RESUMEN
OBJECTIVES: To compare the performance of dual immunostaining of p16INK4a and Ki-67 proteins performed on self-collected vaginal specimens and clinician-collected cervical specimens, and to evaluate the performance of this technique in predicting high-grade disease. METHODS: Women aged 30-59 years (n = 1005) were recruited at two well-women clinics in Papua New Guinea. Each woman provided both cervical and vaginal specimens that were tested for high-risk human papillomavirus (hrHPV) DNA using the Xpert HPV Test (Cepheid) at point of care. A subset of paired cervical and vaginal specimens (n = 243) were selected to undergo CINTec® PLUS (Roche) p16/Ki-67 dual-stain cytology and liquid-based cytology (LBC). RESULTS: Fifty-five pairs (22%) were excluded from further analysis because the smears were not assessable. Of the 189 remaining paired specimens, 74 pairs (39.1%) were positive for one or more hrHPV genotypes. When comparing results of the dual stain, the overall percent agreement, positive and negative percent agreements and κ value between the cervical and vaginal specimens were 87.8% (CI 82.3-92.1%), 64.6% (CI 49.5-77.8%), 95.7% (CI 91.0-98.0%) and 0.65 (CI 0.51-0.79%) respectively. The sensitivity of the dual stain performed on the cervical specimen to predict high-grade disease, determined by LBC, was superior to that of the dual stain performed on the vaginal specimen: 100% (CI 84.6-100%) versus 68.2% (CI 45.1-86.1%). CONCLUSION: Although further evaluation may be warranted, these findings indicate that dual-stain testing of vaginal specimens cannot be advocated as part of cervical screening programmes in low- and middle-income countries. However, dual-stain cytology performed on cervical specimens may have a role in quality assurance in such settings.
Asunto(s)
Cuello del Útero/virología , Técnicas Citológicas , Detección Precoz del Cáncer/métodos , Autoevaluación , Manejo de Especímenes/métodos , Neoplasias del Cuello Uterino/diagnóstico , Adulto , Inhibidor p16 de la Quinasa Dependiente de Ciclina/análisis , Femenino , Humanos , Antígeno Ki-67/análisis , Persona de Mediana Edad , Infecciones por Papillomavirus/diagnóstico , Papúa Nueva Guinea , Sensibilidad y Especificidad , Coloración y Etiquetado/métodos , Neoplasias del Cuello Uterino/genética , Vagina/virología , Displasia del Cuello del Útero/diagnósticoRESUMEN
OBJECTIVES: To compare the performance of self-collected vaginal (V) specimens with clinician-collected cervical (C) specimens for detection of high-risk human papillomavirus (hrHPV) and cervical disease using the Cepheid Xpert HPV, Roche Cobas 4800 HPV and Hologic Aptima HPV assays. METHODS: Women aged 30-59 years (n = 1005) were recruited at two clinics in Papua New Guinea, and they provided specimens for testing at point-of-care using the Xpert HPV Test, and for subsequent testing using the Cobas HPV (n = 981) and Aptima HPV (n = 983) assays. Liquid-based cytology was performed on C specimens to predict underlying high-grade squamous intraepithelial lesions (HSIL). V specimen results of each assay were evaluated against a constructed reference standard and for detection of HSIL or worse. RESULTS: There was substantial (κ >0.6) agreement in hrHPV detection between V and C specimens across all three assays. The sensitivity, specificity, and positive and negative predictive values of Xpert HPV using self-collected V specimens for the detection of HPV type 16 according to the constructed reference standard were 92.1%, 93.1%, 63.6% and 98.9%, respectively; compared with 90.4%, 94.3%, 67.8% and 98.7% for Cobas 4800 HPV; and 63.2%, 97.2%, 75.0% and 95.3% for Aptima HPV. Similar results were observed for all hrHPV types (combined) and for HPV types 18/45, on all three assays. The detection of any hrHPV using self-collected specimens had high sensitivity (86%-92%), specificity (87%-94%) and negative predictive value (>98%) on all assays for HSIL positivity. CONCLUSIONS: Xpert HPV, using self-collected vaginal specimens, has sufficient accuracy for use in point-of-care 'test-and-treat' cervical screening strategies in high-burden, low-resource settings.
