % between 2007 and 2009. Persistent infection with oncogenic human papillomavirus (HPV) is a necessary cause for the development of cervical cancer, and HPV testing, including self-sampling, has been suggested as an alternative method of cervical cancer screening that may alleviate some barriers to screening. Our objective was to determine whether offering self-collected HPV testing screening increased cervical cancer screening rates in rural communities. METHODS: During the 2-year study, three community-based cohorts were assigned to receive either i) a cervical cancer education campaign with the option of HPV testing; ii) an educational campaign alone; iii) or no intervention. Self-collection kits were offered to eligible women at family medicine clinics and community centres, and participants were surveyed to determine their acceptance of the HPV self-collection kit. Paired proportions testing for before-after studies was used to determine differences in screening rates from baseline, and Chi Square analysis of three dimensional 2 × 2 × 2 tables compared the change between communities. RESULTS: Cervical cancer screening increased by 15.2 % (p < 0.001) to 67.4 % in the community where self-collection was available, versus a 2.9 % increase (p = 0.07) in the community that received educational campaigns and 8.5 % in the community with no intervention (p = 0.193). The difference in change in rates was statistically significant between communities A and B (p < 0.001) but not between communities A and C (p = 0.193). The response rate was low, with only 9.5 % (168/1760) of eligible women opting to self-collect for HPV testing. Of the women who completed self-collection, 15.5 % (26) had not had a Pap smear in the last 3 years, and 88.7 % reported that they were somewhat or very satisfied with self-collection. CONCLUSIONS: Offering self-collected HPV testing increased the cervical cancer screening rate in a rural NL community. Women who completed self-collection had generally positive feelings about the experience. Offering HPV self-collection may increase screening compliance, particularly among women who do not present for routine Pap smears.

Stability of cervical specimens in SurePath medium for human papillomavirus testing with the Roche cobas 4800 assay.

The stability of cervical specimens in SurePath preservative fluid for human papillomavirus (HPV) testing with Roche cobas 4800 was determined using a panel of 308 pooled specimens from a colposcopy referral population. The SurePath specimens appeared to be stable for up to 10 weeks at ambient temperature for HPV testing with cobas 4800.

Type-specific prevalence of human papillomavirus in women screened for cervical cancer in Labrador, Canada.

BACKGROUND: A higher incidence of cervical cancer and human papillomavirus (HPV) infection has been reported in northern Canada and in First Nation, Métis and Inuit women, with some evidence to suggest that the HPV type distribution in these populations may be different from the rest of Canada. OBJECTIVE: The objective of this study was to measure the HPV type prevalence in Labrador women to determine if significant differences in HPV types could reduce the effectiveness of HPV vaccination. DESIGN: The prevalence of HPV types was determined in 1,370 women presenting for routine pap screening in Labrador between February and November 2010. Cervical cytology and HPV genotyping were performed on the same liquid-based cytology specimens. RESULTS: The overall prevalence of HPV was 21.4%; cytological abnormalities were found in 8.8% of the participants. HPV 16 and 18 were the most common high-risk HPV types. These two types were found in 52.4% of high-grade lesions. The prevalence in HPV infections was comparable across the Labrador regions. CONCLUSIONS: The present results support the potential effectiveness of the HPV immunization program in Labrador.

Performance of ProEx C and PreTect HPV-Proofer E6/E7 mRNA tests in comparison with the hybrid capture 2 HPV DNA test for triaging ASCUS and LSIL cytology.