Asunto(s)
Detección Precoz del Cáncer/métodos , Papillomavirus Humano 16/aislamiento & purificación , Papillomavirus Humano 18/aislamiento & purificación , Infecciones por Papillomavirus/diagnóstico , Pruebas en el Punto de Atención/estadística & datos numéricos , Manejo de Especímenes/métodos , Displasia del Cuello del Útero/diagnóstico , Neoplasias del Cuello Uterino/diagnóstico , Adulto , Femenino , Humanos , Persona de Mediana Edad , Infecciones por Papillomavirus/virología , Papúa Nueva Guinea , Sensibilidad y Especificidad , Neoplasias del Cuello Uterino/virología , Vagina/virología , Displasia del Cuello del Útero/virologíaRESUMEN
The estimated cervical cancer burden is over ten-fold greater in low- and middle-income countries (LMICs) than in high-income countries. This health gap is thought to be primarily due to limited access to effective screening and treatment programs for cervical pre-cancer and cancer in such settings. The World Health Organization advocates a policy of 'screen and treat' approach to cervical screening in LMICs and subsequently visual inspection of the cervix with acetic acid (VIA) or Lugo's iodine (VILI), followed by ablative cervical cryotherapy if indicated, and this policy has been implemented in many high-burden settings. The performance of VIA/VILI as a primary screening tool for the detection of cervical pre-cancer and cancer has, however, been inconsistent. Recently, many high-income countries have integrated HPV-DNA testing into their cervical cancer screening programs. The comparatively high cost and resource requirements of HPV-based screening have to date prevented many LMICs from doing the same. A significant development has been the entrance of innovative, easy-to-use and highly accurate HPV tests that can be provided at point of care; these could enable LMICs to implement 'test and treat' approaches for cervical cancer screening.
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Detección Precoz del Cáncer , Infecciones por Papillomavirus/diagnóstico , Neoplasias del Cuello Uterino/epidemiología , Biomarcadores de Tumor , Países en Desarrollo , Femenino , Humanos , Tamizaje Masivo/economía , Papillomaviridae , Infecciones por Papillomavirus/complicaciones , Factores Socioeconómicos , Neoplasias del Cuello Uterino/virologíaRESUMEN
OBJECTIVES: Within their local realities, people experience and interpret disease in diverse ways that do not necessarily correlate or converge with Western biomedical interventions. In the high cervical cancer burden setting of Papua New Guinea, understanding how people experience and interpret cervical cancer is necessary for effective intervention. Drawing on work by Street on the production of unstable biomedical knowledge, we explored how ambiguity and uncertainty, coupled with cultural taboos and linguistic limitations, affect what and how people 'know' about women's reproductive organs and their associated disease. DESIGN: A qualitative research approach was used to explore and understand how people in PNG articulate matters of health and disease as they relate to cervical cancer and HPV infection. Specifically, how unstable biomedical knowledge is produced and sustained. We employed a mixed-methods approach in collecting data from 208 (147 women) participants between 2011 and 2012 across 3 provinces in PNG. RESULTS: We found that knowledge and awareness about cervical cancer were poor. Five thematic areas emerged in our analysis, which included the gendered knowledge of women's reproductive health, the burden of cervical cancer in the community and the role (or limitation) of language. We further identified four ways in which ambiguity and uncertainty operate on both sociocultural and biological levels, and in the intersection between to produce unstable biomedical knowledge. These included poor knowledge of where the cervix is located and the uncertainty or unreliability of (lay) diagnoses of disease. CONCLUSION: Local understandings of cervical cancer reflected the limitations of Tok Pisin as a lingua franca as well as the wider uncertain biomedical environment where diagnoses are assembled and shared. There is a clear need to improve understanding of the female reproductive organs in order that people, women in particular, can be better informed about cervical cancer and ultimately better receptive to intervention strategies.