The clinical usefulness of the ProEx C (Becton Dickinson) and PreTect HPV-Proofer E6/E7 mRNA tests (Proofer; Norchip) for the triage of ASCUS and LSIL cytology was determined in comparison with the Hybrid Capture 2 HPV DNA test (HC2; Qiagen). The study population consisted of women with a history of abnormal cytology referred to colposcopy. Histology-confirmed CIN 2+ served as the disease endpoint. The study was based on 1,360 women (mean age 30.7 years), of whom 380 had CIN 2+. Among 315 with ASCUS (CIN 2+, n = 67), the sensitivities of ProEx C, Proofer, and HC2 to detect CIN 2+ were, 71.6, 71.6, and 95.5%, respectively, with a corresponding specificity of 74.6, 74.2, and 35.1%. Among 363 with LSIL (CIN 2+, n = 108), the sensitivities of ProEx C, Proofer, and HC2 were, 67.6, 74.1, and 96.3%, respectively, with a corresponding specificity of 60, 68.2, and 18.4%. Among 225 HC2-positive ASCUS (CIN 2+, n = 64), 105 tested positive by ProEx C, reducing colposcopy referral by 53.3% and detecting 71.9% of CIN 2+; Proofer was positive in 112/225, reducing colposcopy referral by 50.2% and detecting 75.0% of CIN 2+. Among 312 HC2-positive LSIL (CIN 2+, n = 104), 160 tested positive by ProEx C, reducing coloposcopy referral by 48.7% and detecting 66.3% of CIN 2+; Proofer was positive in 159/312, reducing colposcopy referral by 49.0% and detecting 75.0% of CIN 2+. In conclusion, both ProEx C and Proofer have a similar performance profile with a significantly higher specificity but lower sensitivity than HC2 for the detection of CIN 2+. Consequently, although they can reduce colposcopy referral, they will miss a proportion of CIN 2+ cases. This is a major limitation and should be taken into account if these tests are considered for ASCUS or LSIL triage.

Novel microsphere-based method for detection and typing of 46 mucosal human papillomavirus types.

We have developed a novel microsphere-based genotyping method for 46 mucosal human papillomavirus (HPV) types. HPV DNA was amplified by PCR using general primers and typed by hybridization to HPV type-specific probes coupled to sortable microspheres based on the Luminex xMAP technology. Hybridization to each probe was specific for each HPV type without cross-hybridization and sensitive enough to allow typing of HPV contained in clinical specimens. The method was validated with direct sequencing and the Roche Linear Array genotyping method.

Distribution of human papillomavirus genotypes in cervical intraepithelial neoplasia and invasive cervical cancer in Canada.

Infection with high-risk human papillomavirus (HPV) causes cervical intraepithelial neoplasia (CIN) and invasive cervical cancer (ICC). The distribution of HPV types in cervical diseases has been previously described in small studies for Canadian women. The prevalence of 36 HPV genotypes in 873 women with CIN and 252 women with ICC was assessed on cervical exfoliated cells analyzed with the Linear Array (Roche Molecular System). HPV16 was the most common genotype in CIN and ICC. The seven most frequent genotypes in order of decreasing frequency were HPV16, 51, 52, 31, 39, 18, and 56 in women with CIN1, HPV16, 52, 31, 18, 51, 39, and 33 in women with CIN2, HPV16, 31, 18, 52, 39, 33, and 58 in women with CIN3, and HPV16, 18, 45, 33, 31, 39, and 53 in women with ICC. HPV18 was detected more frequently in adenocarcinoma than squamous cell carcinoma (P = 0.013). Adjustment for multiple type infections resulted in a lower percentage attribution in CIN of HPV types other than 16 or 18. The proportion of samples containing at least one oncogenic type was greater in CIN2 (98.4%) or CIN3 (100%) than in CIN1 (80.1%; P < 0.001 for each comparison). Multiple type infections were demonstrated in 51 (20.2%) of 252 ICC in contrast to 146 (61.3%) of 238 women with CIN3 (P < 0.001). Adjusting for multiple HPV types, HPV16 accounted for 52.1% and HPV18 for 18.1% of ICCs, for a total of 70.2%. Current HPV vaccines should protect against HPV types responsible for 70% of ICCs in Canadian women.

Aptima HPV E6/E7 mRNA test is as sensitive as Hybrid Capture 2 Assay but more specific at detecting cervical precancer and cancer.

Detection of human papillomavirus (HPV) E6/E7 oncogene expression may be more predictive of cervical cancer risk than testing for HPV DNA. The Aptima HPV test (Gen-Probe) detects E6/E7 mRNA of 14 oncogenic types. Its clinical performance was compared with that of the Hybrid Capture 2 DNA test (HC2; Qiagen) in women referred for colposcopy and those routinely screened. Aptima was also compared with the PreTect HPV-Proofer E6/E7 mRNA assay (Proofer; Norchip) in the referral population. Cervical specimens collected in PreservCyt (Hologic Inc.) were processed for HPV detection and genotyping with the Linear Array (LA) method (Roche Molecular Diagnostics, Laval, Quebec, Canada). Histology-confirmed high-grade cervical intraepithelial neoplasia (CIN 2) or worse (CIN 2+) served as the disease endpoint. On the basis of 1,418 referral cases (CIN 2+, n = 401), the sensitivity of Aptima was 96.3% (95% confidence interval [CI], 94.4, 98.2), whereas it was 94.3% (95% CI, 92.0, 96.6) for HC2. The specificities were 43.2% (95% CI, 40.2, 46.2) and 38.7% (95% CI, 35.7, 41.7), respectively (P < 0.05). In 1,373 women undergoing routine screening (CIN 2+, n = 7), both Aptima and HC2 showed 100% sensitivity, and the specificities were 88.3% (95% CI, 86.6, 90.0) and 85.3% (95% CI, 83.5, 87.3), respectively (P < 0.05); for women ≥ 30 years of age (n = 845), the specificities were 93.9% (95% CI, 92.3, 95.5) and 92.1% (95% CI, 90.3, 93.9), respectively (P < 0.05). On the basis of 818 referral cases (CIN 2+, n = 235), the sensitivity of Aptima was 94.9% (95% CI, 92.1, 97.7) and that of Proofer was 79.1% (95% CI, 73.9, 84.3), and the specificities were 45.8% (95% CI, 41.8, 49.8) and 75.1% (95% CI, 71.6, 78.6), respectively (P < 0.05). Both Aptima and Proofer showed a higher degree of agreement with LA genotyping than HC2. In conclusion, the Aptima test is as sensitive as HC2 but more specific for detecting CIN 2+ and can serve as a reliable test for both primary cervical cancer screening and the triage of borderline cytological abnormalities.

Clinical performance of the PreTect HPV-Proofer E6/E7 mRNA assay in comparison with that of the Hybrid Capture 2 test for identification of women at risk of cervical cancer.

Human papillomavirus (HPV) DNA testing has a higher clinical sensitivity than cytology for the detection of high-grade cervical intraepithelial neoplasia or worse (CIN 2+). However, an improvement in specificity would be desirable. As malignant transformation is induced by HPV E6/E7 oncogenes, detection of E6/E7 oncogene activity may improve specificity and be more predictive of cervical cancer risk. The PreTect HPV-Proofer assay (Proofer; Norchip) detects E6/E7 mRNA transcripts from HPV types 16, 18, 31, 33, and 45 with simultaneous genotype-specific identification. The clinical performance of this assay was assessed in a cross-sectional study of women referred for colposcopy in comparison with the Hybrid Capture 2 (HC2; Qiagen) test, which detects DNA of 13 high-risk oncogenic HPV types collectively. Cervical specimens were collected in PreservCyt, and cytology was performed using the ThinPrep method (Hologic). The samples were processed for HPV detection with Proofer and HC2 and genotyping with the Linear Array method (Roche Molecular Systems). Histology-confirmed CIN 2+ served as the disease endpoint to assess the clinical performance of the tests. A total of 1,551 women were studied, and of these, 402 (25.9%) were diagnosed with CIN 2+ on histology. The Proofer assay showed a sensitivity of 78.1% (95% confidence interval [CI], 74.1 to 82.1) versus 95.8% (95% CI, 93.8 to 97.8) for HC2 (P < 0.05) and a specificity of 75.5% (95% CI, 73.0 to 78.0) versus 39.6% (95% CI, 36.8 to 42.4), respectively (P < 0.05). The lower sensitivity and higher specificity of Proofer for detection of CIN 2+ can be attributed to the fact that this test detects the expression of E6/E7 genes beyond a threshold from a limited number of oncogenic HPV types. In conclusion, Proofer is more specific than HC2 in identifying women with CIN 2+ but has a lower sensitivity.