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Conocimientos, Actitudes y Práctica en Salud , Incertidumbre , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/epidemiología , Salud de la Mujer , Adolescente , Adulto , Cultura , Femenino , Grupos Focales , Humanos , Persona de Mediana Edad , Infecciones por Papillomavirus/prevención & control , Papúa Nueva Guinea/epidemiología , Investigación Cualitativa , Neoplasias del Cuello Uterino/etiología , Adulto JovenRESUMEN
The World Health Organization has recommended that testing for high-risk human papillomavirus (HPV) (hrHPV) infection be incorporated into cervical screening programs in all settings worldwide. In many high-burden, low-income countries, it will not be feasible to achieve high cervical screening coverage using hrHPV assays that require clinician-collected samples. We conducted the first evaluation of self-collected vaginal specimens compared with clinician-collected cervical specimens for the detection of hrHPV infection using the Xpert HPV test. Women aged 30 to 54 years attending two well-woman clinics in Papua New Guinea were invited to participate and provided self-collected vaginal and clinician-collected cervical cytobrush specimens. Both specimen types were tested at the point of care by using the Xpert HPV test. Women were given their cervical test result the same day. Those with a positive hrHPV test and positive examination upon visual inspection of the cervix with acetic acid were offered same-day cervical cryotherapy. A total of 1,005 women were enrolled, with 124 (12.3%; 95% confidence interval [CI], 10.3%, 14.4%) being positive for any hrHPV infection. There was a 99.4% overall percent agreement (OPA) between vaginal and cervical tests for HPV-16 (95% CI, 98.9%, 99.9%), a 98.5% OPA for HPV-18/45 (95% CI, 97.7%, 99.3%), a 94.4% OPA for other hrHPV infections (95% CI, 92.9%, 95.9%), and a 93.4% OPA for all hrHPV types combined (95% CI, 91.8%, 95.0%). Self-collected vaginal specimens had excellent agreement with clinician-collected cervical specimens for the detection of hrHPV infection using the Xpert HPV test. This approach provides for the first time an opportunity to incorporate point-of-care hrHPV testing into clinical cervical screening algorithms in high-burden, low-income settings.
Asunto(s)
Detección Precoz del Cáncer/métodos , Técnicas de Diagnóstico Molecular/métodos , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/diagnóstico , Sistemas de Atención de Punto , Manejo de Especímenes/métodos , Adulto , Femenino , Humanos , Persona de Mediana Edad , Papúa Nueva GuineaRESUMEN
Human immunodeficiency virus (HIV) is a significant public health issue in Papua New Guinea (PNG). After heterosexual transmission (90%), the second most common route of transmission is vertically from mother to child (3.5%). Before the introduction of molecular methods of HIV testing in PNG, diagnosing exposed infants was problematic because there were no reliable assays available for accurate early infant HIV detection. This study aimed to validate and assess a global gold standard for virological early infant HIV diagnosis in PNG: the AMPLICOR HIV DNA v1.5 assay (Roche) using dried blood spot (DBS) specimens. The assay was validated in three ways: by testing well-characterized DBS and kit controls and by blinded retesting of 42 patient specimens. The assay was further investigated by comparison with a serological assay. The results indicated that the assay was robust and highly reproducible using DBS and kit controls, with 100% sensitivity and specificity. Of the 42 infant DBS specimens that were retested blindly, 100% of the test results were concordant with diagnostic results. Among the 42 infant specimens tested with the Amplicor HIV DNA v1.5 assay we found that 33% of infants (n = 14) were HIV PCR positive and 67% (n = 28) negative. The earliest point of HIV detection established for this study was three months of age. This pilot study indicates that HIV-infected infants in PNG can be effectively diagnosed using virological testing and can thus be started earlier on treatment than was previously possible with serological testing.