Overview of the European and North American studies on HPV testing in primary cervical cancer screening.

Several studies suggest that HPV testing is more sensitive than cytology in primary cervical screening. These studies had different designs and were reported in different ways. Individual patient data were collected for all European and North American studies in which cytology was routinely performed and HPV testing was included as an additional parallel test. More than 60,000 women were included. The sensitivity and specificity of HPV testing were compared with routine cytology, both overall and for ages <35, 35-49 and 50+. The age-specific prevalence of high risk HPV (hr-HPV) was also analysed. HPV testing was substantially more sensitive in detecting CIN2+ than cytology (96.1% vs. 53.0%) but less specific (90.7% vs. 96.3%). The sensitivity of HPV testing was similar in all studies carried out in different areas of Europe and North America, whereas the sensitivity of cytology was highly variable. HPV sensitivity was uniformly high at all ages, whereas the sensitivity of cytology was substantially better in women over the age of 50 than in younger women (79.3% vs. 59.6%). The specificity of both tests increased with age. Positivity rates for HPV testing in women without high-grade CIN were region dependent. These results support the use of HPV testing as the sole primary screening test, with cytology reserved for women who test HPV positive. Large demonstration projects are needed to fully evaluate this strategy.

Evaluation of rubella IgM enzyme immunoassays.

BACKGROUND: Rubella virus generally causes a mild fever, rash illness similar in clinical presentation to infections by other viruses including measles and parvovirus B19. Rubella infections in pregnant women in the first trimester carry a high risk of congenital rubella syndrome (CRS) which can result in severe congenital defects in the infants. The goal of rubella immunization programs is therefore to eliminate CRS. The primary test for the laboratory confirmation of rubella is IgM serology. It is therefore important to evaluate currently available commercial rubella IgM immunoassays to ensure high quality rubella diagnostic testing. STUDY DESIGN: In this study, we compared the performance of seven commercial rubella IgM enzyme immunoassays (EIA) (Meddens, Denka Seiken, Behring, Wampole, Captia, Sigma and Abbott Axsym) using well-defined panels of sera from rubella and non-rubella/rash-illness cases. RESULTS: The Meddens, Denka Seiken, Behring and Wampole rubella IgM EIAs all performed similarly for sensitivity (range of 74.1-76.8%) and specificity (range of 93.9-96.1%). Relative to the other assays, the Axsym had a higher sensitivity (78.9%) but lower specificity (86.5%). The Captia assay had the lowest overall sensitivity (66.4%), while the Sigma assay had a lower specificity (85.6%) in relation to the other assays. CONCLUSIONS: In conclusion, the Meddens, Denka Seiken, Behring and Wampole rubella IgM EIAs are comparable in their overall performance with respect to sensitivity and specificity.

Assessment of immunoglobulin M enzyme immunoassays for diagnosis of measles.

We evaluated the performance of three commercial measles immunoglobulin M enzyme immunoassays from Meddens, Denka Seiken, and Behring. The sensitivities were determined to be 96.7% for the Meddens and Denka Seiken assays and 87.9% for the Behring assay. The specificities of the assays were determined to be 94.6% for Meddens, 98.2% for Denka Seiken, and 98.7% for Behring.

Prevalence of Listeria in Smoked Fish.

Smoked fish samples (71) were surveyed from Newfoundland retail markets and tested for the prevalence of Listeria . Staphylococcus aureus and fecal coliforms were also detected in the samples. Listeria was present in 11.3% of the smoked seafood products; 4 smoked cod, 3 smoked mackerel, and 1 smoked caplin were found to harbor the bacterium. The Food and Drug Administration protocol was also analyzed with regards to testing smoked seafoods. The secondary enrichment broth showed a 68% false-positive rate, whereas all positive samples were detected after 24 h of primary enrichment.